asmarine A 在
sodium thiosulfate 作用下,
以
乙醇 为溶剂,
反应 3.0h,
以100%的产率得到asmarine H
参考文献:
名称:
Asmarines G and H and Barekol, Three New Compounds from the Marine Sponge Raspailia sp.
摘要:
Four asmarines, the known A and F and two new ones G and H, four diterpenes, the known chelodane, barekoxide, and zaatirin and a new one, barekol, and methyl 3-oxo-cholan-24-oate were isolated from the Kenyan sponge Raspailia sp. The structures of all these compounds were established on the basis of MS and NMR data, and the absolute configuration of barekol was determined from the CD measurements of its keto-derivative. The N-15 chemical shifts of the N atoms of the heterocycles of the asmarines were measured from N-15 HMBC experiments, and the influence of various structural features on the delta(N) values studied.
Cribrostatin 6, a dark blue cancer cell growth inhibiting constituent of the Republic of Maldives marine sponge Cribrochalina sp. has been isolated, and its structure (shown below) elucidated, based on a combination of RMS, high field (500 MHz, HMBC, and GOESY experiments) 15N,
1
H- and 13C NMR, and X-ray crystal structure analyses. Cribrostatin 6 also was found to inhibit the growth of a number of pathogenic bacteria and fungi.
Asmarines A−F, Novel Cytotoxic Compounds from the Marine Sponge <i>Raspailia</i> Species
作者:Tesfamariam Yosief、Amira Rudi、Yoel Kashman
DOI:10.1021/np9902690
日期:2000.3.1
Three pairs of nitrogen-containing metabolites, asmarines A-F (1-6), were isolated from the Red Sea sponge Raspailia sp., collected in the Dahlak Archipelago, Eritrea. Although the first pair could fully be separated to give compounds 1 and 2, the other two pairs could only be enriched up to about 80% of one isomer. The structures of the new compounds were established by spectroscopic means. Besides the asmarines, methyl 3-oxo-cholan-24-oate (12) was also isolated. The absolute configuration of asmarine A (1) was determined on the basis of CD measurements of its unstable 18-oxo derivative (7) and mainly the Cotton effect of the dicarbonyl derivative (9) of chelodane (8). A O,N(7')-dimethyl derivative (10) and a second, unexpected, methylated product (11) were obtained from 2.
CYTOTOXIC ALKALOID DERIVATIVES INCLUDING ASMARINE A AND B ISOLATED FROM A SPONGE