Poecillastrosides, Steroidal Saponins From the Mediterranean Deep-Sea Sponge Poecillastra Compressa (Bowerbank, 1866)

Mar Drugs. 2017 Jun 26;15(7):199. doi: 10.3390/md15070199.

Abstract

The first chemical investigation of the Mediterranean deep-sea sponge Poecillastra compressa (Bowerbank, 1866) led to the identification of seven new steroidal saponins named poecillastrosides A-G (1-7). All saponins feature an oxidized methyl at C-18 into a primary alcohol or a carboxylic acid. While poecillastrosides A-D (1-4) all contain an exo double bond at C-24 of the side-chain and two osidic residues connected at O-2', poecillastrosides E-G (5-7) are characterized by a cyclopropane on the side-chain and a connection at O-3' between both sugar units. The chemical structures were elucidated through extensive spectroscopic analysis (High-Resolution Mass Spectrometry (HRESIMS), 1D and 2D NMR) and the absolute configurations of the sugar residues were assigned after acidic hydrolysis and cysteine derivatization followed by LC-HRMS analyses. Poecillastrosides D and E, bearing a carboxylic acid at C-18, were shown to exhibit antifungal activity against Aspergillus fumigatus.

Keywords: Poecillastra compressa; deep-sea; saponins; sponge.

MeSH terms

  • Animals
  • Molecular Structure
  • Porifera / chemistry
  • Porifera / metabolism*
  • Saponins / chemistry*
  • Saponins / metabolism

Substances

  • Saponins