Krishna Srivastava

Synthesis, characterization and biological activity of new cyclization products of 3-(4-substituted benzylidene)-2H-pyrido[1,2-a]pyrimidine 2,4-(3H)-diones

AbstractA method is presented for the synthesis of 4-(substituted phenyl)-3-(3-substituted phenyl)4H-spiro[isoxazole-5,3′-pyrido[1,2-a]pyrimidine]-2′,4′-dione (3), 3-(4-substituted phenyl)-3H-isoxazole[3, 4-d]pyrido[1,2-a]pyrimidin-4-(3aH)-one (4) and 3-(4-substituted phenyl) 3,3a-dihydropyrazolo[3,4-d]pyrido[1,2-a]pyrimidin-4-(2H)-one (5) which consists of the conversion of 2H-pyrido[1,2-a]pyrimidine-2,4(3H)-dione (1) to chalcones (2) and their 1,3-dipolar cycloaddition with appropriate aldoximes to give spiro compounds and heterocyclization using amines to yield isoxazolines and pyrazolines. All the compounds were screened for their antimicrobial and antitubercular activity. Graphical Abstract1,3-Dipolar cycloaddition of pyrido-pyrimidine chalcones with appropriate aldoximes give spiro compounds; heterocyclization using hydroxylamine or hydrazine to yield isoxazolines or pyrazolines, respectively. All the compounds were then screened for their biological (antimicrobial and antitubercular) activity.

Validation of parents and estimation of molecular diversity through SSR markers in maize (Zea mays L.)

India is the third largest consumer of edible oils; an increasing human population increases the demand of oil at an alarming rate. Therefore, there is a need to search new sources of oil in India to fulfill this goal. Molecular markers have facilitated the easy identification of diverse parents for development of superior high oil lines for commercial use. The parental material in the present experiment comprised of ten diverse inbred lines viz., high oil (HIGH OIL, DMHOC-09, DMHOC-15), QPM or intermediate oil (HUZQPM-01, HUZQPM-03, HUZQPM-05, HUZQPM-06) and low oil (HUZM-53, HUZM-265, HUZM478) content containing lines were selected on the basis of yield, yield traits along with oil content at the Agricultural Research Farm, B.H.U., during Kharif 2011 and were subjected to validate the presence of QTL’s linked to oil content and molecular diversity through SSR markers. A total number of 25 polymorphic SSR markers were used to evaluate molecular diversity among parental inbreds. The PIC of 25 SSR primers ranged from 0.42 to 0.50 with an average PIC of 0.46. The molecular validation studies revealed that SSR markers bnlg2086, phi96100, umc1422, bnlg1452, bnlg2244, bnlg1711, umc2319, umc1360, phi119 and phi050 were linked to QTLs for oil content. Therefore, these markers could be used in MAS for estimating high oil content in maize.

Synthesis, characterization, and antimicrobial evaluation of novel spiropiperidones

Abstract Novel spiro derivatives of piperidone 4a–f were synthesized, characterized, and screened against a panel of different bacterial and fungal strains. The study revealed the potential of these molecules for further development as antimicrobial agents.

Chemical shifts of the x-ray K or LIII absorption edges

The x-ray K or L-absorption edge shifts of V, Mn, Mo, Zn, Cu, Co, Pb, Ga, Fe, and Y, when they undergo chemical combination and form compounds, have been calculated. It has been found that the major contribution to the chemical shift comes from the change in the Fermi energy of a metal when it forms a compound. The calculated values for the change in Fermi energy correspond well with the values observed by several workers for the chemical shift.