- Biotransformation of saponins by endophytes isolated from Panax notoginseng
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The biotransformation of the major saponins in Panax notoginseng, including the ginsenosides Rg1, Rh1, Rb1, and Re, by endophytes isolated from P. notoginseng was studied. One hundred and thirty-six endophytes were isolated and screened for their biotransformational abilities. The results showed that five of the tested endophytes were able to transform these saponins. These five strains were identified based on their ITS or 16S rDNA sequences, which revealed that they belonged to the genera Fusarium, Nodulisporium, Brevundimonas, and Bacillus genera. Ten transformed products were isolated and identified, including a new compound 6-O-[α-L-rhamnopyranosyl-(1→2)-β-D- glucopyranosyl]-20-O-β-D-glucopyranosyldammarane-3,6,12,20,24,25-hexaol (3), and nine known compounds, compound K (1), ginsenoside F2 (2), vinaginsenoside R13 (4), vinaginsenoside R22 (5), pseudo-ginsenoside RT4 (6), (20S)-protopanaxatriol (7), ginsenoside Rg1 (8), vinaginsenoside R15 (9), and (20S)-3-O-β-D-glucopyranosyl-6-O-β-D-glucopyranosylprotopanaxatriol (10). This is the first study on the biotransformation of chemical components in P. notoginseng by endophytes isolated from the same plant. Copyright
- Luo, Shao-Liu,Dang, Li-Zhi,Li, Jian-Fang,Zou, Cheng-Gang,Zhang, Ke-Qin,Li, Guo-Hong
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p. 2021 - 2031
(2013/12/04)
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- Three new triterpenoids from Panax ginseng exhibit cytotoxicity against human A549 and Hep-3B cell lines
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Three new triterpenoid derivatives, 3-O-β-Dglucopyranosyl- 20(S)-protopanaxtriol (1), 3-formyloxy-20-O-b-D-glucopyranosyl-20(S)- protopanaxtriol (2) and 26-hydroxyl-24(E)-20(S)-protopanaxtriol (3), along with six known ginsenosides, were isolated from lea
- Ma, Hai-Ying,Gao, Hui-Yuan,Huang, Jian,Sun, Bo-Hang,Yang, Bo
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experimental part
p. 576 - 582
(2012/08/28)
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- Microbial conversion of rare ginsenoside Rf to 20(S)-protopanaxatriol by Aspergillus niger
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In this study, rare ginsenoside Rf was transformed into 20(S)-protopanaxatriol (PPT(S)) by glycosidase from Aspergillus niger. By investing the reaction conditions, the optimal conditions were obtained, as follows: pH 5.0, temperature 55°C, and substrate concentration 1.25 mmol/l. Under optimal conditions, PPT(S) (1.13 μmol) prepared from 1.25 μmol Rf showed a higher yield (90.4%). The enzymatic reaction was analyzed by reversed-phase HPLC, suggesting the transformation pathway: Rf → Rh1(S) → PPT(S).
- Liu, Lei,Gu, Li-Juan,Zhang, Dong-Liang,Wang, Zhen,Wang, Chun-Yan,Li, Zheng,Sung, Chang-Keun
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experimental part
p. 96 - 100
(2010/04/26)
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- Novel Mechanism for Oxidative Cleavage of Glycosidic Bonds: Evidence for an Oxygen Dependent Reaction
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In a previous work from our laboratory, an optimized procedure was worked out for cleavage of the glucosidic bonds in ginsenosides (Cui, J.F.; Garle, M.; Lund, E.; Bjoerkhem, I.; Eneroth, P.Anal.Biochem. 1993, 210, 411-417).When the reaction was performed in n-butanol, alkaline conditions were found to give a considerably better and almost quantitative yield of intact aglyconic-specific products than did acidic conditions.This is surprising in view of the current concept that glucosidic bonds are more stable under alkaline than acidic conditions.It is shown here that the alkaline cleavage is oxygen dependent and that there is little or no conversion when oxygen or air is replaced with nitrogen.Addition of an anti-oxidant, glucose or water also reduces the degree of cleavage under the conditions employed.Replacement of n-butanol for sec-, iso- or 2-methyl-2-propanol, decreased the yield of products to about 75percent and when n- or isopropanol was used as solvent the yield decreased to about 40percent.It was shown that the glucose moiety was completely degraded under the conditions employed and that formate and carbonate, in a ratio of 5/1, were the major products.A mechanistic rationale for the oxygen dependent cleavage of the glucosidic bonds is suggested.The possibility that this mechanism may be of protective importance in biological systems under some specific conditions is also discussed.
- Cui, Jian-Fang,Bystroem, Styrbjoern,Eneroth, Peter,Bjoerkhem, Ingemar
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p. 8251 - 8255
(2007/10/02)
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