Microplastic pollution of commercial fishes from coastal and offshore waters in southwestern Japan.

Microplastic (MP) pollution in the marine environment is a worldwide issue. There is growing concern of consuming MPs through fish, yet the contamination status of fish collected from deeper waters surrounding Japan remains limited. Here, we presented baseline data on MPs in commercially important fishes from the coastal and offshore waters near Kyushu, Japan (East China Sea).

Geographic Variations in the Toxin Profile of the Xanthid Crab in a Single Reef on Ishigaki Island, Okinawa, Japan.

Toxic crabs of the family Xanthidae contain saxitoxins (STXs) and/or tetrodotoxin (TTX), but the toxin ratio differs depending on their habitat. In the present study, to clarify within reef variations in the toxin profile of xanthid crabs, we collected specimens of the toxic xanthid crab and their sampling location within a single reef (Yoshihara reef) on Ishigaki Island, Okinawa Prefecture, Japan, in 2018 and 2019. The STXs/TTX content within the appendages and viscera or stomach contents of each specimen was determined by instrumental analyses.

Homophymamide A, Heterodetic Cyclic Tetrapeptide from a sp. Marine Sponge: A Cautionary Note on Configurational Assignment of Peptides That Contain a Ureido Linkage.

A previously unreported heterodetic cyclic peptide, homophymamide A (), was isolated from a sp. marine sponge. The structure of homophymamide A was determined to be a lower homologue of anabaenopeptins by spectroscopic analysis, chemical degradation, and chemical synthesis.

Structure Elucidation of Calyxoside B, a Bipolar Sphingolipid from a Marine Sponge sp. through the Use of Beckmann Rearrangement.

Marine sponges are an excellent source of biologically active secondary metabolites. We focus on deep-sea sponges for our discovery study. A marine sponge sp.

Myrindole A, an Antimicrobial Bis-indole from a Marine Sponge sp.

Myrindole A, a bis-indole alkaloid, was isolated from the deep-sea sponge sp. The high degree of unsaturation of the molecule complicated the assignment of its structure by standard 2D-NMR experiments but was ultimately achieved by a combination of H-N-HMBC and 1,-ADEQUATE experiments as well as the comparison of measured and calculated CD spectra. Myrindole A showed antimicrobial activity against Gram-positive and Gram-negative bacteria.

Cytotoxic Glycosylated Fatty Acid Amides from a Stelletta sp. Marine Sponge.

We have discovered new glycosylated fatty acid amides, stellettosides, from a Stelletta sp. marine sponge. They were detected through LC-MS analysis of the extract combined with the cytotoxicity assay of the prefractionated sample.