- 1. Anthraquinones of Cissus populnea Guill & Perr (Amplidaceae).
Cissus populnea has been used locally to treat many ailments such as venereal, stomach and skin infections; and also used as laxative or purgative. Economically it has been used as binder in food and in lining dye pits. This work aims at determining the type of anthraquinones from the stem bark of C. populnea which might be a potential source of drugs (laxative/cathartic) using thin layer chramatograpy (TLC) and senna leaf as reference. The analysis showed the stem bark anthroquinone extract to contain physcion and chrysophanol....(more)
Ibrahim H, et al. Afr J Tradit Complement Altern Med 2011;8(2):140-3.
Related Products: Senna Leaf Extract
- 2. Simple and rapid analysis of sennoside A and sennoside B contained in crude drugs and crude drug products by solid-phase extraction and high-performance liquid chromatography.
The sennoside A (SA) and sennoside B (SB) contents of various samples of crude drugs were determined using solid-phase extraction (SPE) and HPLC. The samples examined were crude drugs (senna leaf, senna pods, and rhubarb), conventional crude drug products, and Kampo formulations. The sample solution was purified using an Oasis MAX cartridge, which has strong anion-exchange and reversed-phase properties. The samples containing SA and SB were dissolved in a solution of methanol-0.2% sodium bicarbonate (7:3, v/v) and applied to the Oasis MAX cartridge. The cartridge was washed with a solution of methanol containing 1% acetic acid. SA and SB were eluted with methanol-water-formic acid (70:30:2, v/v), and the eluate was used as the sample solution for HPLC analysis. SA and SB were analyzed using a conventional octadecylsilyl (ODS) column at a detection wavelength of 380 nm; water-acetonitrile-phosphoric acid (800:200:1, v/v) was used as the mobile phase. The SA and SB components in most samples were completely separated from other interfering constituents within 10 min. In particular, several interfering peaks adjacent to the SB peak were eliminated by SPE using the Oasis MAX cartridge. On subjecting the Kampo extracts to an additional recovery experiment, high recovery rates of SA and SB were obtained. The method employed in this study proved to be a simple and rapid method for the quantification of SA and SB....(more)
Yamasaki K, et al. J Nat Med 2010 Apr;64(2):126-32.
Related Products: Senna Leaf Extract
- 3. Anthranoid laxatives influence the absorption of poorly permeable drugs in human intestinal cell culture model (Caco-2).
Interactions between widely used anthranoid laxatives and other simultaneously administered drugs are not known. In this paper, the influence of rhein, danthron, sennidins A/B, sennosides A/B, and senna leaf infusion was investigated on the permeability of furosemide, ketoprofen, paracetamol, propranolol, verapamil, digoxin, and Rhodamine 123 across Caco-2 monolayers. The effects on monolayer integrity ([(14)C]mannitol permeability, TEER) were also determined. The in vitro absorption of highly permeable drugs was not strongly affected during co-administration of the laxatives. Furosemide permeability was enhanced by rhein and danthron (3.6 and 3.0-fold), which may partly be due to opening of the paracellular spaces and/or effects on active efflux. However, the secretory permeability of digoxin and Rho 123 was not strongly affected by rhein and danthron, suggesting that inhibition of MDR1 was not responsible for the increased permeation of furosemide. The absorptive permeability of digoxin was decreased by rhein and danthron, offering evidence for effects on apical membranes. The effects on monolayer integrity were detectable, but reversible. According to presented experiments, daily use of laxatives with well-absorbing drugs would seem unlikely to affect drug permeability, but the effects on the absorption of poorly permeable drugs cannot be excluded....(more)
Laitinen L, et al. Eur J Pharm Biopharm 2007 Apr;66(1):135-45.
Related Products: Senna Leaf Extract
- 4. Defatted sesame seed extract reduces brain oedema by regulating aquaporin 4 expression in acute phase of transient focal cerebral ischaemia in rat.
Brain oedema is the volumetric increase of brain tissue and is known to be linked to vascular factors, including the blood-brain barrier (BBB) and vascular permeability. Besides neuroprotection, inhibition of brain oedema also can be a method to protect the brain against ischaemic insult. Sesame is reported to have various beneficial effects on the cardiovascular and cerebrovascular systems. The neuroprotective effects of defatted sesame seed extract (DSE) in a transient middle cerebral artery occlusion (tMCAo) rat model were reported previously. The current study was planned to investigate whether the neuroprotective effects of DSE is related to brain oedema. The tMCAo rat model was used to investigate the brain water content (BWC) and Evans blue (EB) leakage. Aquaporin 4 (AQP4), matrix metalloproteinase (MMP)-2 and MMP-9 expressions at 4 and 24 h after ischaemia were analysed. In vitro zymography was performed to investigate the effects on MMPs activities. DSE (30, 100, and 300 mg/kg, p.o.) reduced BWC but not EB leakage. DSE inhibited AQP4 expression at 4 h but not at 24 h after ischaemia. It did not show any effects on MMPs expressions and activities. Therefore, DSE might be effective on brain oedema by AQP4 regulation during the acute phase of ischaemia....(more)
Lee K, et al. Phytother Res 2012 Oct;26(10):1521-7.
Related Products: Sesame Seed Extract
- 5. The sesame lignan sesamin attenuates vascular dysfunction in streptozotocin diabetic rats: involvement of nitric oxide and oxidative stress.
The effect of chronic administration of sesamin was studied on aortic reactivity of streptozotocin diabetic rats. Male diabetic rats received sesamin for 7 weeks after diabetes induction. Contractile responses to KCl and phenylephrine and relaxation response to acetylcholine were obtained from aortic rings. Maximum contractile response of endothelium-intact rings to phenylephrine was significantly lower in sesamin-treated diabetic rats relative to untreated diabetics and endothelium removal abolished this difference. Meanwhile, endothelium-dependent relaxation to acetylcholine was significantly higher in sesamin-treated diabetic rats as compared to diabetic ones and pretreatment of rings with nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester significantly attenuated the observed response. Two-month diabetes also resulted in an elevation of malondialdehyde and decreased superoxide dismutase activity and sesamin treatment significantly improved these changes. Therefore, chronic treatment of diabetic rats with sesamin could prevent some abnormal changes in vascular reactivity in diabetic rats through nitric oxide and via attenuation of oxidative stress and tissue integrity of endothelium is necessary for its beneficial effect....(more)
Baluchnejadmojarad T, et al. Eur J Pharmacol 2013 Jan 5;698(1-3):316-21.
