Shikha Singh

Bio: Shikha Singh is an academic researcher from Bennett University. The author has contributed to research in topics: Chemistry & Castor oil. The author has an hindex of 1, co-authored 4 publications receiving 1 citations.

Current challenges and advancements towards discovery and resistance of antibiotics

Abstract: Antibiotics discovery has always played an important role in curing several outpacing resistances. Effective treatments for many of the common infectious diseases have now been possible. The question came up with the nature of infectious diseases, which lead to the discovery of antibiotics and setting up levels along with the discovery of synthetic models. The discoveries in the field of antibiotics have increased the average life expectancy of humans. However, the antibiotic resistance developed by microorganisms is still a matter of concern. The sensitivity and resistivity of bacteria is the most important factor to be discussed while talking about antibiotics. In this review, the era of antibiotic discovery along with recent advances in discovery/development and manufacturing, mechanism of action, and cellular targets of antibiotics along with the major components like sensitivity and antibiotic resistance have been discussed.

Therapeutic enzymes: Discoveries, production and applications

Abstract: Enzymes today play a predominant role in the pharmaceutical industries due to their ability to efficiently and selectively catalyze biochemical reactions in living systems. Since the enzymes have such a considerable impact on human health, the enzyme-based drugs are progressively becoming a research focus, in recent times. Most of these therapeutic enzymes are produced industrially by employing the various types of fermentation techniques, using a suitable expression system which includes a microbial strain (bacteria, yeast, fungi, etc), plant or animal cell culture, and genetically engineered organisms. The advancements in the fields of recombinant DNA technology, protein engineering, material science, enzyme immobilization, and nanotechnology has provided an astounding platform for the development of enzymatic drugs that have varied applications in the treatment of a range of diseases. These enzymes may be broadly classified into four categories which are: enzymes involved in fibrinolysis, cancer treatment, enzyme replacement therapies, and treatment of other rare and common diseases. Several approaches like rational designing, PEGylation, and glycoengineering have made it possible to increase the half-life, stability, and solubility of these enzymes, making them suitable for administration. The discoveries and furtherance with which the therapeutic enzymes are being produced, possessing enhanced stability and biocatalytic activity, have led to new opportunities and prompted new open doors in the field of medication for both therapeutic and analytical purposes. In this review, we have highlighted the function, application, production and purification techniques, enzyme formulations, and stability and activity advancements of different therapeutic enzymes with special emphasis on l -asparaginase, streptokinase, collagenase, and uricase. It is an attempt to evaluate the current discoveries and advancements in therapeutic enzymes to provide a scope of improvement for the existing enzymes and help overcome the challenges to further develop new ones.

A comprehensive review of castor oil‐derived renewable and sustainable industrial products

Abstract: Castor oil is one important raw material that could serve as a renewable feedstock for industries in the age of exhausting fossil fuels. The chemical composition of oil and the structure of hydroxyl fatty acid are responsible for its unique physicochemical properties. The oil has diverse applications from pharmaceuticals to polyamides, from the manufacturing of ski boots to durable frames, and from lubricants to laxatives. The present review gives an insight into the physicochemical properties of castor oil and its application. The oil is used for the production of a great variety of its derivatives. Out of many derivatives of castor oil, four are produced and utilized at a larger scale. The names of the four derivates are ricinoleic acid, sebacic acid, undecylenic acid, and γ‐decalactone. The review will aim toward an insight into the evolved techniques for the manufacturing of these derivatives of castor oil, the biotechnological route of production, and metabolic engineering approaches. Though the industrial significance of castor oil and its derivatives had been known for ages, methods for their production are continuously changing.

Arsenic removal technologies: field applications and sustainability

Abstract: Arsenic is a metalloid and the major cause of concern for the pollution in drinking water and soil. The toxicity issues with the health, while its consumption more than the WHO permissible limit is the major reason for the death of the people, due to contaminated drinking water consumption. With respect to toxicity arsenic(III) form is considered more dangerous. Various methods and technologies have been developed against this global problem. The physical, chemical, and biological remediation technologies were developed to reduce the hazardous effects. The rock mining, volcano eruption, and contaminated soil leaching are the major sources of the groundwater contamination. Biobased remediation methods are focusing these days due to their less side effect and nontoxic nature of the treatment process such as biosorption, biomethylation, and bioaugmentation. This chapter describes the forms of arsenic, their causes, health effects, case study, different types of treatment technologies, and their use in household and commercial level. New advancements based on nanolevel treatment technologies are coming in future to completely remove the arsenic from consumable water and can also provide the benchmarks to develop more accurate technological advancement in removing total contaminations from each kind of source.

Pesticides in water

Abstract: Pesticides are chemical compounds that are widely used to control the pest population. More than 1000 pesticides are used all over the world. Each of them has unique properties and noxious effects. Approximately 5.6 billion pounds of pesticides are used every year across the globe. Only 0.1% of them reach the targeted organisms (pests). They cannot be held within the boundaries of the farms. Irrigation and rainfall increase the risk of leaching and contaminating ground and surface water. The factors like solubility in water, mobility in soil, and application rate determine the infiltration of pesticides into water. The presence of pesticides in drinking water poses life-threatening risks as they are a dangerous environmental pollutant. Maximum permissible limits of pesticides and their residues are legally regulated in each country. Even at the levels considered safe, pesticides have caused a great loss to biodiversity. Therefore their level in the environment needs continuous monitoring. The present work examines the different types of pesticides and their toxic effects on the different organisms in detail. The analysis of the pesticides is also challenging as sample preparation is tedious, and the presence of target analytes is at low levels. This chapter also explores different techniques for the preparation of the sample and their analysis. Different measures of control have also been studied.

