Anti-oral Microbial Flavanes from Broussonetia papyrifera Under the Guidance of Bioassay

ABSTRACT: A new flavane, bropapyriferol (1), and eleven known ones were isolated from the EtOAc part of Broussonetia papyrifera under the guidance of bioassay. The structure of compound 1 was determined by extensive 1D and 2D NMR, [α](D) spectroscopic data and quantum computation. Daphnegiravan F (2) and 5,7,3′,4′-tetrahydroxy-3-methoxy-8,5′-diprenylflavone (3) showed significantly anti-oral microbial activity against five Gram-positive strains and three Gram-negative strains in vitro. Especially, compound 3 was more potent in suppressing Actinomyces naeslundii and Porphyromonas gingivalis (MIC = 1.95 ppm) than the positive control, triclosan. GRAPHICAL ABSTRACT: [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13659-019-0197-y) contains supplementary material, which is available to authorized users.