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The collection of 337 specimens of the Chromodoris species was conducted in Sabang island, Indonesia, from 2013 to 2019. The purpose of this study to investigate the biodiversity and their secondary metabolites related by molecular structures. There are 21 species together with the chemical diversity detected by MS/MS molecular networking approach. The results showed that t he nudibranch species of C. willani and C. geometrica have the highest abundance species, while C. aureopurpurea has the lowest abundance species. The result of the chemical investigation showed that the class of diterpene derivatives was found from all specimens of Chromodoris genus in Sabang island, the western part of the Indonesian Archipelago. Keywords : Nudibranch, biodiversity, chemical diversity, MS/MS molecular networking, Chromodoris genus

Sarcophyton glaucum is one of the most abundant and chemically studied soft corals with over 100 natural products reported in the literature, primarily cembrane diterpenoids. Yet, wide variation in the chemistry observed from S. glaucum over the past 50 years has led to its reputation as a capricious producer of bioactive metabolites. Recent molecular phylogenetic analysis revealed that S. glaucum is not a single species but a complex of at least seven genetically distinct species not distinguishable using traditional taxonomic criteria. We hypothesized that perceived intraspecific chemical variation observed in S. glaucum was actually due to differences between cryptic species (interspecific variation). To test this hypothesis, we collected Sarcophyton samples in Palau, performed molecular phylogenetic analysis, and prepared chemical profiles of sample extracts using gas chromatography-flame ionization detection. Both unsupervised (principal component analysis) and supervised (linear discriminant analysis) statistical analyses of these profiles revealed a strong relationship between cryptic species membership and chemical profiles. Liquid chromatography with tandem mass spectrometry-based analysis using feature-based molecular networking permitted identification of the chemical drivers of this difference between clades, including cembranoid diterpenes (2R,11R,12R)-isosarcophytoxide (5), (2S,11R,12R)-isosarcophytoxide (6), and isosarcophine (7). Our results suggest that early chemical studies of Sarcophyton may have unknowingly conflated different cryptic species of S. glaucum, leading to apparently idiosyncratic chemical variation.

The bioactive compound from the Indonesian Marine Sponge Callyspongia sp.isolated based on bioassay-guided separation with several steps of chromatography has been done. There are 4 major compound known as isocopalane diterpene derivatives together with a plausible new compound, isocopalanol, a polyoxygenated isocopalane diterpene. Isocopalanol has molecular weight [M+H] + 412.576 m/z indicate that the compound has molecular formula C 24 H 44 O 5 determined by LCMS-ESI. This compound has bioactivity IC 50 = 0.1 μg / mL against human pancreatic cancer cell.

Our ongoing interest in the relationships between chemical contents and genetic diversity of the nudibranch Phyllidiella pustulosa and related species found in Okinawa led to identification of a series of nitrogenous sesquiterpenoids. Among them, two new compounds 1 and 2 were elucidated after spectroscopic analysis. Their structures and cytotoxicity against three cell lines are described here.

In a continuous study on the Indonesian marine sponges, we found aHyrtiossponge during our expedition in Lhok Mata Ie, an isolated place around Aceh Besar, Indonesia in 2017. The bioassay-guided separation with several steps of chromatography was applied to give pure material. Moreover, the spectroscopic analysis revealed the presence of puupehenone (1), a unique class of merosesquiterpene together with its analogs (2-3). Their structures and bioactivity against multidrug-resistantEscherichia coli(MDRE. coli) together with several cell lines are described here.

Polybrominated diphenyl ether (PBDE) compounds, derived from marine organisms, originate from symbiosis between marine sponges and cyanobacteria or bacteria. PBDEs have broad biological spectra, therefore, we analyzed structure and activity relationships of PBDEs to determine their potential as anticancer or antibacterial lead structures, through reactions and computational studies. Six known PBDEs (1–6) were isolated from the sponge, Lamellodysdiea herbacea, 13C NMR data for compound 6 are reported for the first time and their assignments are confirmed by their theoretical 13C NMR chemical shifts (RMSE &lt, 4.0 ppm). Methylation and acetylation of 1 (2, 3, 4, 5-tetrabromo-6-(3′, 5′-dibromo-2′-hydroxyphenoxy) phenol) at the phenol functional group gave seven molecules (7–13), of which 10, 12, and 13 were new. New crystal structures for 8 and 9 are also reported. Debromination carried out on 1 produced nine compounds (1, 2, 14, 16–18, 20, 23, and 26) of which 18 was new. Debromination product 16 showed a significant IC50 8.65 ± 1.11, 8.11 ± 1.43 µM against human embryonic kidney (HEK293T) cells. Compounds 1 and 16 exhibited antibacterial activity against Gram-positive Staphylococcus aureus and Gram-negative Klebsiella pneumoniae with MID 0.078 µg/disk. The number of four bromine atoms and two phenol functional groups are important for antibacterial activity (S. aureus and K. pneumoniae) and cytotoxicity (HEK293T). The result was supported by analysis of frontier molecular orbitals (FMOs). We also propose possible products of acetylation and debromination using analysis of FMOs and electrostatic charges and we confirm the experimental result.

In our continuous concern of biodiversity relating to molecular structures in Sabang island, we found complex species of soft coral (genus Lobophytum). Molecular phylogenetic analysis on 82 specimens confirmed the presence of Lobophytum crassum, Lobophytum verum, and Lobophytum rigidum. On the other hand, the identification of chemical profiles was performed by spectroscopy analysis based on metabolomics approaches. As a result, we identified the chemical diversity of cembrane-type diterpenoids class from all specimens. Moreover, metabolomics analysis using feature-based molecular networking showed L. crassum, L. verum, and L. rigidum genes poses fundamental roles in the formation of chemical variations. Our results indicated that cembrane-type diterpenoids were found on all species related to genus Lobophytum in Sabang island, located in the western part of the Indonesian archipelago.

