The study describes the chemical composition and biological activities of essential oils obtained from Vietnamese Phyllanthus anthopotamicus Hand.-Mazz. leaves and stem bark for the first time. GC-MS analysis showed that oxygenated sesquiterpenes (71.87-72.62%) were the predominant class, with spathulenol (37.22-44.49%) as the major constituent. Other major constituents included dihydro-eudesmol (4.46-6.33%), alpha-eudesmol (4.46-6.03%), caryophyllene oxide (3.69-4.68%), tetradecanal (2.85-3.21%), (Z)-dihydro-apofarnesol (2.73-4.82%), and dehydro-aromadendrane (1.44-4.23%). In the experimental assays, both essential oils inhibited alpha-glucosidase, with IC50 values of 198.25-215.07 & micro;g/mL, and showed concentration-dependent cytotoxic, anti-inflammatory, and antimicrobial activities. The leaf essential oil showed greater cytotoxic, anti-inflammatory, and antimicrobial effects than the stem bark essential oil, whereas the stem bark essential oil showed a slightly lower IC50 value against alpha-glucosidase. In silico molecular docking predicted that caryophyllene oxide had the lowest binding energy among the investigated compounds toward human lysosomal acid alpha-glucosidase (-6.7 kcal/mol). ADME and toxicity predictions indicated generally favorable drug- likeness-related properties for most investigated compounds, although some compounds showed predicted toxicity concerns. These findings provide initial evidence of the biological activities of P. anthopotamicus essential oils and support further investigation of their bioactive constituents and mechanisms of action.
The present study compared microwave-assisted hydrodistillation (MWHD) and conventional hydrodistillation (HD) with respect to essential oil yield and antimicrobial activity of oils obtained from disintegrated wild thyme (Thymus serpyllum L.) herb, while the chemical composition of the MWHD-derived essential oil was characterized by GC-MS/GC-FID. MWHD significantly improved the essential oil yield (4.52% w/w) compared with HD (2.99% w/w), demonstrating the efficiency of the intensified extraction process. Gas chromatography-mass spectrometry (GC-MS) analysis identified a thymol-rich chemotype, with thymol (51.8%), gamma-terpinene (24.4%), and p-cymene (19.5%) as the predominant constituents. Antimicrobial activity, evaluated by the disc diffusion and minimum inhibitory concentration (MIC) methods, showed assay-dependent differences between the MWHD- and HD-derived essential oils, with the MWHD-derived oil exhibiting stronger activity against certain tested microorganisms. The lowest MIC value (8 & micro;L/mL) was recorded for Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. In conclusion, under the applied experimental conditions, MWHD provided a higher essential oil yield than HD, while the MWHD-derived oil exhibited stronger antimicrobial activity against certain tested microorganisms.
