Isolation of Cp*Co -Alkenyl Intermediate in Efficient Cobalt-Catalyzed C-H Alkenylation with Alkynes.

A general and efficient procedure for C-H alkenylation of arenes with a broad substrate scope catalyzed by Cp*Co was demonstrated with alkynes. A highly selective mono-alkenylation and sequential bis-C-H bond functionalization was displayed to exemplify the versatility of the cobalt catalyst. Isolation of cationic Cp*Co -alkenyl intermediate was achieved under identical catalytic conditions to further establish the proposed pathway.

Cp*Co -Catalyzed Bis-isoquinolone Synthesis by C-H Annulation of Arylamide with 1,3-Diyne.

Cp*Co -catalyzed highly regioselective mono- and bis-annulation of arylamides with 1,3-diynes using N-OMe as an internal oxidant is demonstrated. This atom-economical transformation does not require any external oxidant and tolerates many functional groups. Various symmetrical and unsymmetrical heterocycles (homo and hetero) are accessed with predictable regio- and chemoselectivity.

Dehydrative Cp*Co(III)-Catalyzed C-H Bond Allenylation.

An efficient, unprecedented reactivity of Cp*Co(III) for the synthesis of tetrasubstituted allenes under mild conditions is disclosed. Electron-rich and highly nucleophilic cobalt facilitates the dehydrative C-H bond allenylation directly from propargylic alcohols without any derivatization. The reaction proceeds via reversible cyclometalation followed by alcohol-directed regioselective alkyne insertion and β-hydroxy elimination to provide the tetrasubstituted allenes.

Long-term outbreak of & third generation cephalosporin use in a neonatal intensive care unit in north India.

Background & Objectives: The indiscriminate use of third generation cephalosporin has contributed to the emergence and widespread dissemination of extended spectrum β lactamases (ESBL) genes in Klebsiella pneumoniae. This study was undertaken to elaborate the genetic behaviour of ESBL - producing K. pneumoniae isolates in the neonatal intensive care unit (NICU) of a tertiary care hospital in north India causing successive outbreaks in context with empirical third generation cephalosporin use.

Iron-Catalyzed Sustainable Synthesis of Pyrrole.

Efficient, sustainable, highly regiospecific substituted pyrroles were synthesized using a well-defined, air stable, molecular iron(0) complex. The developed methodology is broadly applicable and tolerates a variety of functional groups. C-2, C-3, and C-2 & C-4 substituted pyrroles were synthesized in good yield.

Cp*Co(III) -Catalyzed C(sp(3) )-H Bond Amidation of 8-Methylquinoline.

An efficient and external oxidant-free, Cp*Co(III) -catalyzed C(sp(3) )-H bond amidation of 8-methylquinoline, using oxazolone as an efficient amidating agent, is reported for the first time under mild conditions. The reaction is selective and tolerates a variety of functional groups. Based on previous reports and experimental results, the deprotonation pathway proceeds through an external base-assisted concerted metalation and deprotonation process.

Cobalt(iii) catalyzed C-8 selective C-H and C-O coupling of quinoline N-oxide with internal alkynes via C-H activation and oxygen atom transfer.

An efficient, scalable, atom-economical, regio-selective air stable Cp*Co(iii) catalyzed C-H and C-O coupling via a C-H activation/oxygen atom transfer reaction of quinoline N-oxide and an internal alkyne is reported. Such a catalytic transformation is witnessed for the first time with a cobalt catalyst and using N-oxide as a traceless directing group, in contrast to the existing literature. The developed synthetic methodology is straightforward and possesses various functional group tolerances, including heterocycles.

Cobalt(III)-Catalyzed Dehydrative [4+2] Annulation of Oxime with Alkyne by C-H and N-OH Activation.

Efficient, scalable cobalt-catalyzed redox-neutral [4+2] annulation of readily available oximes and alkyne is reported. The developed synthetic methodology is widely applicable and tolerates various functional groups including heterocycles. A stable Cp*Co(III) neutral complex is employed as the catalyst for this redox-neutral [4+2] annulation reaction, which progresses smoothly by way of a reversible cyclometallation without any external oxidizing agent, and produces only water as the side product.

Genetic acquisition of NDM gene offers sustainability among clinical isolates of Pseudomonas aeruginosa in clinical settings.

New Delhi metallo β-lactamases are one of the most significant emerging resistance determinants towards carbapenem drugs. Their persistence and adaptability often depends on their genetic environment and linkage. This study reports a unique and novel arrangement of blaNDM-1 gene within clinical isolates of Pseudomonas aeruginosa from a tertiary referral hospital in north India.

Genetic linkage of blaNDM among nosocomial isolates of Acinetobacter baumannii from a tertiary referral hospital in northern India.

The aim of this study was to evaluate the emergence of blaNDM-1 among clinical isolates of Acinetobacter baumannii isolated from a north Indian tertiary care hospital and to assess the gene cassettes and resistance determinants located within them. In total, 74 A. baumannii were screened for MBL production by the imipenem-EDTA method and were characterised for antibiotic sensitivity.

