Vijeta Sharma

Bio: Vijeta Sharma is an academic researcher from Shiv Nadar University. The author has contributed to research in topics: Plasmodium falciparum & Malaria. The author has an hindex of 7, co-authored 12 publications receiving 86 citations. Previous affiliations of Vijeta Sharma include Jawaharlal Nehru University.

Natural Product Inspired Novel Indole based Chiral Scaffold Kills Human Malaria Parasites via Ionic Imbalance Mediated Cell Death.

Abstract: Natural products offer an abundant source of diverse novel scaffolds that inspires development of next generation anti-malarials. With this vision, a library of scaffolds inspired by natural biologically active alkaloids was synthesized from chiral bicyclic lactams with steps/scaffold ratio of 1.7:1. On evaluation of library of scaffolds for their growth inhibitory effect against malaria parasite we found one scaffold with IC50 in low micro molar range. It inhibited parasite growth via disruption of Na+ homeostasis. P-type ATPase, PfATP4 is responsible for maintaining parasite Na+ homeostasis and is a good target for anti-malarials. Molecular docking with our scaffold showed that it fits well in the binding pocket of PfATP4. Moreover, inhibition of Na+-dependent ATPase activity by our potent scaffold suggests that it targets parasite by inhibiting PfATP4, leading to ionic imbalance. However how ionic imbalance attributes to parasite's death is unclear. We show that ionic imbalance caused by scaffold 7 induces autophagy that leads to onset of apoptosis in the parasite evident by the loss of mitochondrial membrane potential (ΔΨm) and DNA degradation. Our study provides a novel strategy for drug discovery and an insight into the molecular mechanism of ionic imbalance mediated death in malaria parasite.

Integrative natural medicine inspired graphene nanovehicle-benzoxazine derivatives as potent therapy for cancer.

Abstract: Natural products from medicinal plants have always attracted a lot of attention due to their diverse and interesting therapeutic properties. We have employed the principles of green chemistry involving isomerization, coupling and condensation reaction to synthesize a class of compounds derived from eugenol, a naturally occurring bioactive phytophenol. The compounds were characterized structurally by 1H-, 13C-NMR, FT-IR spectroscopy and mass spectrometry analysis. The purity of compounds was detected by HPLC. The synthesized compounds exhibited anti-cancer activity. A 10–12-fold enhancement in efficiency of drug molecules (~ 1 µM) was observed when delivered with graphene oxide (GO) as a nanovehicle. Our data suggest cell death via apoptosis in a dose-dependent manner due to increase in calcium levels in specific cancer cell lines. Interestingly, the benzoxazine derivatives of eugenol with GO nanoparticle exhibited enhanced therapeutic potential in cancer cells. In addition to anti-cancer effect, we also observed significant role of these derivatives on parasite suggesting its multi-pharmacological capability.

Prooxidant Activity of Polyphenols, Flavonoids, Anthocyanins and Carotenoids: Updated Review of Mechanisms and Catalyzing Metals.

Abstract: Natural antioxidants, including polyphenols, flavonoids, anthocyanins and carotenoids, play an important role in the treatment and prevention of a large number of diseases. However, studies indicate that natural antioxidants can act as prooxidants, which produce free radicals and cause DNA damage and mutagenesis. The prooxidant activity is typically catalyzed by metals, particularly transition metals such as Fe and Cu, present in biological systems. In this article, we aim to review new in vitro and in vivo evidence of the prooxidant activity of phenolics, flavonoids, anthocyanins and carotenoids. We highlight the role of catalyzing metals, including transition metals, non-transition metals and metalloids, in the prooxidant activity of natural antioxidants. Prooxidant structure-activity relationships of simple phenolics, flavonoids and anthocyanins and the role of cellular antioxidant defense, including endogenous antioxidant compounds and antioxidant enzymes, are also addressed in this review. In addition, we discuss the question, With respect to in vitro evidence of the prooxidant activity of antioxidants, can we translate this activity into biological systems and the human body? Copyright © 2016 John Wiley & Sons, Ltd.

Lycopene: Progress in microbial production

Abstract: Background Carotenoids are an important group of natural and liposoluble pigments found in plants and microorganisms, displaying yellow, orange or red color. They act as membrane-protective antioxidants which efficiently scavenge 1 O 2. . Lycopene is a red carotenoid with potential in alleviating chronic disease such as some types cancers and coronary heart disease, its production is from vegetable sources (e.g. tomatoes) and chemical synthesis; nonetheless, due to the increasing interest of this molecule, alternative methodologies to produce higher amounts have been developed. Scope and approach This review discusses the biotechnological and economic impact of the microbial production and recovery of lycopene as an alternative bioprocess to obtain this carotenoid. Key findings and conclusions Microbial production of lycopene can be promoted with the addition of inhibitors that prevent chain cyclization during the biosynthesis of β-carotene or genetic engineering; also, the optimization of culture medium and growth conditions of the microorganism can be performed. Actually, potential applications of lycopene imply that its biotechnological production has become increasingly necessary, and reports have described its production using metabolic engineering.

A critical review on multifunctional smart materials ‘nanographene’ emerging avenue: nano-imaging and biosensor applications

Abstract: Smart electronic materials ‘nanographene’ stated, its significant authentication has undergone massive improvements and has emerged as a ‘material of the century’ in materialize fields of ‘Chemical...

The Pictet-Spengler Reaction Updates Its Habits

Abstract: The Pictet-Spengler reaction (P-S) is one of the most direct, efficient, and variable synthetic method for the construction of privileged pharmacophores such as tetrahydro-isoquinolines (THIQs), tetrahydro-β-carbolines (THBCs), and polyheterocyclic frameworks. In the lustro (five-year period) following its centenary birthday, the P-S reaction did not exit the stage but it came up again on limelight with new features. This review focuses on the interesting results achieved in this period (2011-2015), analyzing the versatility of this reaction. Classic P-S was reported in the total synthesis of complex alkaloids, in combination with chiral catalysts as well as for the generation of libraries of compounds in medicinal chemistry. The P-S has been used also in tandem reactions, with the sequences including ring closing metathesis, isomerization, Michael addition, and Gold- or Bronsted acid-catalyzed N-acyliminium cyclization. Moreover, the combination of P-S reaction with Ugi multicomponent reaction has been exploited for the construction of highly complex polycyclic architectures in few steps and high yields. The P-S reaction has also been successfully employed in solid-phase synthesis, affording products with different structures, including peptidomimetics, synthetic heterocycles, and natural compounds. Finally, the enzymatic version of P-S has been reported for biosynthesis, biotransformations, and bioconjugations.