Hydrodistillation of the fresh leaves of Alpinia mutica afforded 0.005% colourless essential oil. GC and GC-MS analysis revealed the presence of 33 components accounting for 92.9% of the total oil, dominated by 20 sesquiterpenes (76.7%) and 10 monoterpenes (8.3%). The major constituent was found to be β-sesquiphellandrene which was 29.2% of the total oil. Soxhlet extraction, followed by repeated column chromatography of the dried leaves yielded two phenolic compounds, identified as 5,6-dehydrokawain and aniba dimer A, together with one amide assigned as auranamide. The structures of these compounds were determined by using spectroscopic analysis. Antibacterial screening of the essential oil, the crude and isolated compounds showed weak to moderate inhibitory activity.
The essential oils obtained by hydrodistillation of the rhizomes of Alpinia aquatica Rosc. syn. Alpinia melanocarpa and Alpinia malaccensis Roscoe were analysed by capillary gas chromatography and gas chromatography-mass spectrometry. Eighteen compounds, representing 98.4% of the essential oil were identified in A. aquatica rhizome oil, with β-sesquiphellandrene in 36.5% being the major constituent, while 20 compounds representing 99.7% of the rhizome oil of A. malaccensis were identified, among which methyl (E)-cinnamate (78.2%) was the major constituent.
The chemical compositions of the essential oil of the rhizome, leaf and stem of Hornstedtia leonurus Retz., collected from Negeri Sembilan, Malaysia,are reported for the first time. The essential oils were extracted using hydrodistillation and analyzed by gas chromatography (GC-FID) and gas chromatography/mass spectrometry (GC/MS). Seventeen (96.4%), thirteen (89.2%) and nine components (98.8%) were successfully identified from the rhizome, stem and leaf oils, respectively. Phenylpropanoids were found to be the major fraction, with methyleugenol being the most abundant compound in all oils with percentage compositions of 76.4% (rhizome), 80.3% (stem) and 74.5% (leaf).
One new sesquiterpene dilactone, coccinine (1) and one new β-carboline alkaloid, daibucarboline F (2) together with 10 known compounds; linderane (3), linderalactone (4), pseudoneolinderane (5), linderanlide C (6), linderanine A (7), epicatechin (8), (-)-taxifolin (9), astilbin (10), L-quercitrin (11) and afzelin (12) were isolated from the stems and leaves of Neolitsea cassia (L.) Kosterm (Lauraceae). The structures of (1 and 2) were established by extensive spectroscopic methods and the known compounds were identified by comparisons with data reported in literature. The relative stereochemistry of compound (1) was assigned by X-ray diffraction analysis with Cu-Kα irradiation. Compounds (3-8) and (10) were evaluated for their α-glucosidase enzymatic inhibitory activity. Compounds (4-6), (8) and (10) exhibited inhibition towards α-glucosidase enzymatic activity with IC50 values ranging from 12.10 to 96.77 μM. This is the first report on the isolation of phytochemicals from N. cassia and their bioactivities.
Methanolic extracts of 70 Malaysia plants were screened for their in vitro antitrypanosomal activity using Trypanosome brucei rhodesience, strain STIB 900 and mouse skeletal cell (L-6) in cytotoxicity activity assay. Results indicated that methanol extract from Elephantopus scaber Linn. (E. scaber) possessed the highest value of antitrypanosomal activity with good selectivity index (antitrypanosomal IC50 of 0.22±0.02 μg/ml, SI value of 204.55). Based on these results, E. scaber was chosen for further study by applying bioassay guided fractionation to isolate its antiprotozoal principle. The antiprotozoal principle was isolated from the ethyl acetate partition through solvent fractionation and crystallization process. The isolated active compound 1 was identified as deoxyelephantopin on the basis of its spectral analysis (FTIR, MS, 1D and 2D NMR).
Hydrodistillation of the fresh stem and leaf of Neolitsea kedahense Gamble, collected from Gunung Jerai, Malaysia followed by the GC-FID and GC-MS analysis revealed the detection of a total of 47 constituents of which 28 (86.4%) from the stem and 31 (96.4%) constituents from the leaf. δ-Cadinene (17.4%), 1-epi-cubenol (11.8%), cyperotundone (9.0%), cis-cadin-4-en-7-ol (7.7%), τ-cadinol (7.1%) and α-cadinol (7.1%) were the principle constituents in the stem oil, whereas β-caryophyllene (18.9%), bicyclogermacrene (18.6%) and trans-muurola-4(14),5-diene (9.8%) were the major constituents in the leaf oil. Among the identified constituents, three constituents namely 7-epi-α-selinene, junenol and cis-cadin-4-en-7-ol have not been found previously from Neolitsea oils. The stem and leaf oils were screened for their α-glucosidase inhibitory and antibacterial activities. Both oils displayed potential α-glucosidase inhibitory activity, while the stem oil possessed weak antibacterial activity against Bacillus subtilis.
β-Carboline bearing indole is one of the heterocyclic compounds that play a vital role in medicinal chemistry with various pharmacological effects such as anticancer, anti-acetylcholinesterase, anti-inflammation, antimalarial, antibacterial, anti-diabetic, and antioxidant. Over the last two decades, many studies on the synthesis and biological activity of indole β-carboline compounds have been conducted yet there is no appropriate data summary has been presented. Thus, the goal of this review was to highlight the synthesis pathway and bioactivity of substituted indole β-carboline reported from 2005 to date. In addition, this will encourage further investigation into the synthesis and evaluation of new indole β-carboline, in the hope of contributing to the development of potentially new medications for the treatment of various ailments.
The chemical compositions, in vitro and in silico anti-dengue activity of the essential oils of the rhizomes of Curcuma longa Linn., C. aeruginosa Roxb., and C. xanthorrhiza Roxb. had been investigated. The C. longa oil was mainly composed of ar-turmerone (54.0%) and curlone (17.7%), while the C. aeruginosa oil was rich in curzerenone (23.4%), 1,8-cineole (21.2%), and camphor (7.1%). Xanthorrhizol (21.6%), β-curcumene (19.5%), ar-curcumene (14.2%), and camphor (9.2%) were the major compounds in the C. xanthorrhiza oil. Among the oils, the C. longa oil was found to be the most active NSB-NS3 protease inhibitor (IC50 1.98 μg/mL). PLS biplot disclosed that the essential oils were classified into three separated clusters based on their characteristic chemical compositions, with C. longa positioned closest to the in vitro anti-dengue activity. Four compounds from the C. longa oil have both hydrogen and hydrophobic bonds that could be responsible for the DENV-2 NS2B-NS3 inhibitory effect.