Related Products: Sesamin
- 6. In vitro inhibition of 7-ethoxyresorufin-O-deethylase (EROD) and p-nitrophenol hydroxylase (PNPH) activities by sesamin in hepatic microsomes from two fish species.
In the present study, we investigated the effect of sesamin on CYP1A (7-ethoxyresorufin-O-deethylase, EROD) and CYP2E1-like activities (p-nitrophenol hydroxylase, PNPH) in hepatic microsomes obtained from Atlantic salmon (Salmo salar) and common carp (Cyprinus carpio). Addition of sesamin to the incubations in a concentration range from 1 to 200 μM decreased the activities of EROD and PNPH in a concentration dependent manner. It is likely that the inhibition of EROD was mechanism-based as demonstrated by the decrease in the IC50 value from 5.9 to 3.2 μM for A. salmon and from 7.9 to 3.0 μM for common carp when 5 min pre-incubation step was included. Similarly, PNPH activity was inhibited by sesamin with a decrease in the IC50 values from 61.7 to 15.2 μM for A. salmon and from 194.3 to 20.7 μM for common carp. Thus, our results indicated that sesamin can act as a mechanism-based inhibitor of EROD and PNPH activity with similar degree of inhibition in both fish species. More importantly, the inhibition of CYP1A, in addition to being mechanism-based, was competitive with K(i) value of 5.3 μM....(more)
Wagner L, et al. Mol Biol Rep 2013 Jan;40(1):457-62.
Related Products: Sesamin
- 7. Long-term intake of sesamin improves left ventricular remodelling in spontaneously hypertensive rats.
This study was designed to evaluate the in vivo cardioprotective effects of food-derived sesamin in spontaneously hypertensive rats (SHR). The study was performed with 17-week-old male normotensive Wistar-Kyoto rats (WKY) and SHR which are untreated or treated with orally administered sesamin for 16 weeks before they were sacrificed. Long-term treatment with sesamin obviously improved left ventricular (LV) hypertrophy and fibrosis in SHR, as indicated by the decrease of LV weight/body weight, myocardial cell size, cardiac fibrosis and collagen type I expression as well as the amelioration of the LV ultrastructure. These effects were associated with reduced systolic blood pressure, enhanced cardiac total antioxidant capability and decreased malondialdehyde content, nitrotyrosine level and transforming growth factor β1 (TGF-β1) expression. All these results suggest that chronic treatment with sesamin improves LV remodeling in SHR through alleviation of oxidative and nitrative stress, reduction of blood pressure and downregulation of TGF-β1 expression....(more)
Li WX, et al. Food Funct 2013 Feb 26;4(3):453-60.
Related Products: Sesamin
- 8. Sesamin synergistically potentiates the anticancer effects of γ-tocotrienol in mammary cancer cell lines.
γ-Tocotrienol and sesamin are phytochemicals that display potent anticancer activity. Since sesamin inhibits the metabolic degradation of tocotrienols, studies were conducted to determine if combined treatment with sesamin potentiates the antiproliferative effects of γ-tocotrienol on neoplastic mouse (+SA) and human (MCF-7 and MDA-MB-231) mammary cancer cells. Results showed that treatment with γ-tocotrienol or sesamin alone induced a significant dose-responsive growth inhibition, whereas combination treatment with these agents synergistically inhibited the growth of +SA, MCF-7 and MDA-MB-231 mammary cancer cells, while similar treatment doses were found to have little or no effect on normal (mouse CL-S1 and human MCF-10A) mammary epithelial cell growth or viability. However, sesamin synergistic enhancement of γ-tocotrienol-induced anticancer effects was not found to be mediated from a reduction in γ-tocotrienol metabolism. Rather, combined treatment with subeffective doses of γ-tocotrienol and sesamin was found to induce G1 cell cycle arrest, and a corresponding decrease in cyclin D1, CDK2, CDK4, CDK6, phospho-Rb, and E2F1 levels, and increase in p27 and p16 levels. Additional studies showed that the antiproliferative effect of combination treatment did not initiate apoptosis or result in a decrease in mammary cancer cell viability. Taken together, these findings indicate that the synergistic antiproliferative action of combined γ-tocotrienol and sesamin treatment in mouse and human mammary cancer cells is cytostatic, not cytotoxic, and results from G1 cell cycle arrest....(more)
Akl MR, et al. Fitoterapia 2013 Jan;84:347-59.
Related Products: Sesamin
- 9. (±)-Asarinin.
Asarinin, C(20)H(18)O(6), was isolated as a racemate from the shrub Zanthoxylum alatum. Both forms of the enantiomerically pure substance, (+)- and (-)-asarinin, have been the subject of a total of five previous structure determinations that are essentially identical except for the absolute stereochemistry. However, there seems to be some confusion in the literature concerning these structure determinations of asarinin and also those of its stereoisomer sesamin. The molecular structure of racemic asarinin differs from that of the pure enantiomers in the orientation of one ring system. In the packing of the racemate, molecules are linked by C-H...O interactions to form ribbons parallel to [101]....(more)
Negi DS, et al. Acta Crystallogr C 2013 Jan;69(Pt 1):87-9.
Related Products: Sesamin
- 10. Sesamin extends the mean lifespan of fruit flies.
The present study investigated the anti-ageing activity of sesamin and its effect on gene expression of superoxide dismutase (SOD), catalase (CAT), methuselah (Mth) and Rpn11 in Drosophila melanogaster. Results demonstrated that 0.2 % sesamin in diet prolonged the mean lifespan of OR wild fruit flies by 12 %, accompanied by up-regulation of SOD1, SOD2, CAT and Rpn11. Sesamin at 0.2 % in diet also attenuated paraquat-induced neurodegeneration with up-regulation of SOD1, SOD2 and Rpn11 in OR wild fruit flies. Supplementation of 0.2 % sesamin in diet increased the survival time of OR wild type flies and Alzheimer flies Aβ42 33769 when they were challenged with paraquat. Furthermore, sesamin-induced increase in the activity and expression of antioxidant enzymes also suggests that the longevity promoting activity of sesamin are possibly due to its action as a hormetin by inducing oxidative stress response-mediated hormesis. It was concluded that sesamin extended the mean lifespan and alleviated the neurodegeneration in Drosophila melanogaster at least mediated by its interaction with genes SOD1, SOD2, CAT, and Rpn11, but not with gene Mth....(more)
Zuo Y, et al. Biogerontology 2013 Jan 6.
