1-O-Alkylglycerol Ethers from the Marine Sponge Guitarra abbotti and Their Cytotoxic Activity

Abstract

The cytotoxicity-bioassay-guided fractionation of the ethanol extract from the marine sponge Guitarra abbotti, whose 1-O-alkyl-sn-glycerol ethers (AGEs) have not been investigated so far, led to the isolation of a complex lipid fraction containing, along with previously known compounds, six new lipids of the AGE type. The composition of the AGE fraction as well as the structures of 6 new and 22 previously known compounds were established using 1H and 13C NMR, GC/MS, and chemical conversion methods. The new AGEs were identified as: 1-O-(Z-docos-15-enyl)-sn-glycerol (1), 1-O-(Z-docos-17-enyl)-sn-glycerol (2), 1-O-(Z-tricos-15-enyl)-sn-glycerol (3), 1-O-(Z-tricos-16-enyl)-sn-glycerol (4), 1-O-(Z-tricos-17-enyl)-sn-glycerol (5), and 1-O-(Z-tetracos-15-enyl)-sn-glycerol (6). The isolated AGEs show weak cytotoxic activity in THP-1, HL-60, HeLa, DLD-1, SNU C4, SK-MEL-28, and MDA-MB-231 human cancer cells. A further cytotoxicity analysis in JB6 P+ Cl41 cells bearing mutated MAP kinase genes revealed that ERK2 and JNK1 play a cytoprotective role in the cellular response to the AGE-induced cytotoxic effects.

Marine natural products

“…[420][421][422] New sterols were reported from Halichondria 1175, Neopetrosia 1176, 1177, and Spongia 1178, 1179; the latter study also reported a fatty acid 1180. 411,423,424 Other manuscripts reported a number of new metabolites that were either not isolated, 425 or the structures presented are inconsistent with the spectroscopic data provided and hence are dubious in nature and not shown as part of this review. [426][427][428][429][430] Numerous rst total syntheses of sponge metabolites were published in 2022.…”