Research on the composition of Caridea cryptic organisms (crustasea) on dead corals of pocillopora in Sabang waters has been conducted on January 2017. The purpose of this study was to identify the composition of Caridea cryptic organisms - found in dead coral Pocillopora. The location of research was decided by purposive sampling methods. The results showed that they were three families (Alpheidae, Hippolythidae, and Palaemonidae) were found at each station. Total number of individuals found as many as 109 individuals scattered into 3 stations. The most abundant families were from Alpheidae family with a total of 79 individuals while the fewest families found were Palaemonidae with a total of 11 individuals. The largest value of dead coral volume was found at Seulako island station which was 3.2 liter as the highest abundance of Caridae organisms (41 individuals). On the other hand, the station of Sumur Tiga was found the smallest coral volume of the two other stations of 1.2 liter with the lowest abundance of Caridea organisms 33 individuals.

The study of Indonesian’s marine sponge Callyspongia Sp. against white spot syndrome virus has been conducted in June 2017. Bioactive metabolite terpene isolated based on methods of bioassay-guided separation. LCMS-ESI spectrum indicate that molecular formula C24H44O5 with molecular weight is 412.576 m/z. FTIR spectrum indicated bioactive metabolite has ether C-O group at 1261 cm-1 and hydroxy group O-H at 3419 cm-1. The spectrum of 1H NMR and 13C NMR indicated that metabolite active compound as polyhydroxy isocopalane. The antiviral activity of isolate compound has been conducted against white spot syndrome virus from Litopenaeus vannamei. The result antiviral activity showed that the compound activity is strong at concentration 60 mg/L with survivability percentage at 34%. The result indicated that polyhydroxy isocopalane has an activity as anti-white spot syndrome activity from Litopenaeus vannamei.

Research on the bioactivity of a compound from Callyspongia sp. as an antibacterial agent against Escherichia coli and Aeromonas hydrophila resistants was conducted. The active metabolite was isolated based on bioassay-guided separation with several steps of chromatography. The FTIR data showed the vibration at 1637.4 cm−1 as C-N imine functional group with the fingerprint region at 1449.0 cm−1 indicated the presence of alkaloid as the active compound. The results of this study informed the inhibitory zone diameter of the extract against E. coli showed an area as wide as 8.10 mm at the concentration of 80 μg mL−1 compared to the inhibitory zone diameter of the positive control Chloramphenicol as wide as 7.50 mm at the concentration of 40 μg mL−1. However, the inhibitory zone of the extract against A. hydrophila displayed an area 8.50 mm in diameter at the concentration of 20 μg mL−1 compared to the zone diameter of the positive control Chloramphenicol as wide as 7.25 mm at the concentration of 40 μg mL−1. Based on the bioassay results, the alkaloid compound from Callyspongia sp. has potential activity against the Gram-positive bacterial resistant of Escheria coli and the Gram-negative bacterial resistant of Aeromonas hydrophila.

The bioactivity of Indonesian Marine Sponge Endectyon delaubenfelsi has been conducted on July 2018. The active metabolite based on bioassay guided-separation with several steps of chromatography. The FTIR spectrum shows that the active metabolite has N-H amine functional groups at 3434.6 cm−1 C-H methyl was detected at 3090.46 cm−1, and the fingerprint region at 1637.27 cm−1 as C-N imine. Based on the FTIR data shows indicate that the active compound as alkaloid. Metabolite active has activity IC50 = 0.2 ug / mL indicates that the active compound from of Endectyon delaubenfelsi has potential activity as the new model to the drug discovery against PANC-1 cell.

Research of Manzamine C, Indole Alkaloids as cancer cell inhibitors in nutrient starvation, from the Indonesian Marine Sponge Xestospongia muta was done on May 2018. The goal of this study is to determine the cytotoxic activity of metabolite compounds of Xetospongia muta under glucose starvation. The active metabolite isolated using bioassay-guided separation with several steps of chromatography. Interpretation of IR data indicates that the active metabolites have the functional group of secondary NH2 at 3435.56 cm1, CH methyl at 2853.39 cm1, CH methylene at 2769.64 cm1 and CN imine at 1637.27 cm1. The LCMS-ESI analysis showed that the active metabolite has a molecular weight [M+H]+ 347.445 m/z which indicates the active metabolite has a molecular formula C23H29N3. The activity of metabolite compounds against PANC-1 cells showed cytotoxic activity under glucose starvation conditions with values IC50=10 μM, whereas no growth inhibition was observed up to 100 μM under the general culture conditions.

Research to determine the selectivity of fraction Rf 0.5 of ethyl acetate extract (EtOAc) of putat air kernel (Barringtonia racemosa) on golden apple snail(Pomacea canaliculata) and local catfish (Clarias batrachus) was conducted in February 2012 at the Laboratory of Chemistry of Teacher Training and Education Faculty and Laboratory of Marine Chemistry of Coordinatorate of Marine and Fisheries of Syiah Kuala University. Thin-layer chromatography was used to separate components in the extract samples, and testing of biological activity based on the procedures recommended by FAO. Golden apple snail and local catfish mortality data were analyzed using Probit program, and value of selectivity (S) was processed according to the Wang and Feng’s formula.The values of LC50 of the fraction Rf 0.5 were 29.26 ppm for P. canaliculata and 44.47 ppm for C. batracus. The selectivity value for the tested organisms was 1.51. This study revealed that the tested extract has bioactive property as molluscicide of P. canaliculata.Key words. Biological activity, thin-layer chromatography, mortality, bioactive property, molluscicide, LC50.