Insights from the molecular mechanism of pyrazinamide to mutated pyrazinamidase linked to the pncA gene in clinical isolates of Mycobacterium tuberculosis.

This study aims to conduct a comprehensive molecular dynamics strategy to evaluate whether mutations found in pyrazinamide monoresistant (PZAMR) strains of Mycobacterium tuberculosis (MTB) can potentially reduce the effectiveness of pyrazinamide (PZA) for tuberculosis (TB) treatment. Five single point mutations of pyrazinamidase (PZAse), an enzyme which is responsible for the activation of prodrug PZA into pyrazinoic acid, found in MTB clinical isolates, namely His82Arg, Thr87Met, Ser66Pro, Ala171Val, and Pro62Leu, were analyzed by the dynamics simulations both in the apo state (unbound state) and in the PZA bound state. The results showed that the mutation of His82 to Arg, Thr87 to Met, and Ser66 to Pro in PZAse affects the coordination state of the Fe2+ ion, which is a cofactor required for enzyme activity. These mutations change the flexibility, stability, and fluctuation of His51, His57, and ASP49 amino acid residues around the Fe2+ ion, culminating in an unstable complex and dissociation of PZA from the PZAse binding site. However, mutations of Ala171 to Val and Pro62 to Leu were found to have no effect on the complex's stability. Based on the results, PZAse mutations of His82Arg, Thr87Met, and Ser66Pro culminated in weak binding affinity for PZA and caused significant structural deformations that led to PZA resistance. Future structural and functional studies, as well as investigations into other aspects of drug resistance in PZAse, will require experimental clarification.Communicated by Ramaswamy H. Sarma.

A New Diterpenoid of Indonesian Scoparia dulcis Linn: Isolation and Cytotoxic Activity against MCF-7 and T47D Cell Lines.

Scoparia dulcis Linn plays an important role in treatment because it contains active compounds that are proven to have a variety of activities, including cytotoxicity on various cancer cells. The objective of this study is to isolate and identify the cytotoxic compounds in the ethyl acetate fraction of Scoparia dulcis, observe cell cycle inhibition and induction of apoptosis in vitro, and carry out molecular studies using in silico studies. A new diterpene compound was isolated from the ethyl acetate fraction of Scoparia dulcis L. of Indonesian origin. Chromatographic methods were used to isolate the compound, spectroscopic methods were used to elucidate its structure, and these data were compared with those reported in the literature. The compound was tested for its cytotoxic activity against two breast cancer cells (MCF-7 and T47D). The results of the isolated compound showed a cytotoxic effect on MCF-7 and T47D breast cancer cells at IC50 70.56 ± 1.54 and <3.125 ± 0.43 µg/mL, respectively. The compound inhibited the growth of MCF-7 and T47D breast cancer cells and the accumulation of cells in the G1 phases, and it induced apoptosis. Based on a spectroscopic analysis, the isolated compound was identified as 2α-hydroxyscopadiol, which is a new diterpenoid. A docking study revealed that the isolate's hydroxyl groups are essential for interacting with crucial residues on the active sites of the ER and PR and caspase-9. The isolate inhibits ER and PR activity with binding energies of -8.2 kcal/mol and -7.3 kcal/mol, respectively. In addition, the isolate was also able to induce apoptosis through the activation of the caspase-9 pathway with an affinity of -9.0 kcal/mol. In conclusion, the isolated compound from S. dulcis demonstrated anticancer activity based on in vitro and in silico studies.

Antibacterial Potency of an Active Compound from Sansevieria trifasciata Prain: An Integrated In Vitro and In Silico Study.

Sansevieria trifasciata Prain holds great potential as a valuable asset in pharmaceutical development. In this study, our focus is to explore and assess the antibacterial activity of various components derived from this plant, including extracts, fractions, subfractions, and isolates, explicitly targeting two common bacteria: Escherichia coli and Streptococcus aureus. The isolated compound, identified as a derivative pyridone alkaloid (5-methyl-11-(2-oxopyridin-1(2H)-yl)undecaneperoxoicacid), demonstrates notable antibacterial effects. The extracts, fractions, subfractions, and isolates reveal significant bacterial growth reductions (p < 0.05). The minimum inhibitory concentration (MIC) values for Escherichia coli were 1.95 ppm, 3.9 ppm, 15.62 ppm, and 7.81 ppm, respectively, while the MIC values for Streptococcus aureus were 1.95 ppm, 1.95 ppm, 15.62 ppm, and 7.81 ppm, respectively. Computational analysis showed the isolates' interaction with key residues on the active site of ß-ketoacyl-ACP synthase from Escherichia coli and TyrRS from Streptococcus aureus. The findings indicate that the isolates exhibit a strong affinity for specific residues, including His333, Cys163, and Phe392 in ß-ketoacyl-ACP synthase, as well as Arg88, His117, Glu160, and Gln213 in TyrRS. Comparative energy calculations using MMPBSA demonstrate the isolates' favorable binding energy (-104,101 kJ/mol for ß-ketoacyl-ACP synthase and -81,060 kJ/mol for TyrRS) compared to ciprofloxacin. The elucidated antibacterial activity and molecular interactions of the isolates present valuable knowledge for future in vitro studies, facilitating the development of novel antibacterial agents targeting diverse bacterial strains.

Unrevealing the Potential of Sansevieria trifasciata Prain Fraction for the Treatment of Androgenetic Alopecia by Inhibiting Androgen Receptors Based on LC-MS/MS Analysis, and In-Silico Studies.

Androgenetic Alopecia (AGA) occurs due to over-response to androgens causing severe hair loss on the scalp, and requires the development of new and efficient drugs to treat this condition. This study explores and identifies secondary metabolites from Sansevieriatrifasciata Prain using the LC-MS/MS and in-silico method. The inhibitory activity of bioactive compounds from S. trifasciata Prain against androgen receptors (PDB ID: 4K7A) was evaluated molecularly using docking and dynamics studies by comparing their binding energies, interactions, and stability with minoxidil. The results of the LC-MS/MS analysis identified Methyl pyrophaeophorbide A (1), Oliveramine (2), (2S)-3', 4'-Methylenedioxy-5, 7-dimethoxyflavane (3), 1-Acetyl-ß-carboline (4), Digiprolactone (5), Trichosanic acid (6) and Methyl gallate (7) from the leaves subfraction of this plant. Three alkaloid compounds (compounds 1, 3, and 4), and one flavonoid (compound 2), had lower docking scores of -7.0, -5.8, -5.2, and -6.3 kcal/mol, respectively. The prediction of binding energy using the MM-PBSA approach ensured that the potency of the four compounds was better than minoxidil, with energies of -66.13, -59.36, -40.39, and -40.25 kJ/mol for compounds 1, 3, 2, and 4, respectively. The dynamics simulation shows the stability of compound 1 based on the trajectory analysis for the 100 ns simulation. This research succeeded in identifying the compound and assessing the anti-alopecia activity of Sansevieria trifasciata Prain. Seven compounds were identified as new compounds never reported in Sansevieria trifasciata Prain. Four compounds were predicted to have better anti-alopecia activity than minoxidil in inhibiting androgen receptors through an in silico approach.