Identification of an antibacterial Withanolide (Dinoxin B) from leaf of Datura inoxia Mill.

Natural medicines are gaining popularity due to the alarming incidence of bacterial resistance even in regions with improved healthcare systems. Hence, there is a distinct and constant need for isolating medicinally active compounds from different natural sources. Taking this into consideration, experiment was done in order to isolate and identify an antibacterial compound from Datura inoxia through bioassay and Mass spectroscopy technique. The ethanol, hexane and aqueous leaf extracts of Datura inoxia were screened fo

Identification of an antibacterial Withanolide (Dinoxin B) from leaf of Datura inoxia Mill.

Natural medicines are gaining popularity due to the alarming incidence of bacterial resistance even in regions with improved healthcare systems. Hence, there is a distinct and constant need for isolating medicinally active compounds from different natural sources. Taking this into consideration, experiment was done in order to isolate and identify an antibacterial compound from Datura inoxia through bioassay and Mass spectroscopy technique. The ethanol, hexane and aqueous leaf extracts of Datura inoxia were screened fo

Emulsification and Hydrolysis of Oil by Syncephalastrum racemosum

A fungal strain, Syncephalastrum racemosum, was isolated from oil-leak contaminated soils from Kanpur, India. The strain was examined for potential to emulsify soybean oil using a 18 per cent oil supplement as carbon source in minimal salt medium. On 72 h growth of the fungus in oil and salt medium, the cellfree supernatant (CFS) showed presence of mono- and di-glycerides indicating degradation of oils to free fatty acids (FFAs). Increasing concentration of oil resulted in enhanced formation of FFAs. The degradation process was observed to be related to the emulsification activity in CFS which was observed to increase with time. The study reports the emulsification and hydrolytic activity of S. racemosum, an activity that can be exploited for increasing the accessibility and treatment of hazardous substance including hydrophobic explosives.Defence Science Journal, 2010, 60(3), pp.251-254, DOI:http://dx.doi.org/10.14429/dsj.60.35

Dinoxin B Withanolide from Datura inoxia Mill as an Effective Phytocompound Against Urinary Tract Infection causing Staphylococcus aureus

Background: Dinoxin B Withanolide was isolated from Datura inoxia and identified with its cytotoxic activity. But its antibacterial properties are not yet evaluated. We have previously reported the broad-spectrum antibacterial property of Dinoxin B Withanolide extracted from D.inoxia on standard strains. Objective: This research has focused to evaluate the efficacy of Dinoxin B Withanolide against infectious Staphylococcus aureus, including resistant strains. Methods: Electrospray Ionization-Mass Spectrometry is used to depict the presence of Dinoxin B withanolide from the chromatographic ethanolic leaf fraction. Antibacterial activity of different concentrations of Dinoxin B(12500-100000 μg/ml) was assessed using the agar diffusion, macro broth dilution, and time-kill assay methods. Docking studies and Drug likeness properties were analyzed. Result: Electrospray Ionization-Mass Spectrometry depicted the presence of Dinoxin B. All the isolates were susceptible to Dinoxin B within the range of 15±0.5mm to 24±0.5mm, and the bacteria were susceptible at a concentration rate of ≤12.5mg/ml. Time-kill assay showed that 25mg/ml of Dinoxin B displayed the highest inhibitory activity after four hours. The MBC values were compatible with the cidal concentration as seen in the time-kill study's growth curve. Computer-aided techniques resulted in a good Docking score towards Quorum-signaling Sar A protein (-7.82)and Penicillin Binding Protein(-6.9). Conclusion: Dinoxin B with its bactericidal properties and significant affinity towards Quorum-signaling Sar A protein and Penicillin Binding Protein can be considered as an effective bioactive compound against Methicillin Resistance Staphylococcus aureus.</jats:p

A conserved HSF :miR169: NF‐YA loop involved in tomato and Arabidopsis heat stress tolerance

International audienceSUMMARY Heat stress transcription factors (HSFs) and microRNAs (miRNAs) regulate different stress and developmental networks in plants. Regulatory feedback mechanisms are at the basis of these networks. Here, we report that plants improve their heat stress tolerance through HSF‐mediated transcriptional regulation of MIR169 and post‐transcriptional regulation of Nuclear Factor‐YA (NF‐YA) transcription factors. We show that HSFs recognize tomato ( Solanum lycopersicum ) and Arabidopsis MIR169 promoters using yeast one‐hybrid/chromatin immunoprecipitation–quantitative PCR. Silencing tomato HSFs using virus‐induced gene silencing (VIGS) reduced Sly‐MIR169 levels and enhanced Sly‐NF‐YA9 / A10 target expression. Further, Sly‐NF‐YA9/A10 VIGS knockdown tomato plants and Arabidopsis plants overexpressing At‐MIR169d or At ‐ nf‐ya2 mutants showed a link with increased heat tolerance. In contrast, Arabidopsis plants overexpressing At ‐ NF‐YA2 and those expressing a non‐cleavable At‐NF‐YA2 form (miR169d‐resistant At ‐ NF‐YA2 ) as well as plants in which At‐miR169d regulation is inhibited (miR169d mimic plants) were more sensitive to heat stress, highlighting NF‐YA as a negative regulator of heat tolerance. Furthermore, post‐transcriptional cleavage of NF‐YA by elevated miR169 levels resulted in alleviation of the repression of the heat stress effector HSFA7 in tomato and Arabidopsis, revealing a retroactive control of HSFs by the miR169:NF‐YA node. Hence, a regulatory feedback loop involving HSFs, miR169s and NF‐YAs plays a critical role in the regulation of the heat stress response in tomato and Arabidopsis plants