Stomopnolides A-B from echinoidea sea urchin Stomopneustes variolaris: prospective natural anti-inflammatory leads attenuate pro-inflammatory 5-lipoxygenase

Abstract

Two fourteen-membered macrocyclic pyrone derivatives named as stomopnolides were identified from the organic extract of echinoidea sea urchin Stomopneustes variolaris by extensive chromatographic purification, and were characterised as methyl 10-butyl-4a-methyl-2-oxo-octahydro-2H-cyclodeca[b]pyran-8-carboxylate (stomopnolide A) and methyl 8²-(4a-methyl-10-(10²-methylbutyl)-2-oxo-octahydro-2H-cyclodeca[b]pyran-8-yl)acetate (stomopnolide B) by spectroscopic methods. The macrocyclic pyrone derivative bearing pyran-8-carboxylate moiety (stomopnolide A) exhibited significantly greater antioxidant properties against 2,2-diphenyl-1-picrylhydrazyl (IC₅₀DPPH 1.43 mM) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (IC₅₀ABTS⁺ 1.63 mM) free radicals than stomopnolide B (IC₅₀ > 1.85 mM) and the commercial standard α-tocopherol (IC₅₀ 1.51 mM). Stomopnolide A exhibited potential attenuation property against pro-inflammatory 5-lipoxygenase (IC₅₀ 2.78 mM) than those exhibited by stomopnolide B (IC₅₀ 3.09 mM) and non-steroidal anti-inflammatory drug, ibuprofen (IC₅₀ 4.50 mM, p < 0.05), which signified the prospective anti-inflammatory activity of the former. The greater electronic parameters of stomopnolide A, along with greater number of hydrogen bonds and docking score obtained from the molecular docking studies attributed its potential anti-inflammatory activity.

Graphical Abstract

Keywords:

• Echinoidea sea urchin
• Stomopneustes variolaris
• stomopnolides A-B
• macrocyclic pyrone derivatives
• antioxidant and anti-inflammatory activity

Acknowledgements

The authors thank the Director, ICAR-CMFRI, and Head, Marine Biotechnology Division, ICAR-CMFRI for guidance and support.

Disclosure statement

The authors declare no competing financial interest.

Additional information

Funding

This work was supported by the Indian Council of Agricultural Research-Central Marine Fisheries Research Institute (ICAR-CMFRI), India under the project titled as “Development of Bioactive Pharmacophores from Marine Organisms” (grant number MBT/HLT/SUB23).