Suhas Pednekar

One-pot multi-component synthesis of 1,4-dihydropyridine derivatives in biocompatible deep eutectic solvents

AbstractAn efficient protocol for the synthesis of differently substituted 1, 4-dihydropyridines in deep eutectic solvents under solvent-free conditions is reported here. Excellent yields of the resultant products have been obtained. Recyclability studies have also been performed for deep eutectic solvents with very little loss in activity up to five recycles. Graphical AbstractAn environmentally benign one-pot synthesis of 1,4-dihdropyridine derivatives using recyclable biocompatible deep eutectic solvent (DES) is reported.

Efficient synthesis of coumarin-based tetra and pentacyclic rings using phospha-palladacycles

Palladacycle 4 has proved to be an efficient catalyst for the intramolecular C–H bond functionalization of coumaryl and pyronyl ethers leading to the synthesis of tri, tetra and pentacyclic compounds, some of which were characterized by X-ray analysis. A microwave-assisted one-pot procedure for obtaining the tetracyclic rings from 4-chlorocoumarin has also been carried out. Mechanistic studies were carried out using GC, UV-Vis and ESI MS.

Nanocomposites and Their Use in Dentistry

Tooth decay or dental caries are one of the common problems faced by people of all ages. A number of solutions are available to overcome the problem among which dental filling material is one of the best. Recent advances in this field of research have come up with the advanced filling material called as resin nanocomposites. Dental resin nanocomposites are comprised of a mixture of the resin matrix, nanofillers, photoinitiator, etc., to be filled into the cavity. Here, nanotechnology plays a crucial role in dentistry. Extensively used nanofillers are silica nanoparticles that give mechanical strength to the filling material. The aim of this chapter is to account for the nanocomposite materials available till the date in the market and the future aspects in this field. This includes replacement of silica nanoparticles by the most efficient titania and to obtain greater efficiency. The nanocomposites can be synthesized at the molecular level by newer methods of synthesis and finally light curing effectively. Titania is superior in many ways than that of silica. Mechanical, chemical, and biological properties of these materials are enhanced than that of materials available in the market. This can give a new protocol for the synthesis of nanocomposite materials for dentistry.

Nucleophilic addition of arylmethylzinc reagents (ArCH2ZnCl) to formaldehyde: An easy access to 2-(hetro)arylethyl alcohols

ABSTRACT The selective addition of arylmethylmagnesium halides with formaldehyde giving arylethyl alcohols is extremely challenging. To circumvent the difficulties, in the current communication, we have reported on the nucleophilic addition of benzyl zinc reagents derived from inexpensive and abundant benzyl chlorides to paraformaldehyde. The reaction investigated herein is hitherto unknown and was found to be selective, operationally simple, atom- and step-economical and high yielding to deliver phenethyl alcohols utilized as key perfumery ingredients in 60–83% yields. After successful establishment of the reaction condition, the reaction was also scaled up successfully to deliver a large-scale preparation of the phenethyl alcohol. GRAPHICAL ABSTRACT

Estrogenic Potential of Flemingia vestita Benth Tubers in Ovariectomized Rat Model

Objective: This study investigates the potential estrogenic activity of the ethanolic extract of Flemingia vestita Benth tubers using ovariectomized rat model. Materials and Methods: The ethanolic extract of F. vestita tubers has been standardized using validated HPLC method in terms of its genistein content (8.43 ± 0.05 mg/g of extract). Three to four week old young albino Wistar female rats were ovariectomized and treated for 14 days post ovariectomy with the standardized ethanolic extract at three different dose levels (100, 250, 500 mg/kg body weight) with a positive control of Estradiol valerate (1 mg/kg/day). The parameters evaluated were uterine weight, uterine glycogen, G6PDH, LDH, 17β-estradiol, progesterone, total cholesterol, triglycerides, HDL and histo architecture of uterus. Results: Treatment with the ethanolic extract of F. vestita tubers showed dose dependent increase in uterine weight, glycogen levels, G6PDH levels, estrogen and progesterone levels when compared with the ovariectomized control. Amongst three dose levels, high dose of plant extract showed significant increase in the uterine weight (p < 0.001), uterine glycogen content (p < 0.001), 17-β estradiol and progesterone levels (p < 0.001), G6PDH and LDH levels (p < 0.001) as well as significant decrease in HDL and triglycerides levels (p < 0.001) compared to ovariectomized control. Histopathological evaluation of uteri sections revealed that the high dose of the plant show increase in the endometrial response as indicated by proliferation of endometrial glands and luminal epithelium of the ovariectomized rats. Conclusion: Thus, these data suggests that ethanolic extract (500 mg/kg body weight) of F. vestita tubers may exhibit good estrogenic activity in ovariectomized rat model.

CLINICAL STUDIES OF GASTRO-INTESTINAL CONDITION USING HOLARRHENA ANTIDYSENTERICA STEM TINCTURE AND ITS COMPARISON WITH SILVER NANOPARTICLES

Efficacy of Holarrhena antidysenterica (H.A.) stem tincture was studied on the patients with gastro-intestinal conditions. The in-vitro experiments of H.A. tincture with Gram positive and Gram negative bacterial cultures show considerable improvement over the commercial tincture due to the reduced particle sizes of the H.A. extract. Plant Secondary Metabolites present in stem extracts of (H.A.) were used to reduce Ag ions to AgNPs in a single-step green synthesis process. FTIR, UV and TEM analysis confirms the above reduction process.