Angelocunhol: New erythroxylane diterpene and other compounds from Simira sampaioana (Rubiaceae)

Abstract

The first Simira sampaioana (Rubiaceae) phytochemical study allowed the isolation and structural determination of a new erythroxylane diterpene named Angelocunhol, 11β,12α-dihydroxy-2,4(18),15-eritroxilatrien-1-one, together with 14 known compounds: simirane B, harman, maxonine, isomalindine, malindine, sitost-4-en-6-ol-3-one, estigmast-4,22-dien-6-ol-3-one, campest-4-en-6-ol-3-one, sitost-4-en-3-one, stigmast-4,22-dien-3-one, campest-4-en-3-one, β-sitosterol, stigmasterol, and stigmast-4,22-dien-3-ol from the wood of a specimen of the species. The structures of these compounds were elucidated on the spectroscopic-data analysis basis, mainly 1H and 13C nuclear magnetic resonance (NMR), including 2D experiments (1H-1H correlation spectroscopy (COSY), nuclear Overhauser spectroscopy (NOESY), heteronuclear multiple-bond correlation-HMBC and heteronuclear single-quantum correlation-HSQC), and high-resolution electrospray mass spectrometry (HRESI-MS).