Three new sesquiterpenes (1–3) and two new rutinosides (4 and 5) along with 17 known compounds (6–22) were isolated from the leaves of Murraya koenigii (L.) Spreng. The new compounds were elucidated as (3R,5S,6R)-3,5,6-trihydroxy-1,1,5-trimethylcyclohexyl-8-butyn-9-one (1), (8E,9R)-ethyl-7-(3S,5R,6S)-3,6-dihydroxy-1,1,5-trimethylcyclohexyl-9-hydroxybut-8-enoate (2), (3R)-3-O-β-d-glucoside-6′-d-apiose-β-ionone (3), 4-O-β-d-rutinosyl-3-methoxyphenyl-1-propanone (4), and 1-O-β-d-rutinosyl-2(R)-ethyl-1-pentanol (5) based on their spectroscopic data. Compounds 1, 4, 5, 18, and 21 (10 μM) exhibited moderate hepatoprotective activities.

Chemical examination of the exuded gum resin of Boswellia carterii resulted in the isolation of nine new prenylaromadendrane-type diterpenes, boscartols A–I (1–9). The structures of these compounds were established by extensive 1D and 2D NMR spectroscopic analyses, mass spectrometric data, and circular dichroism spectra. Compounds 1–3, 5, 6, 8, and 9 (10 μM) showed moderate hepatoprotective activity against d-galactosamine-induced HL-7702 cell damage.

This study reports an investigation of the chemical constituents of Balanophora polyandra Griff. Fifteen compounds were isolated by column chromatography on silica gel, Toyo-pearl HW-40C, Sephadex LH-20 and by HPLC. Their structures were elucidated as 1,4-di-O-galloyl-2-O-[(E)-p-coumaroyl]-β-D-glucopyranose (1), 1-O-galloyl-β-D-pyranglucose (2), 1-p-coumaryl-β-D-pyranglucose (3), 1-O-(E)-caffeoyl-β-D-pyranglucose (4), 1,3-di-O-galloyl-β-D-pyranglucose (5), 1,6-di-O-galloyl-β-D-pyranglucose (6), 1-O-(E)-caffeoyl-4-O-galloyl-β-D-pyranglucose (7), 1-O-(E)-caffeoyl-6-O-galloyl-β-D-pyranglucose (8), 1-O-(E)-caffeoyl-4,6-di-O-galloyl-β-D-pyranglucose (9), 1-O-(E)-caffeoyl-4,6-(S)-HHDP-β-D-pyranglucose (10), 1,2,3,6-tetra-O-galloyl-β-D-pyranglucose (11), 4,6-(S)-hexahydroxydiphenoyl-(α/β)-D-glucose (12), 1-O-(E)-caffeoyl-4,6-[1′,1″-(3′,3″,4′,4″-tetrahydroxydibenzofurandicarboxyl)]-β-D-glucopyranose (13), flavogallonic acid (14), and phloretin-4′-O-β-D-glucoside (15) on the basis of spectral analysis. Compound 1 was a new hydrolyzable tannin, 9 was obtained from this genus for the first time, and compounds 5, 6 and 11–14 were isolated from this plant for the first time.Graphical abstractFifteen compounds were isolated from Balanophora polyandra Griff. and 1,4-di-O-galloyl-2-O-[(E)-p-coumaroyl]-β-D-glucopyranose was a new hydrolyzable tannin.Download full-size image