Related Products: Sesamin
- 11. Evaluation of antioxidative effects of sesamin on the in vivo hepatic reducing abilities by a radiofrequency ESR method.
Antioxidative effects of sesamin (a mixture of sesamin and episesamin) were evaluated in the liver, kidney and inferior vena cava of living rats using a radiofrequency ESR method. TEMPOL, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl, was used as an in vivo redox probe, the half-life of which is believed to be correlated with the antioxidant status. The oral administration of sesamin (250 mg/kg rat weight) 3 h before ESR measurements shortened the half-life of TEMPOL in the liver by 10 - 15% as compared with the controls, but did not affect the other organs. This effect was maintained for at least 3 h after the administration, and then disappeared at 24 h, corresponding to the results of our preliminary pharmacokinetic studies. Changes in the reducing ability were observed only in the hepatic sites of the sesamin-treated rats. These findings suggest that sesamin exhibits effective antioxidant activity in the liver via modulation of the intracellular redox status related to TEMPOL reduction....(more)
Tada M, et al. Anal Sci 2013;29(1):89-94.
Related Products: Sesamin
- 12. Sesamin protects mouse liver against nickel-induced oxidative DNA damage and apoptosis by the PI3K-Akt pathway.
Sesamin (Ses), one of the major lignans in sesame seeds and oil, has been reported to have many benefits and medicinal properties. However, its protective effects against nickel (Ni)-induced injury in liver have not been clarified. The aim of the present study was to investigate the effects of sesamin on hepatic oxidative DNA injury and apoptosis in mice exposed to nickel. Kunming mice were exposed to nickel sulfate with or without sesamin coadministration for 20 days. The data showed that sesamin significantly prevented nickel-induced hepatotoxicity in a dose-dependent manner, indicated by both diagnostic indicators of liver damage (serum aminotransferase activities) and histopathological analysis. Moreover, nickel-induced profound elevation of reactive oxygen species (ROS) production and oxidative stress, as evidenced by an increase of the lipid peroxidation level and depletion of the intracellular reduced glutathione (GSH) level in liver, were suppressed by treatment with sesamin. Sesamin also restored the activities of antioxidant enzymes (T-SOD, CAT, and GPx) and decreased 8-hydroxy-2-deoxyguanosine (8-OHdG) levels in nickel-treated mice. Furthermore, a TUNEL assay showed that nickel-induced apoptosis in mouse liver was significantly inhibited by sesamin. Exploration of the underlying mechanisms of sesamin action revealed that activities of caspase-3 were markedly inhibited by the treatment of sesamin in the liver of nickel-treated mice. Sesamin increased expression levels of phosphoinositide-3-kinase (PI3K) and phosphorylated protein kinase B (PBK/Akt) in liver, which in turn inactivated pro-apoptotic signaling events, restoring the balance between pro- and anti-apoptotic Bcl-2 proteins in the liver of nickel-treated mice. In conclusion, these results suggested that the inhibition of nickel-induced apoptosis by sesamin is due at least in part to its antioxidant activity and its ability to modulate the PI3K-Akt signaling pathway....(more)
Liu CM, et al. J Agric Food Chem 2013 Feb 6;61(5):1146-54.
Related Products: Sesamin
- 13. Inhibitory effects of epi-sesamin on HMGB1-induced vascular barrier disruptive responses in vitro and in vivo.
Nuclear DNA-binding protein high mobility group box 1 (HMGB1) protein acts as a late mediator of severe vascular inflammatory conditions, such as sepsis and septic shock. Epi-sesamin (ESM), an important component of Asarum sieboldii roots, is known to exhibit anti-allergic, anti-nociceptive, and anti-fungal effects. However, little is known of its effects on HMGB1-mediated inflammatory responses. Here, we investigated this issue by monitoring the effects of ESM on lipopolysaccharide (LPS) or cecal ligation and the puncture (CLP)-mediated release of HMGB1, and on modulation of HMGB1-mediated inflammatory responses. ESM potently inhibited HMGB1 release, down-regulated HMGB1-dependent inflammatory responses in human endothelial cells, and inhibited HMGB1-mediated hyperpermeability and leukocyte migration in mice. In addition, treatment with ESM resulted in reduced CLP-induced release of HMGB1 and sepsis-related mortality. Of particular interest, ESM inhibition of HMGB1-mediated anti-inflammatory activity was more potent than that by sesamin (SM), likely due to differences between their three-dimensional structures. These results indicate that ESM could be a candidate therapeutic agent for treatment of various severe vascular inflammatory diseases via inhibition of the HMGB1 signaling pathway....(more)
Lee W, et al. Toxicol Appl Pharmacol 2013 Mar 15;267(3):201-8.
Related Products: Sesamin
- 14. Penicillium sp. mitigates Fusarium-induced biotic stress in sesame plants.
Fusarium-infected sesame plants have significantly higher contents of amino acids (Asp, Thr, Ser, Asn, Glu, Gly, Ala, Val, Met, Ile, Leu, Tyr, Phe, Lys, His, Try, Arg, and Pro), compared with their respective levels in the healthy control. These higher levels of amino acids induced by Fusarium infection were decreased when Penicillium was co-inoculated with Fusarium. Compared with the control, Fusarium-infected plants showed higher contents of palmitic (8 %), stearic (8 %), oleic (7 %), and linolenic acids (4 %), and lower contents of oil (4 %) and linoleic acid (11 %). Co-inoculation with Penicillium mitigated the Fusarium-induced changes in fatty acids. The total chlorophyll content was lower in Fusarium- and Penicillium-infected plants than in the healthy control. The accumulation of carotenoids and γ-amino butyric acid in Fusarium-infected plants was slightly decreased by co-inoculation with Penicillium. Sesamin and sesamolin contents were higher in Penicillium- and Fusarium- infected plants than in the control. PURPOSE OF WORK: To clarify the mechanism of the biocontrol effect of Penicillium against Fusarium by evaluating changes in primary and secondary metabolite contents in sesame plants....(more)
Radhakrishnan R, et al. Biotechnol Lett 2013 Mar 12.
Related Products: Sesamin
- 15. Testing a low molecular mass fraction of a mushroom (Lentinus edodes) extract formulated as an oral rinse in a cohort of volunteers.
