Two new C21 steroids were isolated from the CHCl3 extract of the stem of Marsdenia tenacissima. On the basis of spectroscopic analysis and chemical methods, their structures were elucidated as 17β-tenacigenin B (2)...Two new C21 steroids were isolated from the CHCl3 extract of the stem of Marsdenia tenacissima. On the basis of spectroscopic analysis and chemical methods, their structures were elucidated as 17β-tenacigenin B (2) and 3-O-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D- oleandropyranosyl-tenacigenin C (3). The structure of the known aglycon tenacigenin C was revised as 5α, 9α, 17β-pregnane-3β, 8β, 11α, 12β, 14β-pentanol-20-one. Compound 3 is the first reported glycoside of tenacigenin C.展开更多
Two new C21 steroidal glycosides, cynanauriculoside I and cynanauriculoside II, were isolated from the roots of Cynanchum aurichulatum. Their structures were established using spectroscopic methods including one and ...Two new C21 steroidal glycosides, cynanauriculoside I and cynanauriculoside II, were isolated from the roots of Cynanchum aurichulatum. Their structures were established using spectroscopic methods including one and two-dimensional NMR.展开更多
Besides a series of normal C_(21) steroids from Marsdenia incisa incisa P.T.Li et Y.P.Li, it small amount of novel C_(21) steroidal glycoside (Ⅱ) had been isolated. The mild acidic hydrolysis of (Ⅱ) afforded genin-(...Besides a series of normal C_(21) steroids from Marsdenia incisa incisa P.T.Li et Y.P.Li, it small amount of novel C_(21) steroidal glycoside (Ⅱ) had been isolated. The mild acidic hydrolysis of (Ⅱ) afforded genin-(Ⅰ). By spectroscopic analyses of IR, ELMS, FDMS, ~1H NMR, ^(13)C NMR (DEPT, PRFT), ~1H-~1H COSY, ~1H-^(13)C COSY for (Ⅰ) and (Ⅱ), (Ⅰ) had been deduced as B-nor (7) -6β-formyl-pregnane-3β, 5β, 8β, 12β, 14β, 17β, 20-heptatol, named neomarinogenin; (Ⅱ) had been deduced as neomarinogenin 3-O-β-D-thevetopyranosyl-(1→-4)-β-Dcymaropyranosyl-(1→4)-β-D-cymaropyranoside, named neomarinoside. Their physical and spectral data were as follows. Neomarinogenin (Ⅰ). A colorless prism from Me_2 CO, mp 202—205℃, 〔α〕_D^(17)+28.81°(MeOH, c0.05), C_(21)H_(34)O_8 (Found: C, 60.76; H, 8.19, C_(21)H_(34)O_8, requires C, 60.87. H, 8.21％); IRv_(max)^(KBr)cm^(-1): 3450 (OH), 1700 (C=O), 1050(C-O-C); EIMS m/z: 397 (M-OH), 380 (397-OH), 379, 378 (M-2H_2O), 36; (M-3H_2O), 342 (M-4H_2O), 333,展开更多
A new C_(21) furanoterpene. ent-untenospongin A (2), together with a known related compound. tetradehydrofurospongin-1 (1), has been isolated from the indian marine sponge Hippospongia sp. and its structure was determ...A new C_(21) furanoterpene. ent-untenospongin A (2), together with a known related compound. tetradehydrofurospongin-1 (1), has been isolated from the indian marine sponge Hippospongia sp. and its structure was determined on the basis of spectroscopic data.展开更多
文摘Two new C21 steroids were isolated from the CHCl3 extract of the stem of Marsdenia tenacissima. On the basis of spectroscopic analysis and chemical methods, their structures were elucidated as 17β-tenacigenin B (2) and 3-O-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D- oleandropyranosyl-tenacigenin C (3). The structure of the known aglycon tenacigenin C was revised as 5α, 9α, 17β-pregnane-3β, 8β, 11α, 12β, 14β-pentanol-20-one. Compound 3 is the first reported glycoside of tenacigenin C.
文摘Two new C21 steroidal glycosides, cynanauriculoside I and cynanauriculoside II, were isolated from the roots of Cynanchum aurichulatum. Their structures were established using spectroscopic methods including one and two-dimensional NMR.
基金This work was supported by grants from International Foundation for Science in Sweden and National Science Foundation of China.
文摘Besides a series of normal C_(21) steroids from Marsdenia incisa incisa P.T.Li et Y.P.Li, it small amount of novel C_(21) steroidal glycoside (Ⅱ) had been isolated. The mild acidic hydrolysis of (Ⅱ) afforded genin-(Ⅰ). By spectroscopic analyses of IR, ELMS, FDMS, ~1H NMR, ^(13)C NMR (DEPT, PRFT), ~1H-~1H COSY, ~1H-^(13)C COSY for (Ⅰ) and (Ⅱ), (Ⅰ) had been deduced as B-nor (7) -6β-formyl-pregnane-3β, 5β, 8β, 12β, 14β, 17β, 20-heptatol, named neomarinogenin; (Ⅱ) had been deduced as neomarinogenin 3-O-β-D-thevetopyranosyl-(1→-4)-β-Dcymaropyranosyl-(1→4)-β-D-cymaropyranoside, named neomarinoside. Their physical and spectral data were as follows. Neomarinogenin (Ⅰ). A colorless prism from Me_2 CO, mp 202—205℃, 〔α〕_D^(17)+28.81°(MeOH, c0.05), C_(21)H_(34)O_8 (Found: C, 60.76; H, 8.19, C_(21)H_(34)O_8, requires C, 60.87. H, 8.21％); IRv_(max)^(KBr)cm^(-1): 3450 (OH), 1700 (C=O), 1050(C-O-C); EIMS m/z: 397 (M-OH), 380 (397-OH), 379, 378 (M-2H_2O), 36; (M-3H_2O), 342 (M-4H_2O), 333,
文摘A new C_(21) furanoterpene. ent-untenospongin A (2), together with a known related compound. tetradehydrofurospongin-1 (1), has been isolated from the indian marine sponge Hippospongia sp. and its structure was determined on the basis of spectroscopic data.
