Vegesna S. Raju

Bio: Vegesna S. Raju is an academic researcher from Stevens Institute of Technology. The author has contributed to research in topics: Lactam & Microwave oven. The author has an hindex of 7, co-authored 14 publications receiving 407 citations.

Highly Accelerated Reactions in a Microwave Ovem: Synthesis of Heterocycles

Abstract: Efficient synthesis of a wide variety of heterocycles on 0.1 to 200 g scale was conducted in organic solvents in a commercial microwave oven in a few minutes at a low energy level. Erlenmeyer flasks were adequate reaction vessels since neither high pressure nor high temperature were involved. Fast monitoring of synthetic reactions was achieved by tlc separation and transfer of tlc spot material directly to a solids probe of a chemical ionization mass spectrometer. Microwave oven-induced reaction enhancement (MORE) chemistry is not due to thermolysis: one reaction was conducted successfully in a reaction vial encased in a block of ice.

Reactions accelerated by microwave radiation in the undergraduate organic laboratory

Abstract: The authors have found that with the proper choice of reaction solvent, accelerated reactions can be carried out safely with ordinary glassware in commercial microwave ovens.

Polyhydroxysterols from the Soft Coral Sarcophyton subviride of Andaman and Nicobar Coasts

Abstract: Four new polyhydroxysterols, (24S)-ergost-25-ene-1β, 3β, 5α,6β-tetraol [12], (24S)-ergostane-1β,3β,5α,6β,18,25-hexaol 25-monoacetate [14], (24S)-ergostane-3β,5α,6β,25ξ,26-pentaol 25-monoacetate [16], and gorgostane-1β,3β,5α,6β,25-pentaol [19], besides the known polyhydroxysterols 1, 3, 5, 7, and 10, were isolated from the soft coral Sarcophyton subviride of Katchal Island of Andaman and Nicobar coasts. Structure elucidation of the new compounds was performed through spectral analysis of their peracetyl derivatives 13, 15, 17, and 20; therefore the possibility of partial acetylation in natural sterols could not be ruled out

Thermal and non-thermal interaction of microwave radiation with materials

Abstract: Industrial use of microwave radiation as an alternative to conventional thermal heating has generated interest recently mainly because of the drastic reduction in the processing time. In spite of its wide application, its chemical mechanism of interaction with materials has not been well understood. The current debate on the alternative use of microwave radiation to conventional thermal heating is on the involvement of a “microwave specific effect” other than the well accepted dielectric heating. There are reports of various reactions which show similar kinetics under both microwave and thermal methods at similar temperatures suggesting simple dielectric heating of materials by microwaves. There are also reports which show a clear reaction rate enhancement under microwave radiation compared to the thermal method under similar reaction conditions and temperatures indicating a “microwave specific effect” other than the simple dielectric heating of materials. This paper will discuss the above conflicting results reported in the literature.

Microwave-enhanced enzyme reaction for protein mapping by mass spectrometry: A new approach to protein digestion in minutes

Abstract: Accelerated proteolytic cleavage of proteins under controlled microwave irradiation has been achieved. Selective peptide fragmentation by endoproteases trypsin or lysine C led to smaller peptides that were analyzed by matrix-assisted laser desorption ionization (MALDI) or liquid chromatography-electrospray ionization (LC-ESI) techniques. The efficacy of this technique for protein mapping was demonstrated by the mass spectral analyses of the peptide fragmentation of several biologically active proteins, including cytochrome c, ubiquitin, lysozyme, myoglobin, and interferon α-2b. Most important, using this novel approach digestion of proteins occurs in minutes, in contrast to the hours required by conventional methods.