Fruit juice mediated multicomponent reaction for the synthesis of substituted isoxazoles and their in vitro bio-evaluation

A simple, efficient and eco-friendly procedure for the synthesis of isoxazole derivatives (4a–4h) using one-pot three-component reaction between substituted aldehydes (1a), methyl acetoacetate (2a) and hydroxylamine hydrochloride (3a) has been achieved in presence of Cocos nucifera L. juice, Solanum lycopersicum L. juice and Citrus limetta juice respectively. The homogeneity of synthesized compounds was confirmed by melting point and thin layer chromatography. The synthesized compounds were characterized by using 1H NMR, FTIR and CHN analyses and evaluated for in vitro herbicidal activity against Raphanus sativus L. (Radish seeds). The compounds (4a–4h) were also screened for their fungicidal activity against Rhizoctonia solani and Colletotrichum gloeosporioides. Antibacterial activity was also tested against Erwinia carotovora and Xanthomonas citri. From bio-evaluation data, it was found that compound 4b was most active against Raphanus sativus L. (root) and Raphanus sativus L. (shoot) respectively. Compound 4b was also found most active against both the fungus viz. R. solani and C. gloeosporioides showing maximum percentage growth inhibition i.e. 90.00 against R. solani and 82.45 against C. gloeosporioides at 2000 µg/mL concentration. Compound 4 h has shown maximum inhibition zone i.e. 3.00–9.60 mm against Erwinia carotovora at 2000 µg/mL concentration. Maximum Xanthomonas citri growth was also inhibited by compound 4 h showing inhibition zone 1.00–5.00 mm at highest concentration.

Endophytic Bacteria Pseudomonas aeruginosa PM389 Subsists Host’s (Triticum aestivum) Immune Response for Gaining Entry Inside the Host

The present study was designed to compare the defense response of the host plant towards endophytic bacteria Pseudomonas aeruginosa PM389 and pathogenic bacteria Erwinia carotovora and to correlate the level of defense enzymes vis-a-vis bacterial colonization in the host. Wheat seedlings were treated with 107-108 cells ml-1 endophytic and pathogenic bacteria in the separate experimental set-up, and the level of plant defense enzyme was measured at various time intervals. Comparatively reduced level of most defense enzymes was produced in endophytic bacteria treated plants. While the endophytic bacterial population was almost constant after 24 HAI (hour after inoculation), the population of pathogenic bacteria kept fluctuating during the study period from 24 HAI. Unlike pathogenic bacteria, we observed attenuated defense response in challenged host plants towards endophytic bacteria, which helps endophytes establish inside plant. This study would be useful for understanding the mechanism of colonization and strategies of endophytes to fight against the host defense response.

Screening for the Production and Characterization of L-asparaginase from Endophytic Fungi

L-asparaginase (EC 3.5.11. L-asparagine amidohydrolase) is first enzyme, studied very intensively in human beings with regard to its anti-tumor potential against tumor of lymphoid precursor, acute lymphoblastic leukemia (ALL). The current drugs are suffering from many side effects like immune suppression, infertility, secondary neoplasm. The immunogenic complications associated with its present microbial sources Escherichia coli; Erwinia carotovora limits its medicinal frontier. So there exists a need of switching to novel natural sources to serve as non-immunogenic and better production sources of L-asparaginase. In the present study, four cultures of fungal endophytes viz. TSF-1, TSF-2, TSF-3 and TSF-4 selected on the basis of primary and secondary screening was carried on with L-asparagine as a sole carbon and nitrogen source and phenol red as pH indicator. The maximum protein content was observed to be present in TSF-2 i.e. 2.727 mg /mL and possessed maximum activity of 6.054 Units/ml. Sample was separated by SDS-PAGE, stained by silver staining, showed a single band with molecular weight of approximately ~45kDa.

Bioassay-Guided Isolation of Broad-Spectrum Fungicidal Active Compound from Artemisia ordosica

