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National Committee on Marine Sciences (NCMS)

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Author: search.filters.author.Batucan, Jeremiah D.Has files: Yes

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    Global mass spectrometric analysis reveals chemical diversity of secondary metabolites and 44-Methylgambierone production in Philippine Gambierdiscus strains
    Malto, 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.
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    Mining small molecules from Teredinibacter turnerae strains isolated from Philippine Teredinidae
    Villacorta, Jamaine B.; Rodriguez, Camille V.; Peran, Jacquelyn E.; Batucan, Jeremiah D.; Concepcion, Gisela; Salvador-Reyes, Lilibeth A.; Junio, Hiyas A. (MDPI, 2022-11-21)
    Endosymbiotic relationship has played a significant role in the evolution of marine species, allowing for the development of biochemical machinery for the synthesis of diverse metabolites. In this work, we explore the chemical space of exogenous compounds from shipworm endosymbionts using LC-MS-based metabolomics. Priority T. turnerae strains (1022X.S.1B.7A, 991H.S.0A.06B, 1675L.S.0A.01) that displayed antimicrobial activity, isolated from shipworms collected from several sites in the Philippines were cultured, and fractionated extracts were subjected for profiling using ultrahigh-performance liquid chromatography with high-resolution mass spectrometry quadrupole time-of-flight mass analyzer (UHPLC-HRMS QTOF). T. turnerae T7901 was used as a reference microorganism for dereplication analysis. Tandem MS data were analyzed through the Global Natural Products Social (GNPS) molecular networking, which resulted to 93 clusters with more than two nodes, leading to four putatively annotated clusters: lipids, lysophosphatidylethanolamines, cyclic dipeptides, and rhamnolipids. Additional clusters were also annotated through molecular networking with cross-reference to previous publications. Tartrolon D cluster with analogues, turnercyclamycins A and B; teredinibactin A, dechloroteredinibactin, and two other possible teredinibactin analogues; and oxylipin (E)-11-oxooctadec-12-enoic acid were putatively identified as described. Molecular networking also revealed two additional metabolite clusters, annotated as lyso-ornithine lipids and polyethers. Manual fragmentation analysis corroborated the putative identification generated from GNPS. However, some of the clusters remained unclassified due to the limited structural information on marine natural products in the public database. The result of this study, nonetheless, showed the diversity in the chemical space occupied by shipworm endosymbionts. This study also affirms the use of bioinformatics, molecular networking, and fragmentation mechanisms analysis as tools for the dereplication of high-throughput data to aid the prioritization of strains for further analysis.
    The research was completed under the supervision of the Department of Agriculture-Bureau of Fisheries and Aquatic Resources (DA-BFAR), Philippines in compliance with Prior Informed Consent (PIC) certificate requirements and all required legal instruments and regulatory issuances covering the conduct of the research. The authors would also like to acknowledge the Department of Science and Technology-funded Discovery and Development of Health Products Program (DOST-DDHP) for the LC-MS Facility of the Institute of Chemistry, University of the Philippines Diliman.