查看更多>>摘要：? 2021 Elsevier LtdA new xanthene derivative penicnthene (1), a new citrinin derivative penicitrinone H (2), along with three known analogues were isolated from rice solid culture media of the endophytic fungus Penicillium sp. T2-11 through the application of one strain many compounds (OSMAC) strategy. Their structures and stereochemistry were determined by comprehensive spectroscopic analyses and electronic circular dichroism (ECD) analysis aided by TDDFT-ECD calculations. Penicnthene (1) represented the first xanthene featuring a 3-hydroxy-2-butyl chain functionality. Compounds 1–3 were assessed for their DPPH radical scavenging, antimicrobial, acetylcholinesterase inhibitory, and cytotoxic activities. Both 1 and 2 exhibited radical scavenging activities against DPPH with potency comparable to the positive control trolox. Compound 1 showed remarkable antibacterial activity against Bacillius subtilis with MIC value of 4.0 μg/mL. 2 also displayed potent activity against Staphylococcus aureus. A putative biosynthetic pathway for compounds 1–6 were proposed.
查看更多>>摘要：? 2022 Elsevier LtdA chemoselective iridium-catalyzed transfer hydrogenation of α, β-unsaturated ketones was realized in water. The C[dbnd]C double bonds of 2-benzylidene indanones and analogues were hydrogenated exclusively catalyzed by an iridium complex (0.1 mol%) bearing a pyridine-imidazoline ligand, using a mixture of formic acid/triethyl amine (molar ratio: 5/2) as a hydrogen source in water. A series of 2-benzyl indanones and analogues were obtained with good functional group tolerance and good yields. The practicability of this approach is also demonstrated by a gram-scale synthesis.
查看更多>>摘要：? 2022 Elsevier LtdA novel cembranoid, (1R,7R,8R,11R,12R)-7,8:11,12-bisepoxycembrene A (1), was isolated from an octocoral Sinularia sp. The structure of 1 was elucidated using spectroscopic methods, and its absolute configuration was confirmed by a single-crystal X-ray diffraction analysis.
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