Open Chemistry (Oct 2017)
Antimicrobial sesquiterpenoids from Laurencia obtusa Lamouroux
Abstract
Purification of the organic extract of Laurencia obtusa Lamouroux by column chromatography and preparative thin layer chromatography provided four new compounds: a eudesmane-type sesquiterpenoid [eudesma-4(15),11-diene-5,7-diol (1)], a cuparane-type sesquiterpenoid [10-hydroxycuparaldehyde (2)], and two nor-cuparanes [3-hydroxy-15-nor-cuparan-10β-ol (3) and 2-bromo-3-hydroxy-15-nor-cuparan-10β-ol (4)]. Structural identification was made possible by comparison of spectral data with those reported in the literature. Compounds 3 and 4 are significant as nor-cuparanes are rarely isolated from marine environment. 1 showed moderate anticandidal activity, whereas 2 exhibited reasonable antibacterial activity against multidrug-resistant bacteria (especially Gram-positive). All the compounds are nontoxic to Artemia salina.
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