Viney Chawla

Fullerenes: From Carbon to Nanomedicine

Fullerenes, the third carbon allotrope, have emerged as agents which could revolutionize the treatment of many diseases. Fullerenes possess different biological applications like neuroprotective agents, antioxidants, anti-HIV activity, enzyme inhibition, antiapoptotic activity and the list is ever increasing. Moreover, they are being utilized as drug carrier systems and also for many non-biological applications like superconductors, catalysis and so on. Their size has made them promising agents for nanotechnology. This article aims at outlining the chemistry, properties and non-biological applications of fullerenes and their evolution to biological applications, thereby traversing their evolution from simple carbon allotropes to present day nano-medicinal agents.

Rheological studies on solid lipid nanoparticle based carbopol gels of aceclofenac

Solid lipid nanoparticles (SLN) of aceclofenac were prepared using Taguchi experimental design by Trotta method. The prepared SLN were formulated into a gel preparation, using carbopol 940. Gels were evaluated for drug content, bioadhesion and their stability against change of temperature and shear. The viscosity of prepared gels was found to be temperature independent. Rheological behavior of gels with changing shear was rather complex. Viscosity varied inversely with shear but remained almost constant during short spans of time when shear was kept constant. Viscosity of the gels did not change if shear was not varied. In vitro diffusion studies exhibited an immediate release followed by a sustained release. This could help in maintaining the concentration of bioactives such as aceclofenac in desirable levels at sites of inflammation and injury.

Clinical implications and treatment of dengue

Dengue is a common pathogenic disease often proving fatal, more commonly affecting the tropics. Aedes mosquito is the vector for this disease, and outbreaks of dengue often cause mass damage to life. The current review is an effort to present an insight into the causes, etiology, symptoms, transmission, diagnosis, major organs affected, mitigation and line of treatment of this disease with special emphasis on drugs of natural origin. The disease has a potential to spread as an endemic, often claiming several lives and thus requires concerted efforts to work out better treatment options. Traditional medicine offers an alternative solution and could be explored as a safer treatment option. Development of a successful vaccine and immunization technique largely remains a challenge and a better antiviral approach needs to be worked out to complement the supportive therapy. No single synthetic molecule has found to be wholly effective enough to offer curative control and the line of treatment mostly utilizes a combination of fluid replacement and antipyretics-analgesics like molecules to provide symptomatic relief.

Syntheses, Characterization and Antimicrobial Evaluation of Some 1, 3, 5-Trisubustituted Pyrazole Derivatives

A series of 1, 3, 5-trisubustituted pyrazole derivatives were synthesized and screened for antimicrobial activity. The compounds (2j-o) were evaluated against two gram-positive and two gram-negative bacteria and one fungus, at concentrations of 10 µg/mL and 50 µg/mL. The compounds were founds to be inactive against P. aeruginosa and A. niger but exhibited moderate activity against B. subtilis, E. coli and S. aureus. It can be concluded that the newly synthesized compounds possess promising antimicrobial activity.

Syntheses, characterization and evaluation of novel 2,6-diarylpiperidin-4-ones as potential analgesic-antipyretic agents

A novel series of N-(N-methylpiperazinoacetyl)-2,6-diarylpiperidin-4-one derivatives (1c-3c and 5c) were synthesized, via base catalyzed nucleophilic substitution of N-chloroacetyl-2,6-diarylpiperidin-4-ones (1b-6b) with N-methyl piperazine. The newly synthesized compounds were characterized by FTIR, Mass and NMR spectral studies. All the compounds were screened for their possible analgesic and antipyretic activities. The compound 2c exhibited promising antipyretic activity, comparable to that of paracetamol at 60 mg/kg dose. The compounds 2b and 2c showed significant analgesic profile at a dose of 60 mg/kg and were also found to be more potent than the reference drug, diclofenac sodium. Thus, it can be concluded that the synthesized 2,6-diarylpiperidin-4-ones exhibit promising antipyretic and analgesic activities and could be potential drug candidates.

