Three New Unsaturated Fatty Acids from the Marine Green Alga Ulva fasciata Delile

Abstract

From the dichloromethane extract of the marine green alga Ulva fasciata Delile, collected from the Mediterranean coast of Egypt, three new fatty acids, namely, (E)-11-oxo-octadeca-12-enoic acid (1a), (E)-11-hydroxy-octadeca-12-enoic acid (2a) and 6-hydroxy-oct-7-enoic acid (3a) together with cholesterol were isolated. Analysis of the unpolar part of the extract using GC-MS detected the existence of further ten compounds, namely, dimethylsulfoxide, dimethylsulfone, phenylacetamide, 6,10,14-trimethyl-pentadecan-2-one, 8-heptadecene, dodecane, tridecane, 4-oxo-pentanoic acid, hexadecanoic acid, and the naturally new 1,1 -bicyclohexyl. Structures of the isolated compounds 1a -3a were confirmed by spectroscopic analyses including mass spectra (EI-MS, HR/ESI-MS), 1D and 2D NMR experiments, and by the synthetic conversion into their corresponding methyl esters 1b -3b. The algal extract and its components were comparatively examined against several pathogenic microorganisms, and brine shrimps for cytotoxicity.

Inhibition of Biofilm Formation by Modified Oxylipins from the Shipworm SymbiontTeredinibacter turnerae

“…S12, Supporting Information). Dereplication and further MS/MS fragmentation indicated that 3 is ( E )-11-oxooctadec-12-enoic acid (Figure 2), previously reported from the marine green alga Ulva fasciata [16] (Fig. S10, Supporting Information).…”

“…is (E)-11-oxooctadec-12-enoic acid ( Figure 2), previously reported from the marine green alga Ulva fasciata [16] (Fig. S10, Supporting Information).…”

Marine natural products

“…321 Feeding experiments using 13 C-labelled sodium acetate precursors revealed that all 25 carbon atoms in the skeleton of aspergiolide A, a metabolite of the filamentous fungus Aspergillus glaucus, 322,323 were derived from labelled acetate. A bioactivity-directed analysis of Ulva fasciata (Aabu-Qir, Mediterranean coast, Egypt) characterised three new unsaturated fatty acids 293-295 and a further ten known nonpolar metabolites identified by GC-MS. 331 The ubiquitous monoterpene loliolide 332 was found in thirteen red, brown and green algae from the Black Sea. 325 Biosynthetic studies of curacin A, a metabolite of mixed polyketide-peptideorigin from the cyanobacterium Lyngbya majuscula, 326 revealed an unprecedented decarboxylative chain termination mechanism involving a module containing adjacent sulfotransferase (ST) and thioesterase (TE) catalytic domains.…”

Mapping metabolome changes in Luffa aegyptiaca Mill fruits at different maturation stages via MS-based metabolomics and chemometrics

“…Fatty acids have been reported as bioactive metabolites to lower diabetes incidence [52] . In contrast, biological actions reported for hydroxylated fatty acids (oxylipids) included cytotoxic, anti-inflammatory and antimicrobial effects [53] , previously reported in luffa fruits and seeds [17] , [54] .…”