Premium
Agnatasterone A and B, Unusual Pregnane Steroids Isolated from the North‐East Atlantic Sponge Axinella agnata
Author(s) -
Guella Graziano,
Pietra Francesco
Publication year - 1988
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19880710108
Subject(s) - chemistry , sponge , pregnane , stereochemistry , steroid , acylation , organic chemistry , botany , biochemistry , biology , hormone , catalysis
Abstract Two novel pregnatrienolones isolated in very small amounts from the North‐East‐Atlantic demosponge Axinella agnata (Tetractinomorpha, Axinellida) are unique in having C(2)C(3) (or C(3)C(4)), C(7)C(8), and C(16)C(17) bonds and a 12β‐OH group which, being strongly H‐bonded to a 20‐keto group, resists acylation. 1 H‐ and 13 C‐NMR spectroscopy of the steroids and of products of their selective epoxidation or reduction allow us to propose the structures (+)‐12β‐hydroxy‐5α‐pregna‐2,7,16‐trien‐20‐one ( = agnatasterone A, (+)‐ 1 ), and (+)‐12β‐hydroxy‐5α‐pregna‐3,7,16‐trien‐20‐one ( = agnatasterone B. (+)‐ 5 ), for the two steroids with minimal recourse to model compounds.