Bioprocessing of Marine Chitinous Wastes for the Production of Bioactive Prodigiosin.

Recently, microbial prodigiosin (PG) has received much attention due to its numerous beneficial applications. The aim of this study was to establish the bioprocessing of marine chitinous wastes (MCWs) for the cost-effective preparation of PG. Of the MCWs, demineralized shrimp shell powders (de-SSP) were found to be a potential source of carbon/nitrogen (C/N) for PG production by bacterial fermentation using Serratia marcescens strains. Further, PG scale-up production was investigated in a 15 L bioreactor system, and the highest yield (6200 mg/L) was achieved during fermentation using 5 L of a novel-designed culture broth that included 1.60% C/N sources (a de-SSP/casein ratio of 7/3), 0.02% K2SO4, and 0.05% K2HPO4, with an initial pH of 6-7. Fermentation was conducted in the dark at 27.5 °C for 8.0 h. This study was the first to report on the utilization of shrimp wastes for cost-effective, large-scale (5 L/pilot) PG production with high productivity (6200 mg/L) in a short cultivation time. The combination of 0.02% K2SO4 and 0.05% K2HPO4 was also found to be a novel salt composition that significantly enhanced PG yield. The red compound was purified and confirmed as PG after analyzing its HPLC profile, mass, and UV/vis spectra. The purified PG was then tested for its bioactivities and showed effective anticancer activities, moderated antioxidant activities, and novel anti-NO effects.

Three New Compounds from the Actinomycete Actinocorallia aurantiaca.

Aurantiadioic acids A (1) and B (2), two new furan-containing polyketides, and aurantoic acid A (3), a new natural product, were isolated from the liquid fermentation of the sika deer dung-derived actinomycete Actinocorallia aurantiaca. The structures of the new compounds were established by extensive spectroscopic methods, including 1D & 2D NMR, HRESIMS spectroscopic analysis. The absolute configuration of 3 was assigned by comparison of the specific optical rotations with the reported derivatives. Biological activity evaluations suggested that compounds 1-3 showed weak inhibition on NO production in the murine monocytic RAW 264.7 macrophages with IC50 values of 35.8, 41.8, 45.2 µM, respectively. Compound 3 showed weak inhibition on influenza A virus (A/PuertoRico/8/1934, H1N1) with an EC50 value of 35.9 µM, and a selective index higher than 13.3.

Lanostane triterpenoids from Tricholoma pardinum with NO production inhibitory and cytotoxic activities.

Eight undescribed lanostane triterpenoids, pardinols A‒H, along with one previously reported lanostane triterpenoid, namely saponaceol B, were isolated from the fruiting bodies of Tricholoma pardinum. Their structures and stereoconfigurations were established via combination of extensive spectroscopic analyses, alkaline methanolysis method and TDDFT/ECD calculations. Pardinols B and E-H exhibited certain inhibition activities of nitric oxide (NO) production with IC50 value ranging from 5.3 to 14.7 µM, as well as cytotoxicities against human cancer cell-lines.

Bioactive polyketides and 8,14-seco-ergosterol from fruiting bodies of the ascomycete Daldinia childiae.

Seven previously undescribed polyketides, namely childinins A-G, and one previously undescribed 8,14-seco-ergosterol, namely childinasterone A, were obtained from the fruiting bodies of Daldinia childiae. Their structures and absolute configurations were established via extensive spectroscopic analyses, single-crystal X-ray diffraction, and TDDFT/ECD calculations. Childinins A represents the first example of natural product possessing a previously undescribed 6H-naphtho[2,1-c]chromen-6-one scaffold. The single crystal X-ray diffraction of childinasterone A unambiguously determined the absolute configuration of a 8,14-seco-ergosterol skeleton. Childinins A, B, F and G (MIC90 54.9 µg⋅mL-1) showed anti-bacterial activities. Childinasterone A showed significant anti-NO activity (IC50 21.2 µM) and weak activities against SMMC-7721, MCF-7 and SW480 cell lines.