Although foods are considered enhancing factors for dental caries and periodontitis, laboratory researches indicate that several foods and beverages contain components endowed with antimicrobial and antiplaque activities. A low molecular mass (LMM) fraction of an aqueous mushroom extract has been found to exert these activities in in vitro experiments against potential oral pathogens. We therefore conducted a clinical trial in which we tested an LMM fraction of shiitake mushroom extract formulated in a mouthrinse in 30 young volunteers, comparing the results with those obtained in two identical cohorts, one of which received water (placebo) and the other Listerine. Plaque index, gingival index and bacterial counts in plaque samples were determined in all volunteers over the 11 days of the clinical trial. Statistically significant differences (P < 0.05) were obtained for the plaque index on day 12 in subjects treated with mushroom versus placebo, while for the gingival index significant differences were found for both mushroom versus placebo and mushroom versus Listerine. Decreases in total bacterial counts and in counts of specific oral pathogens were observed for both mushroom extract and Listerine in comparison with placebo. The data suggest that a mushroom extract may prove beneficial in controlling dental caries and/or gingivitis/periodontitis....(more)
Signoretto C, et al. J Biomed Biotechnol 2011;2011:857987.
Related Products: Shiitake Mushroom Extract
- 16. In vitro assessment of shiitake mushroom (Lentinula edodes) extract for its antigingivitis activity.
Gingivitis is a preventable disease characterised by inflammation of the gums due to the buildup of a microbial biofilm at the gingival margin. It is implicated as a precursor to periodontitis, a much more serious problem which includes associated bone loss. Unfortunately, due to poor oral hygiene among the general population, gingivitis is prevalent and results in high treatment costs. Consequently, the option of treating gingivitis using functional foods, which promote oral health, is an attractive one. Medicinal mushrooms, including shiitake, have long been known for their immune system boosting as well as antimicrobial effects; however, they have not been employed in the treatment of oral disease. In the current study, the effectiveness of shiitake mushroom extract was compared to that of the active component in the leading gingivitis mouthwash, containing chlorhexidine, in an artificial mouth model (constant depth film fermenter). The total bacterial numbers as well as numbers of eight key taxa in the oral community were investigated over time using multiplex qPCR. The results indicated that shiitake mushroom extract lowered the numbers of some pathogenic taxa without affecting the taxa associated with health, unlike chlorhexidine which has a limited effect on all taxa....(more)
Ciric L, et al. J Biomed Biotechnol 2011;2011:507908.
Related Products: Shiitake Mushroom Extract
- 17. An examination of antibacterial and antifungal properties of constituents of Shiitake (Lentinula edodes) and oyster (Pleurotus ostreatus) mushrooms.
BACKGROUND:
Antibiotic agents have been in widespread and largely effective therapeutic use since their discovery in the 20th century. However, the emergence of multi-drug resistant pathogens now presents an increasing global challenge to both human and veterinary medicine. It is now widely acknowledged that there is a need to develop novel antimicrobial agents to minimize the threat of further antimicrobial resistance. With this in mind, a study was undertaken to examine the antimicrobial properties of aqueous extracts of 'exotic' Shiitake and Oyster mushrooms on a range of environmental and clinically important microorganisms.
METHOD:
Several batches of Shiitake and oyster mushrooms were purchased fresh from a local supermarket and underwent aqueous extraction of potential antimicrobial components. After reconstitution, aqueous extracts were tested qualitatively against a panel of 29 bacterial and 10 fungal pathogens, for the demonstration of microbial inhibition.
RESULTS:
Our data quantitatively showed that Shiitake mushroom extract had extensive antimicrobial activity against 85% of the organisms it was tested on, including 50% of the yeast and mould species in the trial. This compared favourably with the results from both the Positive control (Ciprofloxacin) and Oyster mushroom, in terms of the number of species inhibited by the activity of the metabolite(s) inherent to the Shiitake mushroom.
CONCLUSIONS:
This small scale study shows the potential antimicrobial effects of Shitake extracts, however further work to isolate and identify the active compound(s) now requires to be undertaken. Once these have been identified, suitable pharmaceutical delivery systems should be explored to allow concentrated extracts to be prepared and delivered optimally, rather than crude ingestion of raw material, which could promote further bacterial resistance....(more)
Hearst R, et al. Complement Ther Clin Pract 2009 Feb;15(1):5-7.
Related Products: Shiitake Mushroom Extract
- 18. Lentinula edodes (Shiitake) mushroom extract protects against hydrogen peroxide induced cytotoxicity in peripheral blood mononuclear cells.
Lentinula edodes (Berk) Pegler, commonly known as Shiitake mushroom has been used as medicinal food in Asian countries, especially in China and Japan and is believed to possess strong immunomodulatory property. In the present study, the methanolic extract of the fruit bodies of L. edodes was investigated for cytoprotective effect against H2O2-induced cytotoxicity in human peripheral blood mononuclear cells (PBMCs) by measuring the activities of xanthine oxidase (XO) and glutathione peroxidase (GPx) . H2O2 at a concentration of 5 microM caused 50% inhibition of PBMCs viability. The extract improved the PBMC viability and exerted a dose-dependent protection against H2O2-induced cytotoxicity. At 100 microg/ml of extract concentration, the cell viability increased by 60% compared with the PBMCs incubated with H2O2 alone. The extract also inhibited XO activity in PBMC, while showing moderate stimulatory effect on GPx. However, in the presence of H2O2 alone, both the enzyme activities were increased significantly. The GPx activity increased, possibly in response to the increased availability of H2O2 in the cell. When the cells were pretreated with the extract and washed (to remove the extract) prior to the addition of H2O2, the GPx and XO activities as well as the cell viability were comparable to those when incubated with the extract alone. Thus, it is suggested that one of the possible mechanisms via which L. edodes methanolic extract confers protection against H2O2-induced oxidative stress in PBMC is by inhibiting the superoxide-producing XO and increasing GPx activity which could rapidly inactivate H2O2....(more)
Kuppusamy UR, et al. Indian J Biochem Biophys 2009 Apr;46(2):161-5.
Related Products: Shiitake Mushroom Extract
- 19. Production of hydroxycinnamoyl-shikimates and chlorogenic acid in Escherichia coli: production of hydroxycinnamic acid conjugates.