To avoid the widespread resistance of commercial fungicides, new broad-spectrum botanical fungicides need to be developed. In previous bioactive screening assays, extracts of Artemisia ordosica Krasch. (A. ordosica) had highly antifungal activities, but the responsible phytochemicals were unidentified. In this study, active compounds of A. ordosica extracts were identified using a bioassay-guided method, and antifungal assays were performed in vitro and in vivo. The bioactive compounds were dissolved in petroleum ether, and the best antifungal fraction contained four compounds: trans-dehydromatricaria ester (TDDE), 7, 4-demetylnringenin, capillarin, and stearic acid. Among them, TDDE exhibited the highest antifungal activity against six pathogenic fungi and five bacteria. It exhibited significant fungicidal activity against Thanatephorus cucumeris and Botrytis cinerea with EC50 values of 0.464 μg/mL and 1.4 μg/mL, respectively. The living tissue bioassay results showed that the relative protection effects (RPE) of TDDE on tomato leaves, tomato fruit, and strawberry leaves infected with B. cinerea reached 76.78%, 86.2%, and 80.89%, respectively. In pot experiments, the RPE on tomato and strawberry plants infected with B. cinerea reached 84.11% and 96.37%, respectively. Morphological and physiological examination showed that TDDE had significant inhibitory effects on mycelial growth, including increased top offshoot, contorted hyphal tips, and extravasated cytochylema. Meanwhile, bactericidal activities of TDDE were significantly higher than kanamycin and streptomycin in five bacteria, and the plant tissue experiments further demonstrated that it had an 88.31% RPE on walnut leaves infected with Xanthomonas campestris pv. jugiandis, 72.18% RPE on potato infected with Erwinia carotovora subsp. carotovora, and 82.50% RPE on kiwifruit branches infected with Pseudomonas syringae pv. actinidiae. The active compounds isolated from A. ordosica in this study show great potential value for developing broad-spectrum fungicides, and also provide an important way to identify and isolate new bioactive products from medicinal plants.

Phytochemical Analysis and Antimicrobial Properties of Eucalyptus torelliana Oils

Normal oil and Essential oil from fresh leaves of Eucalyptus torelliana (F. Muell) were extracted using solvent (Soxhlet) and steam distillation extraction methods respectively. The leaves were screened for the presence of secondary metabolites and the extracted oils for their antimicrobial potentials. The phytochemical screening revealed the presence of Phytates (27.81 mg/g) Phytic acids (7.833mg/g) Oxalates (3.061mg/g) Tannins (2.457mg/g) Phenols (30.00%) Flavonoids (2.948%) Saponins (3.166%) and Alkaloids (2.84%). In addition to this the leaves were found to contain anthraquinone. The two oils extracted from the leaves of Eucalyptus torelliana were studied for their antimicrobial activity against the following isolated microorganisms: Xanthomonas axonopodis, Shigella dysenterine, Pseudomonas solanecearium, Streptococcus faecales, Staphylococcus aureus, Salmonella enterica, Erwinia carotovora, Salmonella typhi. The oils were found to inhibit all the microorganism isolates. The zone of inhibition exhibited by the extracts on the tested microorganism was between 22-6mm. The oil extracts compared favourably with Ampiclox used as a standard control. The results obtained from this study reveals that the oils extracted from Eucalyptus torelliana has antibacterial activities against enteric pathogens and the oil may be potential source of new antimicrobials against enteric organisms.Keywords- Enteric microorganisms, essential oil, Eucalyptus torelliana, secondary metabolites, solvent extraction

Genetic sources of resistance to root rots chicory

Relevance. One of the significant problems in the technology of obtaining root chicory is the protection of root vegetables from the defeat of root rots. The most common lesions of root vegetables chicory various pathogenic species of fungi causing phomosis (Phoma rostrupii Sacc.), gray rot (Botrytis cinerea (R.) Fr.J), wet bacterial rot (Erwinia carotovora (Jones) Holt.). An important place in solving this problem is the breeding of new varieties that are resistant to major diseases and adapted to the conditions of cultivation in the soil-climatic conditions of the chicory-seeding zone. This requires, first of all, to determine the range of donor varieties of the sign of resistance to root rots, both during the growing of culture, and during long-term storage.Material and methods. In 2018-2020, studies were carried out to assess gene sources of different ecological and geographical origin (including against a provocative background) in the Non-Black Earth Zone of the Russian Federation and to isolate donors of resistance to root rot from them. Research on the Rostov Vegetable experimental station on chicory.Results. Studies have shown that the defeat of root vegetables chicory root rots genetic sources were very different from each other, so Harpachi, Luxor did not affect the. root rots neither on the usual nor on provocative backgrounds.

Xanthomonas campestris pv. campestris (black rot).

Black rot is considered the most important worldwide disease of crucifers. The disease is known to exist in the cool coastal climates of northern Europe and North America but was seldom a problem there until the 1990s. Its potential for crop damage is also considered low in New Zealand, and parts of Australia. In many regions of Central and Eastern Europe, Central Asia (Kazakhstan), China, tropical and subtropical regions of Asia, Africa and South America where brassicas are common and cultivated without crop rotation, black rot is always present. Seed production in those regions is commonly associated with high levels of seedborne Xcc (Williams, 1980). Even minor, visually undetectable development of black rot may considerably increase damage to plants by soft rot caused by Erwinia carotovora, Pseudomonas spp. and other opportunistic pathogens (Djalilov et al., 1989).