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M. Sc. Dissertations

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20072
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Subject: Chemistry × End date: 2007 × Start date: 2007 ×
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    ThesisItemOpen Access
    Phytochemical investigation of citrus sinensis var. jaffa and its antifungal activity against fusarium oxysporum
    (CCSHAU, 2007) Vedwati; Kalidhar, S.B.
    Citrus sinensis (L) Osbeck (Syn C. aurantium L. var. sinensis) belongs to family Rutaceae. It is widely cultivated all over the world. It is known for its antimicrobial, Insecticidal and medicinal properties. Fruits of C. sinensis var. Jaffa were collected from Department of Horticulture, CCS HAU, Hisar. Rinds were separated from fruits and extracted with hot methanol. Column chromatography of the extractives over silica gel afforded two compounds. One of these was β-sitosteryl- β-D-glucoside and other was 5-hydroxy-3', 4’- dimethoxy flavanone 7-O-rhamnosyl (14) glucoside. Both these compounds are reported 1st time from this plant. Column chromatography of ethyl acetate extract of juice afforded only one compound i.e. 5-hydroxy -3', 4'-dimethoxy flavanone 7-O-rhamnosyl (1 4) glucoside. The characterization of isolated compounds was carried out on the basis of UV-visible, IR, 1H NMR, Mass spectral data and other properties of the compounds. The methanolic extract of flavido obtained from C. sinensis var. Jaffa was used for antifungal activity at 500, 1000, 1500 and 2000 μg/ml concentration against Fusarium oxysporum and percentage inhibition was recorded. It was noted that the growth of Fusarium oxysporum was inhibited to the maximum extent at concentration 2000 μg/ml with 53% inhibition. Tannins, total sugars, titrable acidity, TSS, moisture content and ascorbic acid contents (Biochemical parameters) were estimated in the juice of C. sinensis var.Jaffa. The juice was found to contain total sugars (10.45 g/100 ml), tannins (78.00 mg/100ml), ascorbic acid (47.90 mg/100ml), TSS (11.55%), moisture content (81.44%) and titrable acidity (1.14 g/100ml).
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    ThesisItemOpen Access
    Chemical constituents of lemongrass (Cymbopogon flexuosus Stapf) oils and their nematicidal activity against meloidogyne javanica
    (CCSHAU, 2007) Maun, Poonam; Madan, V.K.
    Laboratory studies were conducted to study the effects of steam distillation time and silica gel column chromatography on the quality of essential oil of Lemongrass (Cymbopogon flexuosus). Nematicidal activity of aqueous extracts of essential oil of Lemongrass (Cymbopogon flexuosus) was also studied against the root knot nematode Meloidogyne javanica. For steam distillation studies, two Lemongrass varieties viz., CKP 25 and OD 19 and six genotypes viz., NLG 84, NLG 118, HL 2, HL 3, HL 10 and HL 11 were taken and the essential oils of the freshly harvested grasses of these eight varieties/genotypes were extracted by steam distillation using Clevenger apparatus. To obtain the optimum time of steam distillation, two sets of Clevenger apparatus were used for each variety/ genotype. One of the distillation units was labelled as “Full Time Distillation” and another distillation unit was labelled as “Fractional Distillation”. The distillation unit labelled as “Full Time Distillation” was boiled for 4 hours and all the essential oil that distils out from the grass in 4 hours was collected in one glass vial labelled as “Full Time”. The second distillation unit labelled as “Fractional Distillation Unit” was also boiled for 4 hours but the oil fractions recovered at periodical interval of 1 hour were collected in four glass vials and labelled as 0-1 h, 1-2 h, 2-3 h and 3-4 h. Among the various steam distilled oil fractions maximum oil (74.2-82.6%) was recovered in the first hour. The citral-a (44.3-54.3%), citral-b (30.4-35.0%) and total citral (75.1-89.3%) content in all the eight varieties/genotypes was higher in the 0-1 h distilled oil fractions in comparison to “Full Time” distilled oil (the range of citral-a, citral-b and total citral being 43.0-50.7%, 27.5-31.7% and 70.5-82.4%, respectively). The higher citral content in the first hour distilled oil fraction may be due to high volatility of citral-a and citral-b so that majority of these constituents distil out in the first hour itself. Qualitative analysis of oils recovered from some hexane fractions (from 151–400 ml) in silica gel column chromatography studies showed that citral-a (48.6-52.7%), citral-b (29.4-32.5%), and total citral (77.9-81.9%) content was higher in comparison to their contents (44.8%, 29.1% and 73.9%, respectively) in pure oil sample. This may be probably due to adsorption capacity of silica gel with citral-a and citral-b for sometime in the earlier stage and thereafter due to desorption of these constituents in the later stage, citral content increases in the oils recovered from later hexane fractions. Oils recovered from various hexane fractions were found to be effective in controlling root knot nematode Meloidogyne javanica. The mean percent mortality of aqueous extracts of essential oils recovered from various hexane fractions was in the range of 66.3-77.9% as compared to 74.0-75.3% in the aqueous extract of Lemongrass pure oil sample (variety CKP 25). Further, essential oils recovered from various hexane fractions were found to exhibit nematicidal activity to varying extents probably due to different percentages of citral in these oils. Keeping in view the steam distillation and column chromatographic studies, it can be inferred that the first hour (0-1 h) distilled Lemongrass oil is of superior quality and hence, can be used in preparations requiring high quality Lemongrass oil. Further, silica gel as an adsorbent can play a vital role in improving the quality of essential oil of Lemongrasss.