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Research Publications (Applied Sciences)

Permanent URI for this collectionhttp://ir-dev.dut.ac.za/handle/10321/213

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Author: search.filters.author.Baijnath, Himansu

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    The chemical composition of leaf essential oils of Psidium guajava L. (white and pink fruit forms) from South Africa
    (Taylor and Francis, 2015-02-23) Chalannavar, Raju K.; Venugopala, Katharigatta Narayanaswamy; Baijnath, Himansu; Odhav, Bharti
    The leaf oils of Psidium guajava (white fruit) and Psidium guajava (pink fruit) collected in KwaZulu-Natal province of South Africa has been examined by Gas chromatography-Mass spectrometry (GC-MS), and the apparent concentrations were determined by gas chromatography with a flame ionization detector. A total of twenty compounds of 88.9 % from white fruit and forty eight compounds representing 97.5 % from pink fruit of the oils were identified. P. guajava (white fruit) produced oil that was much richer in hydrocarbons (38.8 %), sesquiterpenes hydrocarbons (24.0 %), oxygenated sesquiterpenes (19.1 %) and alcohol (6.8 %). The major constituents of the essential oil were caryophyllene oxide (14.0 %), caryophyllene (13.9 %), 1H-cycloprop[e]azulene (11.6 %), adamantane (9.4 %), 3,7,11-trimethyl-1,6,10-dodecatrien-3-ol (6.8 %), α-cubebene (6.7 %), 1,2,3,4-tetrahydronaphthalene (3.9 %), β-humulene (3.5 %), 1,2,4a,5,6,8a-hexahydronaphthalene (3.2 %) and α-caryophyllene (3.0 %). The leaf oil of P. guajava (pink fruit) contained a mixture of hydrocarbons (30.5 %), sesquiterpene hydrocarbons (25.4 %), alcohol (24.4 %) and oxygenated sesquiterpenes (15.0 %). The major constituents of the essential oil were caryophyllene oxide (13.0 %), tetracyclo[6.3.2.0(2,5).0(1,8)]tridecan-9-ol (12.9 %), caryophyllene (9.5 %), 3,7,11-trimethyl-1,6,10-dodecatrien-3-ol (9.5 %), 1H-cycloprop[e]azulene (8.1 %), Z-3-hexadecen-7-yne (4.6 %) and eudesma-4(14),11-diene (4.1 %). High concentration of caryophyllene oxide and caryophyllene in both the oils suggests its usefulness as natural preservatives in the food industry. The terpenic and ester compounds could contribute to the unique flavor of P. guajava leaves.
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    Chemical composition of essential oil from the seed Arils of Strelitzia nicolai Regel & Koern from South Africa
    (Taylor and Francis, 2015-02-23) Chalannavar, Raju K.; Venugopala, Katharigatta Narayanaswamy; Baijnath, Himansu; Odhav, Bharti
    The essential oil components of arils from seeds of Strelitzia nicolai were investigated by GC and GC-MS. The oil yields of dried arils obtained by hydrodistillation were 0.86 %. Twenty-five compounds representing 94.2 % of the S. nicolai aril oil were identified. The main chemical constituents belongs to alcohols (1.24 %), amides (3.14 %), amine (31.75 %), aromatic compounds (4.86 %), esters (0.65 %), ethers (28.18 %), hydrocarbons (5.13 %) and ketones (19.30 %).
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    The antimosquito properties of extracts from flowering plants in South Africa
    (NCBI, 2013) Chalannavar, Raju K.; Hurinanthan, Vashka; Singh, Alveera; Venugopala, Katharigatta Narayanaswamy; Gleiser, Raquel M.; Baijnath, Himansu; Odhav, Bharti
    Extracts of selected flowering plants, which are considered eco-friendly, are used for the treatment of numerous ailments and vector control worldwide. This has resulted in approximately 25 per cent of currently used drugs being derived from herbal sources. The aqueous and methanolic extracts of twelve plant species, Psidium guajava (pink fruit), Psidium guajava (white fruit), Psidium cattleianum var. cattleianum, Psidium guineense and Psidium X durbanensis, Achyranthes aspera, Alternanthera sessilis, Guilleminea densa, Capparis tomentosa, Leonotis leonurus, Dichrostachys cinerea and Carpobrotus dimidiatus, were tested for insecticidal activity, including larvicidal, adulticidal and repellent activities against the adult female mosquito, Anopheles arabiensis. The extracts of P. guajava (white fruit), C. tomentosa, L. leonurus,D. cinerea, and C. dimidiatus exerted a pronounced inhibitory effect on adult insects, while those of P. guajava (pink fruit), P. X durbanensis, P. cattleianum var. cattleianum, P. guineense, A. aspera, A. sessilis, and G. densa were ineffective and failed to satisfy the criteria set by the World Health Organization. In the tests for repellency against An. arabiensis, all the tested aqueous and methanolic plant extracts except those of A. sessilis repelled 80-100% of mosquitoes. The most effective mosquito repellents were the methanol and aqueous extracts of P. guajava (pink fruit), P. X durbanensis, P. cattleianum var. cattleianum, P. guineense, G. densa,L. leonurus and D. cinerea, which are potential sources of cost effective mosquito repellents to be utilized in malarial endemic areas.
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    Chemical composition of essential oil of Psidium cattleianum var. lucidum (Myrtaceae)
    (Academic Journals, 2012-04-12) Chalannavar, Raju K.; Baijnath, Himansu; Odhav, Bharti; Venugopala, Katharigatta Narayanaswamy
    The aim of this study was to investigate the essential oil composition of Psidium cattleianum var. lucidum from South Africa. The essential oils were extracted by hydrodistillation and the components were identified by gas chromatography coupled to mass spectrometry (GC-MS) to determine the chemical composition of the essential oil. A total of 53 chemical components were identified, accounting for 61% of the essential oil. The major component was caryophyllene oxide (12.43%), while other predominant constituents were identified as bicyclo(4.4.0)dec-l-ene (6.61%), 2,3-butanediol diacetate (4.84%) and patchoulene (4.73%). The presence of many terpenic and ester compounds is thought to contribute to the unique flavor of the P. cattleianum var. lucidum leaves.