Sample checklist of Gastropoda and Bivalvia in Cham Islands, Vietnam.

BACKGROUND: Cham Islands (Cu Lao Cham) is a group of 8 small islands in the Quang Nam province, Central Vietnam. There is only one study that mentioned the diversity of marine molluscs in this area. However, the data on species composition have not been digitised and not stored or shared for other purposes. Our paper aims to share the checklist of marine mollusc species (Bivalvia and Gastropoda) species that we collected from the littoral zone of Cham Islands in May 2017. This is the first digitised and online data of marine molluscs in Vietnam. It is very important for researchers in various fields such as the structure and function of ecology and biodiversity monitoring. NEW INFORMATION: This study provides a checklist of the marine bivalves and snails in the Cham Islands of Vietnam. Moreover, this first widely shared data of biodiversity in Vietnam can trigger biodiversity data papers in this data-poor country.The data of this study will be important inputs for better understanding biodiversity on the Cham Islands and Vietnam as well as for forming the basis for monitoring, exploitation and conservation of biodiversity in this area.In total, 145 taxa were recorded, 46 bivalve taxa and 99 snail taxa, from which 128 were identified to the species level and 17 were identified to the genus level. There are 116 new species records for the Cham Islands.The specimens are currently deposited in the Institute of Ecology and Biological Resources (IEBR), Vietnam Academy of Science and Technology (VAST).

Antiproliferative Activity of Glycosaminoglycan-Like Polysaccharides Derived from Marine Molluscs.

Despite the increasing availability of new classes of cancer treatment, such as immune- and targeted therapies, there remains a need for the development of new antiproliferative/cytotoxic drugs with improved pharmacological profiles that can also overcome drug resistant forms of cancer. In this study, we have identified, and characterised, a novel marine polysaccharide with the potential to be developed as an anticancer agent. Sulphated polysaccharides isolated from the common cockle (Cerastoderma edule) were shown to have antiproliferative activity on chronic myelogenous leukaemia and relapsed acute lymphoblastic leukaemia cell lines. Disaccharide and monosaccharide analysis of these marine polysaccharides confirmed the presence of glycosaminoglycan-like structures that were enriched in ion-exchange purified fractions containing antiproliferative activity. The antiproliferative activity of these glycosaminoglycan-like marine polysaccharides was shown to be susceptible to heparinase but not chondrotinase ABC digestion. This pattern of enzymatic and antiproliferative activity has not previously been seen, with either marine or mammalian glycosaminoglycans. As such, our findings suggest we have identified a new type of marine derived heparan sulphate/heparin-like polysaccharide with potent anticancer properties.

Ancient DNA analysis identifies marine mollusc shells as new metagenomic archives of the past.

Marine mollusc shells enclose a wealth of information on coastal organisms and their environment. Their life history traits as well as (palaeo-) environmental conditions, including temperature, food availability, salinity and pollution, can be traced through the analysis of their shell (micro-) structure and biogeochemical composition. Adding to this list, the DNA entrapped in shell carbonate biominerals potentially offers a novel and complementary proxy both for reconstructing palaeoenvironments and tracking mollusc evolutionary trajectories. Here, we assess this potential by applying DNA extraction, high-throughput shotgun DNA sequencing and metagenomic analyses to marine mollusc shells spanning the last ~7,000 years. We report successful DNA extraction from shells, including a variety of ancient specimens, and find that DNA recovery is highly dependent on their biomineral structure, carbonate layer preservation and disease state. We demonstrate positive taxonomic identification of mollusc species using a combination of mitochondrial DNA genomes, barcodes, genome-scale data and metagenomic approaches. We also find shell biominerals to contain a diversity of microbial DNA from the marine environment. Finally, we reconstruct genomic sequences of organisms closely related to the Vibrio tapetis bacteria from Manila clam shells previously diagnosed with Brown Ring Disease. Our results reveal marine mollusc shells as novel genetic archives of the past, which opens new perspectives in ancient DNA research, with the potential to reconstruct the evolutionary history of molluscs, microbial communities and pathogens in the face of environmental changes. Other future applications include conservation of endangered mollusc species and aquaculture management.

