The antimicrobial potentiality of the methanolic extract of Phyllanthus amarus (Family: Euphorbiaceae) was studied against some drug resistant pathogenic bacterial strains by disc diffusion and agar dilution method. The extract showed significant concentration-dependent antibacterial activity particularly against gram-negative microbes. The study illustrated the claim of the usefulness of the plant in dysenteric and diarrheal infections and also suggested its use in fever. The antibacterial action was mainly due to the isolated phyllanthin.

A series of 7-chloro-2,3-disubstituted-4(3H)-quinazolinones (4a-j) were synthesized by the reaction of 3-amino-7-chloro-2-phenylquinazolin-4(3H)-one (3) with various amines in presence of formaldehyde. The starting material for the compounds was 2-amino-4-chloro benzoic acid. The structures of the compounds were characterized by IR, 1 H NMR, elemental analyses. Docking analysis of quinazolinone derivatives was done with DNA gyrase protein which was carried out by means of the AutoDockTools (ADT) v 1.5.4 and AutoDock v 4.2 programs. All compounds interacted with DNA gyrase protein. Preclinical evaluation of the compounds was ascertained by in silico toxicity, blood-brain barrier and drug like properties. All compounds were investigated for their antibacterial activity. Overall, compound (4b) showed better properties as a drug like candidate.

Dental aerosol disinfection should be considered as one of the most serious issues as they have very harmful microbial flora which could lead to multiple serious infections that commonly infect the operator, assistant, or the patients. Essential oils of nature like Lemon Grass have been proven recently to possess a greater action against gram-positive and gram-negative bacteria, Candida species, Streptococcus mutans, which are considered as the most prevalent oral microbial flora. Hence this study is aimed to determine the antibacterial effect of the Lemon Grass oil on dental aerosol bacteria around the dental unit during the dental procedure. Dental chairs with patients during treatment were included for the study where 5 agar plates with and without Lemon Grass oil application were placed in each chair at a distance of 1 – 1.5 m from the patient's mouth for 48hours and were incubated. Types of bacteria and its count were evaluated. Results showed significant contamination of bacteria in all plates without Lemon Grass oil application, whereas significant contamination was observed in all positive control plates. Lemon Grass represents an antibacterial source that can be as effective as modern medicine against pathogenic microorganisms especially the gram-positive and gram-negative bacteria which are usually present in dental aerosols.