Design, synthesis, and unraveling the antibacterial and antibiofilm potential of 2-azidobenzothiazoles: insights from a comprehensive in vitro study.

The present study reports the synthesis of 2-azidobenzothiazoles from substituted 2-aminobenzothiazoles using sodium nitrite and sodium azide under mild conditions. All the synthesized compounds were examined for their antibacterial activity against Gram (+) bacteria, Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 51299), Bacillus cereus (ATCC 10876) and Gram (-) bacteria, Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 10145), Klebsiella pneumonia (ATCC BAA-2146)and clinical isolates of Gram (+) Methicillin Resistant S. aureus (MRSA) and Multi Drug Resistant E. coli. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values by broth dilution method revealed that compound 2d exhibited significant antibacterial potential against E. faecalis and S. aureus with MIC of 8 µg/mL, while other synthesized compounds had only moderate effects against all the tested species. The compound significantly inhibited the biofilm formation of the bacterial strains below its MIC. The selective cytotoxicity of Compound 2d towards bacterial cells was evidenced on extended exposure of Human Embryonic Kidney-293 cell line to higher concentrations of the compound. Hence, the present study confirmed that compound 2d can be a potential drug candidate for future development as an antibacterial drug.

Gas chromatographic-mass spectrometric analysis, antioxidant, antiproliferative and antibacterial activities of the essential oil of Prangospabularia.

The essential oil composition of the shoot parts of Prangos pabularia, growing in Drass area of Ladakh, India, along with its antioxidant, antibacterial and anticancer activity, is reported for the first time. Gas chromatography coupled with mass spectrometry (GC-MS) revealed the presence of 31 constituents, representing 97.342% of the total essential oil. The major constituents of essential oil were Durylaldehyde (62.161%), Bicyclo [3.1.1] hept-2-en-4-ol (8.846%), Chrysanthenyl acetate (5.120%) followed by unknown (3.420%), (-)-Spathulenol (3.028%), Mesityl aldehyde (2.402%) and Hexahydro farnesyl acetone (1.683%. Cytotoxic activity of the essential oil by MTT assay against human breast adenocarcinoma (MCF7), human breast (HBL-100), human cervical cancer (HELA) and human lung adenocarcinoma epithelial (A549) cells, at four different concentrations (20, 30, 50 & 100 µg/mL) revealed that the activity of 56.12% against A549 (human lung) cell line at 20 µg/mL concentration was the highest. The Essential oil displayed a significant free radical scavenging activity with DPPH. Antibacterial activity was carried out against 3 g positive and 2-g negative bacteria at four different concentrations using Agar Well Diffusion Method taking streptomycin sulphate as reference. The essential oil displayed significant and broad-spectrum antibacterial activity against different bacteria used. The MIC of the oil ranged from 2.06 to 5.00 µg/mL. The zones of inhibition were lesser for Micrococcus and Escherichia coli compared to other strains of bacteria.

Gas Chromatographic-Mass Spectrometric Analysis, Antibacterial, Antioxidant and Antiproliferative Activities of the Needle Essential Oil of Abies pindrow growing wild in Kashmir, India.

The essential oil composition of the leaves of Abies pindrow, growing in Kashmir, India, along with its antioxidant, antibacterial and anticancer activity is reported for the first time. Gas chromatography coupled with mass spectrometry (GC-MS) revealed the presence of 12 constituents, representing 99.9% of the total oil. The major constituents of the oil were limonene (38.9%), α-pinene (36.5%), ß-pinene (6.9%), and α-selinene (4.4%). The essential oil was dominated by the presence of monoterpene hydrocarbons (90.2%), followed by sesquiterpene hydrocarbons (6.761%), oxygenated sesquiterpenes (2.096%) and oxygenated monoterpenes (0.942%). The monoterpene rich essential oil was subjected to antibacterial activity against 4 Gram negative bacteria and 2 Gram positive bacteria at three different concentrations using Agar Well Diffusion Method taking streptomycin sulphate as reference. The oil displayed significant and broad spectrum antibacterial activity against different bacteria used. The minimum inhibitory concentration (MIC) of the active essential oil was determined using Agar Dilution Method. Highest antibacterial activity was shown by the oil against E. Coli (25 mm), and the lowest by Bacillus subtilis (14 mm) and Pseudomonas aeruginosa (14 mm). The oil was subjected to cytotoxic activity by MTT assay against human mammary carcinoma (MCF), human ductal breast epithelial tumour (T47D), human lung adeno-carcinoma epithelial (A549) and rat glial (C6) cell lines at three different concentrations. The results revealed significant sensitization of the cell lines with highest inhibition against human ductal breast epithelial cell line (51%) and the lowest against rat glial cell line (33%) at a concentartion of 50 µg/mL. The oil displayed a significant free radical scavenging activity with DPPH.