Kaurane-type diterpenoids from Chromoleana odorata, their X-ray diffraction studies and potent α-glucosidase inhibition of 16-kauren-19-oic acid

A new diterpenoid, 15-angeloyloxy-16,17-epoxy-19-kauronic acid ( 1), along with five known metabolites, 16-kauren-19-oic acid ( 2), 6′-hydroxy-2′,3′,4,4′-tetramethoxychalcone ( 3), isosakuranetin ( 4), acacetin ( 5), and kaempferide ( 6) was isolated from the organic extracts of the roots of Chromoleana odorata. Their structures were determined by spectroscopic evidences. The structures of 1 and 2 were further confirmed by single-crystal X-ray diffraction studies. Compound 2 exhibited significant α-glucosidase inhibitory and antibacterial activities against Escherichia coli and Bacillus subtilis. A new diterpenoid, 15-angeloyloxy-16,17-epoxy-19-kauronic acid, along with five known metabolite, 16-kauren-19-oic acid, was isolated from the organic extracts of the roots of Chromoleana odorata and confirmed by single-crystal X-ray diffraction studies. 16-Kauren-19-oic acid exhibited significant α-glucosidase inhibitory activity. [Display omitted]