BACKGROUND:
Hydroxycinnamates (HCs) are mainly produced in plants. Caffeic acid (CA), p-coumaric acid (PA), ferulic acid (FA) and sinapic acid (SA) are members of the HC family. The consumption of HC by human might prevent cardiovascular disease and some types of cancer. The solubility of HCs is increased through thioester conjugation to various compounds such as quinic acid, shikimic acid, malic acid, anthranilic acid, and glycerol. Although hydroxycinnamate conjugates can be obtained from diverse plant sources such as coffee, tomato, potato, apple, and sweet potato, some parts of the world have limited availability to these compounds. Thus, there is growing interest in producing HC conjugates as nutraceutical supplements.
RESULTS:
Hydroxycinnamoyl transferases (HCTs) including hydroxycinnamate-CoA shikimate transferase (HST) and hydroxycinnamate-CoA quinate transferase (HQT) were co-expressed with 4-coumarateCoA:ligase (4CL) in Escherichia coli cultured in media supplemented with HCs. Two hydroxycinnamoyl conjugates, p-coumaroyl shikimates and chlorogenic acid, were thereby synthesized. Total 29.1 mg/L of four different p-coumaroyl shikimates (3-p-coumaroyl shikimate, 4-p-coumaroyl shikimate, 3,4-di-p-coumaroyl shikimate, 3,5-di-p-coumaroyl shikimate, and 4,5-di-p-coumaroyl shikimate) was obtained and 16 mg/L of chlorogenic acid was synthesized in the wild type E. coli strain. To increase the concentration of endogenous acceptor substrates such as shikimate and quinate, the shikimate pathway in E. coli was engineered. A E. coli aroL and aroK gene were mutated and the resulting mutants were used for the production of p-coumaroyl shikimate. An E. coli aroD mutant was used for the production of chlorogenic acid. We also optimized the vector and cell concentration optimization.
CONCLUSIONS:
To produce p-coumaroyl-shikimates and chlorogenic acid in E. coli, several E. coli mutants (an aroD mutant for chlorogenic acid production; an aroL, aroK, and aroKL mutant for p-coumaroyl-shikimates production) were made and each mutant was tested using an optimized construct. Using this strategy, we produced 235 mg/L of p-coumaroyl-shikimates and 450 mg/L of chlorogenic acid....(more)
Kim BG, et al. Microb Cell Fact 2013 Feb 5;12:15.
Related Products: Shikimic Acid
- 20. Ameliorative effects of 3,4-oxo-isopropylidene-shikimic acid on experimental colitis and their mechanisms in rats.
The aim of the present study was to investigate the therapeutic effect and mechanism of 3,4-oxo-isopropylidene-shikimic acid (ISA) on 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. (50, 100, 200 mg/kg) was administered for 14 days, 1 day after the induction of colitis by TNBS. The colonic injury and inflammation were assessed by macroscopic damage scores and myeloperoxidase (MPO) activity. Malondialdehyde (MDA) and nitric oxide (NO) levels, and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in plasma were measured with biochemical methods. Prostaglandin E2 (PGE2) level in colon was determined by radioimmunoassay. Expressions of inducible nitric oxide synthase (iNOS), cyclo-oxygenase-2 (COX-2), inhibitor kappa B-alpha (IκBα) and nuclear factor kappa B (NF-κB) p65 proteins in the colonic tissue were detected with immunohistochemistry. Enhanced colonic mucosal injury, inflammatory response and oxidative stress were observed in the animals clystered with TNBS, which was manifested as the significant increase in colon mucosal damage index, MPO activity, levels of MDA, NO and PGE2, as well as the expressions of iNOS, COX-2 and NF-κB p65 proteins in the colonic mucosa, and the significant decrease in expressions of IκBα proteins in the colonic mucosa. However, these parameters were found to be significantly ameliorated in rats treated with ISA at given doses, especially at 100 mg/kg and 200 mg/kg. Administration of ISA may have significant therapeutic effects on experimental colitis in rats, probably due to its mechanism of antioxidation, its inhibition of arachidonic acid metabolism and its modulation of the IκBα/NF-κB p65 expression....(more)
Xing J, et al. Int Immunopharmacol 2013 Mar;15(3):524-31.
Related Products: Shikimic Acid
- 21. Changes in potato phenylpropanoid metabolism during tuber development.
Phenylpropanoid metabolite and transcript expression during different developmental stages were examined in field grown potatoes. Carbohydrate and shikimic acid metabolism was assessed to determine how tuber primary metabolism influences phenylpropanoid metabolism. Phenylpropanoid concentrations were highest in immature tubers, as were some transcript levels and enzyme activities including phenylalanine ammonia lyase (PAL). Phenylpropanoid concentration differences between mature and immature tubers varied by genotype, but in some cases were approximately three-fold. The most abundant phenylpropanoid was chlorogenic acid (5CGA), which decreased during tuber maturation. Hydroxycinnamoyl-CoA:quinate hydroxycinnamoyl transferase (HQT) transcripts were highly expressed relative to other phenylpropanoid genes, but were not well correlated with 5CGA concentrations (r = -0.16), whereas HQT enzyme activity was. In contrast to 5CGA, less abundant chlorogenic isomers increased during development. Concentrations of hydroxycinnamic acid amides were higher in immature tubers, as was expression of arginine- and ornithine decarboxylases. Expression of several genes involved in carbohydrate or shikimate metabolism, including sucrose synthase and DAHP, showed similar developmental patterns to phenylpropanoid pools, as did shikimate dehydrogenase enzyme activity. Sucrose, glucose and fructose concentrations were highest in immature tubers. Exogenous treatment of potatoes with sugars stimulated phenylpropanoid biosynthesis, suggesting sugars contribute to the higher phenylpropanoid concentrations in immature tubers. These changes in phenylpropanoid expression suggest the nutritional value of potatoes varies during development....(more)
Navarre DA, et al. Plant Physiol Biochem 2013 Apr;65:89-101.
Related Products: Shikimic Acid
- 22. A natural isolate producing shikimic acid: isolation, identification, and culture condition optimization.
Shikimic acid has wide use in pharmaceuticals due to its application in the synthesis of drug Tamiflu used in the treatment of Swine flu. The high cost and limited availability of shikimic acid isolated from plants has impeded the use of this valuable building block of the drug. In this context, fermentation route to produce shikimic acid from renewable resources has become increasingly attractive. The present study was embarked upon isolation of wild-type microorganisms able to produce shikimic acid. Out of the 42 isolates obtained from the soil, isolate GR-21 was selected as the best with initial production of 0.54 g/L shikimic acid and later identified as Citrobacter sp. The process optimization resulted in 14-fold increase in the shikimic acid production, thereby claiming this process to be a sustainable alternative for the production of this important biomolecule. The process was further scaled up to 14 L bioreactor to validate the production of shikimic acid. Further, the product formed is shikimic acid was confirmed by FTIR analysis. The current studies suggest that the selected isolate could be used as a promising agent to fulfill the worldwide demand of shikimic acid....(more)
Rawat G, et al. Appl Biochem Biotechnol 2013 Apr;169(8):2290-302.