Diagnostic utility of combination of inducer and inhibitor based assay in detection of Pseudomonas aeruginosa producing AmpC β-lactamase.

The diagnostic utility of inducer and inhibitor based assays among 214 AmpC positive isolates of Pseudomonas aeruginosa were evaluated. Of different methods, combination of ceftazidime-imipenem antagonism and boronic acid inhibition tests came up with maximum sensitivity (76%) and specificity (100%). This combination showed reliability for both inducible and non-inducible AmpC producers.

Evaluation of the performance of nitrate reductase assay for rapid drug-susceptibility testing of mycobacterium tuberculosis in north India.

The objective of the study was to evaluate the performance of nitrate reductase assay (NRA) as a rapid, reliable and inexpensive method for drug-susceptibility testing (DST) of Mycobacterium tuberculosis against first-line antitubercular drugs, such as rifampicin (RIF), isoniazid (INH), streptomycin (STR), and ethambutol (EMB). In total, 286 isolates were subjected to test by proportion method (PM) and NRA. By comparing the results of NRA with those of the gold standard PM, sensitivities and specificities were 98.

Presence of different beta-lactamase classes among clinical isolates of Pseudomonas aeruginosa expressing AmpC beta-lactamase enzyme.

Introduction: Infections caused by Pseudomonas aeruginosa are difficult to treat as the majority of isolates exhibit varying degrees of beta-lactamase mediated resistance to most of the beta-lactam antibiotics. It is also not unusual to find a single isolate that expresses multiple beta-lactamase enzymes, further complicating the treatment options. Thus the present study was designed to investigate the coexistence of different beta-lactamase enzymes in clinical isolates of P.

Compararative evaluation of rK9, rK26 and rK39 antigens in the serodiagnosis of Indian visceral leishmaniasis.

Background: This study was designed for comparative evaluation of two relatively newer recombinant hydrophilic antigens, rK9 and rK26 of Leishmania chagasi along with rK39 (a 39-aminoacid-repetitive immunodominant B-cell epitope of kinesin-related antigen from L. chagasi) and crude soluble antigen (CSA) for the serodiagnosis of Indian visceral leishmaniasis (VL) patients by quantitative ELISA.

Methodology: In the present study a total of 80 subjects comprising of 55 confirmed VL cases and 25 endemic controls (EC) were subjected to ELISA using four different antigens, namely rK9, rK26, rK39 and CSA (derived from Leishmania donovani promastigotes).

Assessment of different tests to detect methicillin resistant Staphylococcus aureus.

The heterogeneous expression of methicillin resistance in Staphylococcus aureus affects the efficiency of tests available to detect it. Not all laboratories have access to accurate molecular tests used for this purpose. This study compares the performances of four phenotypic tests used to detect methicillin resistant S.

Molecular typing of clinical Staphylococcus aureus isolates from northern India using coagulase gene PCR-RFLP.

Molecular typing of total 84 Staphylococcus aureus clinical isolates was performed using coagulase gene PCR. Out of 84 S. aureus strains total 33 different types of S.

Role of beta-lactamase inhibitors in enterobacterial isolates producing extended-spectrum beta-lactamases.

Objectives: To determine the in vitro activity of beta-lactamase inhibitors (clavulanic acid and sulbactam) in combination with third-generation cephalosporins and monobactam against extended-spectrum beta-lactamase (ESBL)-producing members of the Enterobacteriaceae family.

Methods: A total of 361 ESBL-producing enterobacterial isolates obtained from patients of a university hospital were screened for the status of co-production of AmpC beta-lactamase. These strains were further subjected to an MIC study using third-generation cephalosporins and monobactam, and reductions were observed after combining with beta-lactamase inhibitors at a fixed concentration of 4 mg/L.

Emergence of vancomycin resistant Staphylococcus aureus (VRSA) from a tertiary care hospital from northern part of India.

Background: Glycopeptides such as vancomycin are frequently the antibiotics of choice for the treatment of infections caused by methicillin resistant Staphylococcus aureus (MRSA). For the last 7 years incidence of vancomycin intermediate S. aureus and vancomycin resistant S.

Lymphocyte adenosine deaminase activity in children with idiopathic nephrotic syndrome.

Adenosine deaminase (ADA) activity, as a marker of cell-mediated immunity, was evaluated in the serum (S-ADA) and lymphocytes (L-ADA) of 47 children with idiopathic nephrotic syndrome, and 23 healthy controls. The mean S-ADA and L-ADA levels were significantly raised in active nephrotic syndrome (ANS) and in its sub-groups in comparison with controls. The ADA activity was significantly more elevated in relapsers than for the first attack of nephrotic patients, and the frequent relapsers had the highest enzymatic levels both in serum as well as lymphocytes.