National Committee on Marine Sciences (NCMS)
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- Global mass spectrometric analysis reveals chemical diversity of secondary metabolites and 44-Methylgambierone production in Philippine Gambierdiscus strainsMalto, Zabrina Bernice L.; Benico, Garry A.; Batucan, Jeremiah D.; Dela Cruz, James; Romero, Marc Lawrence J.; Azanza, Rhodora V.; Salvador-Reyes, Lilibeth A. (Frontiers Media SA, 2022-02-04)Surveillance and characterization of emerging marine toxins and toxigenic dinoflagellates are warranted to evaluate their associated health risks. Here, we report the occurrence of the ciguatera poisoning-causative dinoflagellate Gambierdiscus balechii in the Philippines. Toxin production and chemical diversity of secondary metabolites in G. balechii GtoxSAM092414, G. balechii Gtox112513, and the recently reported Gambierdiscus carpenteri Gam1BOL080513 were assessed using targeted and untargeted UPLC-MS/MS analysis and radioligand receptor-binding assay (RBA). 44-methylgambierone was produced by all three strains, albeitwith different levels based on RBA and UPLC-HRMS/MS analysis. The fatty acid composition was similar in all strains, while subtle differences in monosaccharide content were observed, related to the collection site rather than the species. Molecular networking using the GNPS database identified 45 clusters belonging to at least ten compound classes, with terpene glycosides, carbohydrate conjugates, polyketides, and macrolides as major convergence points. Species-specific peptides and polyhydroxylated compounds were identified in G. balechii GtoxSAM092414 and G. carpenteri Gam1BOL080513, respectively. These provide a glimpse of the uncharacterized biosynthetic potential of benthic dinoflagellates and highlight the intricate and prolific machinery for secondary metabolites production in these organisms.We would like to thank H. Junio and the Secondary Metabolites Profiling Laboratory of the Institute of Chemistry, University of the Philippines Diliman and K. B. Davis for assistance in the conduct of this study.
- Total polyphenol content of tropical marine and coastal flora: Potentials for food and nutraceutical applicationsNarvarte, Bienson Ceasar V.; Genovia, Tom Gerald T.; Hinaloc, Lourie Ann R.; Gonzaga, Shienna Mae C.; Tabonda-Nabor, April Mae; Palecpec, Flora Maye R.; Dayao, Helen M.; Roleda, Michael Y. (Springer, 2023-07-08)The marine environment is abundant in natural products that are beneficial to humans. Among these compounds are the polyphenols produced by marine flora as secondary metabolites and used as a defense against stressful environmental conditions. Accordingly, recent pharmacological and biomedical studies showed that polyphenols from marine and coastal floras have several important bioactivities including antioxidant property. In this study, we measured the total polyphenol content (TPC) of 75 species of marine-associated flora. The TPC of their methanolic extracts was measured spectrophotometrically using the Folin-Ciocalteu assay and was expressed both as mg phloroglucinol equivalent per g of dry weight (mg PGE g−1 DW) and as mg gallic acid equivalent per g dry weight (mg GAE g−1 DW). The TPC values are higher when expressed in terms of GAE compared to PGE. Also, the mean TPC of tracheopytes (229 ± 43.0 mg PGE g−1 DW) was higher compared to the mean TPC of macroalgae (69.4 ± 9.59 mg PGE g−1 DW). For macroalgae, ochrophytes (97.9 ± 22.7 mg PGE g−1 DW) had the highest mean TPC followed by chlorophytes (80.0 ± 20.5 mg PGE g−1 DW) and rhodophytes (49.5 ± 8.60 mg PGE g−1 DW). Moreover, our study also showed that TPC varied between young and mature tissues, among different color morphotypes and different parts of the plants. Although the concentrations of total polyphenols varied among species, ages, strains and parts of the plant, our study showed that marine and coastal floras are rich sources of polyphenols that could be further examined for their biological activities and other applications in food industry.