Related Products: Shikimic Acid
- 23. Comparative Binding Energy (COMBINE) Analysis for Understanding the Binding Determinants of Type?II Dehydroquinase Inhibitors.
Herein we report comparative binding energy (COMBINE) analyses to derive quantitative structure-activity relationship (QSAR) models that help rationalize the determinants of binding affinity for inhibitors of typeII dehydroquinase (DHQ2), the third enzyme of the shikimic acid pathway. Independent COMBINE models were derived for Helicobacter pylori and Mycobacterium tuberculosis DHQ2, which is an essential enzyme in both these pathogenic bacteria that has no counterpart in human cells. These studies quantify the importance of the hydrogen bonding interactions between the ligands and the water molecule involved in the DHQ2 reaction mechanism. They also highlight important differences in the ligand interactions with the interface pocket close to the active site that could provide guides for future inhibitor design....(more)
Peón A, et al. ChemMedChem 2013 May;8(5):740-7.
Related Products: Shikimic Acid
- 24. Synthesis, Characterization, and Interaction with Biomolecules of Platinum(II) Complexes with Shikimic Acid-Based Ligands.
Starting from the active ingredient shikimic acid (SA) of traditional Chinese medicine and NH2(CH2) n OH, (n = 2-6), we have synthesized a series of new water-soluble Pt(II) complexes PtL(a-e)Cl2, where L(a-e) are chelating diamine ligands with carbon chain covalently attached to SA (L(a-e) = SA-NH(CH2) n NHCH2CH2NH2; L(a), n = 2; L(b), n = 3; L(c), n = 4; L(d), n = 5; L(e), n = 6). The results of the elemental analysis, LC-MS, capillary electrophoresis, and (1)H, (13)C NMR indicated that there was only one product (isomer) formed under the present experimental conditions, in which the coordinate mode of PtL(a-e)Cl2 was two-amine bidentate. Their in vitro cytotoxic activities were evaluated by MTT method, where these compounds only exhibited low cytotoxicity towards BEL7404, which should correlate their low lipophilicity. The interactions of the five Pt(II) complexes with DNA were investigated by agarose gel electrophoresis, which suggests that the Pt(II) complexes could induce DNA alteration. We also studied the interactions of the Pt(II) complexes with 5'-GMP with ESI-MS and (1)H NMR and found that PtL(b)Cl2, PtL(c)Cl2, and PtL(d)Cl2 could react with 5'-GMP to form mono-GMP and bis-GMP adducts. Furthermore, the cell-cycle analysis revealed that PtL(b)Cl2, PtL(c)Cl2 cause cell G2-phase arrest after incubation for 72 h. Overall, these water-soluble Pt(II) complexes interact with DNA mainly through covalent binding, which blocks the DNA synthesis and replication and thus induces cytotoxicity that weakens as the length of carbon chain increases....(more)
Peng Y, et al. Bioinorg Chem Appl 2013;2013:565032.
Related Products: Shikimic Acid
- 25. Fermentative production of shikimic acid: a paradigm shift of production concept from plant route to microbial route.
Different physiological and nutritional parameters affect the fermentative production of shikimic acid. In our study, Citrobacter freundii initially produced 0.62 g/L of shikimic acid in 72 h. However, when process optimization was employed, 5.11 g/L of shikimic acid was produced in the production medium consisting of glucose (5.0 %), asparagine (4.5 %), CaCO3 (2.0 %), at pH 6.0, when inoculated with 6 % inoculum and incubated at 30 ± 1 °C, 200 rpm for 60 h. Preliminary fed-batch studies have resulted in the production of 9.11 g/L of shikimic acid on feeding the production medium by 20 g/L of glucose at 24 h of the fermentation run. Production of similar amount of shikimic acid was observed when the optimized conditions were employed in a 10-L bioreactor as obtained in shake flask conditions. A total of 9.11 g/L of shikimic acid was produced in 60 h. This is approximately 14.69-fold increase in shikimic acid production when compared to the initial un-optimized production conditions. This has also resulted in the reduction of the production time. The present study provides useful information to the industrialists seeking environmentally benign technology for the production of bulk biomolecules through manipulation of various chemical parameters....(more)
Tripathi P, et al. Bioprocess Biosyst Eng 2013 Mar 31.
Related Products: Shikimic Acid
- 26. Involvement of the cell-specific pigment genes pks and sult in bacterial defense response of sea urchins Strongylocentrotus intermedius.
Bacterial infections are one of the most important problems in mass aquaculture, causing the loss of millions of juvenile organisms. We isolated 22 bacterial strains from the cavity fluid of the sea urchin Strongylocentrotus pallidus and used phylogenetic analysis based on 16S rRNA gene sequences to separate the bacterial strains into 9 genera (Aliivibrio, Bizionia, Colwellia, Olleya, Paenibacillus, Photobacterium, Pseudoalteromonas, Shewanella, and Vibrio). Incubating Strongylocentrotus intermedius larvae with a strain from each of the 9 bacterial genera, we investigated the viability of the larvae, the amount of pigment cells, and the level of polyketide synthase (pks) and sulfotransferase (sult) gene expression. Results of the assay on sea urchin development showed that all bacterial strains, except Pseudoalteromonas and Bizionia, suppressed sea urchin development (resulting in retardation of the embryos' development with cellular disorders) and reduced cell viability. We found that pks expression in the sea urchin larvae after incubation with the bacteria of 9 tested genera was significantly increased, while the sult expression was increased only after the treatment with Pseudoalteromonas and Shewanella. Shikimic acid, which is known to activate the biosynthesis of naphthoquinone pigments, increased the tolerance of the sea urchin embryos to the bacteria. In conclusion, we show that the cell-specific pigment genes pks and sult are involved in the bacterial defense response of sea urchins....(more)
Kiselev KV, et al. Dis Aquat Organ 2013 Mar 26;103(2):121-32.
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- 27. Expanding horizons of shikimic acid : Recent progresses in production and its endless frontiers in application and market trends.
