Complete ¹H and ¹³C NMR assignments of three new polyhydroxylated sterols from the South China Sea gorgonian Subergorgia suberosa

Abstract

Three new polyhydroxylated sterols, 3beta,6alpha,11,20beta,24-pentahydroxy- 9,11-seco-5alpha-24-ethylcholest-7,28-diene-9-one (1), 3-(1',2'-ethandiol)-24- methylcholest-8(9),22E-diene-3beta,5alpha,6alpha,7alpha,11alpha-pentaol (2), 24-methylcholest-7,22 E-diene-3beta,5alpha,6beta,25-tetraol (3) together with five known sterols, were isolated from the EtOH/CH2Cl2 extract of the South China Sea gorgonian Subergorgia suberosa. The complete assignments of the 1H and 13C NMR chemical shifts for these new compounds were achieved by means of 1D and 2D NMR techniques, including HSQC, HMBC, 1H--1H COSY, and NOESY spectra.

Marine natural products

“…704 Secosterol 774 and sterols 775 and 776 were isolated from the gorgonian Subergorgia suberosa (Sanya Bay, China). 705 Bioassay-directed fractionation of Clavularia viridis (Green Is., Taiwan) afforded the mildly cytotoxic stoloniferones H-Q 777-786. 706 Mild cytotoxicity was also observed for three of four new trihydroxylated sterols, sinugrandisterols A-D 787-790, isolated from Sinularia grandilobata (Kenting,Taiwan).…”

9,11-Secosteroids with cytotoxic activity from the South China Sea gorgonian coral Subergorgia suberosa

“…Since the first isolation of 9,11-secosterol from the gorgonian Pseudopterogorgia americana in 1972 [1], the members of this type of interesting sterol have increased very quickly and over scores of them have been discovered up to now, from a great variety of marine organisms involving acidians [2], sponges [3], gorgonians [4][5][6][7][8], and particularly soft corals [9][10][11][12][13][14][15][16][17]. Characterized by bond cleavage between C-9 and C-11, 9,11-secosterols have attracted much attention from chemists and pharmacologists due to their versatile biological effects such as antiviral, antimicrobial, cytotoxic, antiinflammatory activities [2,4,[7][8][9][10][14][15][16][17].…”

Ergosterols from the Culture Broth of Marine Streptomyces anandii H41-59

“…However, there is only one single epimer which was isolated up to now. The stereochemistry of 1 at the chiral centers C-3, C-5, C-6, C-18, C-19 and C-17 were confirmed as the same as 5 on the basis of comparison of the NMR spectral data of 1 with those of compounds containing analogous side chain [ 11 , 12 , 13 ], and were further confirmed by NOESY spectral data. Accordingly, the structure of 1 was determined to be ergosta-7,22-diene-3β,5α,6β,27-tetraol and named as ananstrep A.…”

“…Compounds 4 – 13 were characterized as ergosterols by analysis of MS and NMR data and comparison with those in literature. They were identified to be ergosta-7,22-diene-3β,5α,6β,25-tetraol ( 4 ) [ 13 ], ergosta-7,22-diene-3β,5α,6β-triol ( 5 ) [ 11 , 12 ], ergosta-7,22-diene-3β,5α,6α-triol ( 6 ) [ 18 ], ergosta-7,22-diene-3β,5α,6β,9α-tetraol ( 7 ) [ 14 , 15 ], 5α,6α-epoxy-ergosta-8(9),22-diene-3β,7α-diol ( 8 ) [ 16 , 17 ], 5α,6α-epoxy-ergosta-8(14),22-diene-3β,7α-diol ( 9 ) [ 19 ], ergosta-8(9),22-diene-3β,5α,6β,7α-tetraol ( 10 ) [ 20 ], ergosta-8(14),22-diene-3β,5α,6β,7α-tetraol ( 11 ) [ 21 ], ergosta-5,7,22–triene-3β-ol ( 12 ) [ 22 ] and 5β,6β-epoxy-ergosta-8(14),22-diene-3β,7β-diol ( 13 ) [ 23 ]. Most of them were isolated from fungi and sponges earlier.…”