Prajwal Paudel

Volatile constituents of Pinus roxburghii from Nepal.

Background: Pinus roxburghii Sarg. Is one of 3 species of pine found in Nepal, the oil of which is traditionally used to treat cuts, wounds, boils, and blisters. Objective: To obtain, analyze, and examine the anti-microbial and cytotoxic activities of the essential oils of P. roxburghii. Materials and Methods: Three plant parts (cone, needle, and bark) of Pinus roxburghii were collected in Biratnagar, Nepal. The essential oils were obtained by hydrodistillation, and the chemical compositions were determined by GC-MS. The needle and cone essential oils were screened for anti-microbial activity against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Aspergillus niger; brine shrimp (Artemia salina) lethality; and in-vitro cytotoxicity against MCF-7 cells. Results: GC-MS analysis for the cone oil revealed 81 compounds with 78 components being identified (95.5% of the oil) while 98.3% of needle oil was identified to contain 68 components and 98.6% of the bark oil (38 components) was identified. The 3 essential oils were dominated by sesquiterpenes, particularly (E)-caryophyllene (26.8%-34.5%) and α-humulene (5.0%-7.3%) as well as monoterpene alcohols terpinen-4-ol (4.1%-30.1%) and α-terpineol(2.8%-5.0%). The monoterpene δ-3-carene was present only in needle and cone essential oils (2.3% and 6.8%, respectively). Bio-activity assays of the cone essential oil of P. roxburghii showed remarkable cytotoxic activity (100% killing of MCF-7 cells at 100 μg/mL) along with notable brine shrimp lethality (LC50 =11.8 μg/mL). The cone essential oil did not show anti-bacterial activity, but it did exhibit anti-fungal activity against Aspergillus niger (MIC=39 μg/mL). Conclusion: The bioactivity of P. roxburghii essential oil is consistent with its traditional medicinal use.

Volatile analysis and antimicrobial screening of the parasitic plant Cuscuta reflexa Roxb. from Nepal

The essential oil from the parasitic vine Cuscuta reflexa Roxb., collected from Kirtipur, Kathmandu, Nepal, was obtained by hydrodistillation and analysed by gas chromatography–mass spectrometry. From a total of 62 peaks, 61 compounds were identified in the oil, accounting for 99.6% of the oil. The majority of the essential oil was dominated by the relatively rare component cis-3-butyl-4-vinylcyclopentane (26.4%). The oil also contained substantial amounts of limonene (5.1%) and (E)-nerolidol (9.5%). Biological screening for antimicrobial activities did not show appreciable activity against either Gram-positive (Bacillus cereus and Staphylococcus aureus) or Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. However, marginal activity against Aspergillus niger was observed (minimum inhibitory concentration = 313 μg/mL).

Microbiological activities of volatile constituents of Leucas aspera (Willd.) Link from Nepal

Leucas aspera (Willd.) Link [Synonym Leucas plukenetii (Roth) Spreng.] is a species of annual branched herb belonging to the Lamiaceae, and distributed throughout South Asia (India, Bangladesh, Nepal), Malaysia, and Mauritius.[1] L. aspera has been traditionally used as an antipyretic, insecticide,[2] and as a remedy for toothache;[3] its flowers are used as an expectorant, stimulant, diaphoretic, antirheumatic, and antipsoriatic, while its leaves are useful in treating snake bites.[4,5]

Leaf Essential Oil Composition of Citrus japonica from Nepal

Abstract The essential oil from the leaves of Citrus japonica, collected from Biratnagar, Nepal, was obtained by hydrodistillation and analyzed by GC-MS. A total of 42 compounds were identified in the oil, accounting for 99.6 % of the oil. The major components of the leaf oil were identified to be linalool (35.1 %), eugenol (14.8 %), geraniol (12.7 %), and its aldehyde counterpart geranial (7.9 %). The oil also contained smaller amount of nerol (5.3 %), and (Z)-asarone (5.0 %).

Leaf Essential Oil Composition of Kyllinga brevifolia Rottb. from Nepal

Abstract The essential oil from the leaf of Kyllinga brevifolia Rottb., collected from Biratnagar, Nepal, was obtained by hydrodistillation and analyzed by GC-MS. A total of 22 compounds were identified in the oil accounting for 96.1 % of the oil composition. The majority of the essential oil was identified to be occadinol (40.3 %),’L-τ-muurolol (19.5 %), and germacrene D-4-ol (12.5 %). The oil also contained smaller amounts of δ-cadinene (2.9 %), and germacrene D (4.0 %). Reports on the essential oil composition of K. brevifolia from Nepal were compared with a sample from Brazil, which showed that 13-epi-manoyl oxide (26.1 %) and manoyl oxide derivatives constituted the majority of composition with a-cadinol comprising only 0.4 %. However germacrene D was found in similar percentages between Nepal and Brazil samples (4.0 %and 4.2 %, respectively).

The Leaf Essential Oil of Momordica charantia from Nigeria is Dominated by Geijerene and Pregeijerene

The leaf essential oil of Momordica charantia was obtained by hydrodistillation and analyzed by gas chromatography- mass spectrometry. The leaf oil was rich in geijerene (11.2 %), pregeijerene (27.1 %), α-pinene (14.0 %), β-pinene (7.1 %), (E)-caryophyllene (4.6 %), and germacrene D (8.6 %); remarkably different from previous reports of this plant.

Volatile Components from the Stem Bark of Vitellaria paradoxa

Abstract The volatile oil from the stem bark of Vitellaria paradoxa (shea) has been obtained by hydrodistillation and analyzed by GC-MS. The oil is characterized by a high concentration of germacrene D (21.8 %), with smaller quantities of linalool (6.5 %), (E)-caryophyllene (6.3 %), (E)-phytol (4.9 %), and β-elemene (3.8 %). The V. paradoxa bark oil was screened for antibacterial activity but was inactive (MIC ≥ 625 μg/mL).