About the cover

Professoe Uday Maitra is a renowned organic chemist. He is being felicitated on his 60th birthday during his visit to Vidyasagar University in 2017. This page is dedicated to him on this auspicious occasion.

Study of Antioxidant Property of the Rhizome Extract of Polygonatum cirrhifolium (Mahameda) and its use in the green synthesis of Gold nanoparticles
Braja Gopal Bag,* Shib Shankar Dash and Anup Mandal

Prayogic Rasayan 2017, 1 (3), 66-70

DOI: https://www.doi.org/10.53023/p.rasayan-20161008

The antioxidant efficacy of the rhizome extract of Polygonatum cirrhifolium (Mahameda) has been studied against a stable 2, 2-diphenylpicrylhydrazyl (DPPH) radical at room temperature. The chemical constituents present in the rhizome extract have been utilized for the one step synthesis of stable gold nanoparticles at room temperature under very mild conditions. The synthesized gold nanoparticles were well characterized by surface plasmon resonance spectroscopy, high resolution transmission electron microscopy, x-ray diffraction and FTIR studies and a mechanism for the synthesis and stabilization of gold nanoparticles has been described.

Synthetic studies of antascomicin A: Construction of C1-C16 fragment
Jithender Reddy Vakiti and Subhash Ghosh*

Prayogic Rasayan 2017, 1 (3), 71-73

DOI: https://www.doi.org/10.53023/p.rasayan-20170907

This communication describes the stereoselective synthesis of C1-C16 fragment of antascomicin A, a non-immunosuppressive immunophil-binding natural product. Evans aldol reaction was used extensively to install all the stereo centres present in the fragment. The hemikatel present in the fragment was synthesized via DMP-mediated oxidation of -hydroxy amide followed by acid catalyzed hemiketalization.

Terpenoids as Renewable Nano-Sized Building Blocks.
Braja Gopal Bag,* Abir Chandan Barai, Sk Nurul Hasan, Subhajit Das, Chhabi Garai, Subrata Ghorai, Saikat Kumar Panja

Prayogic Rasayan 2017, 1 (3), 74-81

DOI: https://www.doi.org/10.53023/p.rasayan-20170815

Terpenoids are a large and structurally group of natural products containing multiple five carbon containing isoprene units. Previously we have reported that irrespective of their acyclic or alicyclic nature, all the triterpenoids containing 30C's have nano-metric lengths. In the current studies, detailed computations have been carried out with 120 naturally occurring mono- (C10), sesqui- (C15), di- (C20), sester- (C25), sesqua- (C35) and tetra- (C40) terpenoids using Gaussian 09 software with Gauss view 07 and molecular mechanics calculation using Serena software. The heat of formation and the calculated molecular lengths obtained by the two methods were compared. Interestingly, monoterpenoid to tetraterpenoid all the terpenoids (except three monoterpenoid and one sesqui-terpenoid) have molecular lengths above one nanometer making them useful as nano-sized building blocks.

Ficus carica Linn (Dumur) Fruit Extract Mediated Green Synthesis of Gold Nanoparticles and its Application in Catalytic Reduction
Shib Shankar Dash, Braja Gopal Bag* and Abhisek Midya

Prayogic Rasayan 2017, 1 (3), 82-86

DOI: https://www.doi.org/10.53023/p.rasayan-20170905

The fruit extract of Ficus carica Linn (Dumur) is rich in different types of plant secondary metabolites such as terpenoids, polyphenols including flavanoids, etc. We have demonstrated the use of the fruit extract for the synthesis of gold nanoparticles in water at room temperature under very mild conditions. There was no need of additional stabilizing or capping agents and the synthesis of the gold nanoparticles was complete in several minutes. The gold nanoparticles were characterized by HRTEM, EDX, SAED, Surface Plasmon Resonance Spectroscopy and X-Ray diffraction studies. The freshly prepared gold nanoparticles have been used as an efficient catalyst for the sodium borohydride reduction of 4-nitrophenol to 4-aminophenol in water at room temperature and the kinetics of the reduction reaction have been studied spectrophotometrically.

Synthesis of 6-hydroxy-N-(6-methylpyridin-2-yl) naphthalene-2-carboxamide and its alkoxy analogues
Braja G. Bag,* Subrata Ghorai, Saikat K. Panja, Shaishab K. Dinda, Koushik Paul

Prayogic Rasayan 2017, 1 (3), 87-92

DOI: https://www.doi.org/10.53023/p.rasayan-20170521

6-hydroxy-N-(6-methylpyridin-2-yl)naphthalene-2-carboxamide and its alkoxy analogues bearing long alkyl chains have been synthesized using 6-hydroxy-2-naphthoic acid and 2-amino-6-picoline. The facile synthetic scheme reported here using conventional laboratory reagents opens up a new strategy for the generation of libraries of such compounds in high yields. The H-bond donor acceptor groups along with the reactive 2-naphthol moiety present in the target compounds make them useful for their use in self-assembly and self-replication studies.