humulene and cadinol

Mosquitoes (Diptera: Culicidae) are important vectors of terms of public health relevance, especially in tropical and sub-tropical regions. The continuous and indiscriminate use of conventional pesticides for the control of mosquito vectors has resulted in the development of resistance and negative impacts on non-target organisms and the environment. Therefore, there is a need for development of effective mosquito control tools. In this study, the larvicidal and repellent activity of Zingiber nimmonii rhizome essential oil (EO) was evaluated against the malaria vector Anopheles stephensi, the dengue vector Aedes aegypti, and the lymphatic filariasis vector Culex quinquefasciatus. The chemical composition of the EO was analyzed by gas chromatography-mass spectroscopy (GC-MS). GC-MS revealed that the Z. nimmonii EO contained at least 33 compounds. Major constituents were myrcene, β-caryophyllene, α-humulene, and α-cadinol. In acute toxicity assays, the EO showed significant toxicity against early third-stage larvae of An. stephensi, Ae. aegypti, and Cx. quinquefasciatus, with LC50 values of 41.19, 44.46, and 48.26 μg/ml, respectively. Repellency bioassays at 1.0, 2.0, and 5.0 mg/cm(2) of Z. nimmonii EO gave 100 % protection up to 120, 150, and 180 min. against An. stephensi, followed by Ae. aegypti (90, 120, and 150 min) and Cx. quinquefasciatus (60, 90, and 120 min). Furthermore, the EO was safer towards two non-target aquatic organisms, Diplonychus indicus and Gambusia affinis, with LC50 values of 3241.53 and 9250.12 μg/ml, respectively. Overall, this research adds basic knowledge to develop newer and safer natural larvicides and repellent from Zingiberaceae plants against malaria, dengue, and filariasis mosquito vectors.

Topics: Acyclic Monoterpenes; Aedes; Alkenes; Animals; Anopheles; Culex; Dengue; Elephantiasis, Filarial; Gas Chromatography-Mass Spectrometry; Insect Repellents; Insecticides; Larva; Malaria; Monocyclic Sesquiterpenes; Monoterpenes; Mosquito Control; Mosquito Vectors; Oils, Volatile; Plant Leaves; Polycyclic Sesquiterpenes; Sesquiterpenes; Terpenes; Zingiberaceae

The composition of essential oil isolated from Senecio nudicaulis Wall. ex DC. growing wild in Himachal Pradesh, India, was analysed, for the first time, by capillary gas chromatography (GC) and GC-mass spectrometry. A total of 30 components representing 95.3% of the total oil were identified. The essential oil was characterised by a high content of oxygenated sesquiterpenes (54.97%) with caryophyllene oxide (24.99%) as the major component. Other significant constituents were humulene epoxide-II (21.25%), α-humulene (18.75%), β-caryophyllene (9.67%), epi-α-cadinol (2.90%), epi-α-muurolol (2.03%), β-cedrene (1.76%), longiborneol (1.76%), 1-tridecene (1.16%) and citronellol (1.13%). The oil was screened for antioxidant activity using DPPH, ABTS and nitric oxide-scavenging assay. The oil was found to exhibit significant antioxidant activity by scavenging DPPH, ABTS and nitric oxide radicals with IC50 values of 10.61 ± 0.14 μg mL(- 1), 11.85 ± 0.28 μg mL(- 1) and 11.29 ± 0.42 μg mL(- 1), respectively.

Topics: Acyclic Monoterpenes; Alkenes; Antioxidants; Gas Chromatography-Mass Spectrometry; India; Monocyclic Sesquiterpenes; Monoterpenes; Oils, Volatile; Plant Oils; Plants, Medicinal; Polycyclic Sesquiterpenes; Senecio; Sesquiterpenes; Terpenes

This work aimed to investigate chemical composition of essential oils obtained from Zanthoxylum dissitum leaves and roots and their insecticidal activities against several stored product pests, namely the cigarette beetle (Lasioderma serricorne), red flour beetle (Tribolium castaneum) and black carpet beetle (Attagenus piceus). The analysis by GC-MS of the essential oils allowed the identification of 28 and 22 components, respectively. It was found that sesquiterpenoids comprised a fairly high portion of the two essential oils, with percentages of 74.0% and 80.9% in the leaves and roots, respectively. The main constituents identified in the essential oil of Z. dissitum leaves were δ-cadinol (12.8%), caryophyllene (12.7%), β-cubebene (7.9%), 4-terpineol (7.5%) and germacrene D-4-ol (5.7%), while humulene epoxide II (29.4%), caryophyllene oxide (24.0%), diepicedrene-1-oxide (10.7%) and Z,Z,Z-1,5,9,9-tetramethyl-1,4,7-cycloundecatriene (8.7%) were the major components in the essential oil of Z. dissitum roots. The insecticidal activity results indicated that the essential oil of Z. dissitum roots exhibited moderate contact toxicity against three species of storage pests, L. serricorne,T. castaneum and A. piceus, with LD50 values of 13.8, 43.7 and 96.8 µg/adult, respectively.

Topics: Animals; Coleoptera; Insect Repellents; Insecticides; Monocyclic Sesquiterpenes; Oils, Volatile; Plant Leaves; Plant Roots; Polycyclic Sesquiterpenes; Sesquiterpenes; Sesquiterpenes, Germacrane; Terpenes; Zanthoxylum

Essential oils hydrodistilled from the leaves and stem barks of Goniothalamus macrocalyx Ban., Goniothalamus albiflorus Ban. and Goniothalamus tamirensis Pierre ex Fin. & Gagnep. growing in Vietnam were analysed by gas chromatography (GC) and GC-coupled with mass spectrometry. α-Pinene (1.7-50.0%), β-pinene (tr-6.8%), β-myrcene (tr-1.5%), (E)-β-ocimene (tr-4.6%), β-caryophyllene (9.9-12.8%), aromadendrene (0.2-6.0%), α-humulene (1.7-6.9%), α-cadinol (1.2-14.5%), δ-cadinene (0.1-10.3%) and n-hexadecanoic acid (0.2-1.9%) were common to the oil samples. α-Pinene (50.0%) was the most abundant single constituent of the leaf oil of G. macrocalyx, whereas the major compounds of the stem were α-cadinol (14.5%), β-caryophyllene (10.3%) and octadecanoic acid (8.2%). Benzoic acid (18.4%), β-caryophyllene (12.4%) and α-pinene (10.3%) were present in the leaf of G. albiflorus, whereas limonene (21.2%), β-caryophyllene (12.8%) and α-phellandrene (9.3%) were identified in the stem. The leaf oil of G. tamirensis was characterised by abundance of α-pinene (33.4%), viridiflorol (18.5%) and β-caryophyllene (12.4%), whereas γ-gurjunene (11.2%), β-caryophyllene (10.9%) and δ-cadinene (10.3%) predominates in the stem oil.

Topics: Acyclic Monoterpenes; Alkenes; Azulenes; Bicyclic Monoterpenes; Bridged Bicyclo Compounds; Chromatography, Gas; Cyclohexane Monoterpenes; Gas Chromatography-Mass Spectrometry; Goniothalamus; Monocyclic Sesquiterpenes; Monoterpenes; Oils, Volatile; Plant Bark; Plant Leaves; Polycyclic Sesquiterpenes; Sesquiterpenes; Terpenes