PHYTOCHEMICAL ANALYSIS AND ANTIBACTERIAL ACTIVITY OF IPOMOEA INDICA PLANT LEAF EXTRACTS

Objective: The objective of this study was to phytochemical analysis and antibacterial activity of the Ipomoea indica plant leaves extracts.Methods: The crude powder of the plant leaf samples of I. indica was extracted using methanol and aqueous solvents and subjected to qualitative phytochemical analysis. The antibacterial activity of the aqueous and methanol extracts was tested at different for concentrations. The extract was tested against bacterial strains like Staphylococcus aureus, Enterococcus faecalis, Salmonella typhi, and Escherichia coli.Results: The phytochemical screening revealed the presence of alkaloids, flavonoids, terpenoids, glycoside, reducing sugars, saponins, steroids and tannins in the solvent extract. The antibacterial activity was performed by using the disc diffusion method, where the largest zone of inhibition was obtained with aqueous extract 75µ concentration against Salmonella typhi (26 mm). The antibacterial activity was compared with the standard antibiotics like Streptomycin.Conclusion: This study suggests that the aqueous extract of the I. indica leaves possesses bioactive compounds with antibacterial activity against the bacterial strains, which can be used to formulate new antibacterial drugs for disease control

Design, 2D QSAR Studies, Molecular Docking, and Synthesis of Novel Triazole Derivatives as an Antifungal Agents

A quantitative analysis of the structure-activity relationship (QSAR) was performed on a data set of 46 compounds of 1,2,3 and 1,2,4-triazole derivatives. The QSAR study performed using QSARINS software has yielded a robust, stable, and predictive model. The developed 2D-QSAR model was used to predict the biological activity of newly designed 1,2,4-triazole derivatives as antifungal agents against Cytosolic leucyl tRNA synthetase. All the designed compounds were subjected to molecular docking studies for structural and interaction information. Fluconazole and all designed compounds 3a-z were docked in the active site of Cytosolic leucyl tRNA synthetase and FDE was calculated. Compounds 3m, 3o, 3q, 3r, and 3u had good negative FDE values of -8.4, -8.5, -8.2, 8.6, and -8.2 respectively than fluconazole. Molecular docking studies revealed that the designed compounds interacted with Cytosolic leucyl tRNA synthetase mainly through a hydrogen bond, hydrophobic and pi-stacked interactions. In silico studies were performed for all the compounds using Swiss ADME, PreADMET, Molinspiration, and Protox II. Based on docking and insilico studies, five compounds with a good docking score and passing Lipinski’s rule were selected for synthesis. Chemical structures of the synthesized compounds were ascertained based on their spectral data (IR and Mass). Invitro antifungal activity for the synthesized compounds was performed by the Agar-Well diffusion method. The analysis of antifungal activity results indicated that the compound 3m with 4-chloro-2-nitro aniline derivative, compound 3o with 3-nitro aniline derivative, compound 3q with 2-chloro aniline derivative, compound 3u with 2-chloro-4-nitro aniline derivative showed excellent activity and compound 3r with N-N-dimethyl aniline derivative exhibited lesser activity than standard amphotericin B against Candida albicans strain

Foliar application of microbial-enriched compost tea enhances growth, yield and quality of muskmelon (Cucumis melo L.) cultivated under fertigation system

Microbial-enriched compost tea (CT) is a water extract of compost that is amended with nutrient supplements during brewing to enhance their microbial diversity. The potential use of fertigation nutrients via drip irrigation system followed by weekly foliar application of microbial-enriched CT on growth of muskmelon (Cucumis melo L.) and suppression of powdery mildew caused by Golovinomyces cichoracearum DC. was studied under rain shelter conditions. Full and half strength fertigation nutrients in combination with weekly foliar application of microbial-enriched CT, fungicide (Daconil®@2 g L−1) or water as a control were utilised in this study. The study showed that there was no added advantage in using full strength fertigation nutrients in terms of chlorophyll content, mean flower formation, mean fruit set, disease severity, and disease progress (AUDPC) or epidemic rate. A repeat trial was also conducted using half strength fertigation nutrients (twice a day) in combination with weekly foliar application of microbial-enriched CT or Daconil®, as a result there was reductions in the disease severity by 38 and 21%, respectively. In addition, a delay in disease onset for two weeks was observed in the plants treated with either microbial-enriched CT or Daconil®. The experimental results revealed significant variations in the yield and fruit qualities amongst the treatments. There were 18.3, 16.21, 8.81, 7.11 and 7.50% increases in mean fruit fresh weight (kg), total soluble solids concentration (°Brix), firmness (N), linear increment in the diameter (cm) and mesocarp size (cm) of muskmelon fruits, respectively after the application of half strength fertigation nutrients in combination with the weekly foliar application of microbial-enriched CT as compared with the control. Thus, it is rational to conclude that a reduced strength of the nutrients in the fertigation systems in combination with weekly foliar application of microbial-enriched CT could be used successfully as a biofertiliser and a bioprotectant on muskmelon crop without compromising their fruit quality

