Acylated Glycosides of Hydroxy Fatty Acid Methyl Esters Generated from the Crude Resin Glycoside (Pharbitin) of Seeds of <i>Pharbitis nil</i> by Treatment with Indium(III) Chloride in Methanol
Treatment of the crude ether-insoluble resin glycoside (convolvulin) from seeds of Pharbitis nil (Pharbitis Semen), called pharbitin, with indium(III) chloride in methanol provided seven oligoglycosides of hydroxy fatty acid methyl esters partially acylated by 2-methyl-3-hydroxybutyric (nilic) and 2S-methylbutyric acids. Their structures were elucidated on the basis of NMR and MS data and chemical
Pharesinosides A-G, acylated glycosidic acid methyl esters derivatized by NH 2 silica gel on-column catalyzation from the crude resin glycosides of Pharbitis Semen
作者:Li-Juan Bai、Jian-Guang Luo、Chen Chen、Ling-Yi Kong
DOI:10.1016/j.tet.2017.03.059
日期:2017.5
of Pharbitis nil), led to the isolation of seven new acylated glycosidic acidmethyl esters, Pharesinosides A-G (1–7), along with four known ones (8–11). These compounds (1–11) were considered to be generated via methyl esterification of the carboxyl group in acylated glycosidic acids. Their structures including stereochemistry were elucidated on the basis of a combination of the spectroscopic and chemical
Varitatin A, a Highly Modified Fatty Acid Amide from <i>Penicillium variabile</i> Cultured with a DNA Methyltransferase Inhibitor
作者:Xueqian He、Zhenzhen Zhang、Yinghan Chen、Qian Che、Tianjiao Zhu、Qianqun Gu、Dehai Li
DOI:10.1021/acs.jnatprod.5b00742
日期:2015.11.25
A new, highly modified fatty acid amide, varitatin A (1), was isolated from the fungus Penicillium variabile HXQ-H-1 cultivated with the DNA methyltransferase inhibitor 5-azacytidine. The structure including the absolute configuration of 1 was established by analysis of NMR and MS data, together with chemical degradation and Mosher's method based on MPA esters. Compound 1 showed cytotoxicity against HCT-116 cells with an IC50 value of 2.8 mu M and also inhibited the effects of protein tyrosine kinases.
[GRAPHICS]The absolute configuration of the side chain of scyphostatin (1) has been established. The chemical degradation of 1 gave 4 and 9, which correspond to the C7'-C12' and C13'-C16' fragments of the natural products, respectively. The spectroscopic data and [alpha](D) values of both compounds were compared to those of authentic samples. The results show that the absolute configuration of 1 is 8'R,10'S,14'R.
NODA, NAOKI;KOGETSU, HIROKUNI;KAWASAKI, TOSHIO;MIYAHARA, KAZUMOTO, PHYTOCHEMISTRY, 29,(1990) N1, C. 3565-3569