Lipids of the tropical seagrass Thallassia hemprichii

The component sterols, alcohols, hydrocarbons, monocarboxylic, α,ω-dicarboxylic and α- and ω-hydroxy acids from the leaves and roots of the tropical seagrass Thallassia hemprichii are reported. The leaves contained significant concentrations of cholest-5-en-3β-ol, a sterol not normally detected in either higher plants or seagrasses. The lower abundance of polyunsaturated fatty acids found in both the leaves and roots compared to other seagrass species may be a result of the warmer waters from which this species was collected. Solvent-extractable, long-chain (> C₂₂)α,ω-diacids, α- and ω-hydroxy and monocarboxylic acids were also isolated from the leaves. The distribution pattern of these lipids should enable these components along with other distinctive components to be used as chemical markers for this seagrass.