The leaves and stem bark extracts of B. penangiana were screened to evaluate their antioxidant, antimicrobial,tyrosinase, lipoxygenase, and acetylcholinesterase activities. Evaluation of antioxidant activities were tested against DPPH, ABTS, and total phenolic content (TPC) assays. The antimicrobial activity were investigated by microdilution method for determination of MIC, MBC, and MFC. Tyrosinase and lipoxygenase inhibitory activities were analysed using mushroom tyrosinase and lipoxygenase enzymes, respectively. In addition, the acetylcholinesterase activity was tested using cholinesterase enzyme. The methanol extract of stem bark showed the highest phenolic content (176.8 mg GAE/g), DPPH free radical scavenging (IC50 95.5 μg/mL), ABTS (IC50 124.8 μg/mL), and lipoxygenase inhibitory activity (I: 46.3%). All extracts showed from moderate to weak activity with MIC/MBC/MFC values in the ranged of 62.5-1000 µg/mL. The ethyl acetate stem bark extract revealed the highest percentage i.....

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In this study, the roots of Garcinia hombroniana were chemically investigated, in which novel derivatives of xanthone and benzophenone, known as garcihomxanthone (1) and garcihombrianone (2), respectively, together with garceduxanthone (3), cheffouxanthone (4), norathyriol (5), and 2,3′,4,5′-tetrahydroxy-6-methoxybenzophenone (6) were isolated.. The structures of these compounds were elucidated by extensive spectroscopic techniques and evaluated based on references with previous literature data.  ..

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As part of our continuing search to explore novel natural compounds from Beilschmiedia species, we have carried out a phytochemical study of the leaves and stem bark extracts of B. penangiana. As a result, four alkaloids, (+)-reticuline (1) [8], (+)-boldine (2) [9], (+)-norboldine (3) [10], and lindcarpine (4) [10] together with five other compounds, β-sitosterol (5) [7], β-sitostenone (6) [7], lupeol (7) [6], lupenone (8) [6], and taraxerol (9) [7], were successfully isolated  ..

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[No abstract available]..

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Chemical constituents and lipoxygenase inhibitory activity of the aerial part of Piper stylosum have been studied. Fractionation and purification of the extracts afforded five lignans, identified as yangambin (1), sesamin (2), syringaresinol (3), pinoresinol (4), and medioresinol (5), together with other constituents; 4-allyl resorcinol, β-sitosterol, β-sitostenone, taraxerol, vanilin, and vanilic acid. The structures of these compounds were established by analysis of their spectral data, as compared to that of reported compounds. The lipoxygenase inhibitory activity of the extracts and isolated lignans were also evaluated..

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This study was designed to examine the chemical composition and anticholinesterase inhibitory activity of the essential oil of Pseuduvaria macrophylla (Oliv.) Merr. (Annonaceae) from Malaysia. The essential oil was obtained by hydrodistillation and fully analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The analysis led to the identification of thirty-four chemical components that represented 87.7 ± 0.5% of the total oil. The essential oil was found to be rich in germacrene D (21.1 ± 0.4%), bicyclogermacrene (10.5 ± 0.5%), d-cadinene (5.6 ± 0.2%), a-copaene (5.1 ± 0.3%), and a-cadinol (5.0 ± 0.3%). Anticholinesterase activity was evaluated using Ellman method. The essential oil showed weak inhibitory activity against acetylcholinesterase (I%: 32.5%) and butyrylcholinesterase (I%: 35.4%) assays. Our findings demonstrate that the essential oil could be very useful for the characterization, pharmaceutical and therapeutic applications of the essent.....

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