- Synthesis of Ocotillol-Type Ginsenosides
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A total of 14 ocotillol-type ginsenosides were conveniently synthesized employing glycosylation of ocotillol sapogenin derivatives with glucosyl ortho-alkynylbenzoate donors under the promotion of a gold(I) catalyst as the key step. Relying on a rational protecting group strategy and the unexpected regioselectivity of the glycosylation of the 3,25-diol sapogenins (2a/2b, 5a/5b) for the tertiary 25-OH, mono 3-O-glucosyl ocotillol-PPD, 6-O-glucosyl ocotillol-PPT, 25-O-glucosyl ocotillol-PPD/PPT and 3,25-di-O-glucosyl ocotillol-PPD/PPT ginsenosides were prepared in which the configuration at the C-24 is either R or S.
- Shen, Renzeng,Cao, Xin,Laval, Stephane,Sun, Jiansong,Yu, Biao
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p. 10279 - 10294
(2016/11/17)
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- 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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