Shikimic acid is an industrially important chiral compound used as a key ingredient in formulation of drug Oseltamivir phosphate (Tamiflu) for the treatment of swine/avian flu. The high cost and limited availability of shikimic acid isolated from plants has detained the use of this valuable building block of the drug. It is a versatile compound having many characteristic properties for many synthetic reactions particularly in pharmaceuticals and cosmetic industries. By virtue of being a natural product, the relevant biochemical pathway in microorganisms can be harnessed into fermentation processes to produce shikimic acid. This is an excellent alternative for the sustainable and efficient production of shikimic acid over the tedious and cumbersome process of plant based extraction methods. Various strategies of shikimic acid production are reviewed and an account of comparison of their challenges, promises and restraint is presented. Furthermore, present review attempts to focus on the market trend of shikimic acid due to its high demand with particular emphasis laid on the pandemics of swine flu. This review not only covers the recent advances in shikimic acid production but also highlights the versatile applications and its market scenario. The concluding remarks and its potential as a commercial bulk chemical are discussed in the light of current research....(more)
Rawat G, et al. Appl Microbiol Biotechnol 2013 Apr 5.
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- 28. Synthesis of benzoquinone ansamycin-inspired macrocyclic lactams from shikimic Acid.
One is not like the other: The title approach proceeds by stepwise coupling of three relatively simple substrates. Three natural product-inspired agents are described, one of which has natural product-like toxicity for HeLa and MCF7 cells. It is isoform-selective, thus targeting Hsp90α/β over Grp94, and adopts a conformation similar to that of geldanamycin when complexed with Hsp90....(more)
Jeso V, et al. Angew Chem Int Ed Engl 2013 Apr 26;52(18):4800-4.
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- 29. Seventy-two-hour release formulation of the poorly soluble drug silybin based on porous silica nanoparticles: in vitro release kinetics and in vitro/in vivo correlations in beagle dogs.
The objective of this study was to prepare a 72 h-release formulation of silybin (72 h-SLB) using a combination of solid dispersion, gel matrix and porous silica nanoparticles (PSNs) and to investigate the in vitro/in vivo correlations (IVIVCs). The results of scanning electron microscopy and N(2) adsorption demonstrated that empty PSNs possessed a spherical shape, a highly porous structure, a large specific surface area (385.89 ± 1.12 m(2)/g) and a small pore size (2.74 nm on average). The in vitro dissolution profiles of both 72 h-SLB and silybin-loaded PSNs in different concentrations (0.01, 0.06 and 0.08M) of Na(2)CO(3) solutions revealed that 0.06 M Na(2)CO(3) solution was the optimal medium in which silybin could be released from 72 h-SLB with first-order release kinetics and from PSNs with Higuchi kinetics. Furthermore, the IVIVCs of 72 h-SLB and silybin-loaded PSNs in beagle dogs were also established. Using 0.06 M Na(2)CO(3) solution as the in vitro dissolution medium, a good linear relationship could be achieved for both 72 h-SLB and silybin-loaded PSNs. The findings support the fact that the 72 h-SLB (consisting of solid dispersion, regular gel matrix and PSNs) together with Na(2)CO(3) solution as an in vitro dissolution medium can be developed into a promising formulation for poorly soluble drugs, which enjoys a good IVIVC....(more)
Cao X, et al. Eur J Pharm Sci 2013 Jan 23;48(1-2):64-71.
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- 30. Synchronized and controlled release of multiple components in silymarin achieved by the osmotic release strategy.
The pharmacological activity of herbal medicines is determined by the active components ratio that defines the medicine. Significant alteration of the components ratio will lead to major changes in the pharmacological activities. In designing sustained or controlled release delivery systems of herbal medicines, we developed the concept of synchronized release which was characterized by keeping active components' initial ratio throughout the whole release process. In this study, this concept was extended by developing a novel synchronized release system based on osmotic release strategy, which was designed as a monolithic osmotic tablet consisting of a tablet core and semi-permeable coating of cellulose acetate with mechanically perforated release orifices. The rationale of synchronized release lies in simultaneous release of silymarin multiple components in a solubilized state through the release orifices. To ensure quick solubilization of multiple components, silymarin was first formulated as fast-release solid dispersion before formulating into the osmotic tablet. The concept of synchronized release was well proved by the results of high similarity of the release profiles of the five active components in silymarin (taxifolin, silychristin, silydianin, silybin and isosilybin). Zero-order release profiles can be maintained up to approximately 20 h. High synchronicity and controlled release can be achieved by adjusting the formulation variables. It is indicated that the osmotic release strategy has great potential to achieve synchronized and controlled release of multiple components in herbal medicines....(more)
Xie Y, et al. Int J Pharm 2013 Jan 30;441(1-2):111-20.
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- 31. Enhanced bioactivity of silybin B methylation products.
Flavonolignans from milk thistle (Silybum marianum) have been investigated for their cellular modulatory properties, including cancer chemoprevention and hepatoprotection, as an extract (silymarin), as partially purified mixtures (silibinin and isosilibinin), and as pure compounds (a series of seven isomers). One challenge with the use of these compounds in vivo is their relatively short half-life due to conjugation, particularly glucuronidation. In an attempt to generate analogues with improved in vivo properties, particularly reduced metabolic liability, a semi-synthetic series was prepared in which the hydroxy groups of silybin B were alkylated. A total of five methylated analogues of silybin B were synthesized using standard alkylation conditions (dimethyl sulfate and potassium carbonate in acetone), purified using preparative HPLC, and elucidated via spectroscopy and spectrometry. Of the five, one was monomethylated (3), one was dimethylated (4), two were trimethylated (2 and 6), and one was tetramethylated (5). The relative potency of all compounds was determined in a 72 h growth-inhibition assay against a panel of three prostate cancer cell lines (DU-145, PC-3, and LNCaP) and a human hepatoma cell line (Huh7.5.1) and compared to natural silybin B. Compounds also were evaluated for inhibition of both cytochrome P450 2C9 (CYP2C9) activity in human liver microsomes and hepatitis C virus infection in Huh7.5.1 cells. The monomethyl and dimethyl analogues were shown to have enhanced activity in terms of cytotoxicity, CYP2C9 inhibitory potency, and antiviral activity (up to 6-fold increased potency) compared to the parent compound, silybin B. In total, these data suggested that methylation of flavonolignans can increase bioactivity....(more)
Sy-Cordero AA, et al. Bioorg Med Chem 2013 Feb 1;21(3):742-7.
