Search

This study was designed to investigate the chemical constituents from Actinodaphne pruinosa growing in Malaysia. A phytochemical investigation of the leaves part resulted in the isolation of boldine (1), norboldine (2), laurotetanine (3), reticuline (4), syringaresinol (5), lupeol (6), and taraxerol (7). The structures of the isolated phytochemicals were established by analysis of their spectroscopic data, as well as the comparison with that of reported data. Notably, this is the first time to report the isolation and structural elucidation of the constituents from the leaves part of A. pruinosa. [ABSTRACT FROM AUTHOR]

The chemical composition of the essential oil of Knema kunstleri Warb. (Myristicaceae) was investigated for the first time. The essential oil was obtained by hydrodistillation and fully characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). In total, 36 components were identified in the essential oil, which made up 91.7% of the total oil. The essential oil is composed mainly of β-caryophyllene (23.2%), bicyclogermacrene (9.6%), δ-cadinene (7.3%), α-humulene (5.7%), and germacrene D (4.3%). The essential oil showed moderate activity towards DPPH free-radical scavenging and lipoxygenase inhibition. To the best of our knowledge, this is the first study of the composition and bioactivities of the essential oil report concerning the genus Knema. [ABSTRACT FROM AUTHOR]

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%), δ-cadinene (5.6 ± 0.2%), α-copaene (5.1 ± 0.3%), and α-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 essential oil from Pseuduvaria macrophylla. [ABSTRACT FROM AUTHOR]

Chemical composition and acetylcholinesterase activity of the essential oil of Chassalia curviflora (Wall.) Thwaites (Rubiaceae) was examined for the first time. The essential oil was obtained by hydrodistillation and fully characterised by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of twenty-seven components were identified in the essential oil, which made up 91.2% of the total oil. The essential oil is composed mainly of caryophyllene oxide (22.4%), β-caryophyllene (16.5%), germacrene D (11.8%), (E)-nerolidol (9.2%), and elemol (5.5%). The essential oil showed significant activity against acetylcholinesterase with a percentage inhibition of 70.5%. [ABSTRACT FROM AUTHOR]

The chemical composition of the essential oil from the leaves of Alseodaphne perakensis (Gamble) Kosterm (Lauraceae) growing in Perak, Malaysia was investigated for the first time. The essential oil was obtained by hydrodistillation and fully characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 37 components (90.9 ± 2.5%) were successfully identified in the essential oil which were characterized by high proportions of bicyclogermacrene (15.8 ± 0.5%), δ-cadinene (11.7 ± 0.2%), γ-cadinene (6.3 ± 0.4%), and aromadendrene (5.6 ± 0.5%). [ABSTRACT FROM AUTHOR]

A convenient and simple radical cation cyclisation of 3,5-dimethoxystilbene was developed using the commercially available FeCl3 under mild condition. It enabled the construction of a new class of indolostilbenes (i.e., indole-stilbene hybrid). Various parameters were investigated to obtain better yields (more than 42%) compared with the previously reported. The synthesised indolostilbenes were characterised, and their mechanism of formation was discussed. The synthesised compounds were submitted for biological assay on NG108-15 cell viability and H2O2-induced cytotoxicity. The result showed that two indolostilbenes have promising protective activity against H2O2. [ABSTRACT FROM AUTHOR]

Plants of the genus Piper have long been used as medicinal herbs. The chemistry of Piper species has been widely investigated and phytochemical investigations conducted in all parts of the world have led to the isolation of a number of physiologically active compounds. Thus, this study was carried out to investigate the phytochemicals from Piper abbreviatum and their acetylcholinesterase inhibitory activity, which has not been previously investigated. Fractionation and purification of the aerial parts of P. abbreviatum led to the isolation and identification of five methoxylated flavonoids, namely 5,7-dimethoxyflavone, 4',5,7-trimethoxyflavone, 3',4',5,7-tetramethoxyflavone, 5-hydroxy-7-methoxyflavone, 5-hydroxy-4',7-dimethoxyflavone, together with lupeol, lupenone, ß-sitosterol, and ß-sitostenone. The structures of these compounds were obtained by analysis of their spectroscopic data, as well as the comparison with that of reported data. Acetylcholinesterase inhibitory activity revealed that all isolated flavones were found to inhibit AChE with percentage inhibition values ranged from 24.2 to 58.2%. This is the first report on the isolation of methoxylated flavonoid from P. abbreviatum. The high variants of flavonoid compounds from this species may be used as chemotaxonomic markers for this Piper species. [ABSTRACT FROM AUTHOR]

One new aporphine named tavoyanine A (1), along with four known aporphines laetanine (2), roemerine (3), laurolitsine (4), and boldine (5), and one morphinandienone type sebiferine (6) were isolated from the leaves of Phoebe tavoyana (Meissn.) Hook f. (Lauraceae). The isolation was achieved by chromatographic techniques, and the structural elucidation was performed via spectral methods. This paper also reports the antiplasmodial activity of roemerine (3), laurolitsine (4), boldine (5), and sebiferine (6). The results showed that 3–6 have a potent inhibitory activity against the growth of Plasmodium falciparum 3D7 clone, with IC50 values of 0.89, 1.49, 1.65, and 2.76 µg/ml, respectively. [ABSTRACT FROM AUTHOR]