Bioactive constituents of Broussonetia papyrifera and Antirhea acutata.

摘要

An ethyl acetate-soluble extract of Broussonetia papyrifera (L.) L'Hér. ex Vent. (Moraceae) was found to significantly inhibit aromatase activity in an in vitro assay (74% inhibition at 80 μg/mL). Bioassay-guided fractionation led to the isolation of five new active compounds, 5,7,2′,4′-tetrahydroxy-3-geranylflavone, isogemichalcone C, 3′-[γ-hydroxymethyl-( E)-γ-methylally1]-2,4,2′,4′ -tetrahydroxychalcone 11′-O-coumarate, demethylmoracin I, and (2S)-2′,4 ′-dihydroxy-2″-(1-hydroxy-1-methylethyl)-dihydrofuro[2,3- h]flavanone, and ten active compounds of known structure, isolicoflavonol, (2S)-abyssinone II, (2S)-5,7,2′ ,4′-tetrahydroxyflavanone, (2S)-euchrenone a7, broussoflavonol F, (2S)-naringenin, broussonin A, 2,4,2 ′,4′-tetrahydroxy-3′-prenylchalcone, moracin N, and albanol A, with their IC₅₀ values ranging from 0.1–31.1 μM. Also, (2S)-2′,4′-dihydroxy-2 ″-(1-hydroxy-1-methylethyl)-dihydrofuro[2,3-h]flavan one showed 50% inhibitory activity in mouse mammary organ culture model at a dose of 100 ng/mL. Additionally, six new compounds, 6-geranyl-5,7,3 ′,4′-tetrahydroxyflavonol, 6-geranyl-5,7,3 ′,4′-tetrahydroxy-3 methoxyflavone, (2 S)-7,4′-dihydroxy-3′-prenylflavan, {09}{09}{09}{09}{09}1-(2,4-ihydroxyphenyl)-3-(4-hydroxyphenyl)propane, 1-(2,4-dihydroxy-3-prenylphenyl)-3-(4-hydroxyphenyl)propane, and 1-(4-hydroxy-2-methoxyphenyl)-3-(4-hydroxy-3-prenylphenyl)propane, and 21 known compounds, (2S)-demethylbroussin, (2S)-2 ′,4′-dihydroxy-7-methoxy-8-prenylflavan, (2R,3R) lespedezaflavanone C, bavachin, (2R,3R)-katuranin, gancaonin P, (2 R,3R)-5,7,2′,4′ -tetrahydroxyflavanonol, broussonins B, E, and F, broussochalcones A, and B, isobavachalcone, 2,4,2′,4′-tetrahydroxychalcone, moracins D, I, and M, loliolide, marmesin, trans-resveratrol, and 5,7-dihydrocoumarin, were isolated and characterized as inactive compounds when evaluated with the in vitro aromatase assay (IC ₅₀ > 20 μg/mL).; An ethyl acetate-soluble extract of Antirhea acutata (DC.) Urb. (Rubiaceae) showed significant activities in a cyclooxygenase-1 (COX-1) inhibition assay (100% inhibition at 70 μg/mL) and in a 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical antioxidant assay (IC₅₀ 34.7 μg/mL). Bioassay-guided fractionation of COX-1 active fractions led to the isolation of two novel active compounds, (6S)-hydroxy-29-nor-3,4- seco-cycloarta-4(30),24-dien-3-oic acid and (6S)-hydroxy-(24 ξ)-hydroperoxy-29-nor-3,4-seco-cycloarta-4(30),25-dien-3-oic acid methyl ester, with IC₅₀ values 43.7 and 45.7 μM, respectively, when evaluated with the COX-1 assay, and 4.7 and 18.4 μM, respectively, when evaluated with the COX-2 assay. Additionally, five novel compounds, (3 S,24S),25-trihydroxy-9,19-cycloartan-29-oic acid, (6S)-hydr