Biomedical subjects

Asha Chaubey

Publications and source records attributed to Asha Chaubey.

7 recordsLinked to original sources

PubMed2026

Secondary metabolite profiling of rare Micromonospora spp. from cold desert of NW Himalayas via multi-omics analysis.

INTRODUCTION: The genus Micromonospora is a prolific producer of specialized metabolites with pharmacological and agronomic relevance. Natural products derived from the genus Micromonospora have a distinctive chemical diversity and enormous therapeutic potential, thus represent a potential source for drugs and drug leads. OBJECTIVE: To explore the biosynthetic potential of four Micromonospora strains isolated from cold desert of NW Himalayas through genome mining and to correlate predicted biosynthetic gene clusters with chemical features detected by untargeted LC-HRMS metabolomics. METHOD: High-quality genomes were annotated for BGCs and matched against untargeted LC-HRMS features (peak picking, alignment, and annotation to chemical classes). Each isolate was grown in triplicate, and fermented broth was pooled for further metabolomic studies. RESULTS: By integrating genomic and metabolomic approaches, specialized biosynthetic gene clusters and strain-based putative metabolite classes were identified. LRS1 showed elevated xanthines (RiPP/siderophore), LRS3 had phenolic glycosides (hybrid PKS/NRPS), LRS4 showed 70-fold hydroxycinnamate enrichment (Type II PKS), and LRS5 displayed p-benzoquinone enrichment (Type III PKS). The metabolite profile of each strain aligned with its predicted biosynthetic gene cluster composition. CONCLUSION: Under a single growth regime, each Micromonospora strain exhibits a distinct metabolomic profile. This metabologenomics workflow can be further explored to isolate specialized metabolites with potential therapeutic and agricultural value.

Micromonospora↗

PubMed2006

Arthrobacter sp. lipase immobilization for improvement in stability and enantioselectivity.

Arthrobacter sp. lipase (ABL, MTCC no. 5125) is being recognized as an efficient enzyme for the resolution of drugs and their intermediates. The immobilization of ABL on various matrices for its enantioselectivity, stability, and reusability has been studied. Immobilization by covalent bonding on sepharose and silica afforded a maximum of 380 and 40 IU/g activity, respectively, whereas sol-gel entrapment provided a maximum of 150 IU/g activity in dry powder. The immobilized enzyme displayed excellent stability in the pH range of 4-10 and even at higher temperature, i.e., 50-60 degrees C, compared to free enzyme, which is unstable under extreme conditions. The resolution of racemic auxiliaries like 1-phenyl ethanol and an intermediate of antidepressant drug fluoxetine, i.e., ethyl 3-hydroxy-3-phenylpropanoate alkyl acylates, provided exclusively R-(+) products ( approximately 99% ee, E=646 and 473), compared to cell free extract/whole cells which gave a product with approximately 96% ee (E=106 and 150). The repeated use (ten times) of covalently immobilized and entrapped ABL resulted in no loss in activity, thus demonstrating its prospects for commercial applications.

Arthrobacter↗

PubMed2005

Application of electrochemically prepared polypyrrole-polyvinyl sulphonate films to DNA biosensor.

Double stranded calf thymus deoxyribonucleic acid (DNA) was physisorbed onto polypyrrole-polyvinyl sulphonate (PPY-PVS) films electrochemically deposited onto indium-tin-oxide (ITO) coated glass plates. These DNA immobilized PPY-PVS films optimized for various conditions, such as polymerization potential, pH of buffer, DNA concentration and scan rate were characterized using Fourier-transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM) and cyclic voltammetry (CV) techniques, respectively. The amperometric response studies of these DNA/PPY-PVS electrodes were carried out as a function of 2-aminoantharcene (2-AA, 0.01-20 ppm) and o-chlorophenol (OCP, 0.1-30 ppm) concentration, respectively at 25 degrees C. The observed amperometric current arising due to oxidation of guanine in the DNA/PPY-PVS films decreased linearly with the increase in the concentration of 2-AA and OCP. It has been revealed that 10 ppm of 2-AA is sufficient to reduce the observed guanine oxidation peak current by approximately -95+/-10% as compared to the reported values. A 25 ppm of OCP was capable enough to reduce the guanine oxidation current to zero. These DNA/PPY-PVS electrodes were found to have a shelf life of about 4 months when stored at 25 degrees C.

Anthracenes↗

PubMed2004

Poly-3-hexyl thiophene Langmuir-Blodgett films for application to glucose biosensor.

Langmuir-Blodgett films of poly(3-hexyl thiophene) have been prepared by simultaneous entrapment of glucose oxidase and transferred onto the indium-tin-oxide coated glass plates. The films have been characterized by FTIR spectroscopy and detailed response studies have been performed with respect to glucose concentration, temperature, and storage time. These P3HT/SA/GOX electrodes have been utilized for glucose estimation from 100-500 mg/dL by amperometric method. The electrodes have been found to have sensitivity of 0.75 nA/mg/dL detection limit of 50 mg/dL and shelf life of about 75 days at 4 degrees C.

Biosensing Techniques↗

PubMed2003

Application of polyaniline/sol-gel derived tetraethylorthosilicate films to an amperometric lactate biosensor.

The electrochemical entrapment of polyaniline (PANI) onto sol-gel derived tetraethylorthosilicate (TEOS) films deposited onto indium-tin-oxide (ITO) coated glass has been utilized for immobilization of lactate dehydrogenase (LDH). The performance of these sol-gel/PANI/LDH electrodes has been investigated as a function of the lactate concentration, applied potential, pH of the medium and interferents. The amperometric response of the electrodes under optimum conditions exhibited a linear relationship from 1 mM to 4 mM. An attempt has been made to extend the linearity up to 10 mM for lactate by coating an external layer of polyvinyl chloride (PVC) over the sol-gel/PANI/LDH electrodes with a correlation coefficient of 0.89. These sol-gel/PANI/LDH electrodes have a response time of about 60 s, a shelf life of about 8 weeks at 0-4 degrees C and have implications in a lactate biosensor.

Aniline Compounds↗

PubMed2002

Application of conducting polymers to biosensors.

Recently, conducting polymers have attracted much interest in the development of biosensors. The electrically conducting polymers are known to possess numerous features, which allow them to act as excellent materials for immobilization of biomolecules and rapid electron transfer for the fabrication of efficient biosensors. In the present review an attempt has been made to describe the salient features of conducting polymers and their wide applications in health care, food industries, environmental monitoring etc.

Biosensing Techniques↗

PubMed2002

Mediated biosensors.

Direct electrode transfer between enzyme and the electrode in biosensors requires high efficiency therefore, synthetic replacement for oxygen led to the development of enzyme mediators and modified electrodes in biosensor fabrication. In this context, a number of electron acceptors and complexes have been used. Present paper gives an overview of various methodologies involved in the mediated systems, their merits and wide applications.

Biosensing Techniques↗