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Rhamnus caroliniana (Rhamnaceae), or Carolina buckthorn, is a plant commonly found in the southeastern United States that was used in Cherokee traditional medicine. To date, there have been no reports on the phytochemical constituents of R. caroliniana. The bark of R. caroliniana was collected and extracted with chloroform. The crude chloroform extract was subjected to preparative column chromatography on silica gel leading to the isolation of two anthraquinones (chrysophanol and physcion), the bianthrone ararobinol, the dihydroxynaphthalene torachrysone, and the fatty alcohol 1-docosanol. The bark essential oil of R. caroliniana was obtained by hydrodistillation and analyzed by gas chromatography - mass spectrometry. The major bark volatiles were the anthrone chrysarobin-(24.2%), the piperidine alkaloid piperine (15.4%), and the dibenzoxepin pacharin (7.5%).

The chemical composition of the essential oils obtained from aerial parts of Nepeta alatavica Lipsky, N. nuda L, and N. olgae Regel (Lamiaceae), growing wild in Central Asia (Tajikistan and Uzbekistan), were analyzed by GLC and GLC-MS. The main constituents of the essential oil from N. nuda were 1,8-cineole (24.6%), 4a-α,7-β,7a-α-nepetalactone (21.0%), germacrene D (13.5%), and β-caryophyllene (12.7%), whereas those of N. alatavica were thymol (48.5%) verbenone (7.7%), and carvacrol (7.5%). In the essential oil of N. olgae the most abundant compounds were acetylcyclohexene (31.5%), 4-tridecyne (13.2%), 2-methyl cyclopentanone (6.8%) and 1,8-cineole (6.0%). The potential antioxidant activity of these essential oils was studied by using DPPH, ABTS and FRAP assays. The essential oil of N. alatavica showed the highest in vitro free radical scavenging activity, probably due to its high thymol and carvacrol content.

Rhododendron anthopogon D. Don., A small compact Himalayan shrub growing in Nepal, is a known medicinal plant used to treat sore throat, colds, blood disorders, bone disease, potato allergies, and vomiting, and to relieve liver disorders, headaches and back pain. The present study investigated the chemical composition and bioactivities of the leaf essential oil from R. anthopogon from Dhankuta, Nepal. The essential oil from leaves was obtained by hydrodistillation and a detailed chemical analysis was conducted by gas chromatography - mass spectrometry.(GC-MS). The enantiomeric distribution of monoterpenoid components was determined using chiral gas chromatography and represents the first chiral examination of R. anthopogon essential oil. The essential oil was screened for antimicrobial activity using the microbroth dilution test, and for cytotoxic activity against MCF-7, MDA-MB-231, and 5637 using the MTT assay. A total of 70 volatile componeits were identified from the essential oil. The major components were α-pinene (21.5%), δ-cadinene (13.8%), β-pinene (9.5%), limoiene (5.9%), δ-amorphene (4.6%), α-muurolene (4.5%), and (E)-daryophyllene (3.2%) with other minor constituents (< 3%). The essential oil showed marginal antibacterial and.cytotoxic activities, but no antifungal effects.

The essential oil from the aerial parts of Blumea lacera collected from Biratnagar, Nepal, has been obtained by hydrodistillation and analyzed by gas chromatography - mass spectrometry. The major component from the oil, (Z)-lachnophyllum ester, was isolated by preparative silica gel chromatography. B. lacera oil was dominated by (Z)-lachnophyllum ester (25.5%), (Z)-lachnophyllic acid (17.0%), germacrene D (11.0%), (E)-β-farnesene (10.1%), bicyclogermacrene (5.2%), (E)-caryophyllene (4.8%), and (E)-nerolidol (4.2%). Also detected in the oil were (E)-lachnophyllic acid (3.3%) and (E)-lachnophyllum ester (1.7%). (Z)-Lachnophyllum ester exhibited cytotoxic activity against MDA-MD-231, MCF-7, and 5637 human tumor cells, as well as antibacterial and antifungal activity.

The essential oil of Matricaria chamomilla, collected from Nepal, was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The major components in Nepalese chamomile oil were (E)-β-famesene (42.2%), α-bisabolol oxide A (22.3%), (E,E)-α-famesene (8.3%), cis-bicycloether (5.0%), α-bisabolol oxide B (4.5%), and α-bisabolone oxide A (4.0%). A cluster analysis based on the chemical compositions of 48 samples of chamomile oil reported in the literature has revealed seven chemotypes, and the oil from Nepal represents the (E)-β-farnesene chemotype. The chamomile oil was screened for antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger, and toxicity toward MCF-7 breast tumor cells, Artemia salina, Chaoborus plumicornis, Caenorhabditis elegans, and Drosophila melanogaster.

The essential oil from the dried rhizome of Nardostachys grandiflora, collected from Jaljale, Nepal, was obtained in 1.4% yield, and a total of 72 compounds were identified constituting 93.8% of the essential oil. The rhizome essential oil of N. grandiflora was mostly composed of calarene (9.4%), valerena-4,7(11)-diene (7.1%), nardol A (6.0%), 1(10)-aristolen-9β-ol (11.6%), jatamansone (7.9%), valeranal (5.6%), and cis-valerinic acid (5.7%). The chemical composition of N. grandiflora rhizome oil from Nepal is qualitatively very different than those from Indian, Chinese, and Pakistani Nardostachys essential oils. In this study we have evaluated the chemical composition and biological activities of N. grandiflora from Nepal. Additionally, 1(10)-aristolen-9β-ol was isolated and the structure determined by NMR, and represents the first report of this compound from N. grandiflora. N. grandiflora rhizome oil showed in-vitro antimicrobial activity against Bacillus cereus, Escherichia coli, and Candida albicans (MIC = 156 μg/mL), as well as in-vitro cytotoxic activity on MCF-7 cells.