Biosorption studies on powder of stem of Acacia nilotica Removal of arsenic

Abstract: In present study a biomass derived from the stem of Acacia nilotica has been investigated to remove As ions from surface water samples of different origins (lake, canal and river). The effects of various parameters viz. pH, biosorbent dosage, contact time and temperature on the biosorption processes were systematically studied. Experimental data were modeled by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. It was observed that As biosorption best fitted to the Langmuir and Freundlich isotherms. The mean sorption energy (E) calculated from D-R model, indicated physico-chemical biosorption. Study of thermodynamic parameters revealed the endothermic, spontaneous and feasible nature of biosorption process. The pseudo-second-order rate equation described better the kinetics of As biosorption with good correlation coefficients than pseudo-first-order equation. The biomass of A. nilotica was found to be effective for the removal of As with 95% sorption efficiency at a concentration of <200 microg/L of As solution, and thus uptake capacity is 50.8 mg As/g of biomass. The A. nilotica biomass could be used as a low-cost biosorbent for As ion removal.

A review on synthetic account of 1,2,4-oxadiazoles as anti-infective agents

Abstract: Most of the currently marketed drugs consist of heterocyclic scaffolds containing nitrogen and or oxygen as heteroatoms in their structures. Several research groups have synthesized diversely substituted 1,2,4-oxadiazoles as anti-infective agents having anti-bacterial, anti-viral, anti-leishmanial, etc. activities. For the first time, the present review article will provide the coverage of synthetic account of 1,2,4-oxadiazoles as anti-infective agents along with their potential for SAR, activity potential, promising target for mode of action. The efforts have been made to provide the chemical intuitions to the reader to design new chemical entity with potential of anti-infective activity. This review will mark the impact as the valuable, comprehensive and pioneered work along with the library of synthetic strategies for the organic and medicinal chemists for further refinement of 1,2,4-oxadiazole as anti-infective agents.

Tools for Computational Design and High-Throughput Screening of Therapeutic Enzymes.

Abstract: Therapeutic enzymes are valuable biopharmaceuticals in various biomedical applications. They have been successfully applied for fibrinolysis, cancer treatment, enzyme replacement therapies, and the treatment of rare diseases. Still, there is a permanent demand to find new or better therapeutic enzymes, which would be sufficiently soluble, stable, and active to meet specific medical needs. Here, we highlight the benefits of coupling computational approaches with high-throughput experimental technologies, which significantly accelerate the identification and engineering of catalytic therapeutic agents. New enzymes can be identified in genomic and metagenomic databases, which grow thanks to next-generation sequencing technologies exponentially. Computational design and machine learning methods are being developed to improve catalytically potent enzymes and predict their properties to guide the selection of target enzymes. High-throughput experimental pipelines, increasingly relying on microfluidics, ensure functional screening and biochemical characterization of target enzymes to reach efficient therapeutic enzymes.

Electrochemical-enhanced Fe3O4/biochar activates peroxymonosulfate (E/nano-Fe3O4/BC/PMS) for degradation of oxytetracycline.

Abstract: To find cost-effective and environmentally friendly free radical activators to stimulate peroxymonosulfate (PMS) oxidative degradation of organic pollutants, nano-Fe3O4/biochar (BC) composites were prepared and characterized in this work to examine their effectiveness in stimulating PMS oxidative degradation of Oxytetracycline (OTC) in water enhanced with electrochemical degradation. When the mass ratio of nano-Fe3O4 to BC is 1:1, the catalyst nano-Fe3O4/BC exhibits the most obvious degradation effect on OTC. After 4 h of degradation, the OTC concentrations were reduced from 20 to 2.65 mg L−1, while treated with a single nano-Fe3O4 and a single BC are reduced by only 67.7% and 61.8%. Anions HCO3− and H2PO4− significantly inhibit OTC degradation, and HCO3− has a stronger inhibitory effect than H2PO4−, while Cl− and NO3− can promote OTC degradation. Quenching test and electron spin paramagnetic resonance (EPR) detection showed that singlet oxygen (1O2) was the main active species in the degradation process, followed by hydroxyl radical (·OH). When reused for the third time, the removal rate of OTC by nano-Fe3O4/BC composites with mass ratios of 1:4, 1:2 and 1:1 was still more than 70%. Therefore, the nano-Fe3O4/BC composite is a promising PMS activator, which can realize the rapid oxidative degradation of OTC.

CuO nanosheets incorporated scrap steel slag coupled with persulfate catalysts for high-efficient degradation of sulfonamide from water.

Abstract: A highly efficient and magnetically recoverable persulfate (PS) catalyst was prepared for the removal of sulfonamide (SMD) from wastewater, which is difficult to be degraded by the conventional biological treatment. In this study, the scrap steel slag (SSS) was used as supporting carrier and the CuO nanosheet was incorporated on the surface of SSS. The optimal conditions were determined as follows: the dosage of CuO/SSS was 1 g L-1, the PS concentration was 4 mM and the optimal initial pH was 6.85. Under the optimal conditions, the maximum SMD removal efficiency of 80.29% was achieved within 30 min by using CuO/SSS + PS. In addition, the CuO/SSS + PS system had a wide pH range (5-9) and more than 60% removal efficiency of SMD could be obtained with the pH between 3 and 11. The mechanism based on the phase transformation of Cu(I/II), Cu(II/III) and Fe(II/III) was elucidated by using different analytical techniques, such as SEM, XRD, XPS, BET, FTIR, VSM characterization and free radical analysis. This study provided a new pathway for the SSS resource utilization and the effective degradation of SMD from the refractory wastewater by using CuO/SSS catalyst coupled with PS system.