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  • Author: Yana M. Syah x
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Abstract

Phytochemical investigation of the acetone extract of Macaranga javanica leaves afforded three new prenylated 9,10-dihydrophenanthrenes, macajavanicins A–C (1–3). Structures of these compounds were elucidated mainly by NMR and mass spectral data. Along with compounds 1–3, two known prenylated dihydrostilenes, laevifolins A and B (4, 5), were also isolated. The presence of these new 9,10-dihydrophentanthrene derivatives is the first time in the genus Macaranga, and its chemotaxonomic significances are briefly discussed. The antibacterial properties of compounds 1–5 against eight pathogenic bacteria are also described.

Abstract

A new phenolic sesquiterpene, dysoxyphenol (1), and the known sesquiterpene, 7R,10S-2-hydroxycalamenene (2), were isolated from the acetone extract of Dysoxylum densiflorum seeds. The structures of these compounds were determined based on physical, Nuclear Magnetic Resonance, and mass spectral data. Both compounds were evaluated for their antibacterial and antifungal properties against seven pathogenic bacteria and two wood-rotting fungi, respectively. The results showed that both compounds have significant antibacterial properties only against Bacillus subtilis (Minimum Inhibitory Concentration 28 μM), while in the antifungal evaluation compound 1 was found to be more active than compound 2. Therefore, compound 1 has promising antifungal properties that can be developed further for finding new antifungal agents.

Abstract

Previously we had isolated two prenylated flavanones and two prenylated dihydrochalcones, macatrichocarpins A-D (1 - 4), from the acetone extract of the leaves of Macaranga trichocarpa. Reexamination of the fractions containing minor components resulted in the isolation of four more flavonoid derivatives, including two new prenylated dihydrochalcones, oxymacatrichocarpin C (5) and isomacatrichocarpin C (6). The structures of these compounds were determined by the analysis of UV, NMR, and mass spectral data. The eight isolated flavonoids were tested on eight pathogenic bacteria and found to be mostly moderate antibacterial agents, with the lowest MIC value of 26.5 μM achieved by the flavanone macatrichocarpin A (1) against Bacillus subtilis.

A new methylated flavonol, 5,7,2 ′,4 ′-tetrahydroxy-3-methoxyflavone (1), had been isolated from the methanol extract of the wood of Morus australis, along with nine known compounds, kuwanon C (2), morusin (3), morachalcone A (4), oxyresveratrol (5), 4 ′-(2-methyl-2-buten- 4-yl)oxyresveratrol (6), moracins M (7) and C (8), alboctalol (9), and macrourin B (10). The structures of these compounds were determined based on spectral evidence, including UV, IR, NMR, and mass spectra. Cytotoxic properties of compounds 1 →10 were evaluated against murine leukemia P-388 cells. The prenylated stilbene 6 and 2-arylbenzofuran 8, and morusin (3) were found to have strong cytotoxic effects with IC50 values of 6.9, 8.7, and 10.1 μM, respectively.

Abstract

A new modified stilbene dimer, diptoindonesin D (1), was isolated from the acetone extract of the tree bark of Hopea dryobalanoides, together with seven known compounds, parviflorol (2), (D)-balanocarpol (3), heimiol A (4), hopeafuran (5), (+)-α-viniferin (6), vaticanol B (7) and (D)-hopeaphenol (8). Cytotoxic properties of compounds 1-8 were evaluated against murine leukemia P-388 cells. Compound 8 was found to be the most active with IC50 of 5.7 μm

Abstract

Two new prenylated flavones, artoindonesianins Z-1 (1) and Z-2 (2), together with two other known prenylated flavones, artobiloxantone (3) and cycloartobiloxanthone (4), had been isolated and identified from the chloroform extract of the tree bark of Artocarpus lanceifolius. The structures of these compounds were determined based on spectroscopic data, including UV, IR, 1-D and 2-D NMR, and mass spectra. The significance of the presence of the isolated compounds to the chemotaxonomy of Artocarpus is briefly discussed.

A new flavanone, 7-hydroxy-5,6-dimethoxyflavanone (1), together with three other flavonoids, didymocarpin (2), 2′,4′-dihydroxy-5′,6′-dimethoxychalcone (3), and isodidymocarpin (4), had been isolated from the methanol extract of the tree bark of Cryptocarya costata. The structures of these compounds were determined based on spectral evidence, including UV, IR, 1-D and 2-D NMR, and mass spectra. Cytotoxic properties of compounds 1-4 were evaluated against murine leukemia P-388 cells. The chalcones 3 and 4 were found to have substantial cytotoxicity with IC50 of 5.7 and 11.1 μᴍ, respectively.