1H NMR spectroscopy-guided isolation of new sucrose esters from Physalis alkekengi var. franchetii and their antibacterial activity

Abstract

Ten new sucrose esters, physakengoses A–J (1−10), were isolated from the aerial parts of Physalis alkekengi var. franchetii under the guidance of 1H NMR spectroscopy. Their structures were determined by spectroscopic analyses (HRESIMS, 1D and 2D NMR, and ESIMS) and chemical methods. These new compounds were tested for antibacterial activities against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli. Among them, compounds 2 and 5–8 showed potent inhibitory effects against test strains with MIC values ranging from 3.5 to 14.9μg/mL. These findings may indicate that the P. alkekengi var. franchetii has potential application as an ingredient in pharmaceuticals.