Syntheses of 2-(6’-Fluorobenzothiazol-2’-ylamino)-4, 6-(disubstituted thiouriedo)-1,3-pyrimidine Derivatives as Antimicrobial Agents

A new series of 1,3-pyrimidine derivatives (3a-f) have been synthesized by reacting 2,4,6-Trichloropyrimidine with nucleophilic reagents 2-amino-6-fluorobenzothiazole (1) in the presence of acetone. The (4,6- dichloro-pyrimidin-2-yl)-amine (2) so produced was then reacted to two moles of phenylthiourea derivatives to yield title compounds (3a-f). The structural assessment of the compounds (3a-f) was made on the basis of spectral data. The synthesized compounds were screened for their in vitro growth inhibiting activity against different strains of bacteria viz., B. subtilis, E. coli, P. aeruginosa and S. aureus using agar diffusion technique. Compounds 3c and 3f exhibited highest antibacterial activity.

Pectin, beta-cyclodextrin, chitosan and albumin based gastroprotective systems for piroxicam maleate: Synthesis, characterization and biological evaluation

In order to optimize drug action, new drug formulations have been developed based upon the prodrug approach. This study was inspired by the increasing interest in the field of macromolecular prodrugs and Piroxicam maleate was used as a model drug. A total of five prodrugs were synthesized using beta cyclodextrin, chitosan, pectin, egg albumin, bovine serum albumin. The synthesized conjugates were characterized on the basis of UV, IR and NMR techniques. In-vitro hydrolysis studies were carried out at pH 1.2, pH 7.4, pH 9.0 and in 80% human plasma followed by in-vivo evaluation of analgesic, anti-inflammatory and anti-ulcerogenic potential. The extent of hydrolysis was found to be proportional to increase in pH. Beta cyclodextrin conjugate was found to possess significant analgesic activity whereas chitosan conjugate was found to be the best anti-inflammatory. Pectin conjugate provided maximum protection against ulcers.

Design and microwave facilitated green synthesis of 2-[4-(3-carboxymethyl, methoxy carbonylmethyl-2,4-dioxo and 4-oxo-2-thioxo-thiazolidin-5-ylidenemethyl)-phenoxy]-2 and 3-methyl propionic acid ethyl ester derivatives: a novel structural class of antidyslipidemic agents

An interesting hybrid molecular framework comprising of benzylidenethiazolidin-4-one, chalcone and fibrate was designed and synthesized (BRF1–12) in order to develop safe and efficacious compounds for the treatment of dyslipidemia, and related complications such as atherosclerosis. The synthesized derivatives were characterized by Fourier transform infrared spectroscopy, mass, and nuclear magnetic resonance spectral studies and evaluated for their antihyperlipidemic potential, using in vivo and in silico methods. All the synthesized compounds exhibited promising antidyslipidemic activity comparable to, and sometimes better than that of, the standard drug-fenofibrate at the tested dose of 30 mg/kg body weight. The most active compounds of the series, BRF4 and BRF6, demonstrated significant antidyslipidemic profile by lowering low density lipoprotein cholesterol, very low density lipoprotein cholesterol, and triglyceride and increasing the level of high density lipoprotein cholesterol, thereby decreasing the atherogenic index. Overall, these effects of BRF4 and BRF6 were found to be more potent than fenofibrate, in lipid lowering activity and reducing atherogenic index. Structure–activity relationship studies conclusively established that the presence of N-acetic acid methyl ester at 3rd position of the thiazolidin-4-one nucleus, and a C-3 fibric acid moiety at benzene nucleus were instrumental for enhanced biological activity. The binding mode of benzylidenethiazolidin-4-one fibrate class of compounds, showing crucial hydrogen bonds and pi–pi stacking interactions with the key amino acid residues Phe118, His440, and Tyr464 at the active site of PPARα receptor, was assessed by molecular docking studies.