Phenol esters and other constituents from the stem barks of Stereospermum acuminatissimum

Abstract

A new ester, 2-(4′-hydroxyphenyl)ethyl dotriacontanoate (1), and a new inseparable mixture of octacosan-1,28-dioldiferulate and triacontan-1,30-dioldiferulate (2) were isolated from the stem barks of Stereospermum acuminatissimum, along with 24 known compounds including 4 triterpenoids, 11 anthraquinones, 2 lignans, 3 phenylpropanoids, 2 4-hydroxyphenethyl esters, 1 methoxyphenol, and 1 iridoid. The structures of the new metabolites were determined with the help of spectroscopic data including extensive 2D NMR spectroscopy. The known compounds were identified by comparison of their physical and spectroscopic data with those reported in the literature. The compounds were tested against Candida albicans ATCC 24433, C. albicans ATCC 90028, Candida glabrata ATCC 90030, Candida krusei ATCC 6258, and Candida parapsilosis ATCC 22019. Some of them were moderately active.

Keywords:

• Stereospermum acuminatissimum
• Bignoniaceae
• phenol esters
• antifungal activity

Acknowledgements

The authors gratefully acknowledge the support from the Academy of Sciences for the Developing World (TWAS) and the Chinese Academy of Sciences (CAS) through a CAS-TWAS fellowship to SVTS at the Shanghai Institute of Materia Medica, Shanghai, China.