Browsing by Author "Sumona Kumari"
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ThesisItem Open Access Phytoconstituents and antimicrobial studies on aerial parts of Nyctanthes arbor-tristis Linn. (Harsingar)(CCSHAU, 2017) Sumona Kumari; Rajvir SinghPlant materials viz. leaves, flowers, seeds, stem and bark were collected from CCS HAU, Hisar. These were extracted with methanol. Extractives were divided into three parts: first part used for phytochemical analysis, second part for column chromatography and third part for determination of antimicrobial activity. Phytochemical analysis of leaves, fruit and seed of N. arbor-tristis revealed the presence of alkaloids, flavonoids, phytosterol, phenolics, tannins, glycosides and saponins. Column chromatography over silica gel (60-120 mesh) afforded twenty six compounds. Seven compounds namely, 21α-hydroxyfriedel-4-(23)-en-3-one, β-sitosterol, 1-triacontanol, friedel-1-ene-3-one, pelargonic acid, lignoceric acid and 1,4-O-β-D-glucopyranoside were isolated and characterized from stem. Another seven compounds namely, methyl tetracosanoate, octacosane, tetrapentacontane, 3β- hydroxy olea-12-ene-28-oic acid, β-sitosterol, stigmastan-3-en-6-ol and bis (cis-13-docosenamido) methane were isolated and characterized from Nyctanthes arbor-tristis flowers. Similarly two compounds were isolated from bark and five compounds were isolated from leaves and seeds of Nyctanthes arbor-tristis. Methanolic extract and five fractions (hexane, benzene, ethyl acetate, chloroform and acetone) of leaves, flowers, seeds, stem and bark of Nyctanthes arbor-tristis were tested for antimicrobial activity against Rhizoctonia solani, Mycogone perniciosa, Xanthomonas axonopodis pv. citri, Pseudovorax sp. and Dickeya zeae at 250, 500, 1000 and 2000 μg/ml concentrations. Poisoned food technique for antifungal activity and inhibition zone method was employed for antibacterial activity. Irrespective of concentrations, benzene fraction of leaves was found highly active against Rhizoctonia solani with 89.58 % inhibition at 2000 μg/ml concentration and 225 μg/ml EC50 value. Methanol extract exhibited highest antibacterial activity against Xanthomonas axonopodis pv. citri and Pseudovorax sp. with 12.00 and 4.00 mm of zone of inhibition at 2000 μg/ml concentration. Xanthomonas axonopodis pv. citri was found most sensitive to extract and fractions of N. arbor-tristis. Leaves and seeds fractions of N. arbor-tristis exhibited maximum growth inhibition against the tested phytopathogens.ThesisItem Open Access Synthesis and studies on some carbamates as potential nematicidal agents(CCSHAU, 2011) Sumona Kumari; Rajvir SinghThe extensive use of pesticides together with synthetic fertilizers has caused a very rapid increase in agriculture productivity since last many years. But threat is still persist from several diseases caused by different insects/pests because one third of crops are lost due to these pests and diseases. Among different pests, the plant parasitic nematodes cause significant losses in major crops in India. So the reduction of losses caused by these pests is obvious strategy to increase food supply. The nematodes, a tiny worm like creature mainly feed on roots and take their nutrition from plant cell cytoplasm. Among nematodes, Meloidogyne javanica is most common species of root-knot nematode worldwide. Except insecticides, there is no specific, effective and cheap nematicide available on which one can depend to control nematodes. Also the use of these chemicals creating environmental problems and hazards to non-target organisms.The biological activities shown by carbamates, their importance as agrochemicals and as a part of our ongoing new nematicide development programme, a series of 3- (substitutedphenyl)-1-(4-hydroxyphenyl)-2-propen-1-one(14-25), substituted 2H-1-benzopyran-2-one (42-45) and their derivatives carbamates (47-51) were synthesized. The chemical structures of newly synthesized compounds were elucidated by IR, 1HNMR, and other physical and analytical data. The synthesized compounds were evaluated for their nematicidal activity against root-knot nematode (Meloidogyne javanica). The bioactive assay showed that compound 45 among 42-45 and compound 47-51 were most toxic to nematodes and showed 100 % mortality at all concentrations (upto 7.5 ppm). The compounds showed spectacular prospects for further research and use in the field. The findings suggested that the chalcone and coumarin framework is an attractive template for synthesis of nematicides. These compounds needs further exploration for their possible use as nematicides and deserve further investigation.