Nuclear magnetic resonance (NMR) spectroscopy is a technique that detects the chemical environment of atomic nuclei by the absorption of radio-frequency electromagnetic radiation when in the ...

Department of Chemistry, Stanford University, 337 Campus Drive, Stanford, California 94305, United States ...

Key Laboratory of Computational Chemistry-Based Natural Antitumor Drug Research & Development, Liaoning Province; Engineering Research Center of Natural Medicine Active Molecule Research & Development ...

The hydrazones were obtained in the usual fashion by reaction of the carbonyl group (C16) with selected hydrazines. The 13 C NMR data showed the characteristic signal of C=N group at 162-174 ppm. The ...

Portions of 1 g of the sunscreen UVA-UVB 5% Pemulen TR-1 gel (incorporated with the extracts or compound 4, and the sunscreen UVA-UVB 5% Pemulen TR-1 gel alone) were weighed. Subsequently, dilutions ...