Extraction and Quantification of Bioactive Tyrian Purple Precursors: A Comparative and Validation Study from the Hypobranchial Gland of a Muricid Dicathais orbita.

Muricidae are marine molluscs known for the production of Tyrian purple and bioactive precursor compounds. A validation study for the extraction and analysis of secondary metabolites found in the hypobranchial gland of the muricid Dicathais orbita is reported, using high performance liquid chromatography-mass spectrometry (HPLC-MS) with diode array detector (DAD). Quantification of the dominant secondary metabolites from D. orbita is described, followed by a comparison of solvent extraction procedures and stability studies. The intra- and inter-day relative standard deviation (RSD) for tyrindoxyl sulphate was 0.46% and 0.17%, respectively. The quantification was linear for standards murexine, 6-bromoisatin, and tyrindoxyl sulphate. The limits of detection were 0.03, 0.004, and 0.07 mg/mL, respectively, and the limits of quantification were 0.09, 0.01, and 0.22 mg/mL, respectively. The results showed that alcoholic solvents were better for extracting choline ester and indoxyl sulphate ultimate precursors, while chloroform was more suitable for the extraction of the intermediate precursors. Multivariate analysis revealed significant differences in extract composition according to the solvent used. Stability testing showed an increase of the oxidative compounds 6-bromoisatin and putative tyrindoxyl S-oxide sulphate in the ethanol extracts while more degradation products were seen in the chloroform extracts after months of cold storage. The validated method was found to be simple, reproducible, precise, and suitable for quantification of the secondary metabolites of muricid molluscs for dye precursor and nutraceutical quality control, as well as applications in marine chemical ecology.

A new labdane diterpene from the limpet Trimusculus peruvianus / Un nuevo diterpeno labdano aislado del molusco Trimusculus peruvianus

The family Trimusculidae produces labdane diterpenes, which differ in the degree and type of esterification with acetoxy and isovaleroyl ester predominantly. Here we describe the isolation from the marine pulmonate Trimusculus peruvianus, collected on intertidal rocks of Chilean coasts, of a new diterpene closely related to the above mentioned characteristics. It structure was determined by spectroscopic data. The compounds were subjected to toxicity tests using nauplii and cysts of Artemia salina. The known compounds isolated in this study have shown an ability to inhibit egg hatch of A. salina.

La familia Trimusculidae produce diterpenos tipo labdano, que difieren en el grado y tipo de esterificación con esteres acetato e isovalérico predominantemente. En este trabajo describimos el aislamiento de un nuevo diterpeno con las características ya mencionadas y de otros ya conocidos desde el molusco marino pulmonado Trimusculus peruvianus, recolectado en la zona intermareal del litoral chileno. Su estructura fue determinada a través de métodos espectroscopicos. Los compuestos fueron sometidos a ensayos de toxicidad y eclosión de los huevos de Artemia salina.

Marine compounds selectively induce apoptosis in female reproductive cancer cells but not in primary-derived human reproductive granulosa cells.

Anticancer properties of tyrindoleninone and 6-bromoisatin from Dicathais orbita were tested against physiologically normal primary human granulosa cells (HGC) and reproductive cancer cell lines. Tyrindoleninone reduced cancer cell viability with IC50 values of 39 µM (KGN; a tumour-derived granulosa cell line), 39 µM (JAr), and 156 µM (OVCAR-3), compared to 3516 µM in HGC. Apoptosis in HGC's occurred after 4 h at 391 µM tyrindoleninone compared to 20 µM in KGN cells. Differences in apoptosis between HGC and KGN cells were confirmed by TUNEL, with 66 and 31% apoptotic nuclei at 4 h in KGN and HGC, respectively. These marine compounds therefore have potential for development as treatments for female reproductive cancers.