U. Suryanarayana Murty

Antimicrobial constituents from the rhizomes of Rheum emodi.

The bioassay-guided chemical examination of the rhizomes of R. emodi resulted in the isolation of two new oxanthrone esters, revandchinone-1, revandchinone-2, a new anthraquinone ether revandchinone-3 and a new oxanthrone ether, revandchinone-4. Their structures were established based on spectroscopic and degradative evidence. Occurrence of oxanthrone ether is reported for the first time. The anti bacterial and anti fungal activity of the isolates is studied.

MICROWAVE ASSISTED SYNTHESIS AND ΑΝΤΙMICROBIAL ACTIVITY OF 2,2-DIMETHYL CHROMENES

2,2-Dimethyl chromenes (lb-9b) were prepared from corresponding propargyl ethers (la-9a) under microwave conditions in high yields and anti microbial activity of compounds (6b & 7b) is reported.

Deorphanization of Malonyl CoA:ACP Transacylase Drug Target in Plasmodium falciparum (PfFabD) Using Bacterial Antagonists: A ‘Piggyback’ Approach for Antimalarial Drug Discovery

Quest for new drug targets in Plasmodium sp. has underscored malonyl CoA:ACP transacylase (PfFabD) of fatty acid biosynthetic pathway in apicoplast. In this study, a “piggyback” approach was employed for the receptor deorphanization using inhibitors of bacterial FabD enzymes. Due to the lack of crystal structure, theoretical model was constructed using the structural details of homologous enzymes. Sequence and structure analysis has localized the presence of two conserved pentapeptide motifs: GQGXG and GXSXG and five key invariant residues viz., Gln109, Ser193, Arg218, His305 and Gln354 characteristic of FabD enzyme. Active site mapping of PfFabD using substrate molecules has disclosed the spatial arrangement of key residues in the cavity. As structurally similar molecules exhibit similar biological activities, signature pharmacophore fingerprints of FabD antagonists were generated using 0D‐3D descriptors for molecular similarity‐based cluster analysis and to correlate with their binding profiles. It was observed that antagonists showing good geometrical fitness score were grouped in cluster‐1, whereas those exhibiting high binding affinities in cluster‐2. This study proves important to shed light on the active site environment to reveal the hotspot for binding with higher affinity and to narrow down the virtual screening process by searching for close neighbors of the active compounds.

Antimicrobial efficacy of secondary metabolites from Glomerella cingulata

Fungi are known to produce a vast array of secondary metabolites that are gaining importance for their biotechnological applications. Early reports suggest that G. cingulata has the capability to transform many compounds by various enzymatic actions. Therefore, the focus of this study was to determine the antibacterial and antifungal activity of crude ethyl acetate extract of G. cingulata using agar cup bioassay method. Crude extract of G. cingulata exhibited remarkable antifungal activity against Rhizopus oryzae, Chrysoporium tropicum and Beauveria bassiana but no antifungal activity was found against Alternaria tenuissima and Aspergillus niger at any concentrations. The crude extract presented no antibacterial activity against Gram positive and Gram negative bacteria at any concentration.

Filaria Monitoring Visualization System: A New Dimension for Integrated Control of Lymphatic Filariasis

The nineteenth and twentieth centuries had been exciting times for investigation of transmissible diseases. Pathogens were cultivated from diseased humans and animals, vaccines were developed and immunity studies carried out for use in diagnosis and prevention of disease. Koch’s postulates were promulgated and used to prove that various microorganisms were the cause of diseases. Quarantine was practiced to prevent the spread of diseases that were transmitted directly from one person to another. Antibiotics and other chemotherapeutic agents have been improved to suppress many serious diseases. Despite these successes, failures lurked in the background. The dark shadow was cast on many vector-borne diseases, which had complex epidemiology and reservoirs in various animals other than humans, and flared up unpredictably. The vector-borne agents include the whole spectrum of infectious agents: viruses, rickettsia, bacteria, protists and helminths. Except for the blood flukes (Schistosoma spp.), most of the disease agents were found to be transmitted by arthropods viz., lice, bugs, mosquitoes, black flies, midges, sand flies, ticks and mites. Among all the blood-feeding group of insects, mosquitoes are by far the most important from the standpoint of human health, responsible for transmission of many pathogens that cause mortality and morbidity.

Integrated Disease Management of Japanese Encephalitis in India

Mosquitoes are a well-known group of insects (Order: Diptera, Family: Culicidae) that annoy man and transmit several human diseases. Mosquitoes are the only vectors of pathogens causing malaria, filariasis, Japanese encephalitis (JE), dengue, yellow fever, chikungunya and several other diseases in humans. It was the nineteenth and early twentieth centuries when scientists started to thoroughly investigate transmissible diseases. As early as 1848, Joseph Nott first proposed that yellow fever and malaria were transmitted by mosquitoes. In 1878, Manson showed that the mosquito Culex quinquefasciatus transmitted roundworm to humans. Towards the end of the nineteenth century, scientists discovered a number of vector-borne diseases, which were found to be transmitted by arthropods. In 1897, Sir Ronald Ross showed that malaria was transmitted by mosquitoes. Today four species of human malarial parasites, two species of filarial parasites and a number of arboviruses remain as the principal causes of human mortality and morbidity in the world. Approximately 100 of the arboviruses can infect humans, and about 40 are known to infect livestock. Human arboviral diseases are classified clinically by the predominant syndrome caused by them as encephalitis, febrile illness and haemorrhagic fever. Japanese encephalitis virus (JEV), a flavivirus, represents the most significant aetiology of arboviral encephalitis worldwide.