Synthesis and Biological Evaluation of Analogues of Butyrolactone I as PTP1B Inhibitors

Structurally Diverse Diterpenoids from the Sanya Bay Nudibranch Hexabranchus sanguineus and Its Sponge-Prey Chelonaplysilla sp

Investigation of the South China Sea nudibranch Hexabranchus sanguineus from Sanya Bay afforded, in addition to three known compounds, nine new diterpenoids of the 5,19-cycloclerodane- (sanyanolides A-D), clerodane- (sanyanolide E) and subersin- (sanyanolides F-I) type. Remarkably, six diterpenoids aforementioned from H. sanguineus were also isolated from the sponge Chelonaplysilla sp. from the same water region, suggesting a trophic relationship between H. sanguineus and Chelonaplysilla sp. The structure and absolute configuration of new compounds were established by a combination of spectroscopic data, X-ray diffraction analysis and/or time-dependent density functional theory/electronic circular dichroism calculations. A plausible biogenetic relationship between these diterpenoids, along with the chemo-ecological implications of their co-occurrence in the two organisms investigated, was proposed and discussed. In in vitro bioassays, echinoclerodane A exhibited a potent inhibitory effect (IC₅₀ =2.81 μM) on LPS-induced inflammatory response in RAW 264.7 macrophage cells. In addition, echinoclerodane A and oculatolide showed considerable antibacterial activities with MIC values ranging from 1.0 to 8.0 μg/mL.

Butyrolactone I attenuates inflammation in murine NASH by inhibiting the NF-κB signaling pathway

Nonalcoholic steatohepatitis (NASH) is the development of non-alcoholic fatty liver disease (NAFLD) and a key element in the exacerbation of NAFLD. Since there are currently no drugs approved by the U.S. Food and Drug Administration to treat this disease, the search for treatments that can be translated into clinical use is urgent. Butyrolactone I (BLI), isolated from Aspergillus terreus, is an active compound possessing multiple biological activities. However, the effects of BLI on NASH have never been reported. In this study, RAW264.7 cells stimulated by lipopolysaccharide (LPS) were applied to study the anti-inflammatory effect and the underlying mechanisms of BLI in vitro. Following this, mice fed with high-fat and -fructose diet (HFFD) were used to explore the alleviation of NASH by BLIin vivo. We found that BLI attenuated inflammation in LPS-induced RAW264.7 cells by inhibiting the NF-κB signaling pathway and downregulating the expression of iNOS and COX-2. Moreover, results of experiments in vivo demonstrated that BLI reduced serum transaminase levels, decreased hepatic fat accumulation, inhibited inflammation, suppressed oxidative stress, and ameliorated liver fibrosis. For the first time, we investigated the role of BLI in the treatment of murine NASH. We found that BLI alleviates NASH partly by inhibiting the NF-κB pathway of signaling. Given its hepatoprotective effects and non-toxic properties, BLI can be a novel and effective drug for NASH patients.

Multi-Mechanistic In Vitro Evaluation of Antihyperglycemic, Antioxidant and Antiglycation Activities of Three Phenolic-Rich Indian Red Rice Genotypes and In Silico Evaluation of Their Phenolic Metabolites

The study evaluated the antidiabetic potential of three traditional Indian red rice genotypes/RR (Kattuyanam/KA, Chennangi/CH & Karungkuruvai/KU) using a combination of in vitro, metabolomics (Quadrupole-Time of Flight-Liquid chromatography-Mass spectrometry/Q-TOF-LC-MS/MS), and in silico techniques. In terms of antihyperglycemic potential, KA exhibited the highest inhibitory activity against α-amylase; CH against α-glucosidase; and KU against DPPIV and PTP1B enzymes. KA exhibited the highest antioxidant activity (DPPH, FRAP, and ABTS) and greater inhibition of protein glycation compared to other RR indicating its potential to mitigate diabetic complications. The metabolomic analysis confirmed the presence of 99 phenolics in the sample extracts (KU-71, KA-70, CH-68). Molecular docking studies revealed seven metabolites to be good inhibitors of the four target enzymes and activators of insulin receptor substrate/IRS. The antihyperglycemic and oxidation-glycation reduction composite index revealed KA to have the highest overall antidiabetic potential. Hence, the RR could be utilized in functional foods with a multi-barrelled strategy for diabetes prevention/management.

Research progress of environmentally friendly marine antifouling coatings

The antifouling mechanisms and research progress in the past three years of environmentally friendly marine antifouling coatings are introduced in this work.