Dengue virus belongs to the virus family Flaviviridae. Dengue hemorrhagic disease caused by dengue virus is a public health problem worldwide. The viral non structural 2B and 3 (NS2B-NS3) protease complex is crucial for virus replication and hence, it is considered to be a good anti-viral target. Leaf extracts from Carica papaya is generally prescribed for patients with dengue fever, but there are no scientific evidences for its anti-dengue activity; hence we intended to investigate the anti-viral activity of compounds present in the leaves of Carica papaya against dengue 2 virus (DENV-2). We analysed the anti-dengue activities of the extracts from Carica papaya by using bioinformatics tools. Interestingly, we find the flavonoid quercetin with highest binding energy against NS2B-NS3 protease which is evident by the formation of six hydrogen bonds with the amino acid residues at the binding site of the receptor. Our results suggest that the flavonoids from Carica papaya have significant anti-dengue activities.AbbreviationsADME - Absorption, distribution, metabolism and excretion, BBB - Blood brain barrier, CYP - Cytochrome P450, DENV - – Dengue virus, DHF - Dengue hemorrhagic fever, DSS - Dengue shock syndrome, GCMS - – Gas chromatography- Mass spectrometry, MOLCAD - Molecular Computer Aided Design, NS - Non structural, PDB - Protein data bank, PMF - Potential Mean Force.

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Upper respiratory tract infection (URTI) is an acute infection which involves the upper respiratory tract: nose, sinuses, tonsils and pharynx. URT infections are caused mainly by pathogenic bacteria like Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus. Conventionally, β-lactam antibiotics are used to treat URT infections. Penicillin binding proteins (PBPs) catalyze the cell wall synthesis in bacteria. β-Lactam antibiotics like Penicillin, Cephalosporins, Carbapenems and Monobactams inhibit bacterial cell wall synthesis by binding with PBPs. Pathogenic bacteria have efficiently evolved to resist these β-lactam antibiotics. New generation antibiotics are capable of inhibiting the action of PBP due to its new and peculiar structure. New generation antibiotics and Penicillin derivatives are selected in this study and virtually compared on the basis of interaction studies. 3-Dimensional (3D) interaction studies between Lactivicin, Cefuroxime, Cefadroxil, Ceftaroline, Ceftobiprole and Penicillin derivatives with PBPs of the above-mentioned bacteria are carried out. The aim of this study was to suggest a potent new generation molecule for further modification to increase the efficacy of the drug for the URTI.

AmpC β-lactamase is a cephalosporinase, which exhibits resistance against all existing β-lactam antibiotics except carbapenems. Their occurrence in many bacterial pathogens poses a threat to public health and is a growing concern in the medical world. The ampC gene is highly inducible in the presence of β-lactam antibiotics and can be expressed in high levels due to mutation. This inducible expression is regulated by several functional genes. Several studies on functional relationship of these genes and its resistance mechanisms are carried out but it still lacks comprehensible evidences. Thus, in our current study, we used computational gene networks to analyze ampC gene. Based on its interaction type, co-expression, Gene Ontology, and text mining, a functional interaction network is constructed. Around 247 functional genes in 15 different bacterial genus have a functional association with ampC gene. It is predicted that 19.8% ampD, 13.3% frdD, 8.5% gcvA, 2.4% ampR, and 55.7% of other functional partners are associated with ampC gene. Our present study provides a glimpse about the functional gene network of ampC gene and also provides the integrated evidence for ampC gene in regulating the β-lactamase production and its role in antibiotic resistance.

Aromatic-aromatic hydrogen bonds are important in many areas of chemistry, biology and materials science. In this study we have analyzed the roles played by the π-π interactions in interleukins (ILs) and tumor necrosis factor (TNF) proteins. Majority of π-π interacting residues are conserved in ILs and TNF proteins. The accessible surface area calculations in these proteins reveal that these interactions might be important in stabilizing the inner core regions of these proteins. In addition to π-π interactions, the aromatic residues also form π-networks in ILs and TNF proteins. The results obtained in the present study indicate that π-π interactions and π-π networks play important roles in the structural stability of ILs and TNF proteins.