New Diarylheptanoids from Amomum muricarpum ELMER

Abstract

Amomum muricarpum ELMER (Zingiberaceae) is a medicinal plant 2-3 m tall which is distributed in dense forests in Guangdong and Guangxi provinces (China) at 300-1000 m above sea level.1) The plant is also distributed in the Philippines and recently was found in Vietnam by a group of botanic taxonomists of the Vietnam Academy of Science and Technology. The lack of phytochemical reports on A. muricarpum prompted us to investigate the species that grows in Vietnam. We succeeded in the isolation of the two new diarylheptanoids 1 and 2 together with the three known compounds 3-5, of which the isolation and structure determination are described in this paper.The extraction of the oven-dried rhizomes of A. muricarpum with MeOH and sequential fractionation using solvents of increasing polarities gave n-hexane-, CH 2 Cl 2 -, EtOAc-, and 1-BuOH-soluble fractions. The isolation of compounds 1-5 ( Fig. 1) . The locations of the carbonyl group at C-3 and methoxyl group at C-5 were unambiguously determined with the 1 H-1 H correlated spectroscopy (COSY) and heteronuclear multiple bond correlation (HMBC) spectra of 1 (Fig. 2). The absolute stereochemistry of the methoxyl group was determined to be 5R on the basis of the negative sign of the optical rotation and positive Cotton effect associated with the carbonyl n→p* transition at 350 nm (De ϩ0.57) in the circular dichroism (CD) spectrum of 1 in comparison with those of a series of analogous compounds.2) Thus the structure of 1 was determined to be (5R)-5-methoxy-1,7-bis(3,4-dihydroxyphenyl)-3-heptanone, which was given the trivial name muricarpone A.Compound 2 was obtained as a syrup. Its molecular formula was determined to be C 19 H 22 O 5 based on the results of negative-ion HR-FAB-MS. The IR spectrum exhibited a hydroxyl absorption band at 3286 and a ketone band at 1696 cm Ϫ1. The 1 H-, 13 C-NMR (Table 1), and DEPT spectra of 2 disclosed the presence of seven carbons of the heptane chain including the isolated carbonyl group [d C 213.7 (s), 45.3 (t), 43.6 (t), 35.9 (t), 32.1 (t), 30.4 (t), 24.3 (t)] and two identical 3,4-dihydroxyphenyl moieties. The asymmetrical nature of the heptane chain was evident from the appearance of all seven carbons in the 13 C-NMR spectrum. The carbonyl group was located at C-3 by comparing the 13 C chemical shifts of 2 with those of yakuchinone A.3) This assignment was further confirmed in the HMBC experiment (Fig. 3). A and B, together with three known diarylheptanoids, 1,7-di-(3,4-dihydroxyphenyl)-4-hepten-3-one, 1-(3,4-dihydroxyphenyl)-7-(4؆-hydroxyphenyl)-4-hepten-3-one, and 1,7-bis(p-hydroxyphenyl)-4-hepten-3-one, were isolated from the rhizomes of Amomum muricarpum ELMER (Zingiberaceae). Their structures were determined using spectroscopic analyses.

A new diarylheptanoid from the bark ofAlnus japonica

“…The absolute stereochemistry of C-5 was further concluded as 5R on the basis of the positive Cotton effect associated with the carbonyl n ! p * transition at 306 nm (D1 þ 9.45) in the circular dichroism (CD) spectrum of 1 consistent with those of similar compounds [9,10]. Based on the above evidence, compound 1 was determined to be 5R-1,7-bis(3,4-dihydroxyphenyl)-5-hydroxyheptane-3-one, namely epihirsutanonol.…”

Effects of Mace and Nutmeg on Human Cytochrome P450 3A4 and 2C9 Activity

“…The n-hexane and EtOAc extracts were subjected to column chromatography over a silica gel developed with n-hexane-EtOAc solvent system. The eluates were further purified by a preparative TLC and/or HPLC to furnish a new compound (1) together with 16 compounds, 1-(2,6-dihydroxyphenyl)-9-3,4-dihydroxyphenylnonan-1-one (malabaricone C) (2), 13) 2-(4-allyl-2,6-dimethoxyphenoxy)-1-(4-hydroxy-3-methoxyphenyl)-propan-1-ol (3), 14) 1-acetoxy-2-(4-allyl-2,6-dimethoxyphenoxy)-1-(4-hydroxy-3-methoxyphenyl)propane (4), 15) 7,8-dihydro-7-(4-hydroxy-3,5-dimethoxyphenyl)-3Ј-methoxy-8-methyl-1Ј-trans-propenylbenzofuran (5), 16) 7,8-dihydro-7-(4-hydroxy-3-methoxyphenyl)-3Ј-methoxy-8-methyl-1Ј-transpropenylbenzofuran (6), 17) 5-hydroxyeugenol (7), 18) 7,8-dihy- The final concentration of each spice extract was 100 mg/ml (nϭ2).…”

Antioxidative and Hepatoprotective Diarylheptanoids from the Bark ofAlnus japonica

“…The H of the phenolic hydroxy groups resonates at δ = 5.79 and 8.01, which is not consistent with a hydroxy group chelated by the C-20 keto function. Phenolic H chelated with a keto function resonates at 12.27-13.43 ppm in diterpenes of the same skeleton [13,14]. H-H correlation spectra of the isolated compound showed two sequences that differ from that required for the reported structure of rosmaridiphenol [11,12].…”

“…These findings suggested that 1a and 1b were two isomers in terms of the positions of the two phenyl groups, a 4-hydroxy phenyl group, and a 3,4-dihydroxy phenyl group, similar to alnuside A (5) and alnuside B (6), in which compound 1b, (4E)-1-(3, 4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-heptene-3-one, was isolated from Alnus rubra Bong. [13] and Amomum muricarpum Elmer [14]. Interestingly, alusenone (1a), (4E)-1-(4-dihydroxyphenyl)-7-(3,4-hydroxyphenyl)-heptene-3-one, has not been isolated previously.…”