The essential oils from the leaves of Artemisia dubia, A. indica, and A. vulgaris growing wild in Nepal were obtained by hydrodistillation and analyzed by GC-MS. The major components in A. dubia oil were chrysanthenone (29.0%), coumarin (18.3%), and camphor (16.4%). A. indica oil was dominated by ascaridole (15.4%), isoascaridole (9.9%), trans-p-mentha-2,8-dien-1-ol (9.7%), and trans-verbenol (8.4%). The essential oil of Nepalese A. vulgaris was rich in α-thujone (30.5%), 1,8-cineole (12.4%), and camphor (10.3%). The essential oils were screened for phytotoxic activity against Lactuca sativa (lettuce) and Lolium perenne (perennial ryegrass) using both seed germination and seedling growth, and all three Artemisia oils exhibited notable allelopathic activity. A. dubia oil showed in-vitro cytotoxic activity on MCF-7 cells (100% kill at 100 μg/mL) and was also marginally antifungal against Aspergillus niger (MIC = 313 μg/mL). DFT calculations (B3LYP/6-31G*) revealed thermal decomposition of ascaridole to be energetically accessible at hydrodistillation and GC conditions, but these are spin-forbidden processes. If decomposition does occur, it likely proceeds by way of homolytic peroxide bond cleavage rather than retro-Diels-Alder elimination of molecular oxygen.

Background: The chemical composition and bioactivities of essential oils (EOs) of fingered citron (Citrus medica L. var. sarcodactylis (Noot.) Swingle) are considerably sensitive and lapsible during high-temperature processing of traditional separating techniques. In the present research, vacuum distillation and ultrafiltration were utilized in order to process the concentrated juice from fingered citron, obtaining a high-quality essential oil. Methods: In order to compare the essential oils obtained by conventional means, the chemical compositions of the essential oils were analyzed using GC-MS, before antimicrobial and antioxidant screening assays were carried out. Results: Oil which had been subjected to vacuum distillation was shown to maintain most of the distinctiveness of the fingered citron, due to its high content of characteristic flavor components and low content of cyclic oxygenated monoterpenoids. Interestingly, the oil obtained by ultrafiltration showed notable in vitro antimicrobial activity. The DPPH· radical-scavenging assay method revealed that the antioxidant abilities were as follows, presented in descending order: vacuum distillation oil > hydrodistillation oil > ultrafiltration oil. Conclusions: The essential oil obtained by vacuum distillation could be combined with the juice produced from fingered citron to create one of the most promising techniques in the fine-processing of citron fruits.

The aerial parts of Ocimum basilicum L. were collected from four different geographical locations, Sindhuli and Biratnagar (Nepal), Chormaghzak village (Tajikistan), and Sana'a (Yemen). The essential oils were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry. A cluster analysis of 179 essential oil compositions revealed six major chemotypes: Linalool, eugenol, estragole, methyl eugenol, 1,8-cineole, and geraniol. All four of the basil oils in this study were of the linalool-rich variety. Some of the basil oils were screened for bioactivity including antimicrobial, cytotoxicity in human cancer cells, brine shrimp lethality, nematicidal, larvicidal, insecticidal, and antioxidant. The basil oils in this study were not notably antibacterial, cytotoxic, antioxidant, nor nematicidal, but were active in the brine shrimp lethality test, and did show larvicidal and insecticidal activities.

Antibacterial properties of Nepalese plant species -Myrica esculenta, Mahonia nepaulensis, Madhuca longifolia and Schima wallichii were evaluated on human pathogenic microorganisms: Salmonella typhi, Staphylococcus aureus and Escherichia coli. The plants were found to possess phytochemicals-saponins, glacosides, flavonoids, tannins and alkaloids. Methanolic extract from these plants showed antimicrobial activity against tested organisms. Similarly, Brine shrimp lethality test of extracts showed the LC50 values of 15.4 ppm, 136.4 ppm, 76.9 ppm and 76.0 ppm for M. esculenta, M. nepaulensis, M. longifolia and S. wallichii respectively, which suggests that these plants are less toxic to human consumption for drug purpose.