Antibacterial p-terphenyl and α­pyrone derivates isolated from the marine-derived actinomycete Nocardiopsis sp. HDN154086.

Assisted by OSMAC strategy, one new p-terphenyl and two new α­pyrone derivates, namely nocarterphenyl I (1) and nocardiopyrone D-E (2-3), were obtained and characterized from the marine sediment-derived actinomycete Nocardiopsis sp. HDN154086. The structures of these compounds were determined on the basis of MS, NMR spectroscopic data and single-crystal X-ray diffraction. Compound 1 with a rare 2,2'-bithiazole structure among natural products showed promising activity against five bacteria with MIC values ranging from 0.8 to 1.6 µM and 3 exhibited notable antibacterial activity against MRSA compared the positive control ciprofloxacin.

Titanium-Mediated aza-Nazarov Annulation for the Synthesis of N-Fused Tricycles: A General Method to Access Lamellarin Analogues.

Fused heterocycles with nitrogen incorporation are of particular bioactive use and high importance in many research fields, especially isoquinoline-based [6/6/5] tricycles. Here, we report a unique strategy to access multifunctional N-fused tricycles from α,ß-unsaturated isoquinoline ketone and sulfonamide under mild reaction conditions. The methodology features wide substrate tolerance, and a set of N-fused heteroarenes including quinoline, phthalazine, quinazoline, quinoxaline, and benzothiazole cores are furnished efficiently. Moreover, the protocol is easy to scale up to synthesize lamellarin analogues, and the amide group of the product is also easy to transfer to other functional groups.

One-pot method based on deep eutectic solvent for extraction and conversion of polydatin to resveratrol from Polygonum cuspidatum.

The acquisition of resveratrol from Polygonum cuspidatum is complicated and costs organic solvents due to extraction and hydrolysis of its corresponding glycoside (polydatin). In this work, a novel one-pot method based on deep eutectic solvent (DES) was developed for simultaneous extraction and conversion of polydatin to resveratrol from Polygonum cuspidatum for the first time. The extraction yield of resveratrol by DES-based one-pot method were significantly higher than that of water, methanol and ethanol. After optimization by One-Variable-at-a-Time and response surface methodology, the extraction yield of resveratrol reached 12.26 ± 0.14 mg/g within 80 min. The conversation efficiency of polydatin to resveratrol in Polygonum cuspidatum from five different origins was more than 96.3%. Scanning electron microscope results indicated the selected DES disrupted plant cell walls to enhance the yield of resveratrol. The results indicated that one green method was successfully established for efficient extraction and conversion of polydatin to resveratrol from Polygonum cuspidatum.