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Updated: Apr 28, 2026

Determination of Total Lipid and Lipid Classes in Marine Samples
Published on: December 11, 2021
Didemnacerides A and B: two new glycerides from Red Sea ascidian Didemnum species
Sabrin R M Ibrahim1, Gamal A Mohamed, Lamiaa A Shaala
1a Department of Pharmacognosy and Medicinal Chemistry , Faculty of Pharmacy, Taibah University , Al Madinah Al Munawwarah 41477 , Saudi Arabia.
Abstract:
Two new glycerides, didemnacerides A (1) and B (2), together with three known sterols, 24-ethyl-25-hydroxycholesterol (3), cholest-6-en-3,5,8-triol (4) and cholestane-3β,5α,6β-26-tetrol (5), were isolated from the Red Sea ascidian Didemnum sp. Their structures were elucidated by using extensive 1D ((1)H, (13)C) and 2D ((1)H-(1)H COSY, HSQC and HMBC) NMR studies and mass spectroscopic data (GC-MS and HR-MS) as well as alkaline hydrolysis followed by GC-MS and NMR spectral analyses of the fatty acid methyl esters. This is the first report of compounds 3-5 from the Red Sea ascidian Didemnum species.
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