The essential oils from the leaves, fruits, roots, and stems of Solanum xanthocarpum, growing wild in Nepal, have been obtained and analyzed by gas chromatography-mass spectrometry. The fruit volatiles were dominated by benzyl benzoate (21.7%) and (E,E)-geranyl linalool (12.6%); heptacosane (20.0%) was the major component of the leaf oil; the stem oil was dominated by palmitic acid (28.9%), heptacosane (12.8%) and linoleic acid (10.1%); while solavetivone (22.9%), palmitic acid (21.0%), and linoleic acid (8.2%) were the major components of the root essential oil. There do not seem to be any common phytochemical taxonomic markers in the essential oils of Solanum spp; the chemical diversity observed in this genus mirrors the taxonomic diversity.

This work examines the biological activity of essential oils of Cinnamomum camphora leaves, C. glaucescens fruit, and C. tamala root from Nepal. The oils were screened for phytotoxic activity against lettuce and perennial ryegrass, brine shrimp lethality, and antibacterial, antifungal, cytotoxic, insecticidal, and nematicidal activities. C. camphora leaf essential oil was phytotoxic to lettuce, antifungal to Aspergillus niger, and insecticidal, particularly toward midge and butterfly larvae, fruit flies, and fire ants. C. camphora oil was also toxic to brine shrimp and human breast tumor cells. C. glaucescens fruit essential oil showed notable nematicidal activity, as well as termiticidal and mosquito larvicidal activity. The root essential oil of C. tamala was toxic to mosquito larvae and fire ants.

The essential oils from the leaves of Juglans regia, collected from Kathmandu, Nepal, and Juglans nigra from Huntsville, Alabama, USA, were obtained by hydrodistillation and analyzed by GC-MS. A total of 69 compounds were identified in the J. regia oil, accounting for 99.0% of the eluting components of the oil while three different samples of J. nigra were analyzed identifying a total of 99.3%, 99.4% and 99.7% of the oils. The leaf essential oil of J. regia was dominated by the aromatic compounds eugenol (27.5%) and methyl salicylate (16.2%), and the sesquiterpenes germacrene D (21.4%) and (E)-beta-farnesene (8.2%). The essential oils from three different samples of. J. nigra contained (E)-caryophyllene (17.3%-20.4%) and germacrene D (7.1%-22.5%) with smaller amounts of juglone (1.0%-8.8%), alpha-hydrojuglone (1.0-9.5%), and delta-cadinene (3.8%-8.7%). J. regia leaf oil, devoid of juglone, showed allelopathic activity, while J. nigra leaf oil was less phytotoxic. The presence of eugenol and methyl salicylate in the leaves of J. regia are consistent with the traditional uses of this plant to treat toothache, rheumatism, and fungal infections.

Four essential oils from the leaf (P23) and rhizomes (P19, P22, P24) of Acorus calamus L., collected from various parts of Nepal, were obtained by hydrodistillation and analyzed by GC-MS. From a total of 61 peaks, 57 compounds were identified among the four essential oils accounting for 94.3%, 96.2%, 97.6%, and 94.1% of the oils, respectively. All of the essential oils were dominated by (Z)-asarone (78.1%-86.9%). The essential oils also contained (E)-asarone (1.9%-9.9%) and small amounts of gamma-asarone (2.0-2.3%), (Z)-methyl isoeugenol (1.5-2.0%), and linalool (0.2-4.3%). Allelopathic testing of the rhizome oil showed inhibition of seed germination of Lactuca sativa and Lolium perenne with IC50 values of 450 and 737 microg/mL, respectively. The rhizome essential oil demonstrated stronger seedling growth inhibition of L. perenne than of L. sativa, however. The rhizome oil also showed notable brine shrimp lethality (LC50 = 9.48 microg/mL), cytotoxic activity (92.2% kill on MCF-7 cells at 100 microg/mL), and antifungal activity against Aspergillus niger (MIC = 19.5 microg/mL).

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 alpha-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 microg/mL) and was also marginally antifungal against Aspergillus niger (MIC = 313 microg/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.

The essential oils from the seed and rind of Amomum subulatum Roxb. (collected from Nepal) were obtained by hydrodistillation and analyzed by GC-MS. A total of 87 components were identified among the two essential oils accounting for 99.1%, and 99.0% of the oils, respectively. The two essential oils were dominated by the monoterpenoids 1,8-cineole (60.8% and 39.0%), alpha-pinene (6.4% and 4.8%), beta-pinene (8.3% and 17.7%), and alpha-terpineol (9.8% and 12.3%). Allelopathic testing of the seed essential oil showed an inhibition of seed germination of Lactuca sativa and Lolium perenne, with IC50 values of 1583 and 1674 microg/mL, respectively. The seed essential oil demonstrated a stronger seedling growth inhibition of L. perenne than of L. sativa. A. subulatum seed and rind oils also showed moderate brine shrimp lethality (LC50 = 28.1 +/- 3.0 and 15.0 +/- 9.0 microg/mL, respectively). The seed and rind oils were only marginally cytotoxic (20% and 30%% kill on MCF-7 cells at 100 microg/mL, respectively), and antibacterial (MIC > or = 313 microg/mL), but A. subulatum rind oil was appreciably active against the fungus Aspergillus niger (MIC = 19.5 microg/mL). The essential oils of A. subulatum were also screened for nematocidal activity against Caenorhabditis elegans and insecticidal activity against the fruit fly (Drosophila melanogaster) and the red imported fire ant (Solenopsis invicta x richteri). The seed oil was only marginally toxic to the fire ant (LC50 = 1500 microg/mL), but moderately toxic to the nematode and the fruit fly (LC50 = 341 and 441 microg/mL, respectively).