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- 32. Interaction of silymarin flavonolignans with organic anion-transporting polypeptides.
Organic anion-transporting polypeptides (OATPs) are multispecific transporters mediating the uptake of endogenous compounds and xenobiotics in tissues that are important for drug absorption and elimination, including the intestine and liver. Silymarin is a popular herbal supplement often used by patients with chronic liver disease; higher oral doses than those customarily used (140 mg three times/day) are being evaluated clinically. The present study examined the effect of silymarin flavonolignans on OATP1B1-, OATP1B3-, and OATP2B1-mediated transport in cell lines stably expressing these transporters and in human hepatocytes. In overexpressing cell lines, OATP1B1- and OATP1B3-mediated estradiol-17β-glucuronide uptake and OATP2B1-mediated estrone-3-sulfate uptake were inhibited by most of the silymarin flavonolignans investigated. OATP1B1-, OATP1B3-, and OATP2B1-mediated substrate transport was inhibited efficiently by silymarin (IC50 values of 1.3, 2.2 and 0.3 µM, respectively), silybin A (IC50 values of 9.7, 2.7 and 4.5 µM, respectively), silybin B (IC50 values of 8.5, 5.0 and 0.8 µM, respectively), and silychristin (IC50 values of 9.0, 36.4, and 3.6 µM, respectively). Furthermore, silymarin, silybin A, and silybin B (100 µM) significantly inhibited OATP-mediated estradiol-17β-glucuronide and rosuvastatin uptake into human hepatocytes. Calculation of the maximal unbound portal vein concentrations/IC50 values indicated a low risk for silymarin-drug interactions in hepatic uptake with a customary silymarin dose. The extent of silymarin-drug interactions depends on OATP isoform specificity and concentrations of flavonolignans at the site of drug transport. Higher than customary doses of silymarin, or formulations with improved bioavailability, may increase the risk of flavonolignan interactions with OATP substrates in patients....(more)
Köck K, et al. Drug Metab Dispos 2013 May;41(5):958-65.
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- 33. Biosafety and antioxidant effects of a beverage containing silymarin and arginine. A pilot, human intervention cross-over trial.
The study objective was to investigate the potential of a beverage containing silymarin and l-arginine to alter basic physiological and urodynamic parameters in 22 normal healthy men aged 38-59years. The volunteers drank 500ml/day beverage without silymarin and l-arginine for 10days followed, after a 7-day washout period, by the beverage with 400mg silymarin and 295mg l-arginine for 10days. Blood and urine samples were collected on days 0, 10 and 27. The beverages were well-tolerated with no adverse effects. Most of the biochemical, hematological and urodynamic parameters remained unchanged. Total antioxidant capacity, total level of antioxidants, lipoperoxidation products (malondialdehyde), advanced oxidation products of proteins in plasma and glutathione, glutathione peroxidase, glutathione reductase, superoxide dismutase and catalase levels in erythrocytes were not influenced. Serum γ-glutamyl transferase, malondialdehyde level and activity of glutathione S-transferase in erythrocytes were lowered at day 27 and the concentration of total plasma SH-groups was higher on day 10. Using an ex vivo system, we found that silymarin/silybin at 10-100μM is able to adsorb onto human erythrocytes and the complexes displayed antioxidant properties as studied using ex situ square-wave voltammetry. The trial showed that silymarin in vivo may protect erythrocytes against oxidative damage....(more)
Valentová K, et al. Food Chem Toxicol 2013 Jun;56:178-83.
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- 34. Direct Targeting of MEK1/2 and RSK2 by Silybin Induces Cell-Cycle Arrest and Inhibits Melanoma Cell Growth.
Abnormal functioning of multiple gene products underlies the neoplastic transformation of cells. Thus, chemopreventive and/or chemotherapeutic agents with multigene targets hold promise in the development of effective anticancer drugs. Silybin, a component of milk thistle, is a natural anticancer agent. In the present study, we investigated the effect of silybin on melanoma cell growth and elucidated its molecular targets. Our study revealed that silybin attenuated the growth of melanoma xenograft tumors in nude mice. Silybin inhibited the kinase activity of mitogen-activated protein kinase (MEK)-1/2 and ribosomal S6 kinase (RSK)-2 in melanoma cells. The direct binding of silybin with MEK1/2 and RSK2 was explored using a computational docking model. Treatment of melanoma cells with silybin attenuated the phosphorylation of extracellular signal-regulated kinase (ERK)-1/2 and RSK2, which are regulated by the upstream kinases MEK1/2. The blockade of MEK1/2-ERK1/2-RSK2 signaling by silybin resulted in a reduced activation of NF-κB, activator protein-1, and STAT3, which are transcriptional regulators of a variety of proliferative genes in melanomas. Silybin, by blocking the activation of these transcription factors, induced cell-cycle arrest at the G1 phase and inhibited melanoma cell growth in vitro and in vivo. Taken together, silybin suppresses melanoma growth by directly targeting MEK- and RSK-mediated signaling pathways. Cancer Prev Res; 6(5); 455-65. ©2013 AACR....(more)
Lee MH, et al. Cancer Prev Res (Phila) 2013 May;6(5):455-65.
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- 35. HiFSA Fingerprinting Applied to Isomers with Near-Identical NMR Spectra: The Silybin/Isosilybin Case.
This study demonstrates how regio- and diastereo-isomers with near-identical NMR spectra can be distinguished and unambiguously assigned using quantum mechanical driven (1)H iterative Full Spin Analysis (HiFSA). The method is illustrated with four natural products, the flavonolignans silybin A, silybin B, isosilybin A, and isosilybin B, which exhibit extremely similar coupling patterns and chemical shift differences well below the commonly reported level of accuracy of 0.01 ppm. The HiFSA approach generated highly reproducible (1)H NMR fingerprints that enable distinction of all four isomers at (1)H frequencies from 300 to 900 MHz. Furthermore, it is demonstrated that the underlying numeric (1)H NMR profiles, combined with iterative computational analysis, allow parallel quantification of all four isomers, even in difficult to characterize reference materials and mixtures. The results shed new light on the historical challenges to the qualitative and quantitative analysis of these therapeutically relevant flavonolignans and open new opportunities to explore hidden diversity in the chemical space of organic molecules....(more)
Napolitano JG, et al. J Org Chem 2013 Apr 5;78(7):2827-39.
Related Products: Silybin