A new antimalarial sterol, kaimanol (1), along with a known sterol, saringosterol (2) was isolated from the Indonesian Marine sponge, Xestospongia sp. The chemical structure of the new compound was determined on the basis of spectroscopic evidences and by comparison to those related compounds previously reported. Isolated compounds, 1 and 2 were evaluated for their antiplasmodial effect against Plasmodium falciparum 3D7 strains. Compounds 1 and 2 exhibited antiplasmodial activity with IC50 values of 359 and 0.250 nM, respectively.
Marine sponges are acknowledged as a bacterial hotspot and resource of novel natural products or genetic material with industrial or commercial potential. However, sponge-associated bacteria are difficult to be cultivated and the production of their desirable metabolites is inadequate in terms of rate and quantity, yet bioinformatics and metagenomics tools are steadily progressing. Bacterial diversity profiles of high-microbial-abundance wild tropical marine sponges Aaptos aaptos and Xestospongia muta were obtained by sample collection at Pulau Bidong and Pulau Redang islands, 16S rRNA amplicon sequencing on Illumina HiSeq2500 platform (250 bp paired-end) and metagenomics analysis using Ribosomal Database Project (RDP) classifier. Raw sequencing data in fastq format and relative abundance histograms of the dominant 10 species are available in the public repository Discover Mendeley Data (http://dx.doi.org/10.17632/zrcks5s8xp). Filtered sequencing data of operational taxonomic unit (OTU) with chimera removed is available in NCBI accession numbers from MT464469 to MT465036.