Histopathological changes induced by Meloidogyne incognita in some ornamental plants

Histopathological changes induced by the root-knot nematode (Meloidogyne incognita) in five ornamental plants, specifically, Calendula (Calendula officinalis), Centaurea (Centaurea montana), Papaver (Papaver somniferum), Chrysanthemum (Chrysanthemum morifolium) and Dianthus (Dianthus caryophyllus), were investigated. Based on the galling index (GI), Centaurea was classified as susceptible, Calendula as moderately susceptible, and Papaver as moderately resistant, while Chrysanthemum and Dianthus were highly resistant to M. incognita infection. The histopathology of the galled roots of Centaurea, Calendula, and Papaver during later stages of infection showed that nematodes were localized entirely within the cortex and generally oriented horizontally to the vascular cylinder. Most of the females were mature, and a few of them were associated with egg masses. Giant cells with a variation in cell sizes were observed in the galled roots of all three of the plant species and exhibited a granular cytoplasm and hypertrophied nuclei as a typical reaction to nematode feeding

Bio-intensive management of fungal diseases of fruits and vegetables utilizing compost and compost teas

Compost has been used in agriculture and horticulture for a long time as a fertilizer or a soil conditioner. However, in recent years the focus has been placed on the disease-suppressive effects of the compost and its aqueous extracts. Several composts and their water extracts have been investigated on different diseases especially on those caused by soilborne pathogens throughout the world. Conversely, an increase in disease incidence has also been reported. Therefore, it remains the fact that compost application can suppress the diseases in positive, neutral, and even negative manner. This makes the utilization of compost intricate as a robust prevalent approach to mitigate plant diseases. The mechanisms involved in the disease suppression are not fully known. The disease-suppressive effect of the compost could be attributed to various mechanisms including the presence of antagonistic microbes and unidentified chemical factors in them, antibiosis, and induction of systemic resistance in plants and improvement of the overall health of plants. This chapter focuses on the influence of compost and compost teas on the suppression of foliar and soilborne fungal diseases of fruits and vegetables. The factors limiting and enhancing their efficacy will also be discussed

Microbial starter for the enhancement of biological activity of compost tea.

Compost tea is gaining importance as an alternative to chemical fertilizers and pesticides. The microbial population in the compost tea contributes toward its effectiveness. An attempt was made to enhance the biological activity of compost tea by fortification with microbial substrates. Humic acid and yeast extract (4:7 w/w 100 g-1 compost) when used as microbial starter during brewing of compost tea significantly (P less than or equal to 0.05) enhanced the microbial population. There was a ten to hundred fold percentage increase for total bacteria, fungi and actinomycetes compared to control. The stability of microbial enriched compost tea was maintained up to four months of storage based on significantly higher number of viable cell counts when compared to compost tea without substrates (control). The viable microbial cell counts over a storage period of six months was 8.5x10(9), 4.6x10(6), 3.5x10(4), 3.9x10(4), 1.4x10(5), 4.8x10(4) and 7.3x10(5) for other bacteria

A new variety of Gymnosporia emarginata (Celastraceae) from the Coromandel Coast of Peninsular India

A new variety, Gymnosporia emarginata (Willd.) Thwaites var. coromandelica N.Balach. & P. Umamaheswari (Celastraceae) has been described from Tamil Nadu, India. The diagnostic characters of this variety are: long stamens, ovary immersed in the disc, style sessile and stigma lobes converged. Detailed descriptions, differences in characters between the 2 varieties, ITS based phylogenetic analysis and related images are provided for easy identification