Chemical Constituent and Biological Activities of Spatoglossum asperum J. Agardh from Oman Sea

Abstract

Background: In this investigation, we aimed to purify and elucidate compounds from Spatoglossum asperum J. Agardh (Dictyotaceae). Moreover, general toxicity, anti-proliferative, antibacterial and antioxidant properties of crude extracts were studied. Methods: The extract was isolated by petroleum ether (PE), dichloromethane (DCM) and methanol (MeOH) using Soxhlet. The PE and DCM extracts were subjected to vacuum liquid chromatography (VLC) and elution was done by n-hexane and ethyl acetate mixtures. Collected fractions were analyzed by gas chromatography/mass spectroscopy (GC/MS). The fraction of PE (eluted by ethyl acetate: hexane (8: 92) mixture) was subjected to column chromatography (CC) using a gradient mixture of ethyl acetate and chloroform mixture and compound (1) and (2) were purified. The structures of the isolated compounds were elucidated on the basis of extensive spectroscopic analyses including UV, 1D and 2D NMR spectra. The antioxidant activity of all extracts was assessed using the DPPH method and anti-proliferative activity was evaluated by MTT assay. Brine shrimp lethality assay (BSLA) was also used to determine the general toxicity of extracts. NMR data and facts retrieved from literature showed that compound (1) and (2) were caulerpin and trioleoylglycerol, respectively. Results and Conclusion: All crude extracts showed weak cytotoxic activity against L5178Y mouse lymphoma cells compared with podophyllotoxin. Finally, GC/MS analysis showed that tocopherol (11.44%), fucosterol (11.6%) and isoaromadendrene epoxide (7.83%) were the most abundant components in PE extract and stigmas-5-3 ol (20.22%), isoaromadendrene epoxide (22.01%) and tocopherol (4%) were the major compounds in DCM extract. Conclusively, our results showed that Spatoglossum asperum is a hopeful source for the different bioactive sterols including fucosterol and tocopherol.