Polymeric Systems for Amorphous Δ9-Tetrahydrocannabinol Produced by a Hot-melt Method. Part II: Effect of Oxidation Mechanisms and Chemical Interactions on Stability

Valorisation of grape pomace: Fractionation of bioactive flavan-3-ols by membrane processing

In continuation to our efforts in finding potential therapeutic agents, a variety of biologically significant semicarbazones were synthesized by the reaction of different carbonyl compounds with phenyl semicarbazides through microwave irradiation. Initially, 18 semicarbazones were studied for their antimicrobial, antitumor, and antioxidant potential. None of the tested compounds showed any antibacterial activity; however, some compounds showed significant antifungal activity. Interestingly, all compounds showed antitumor activity when tested against tumors grown on potato discs. These compounds were also tested for their effect on OH radical-induced oxidative DNA damage. All the compounds showed DNA protection to varying extent. Based on the promising results of antitumor and antioxidant activities, another set of 24 semicarbazones was synthesized, and all of these semicarbazones were evaluated for their antioxidant potential. The results showed that the semicarbazones derived from 2-nitrobenzaldehyde and acetophenone were the most active 2,2-diphenyl-1-picrylhydrazyl 9 (DPPH) free radical scavengers. The overall results have led to the identification of some interesting compounds which seem to have great potential to be developed into effective anticancer drugs.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1747-0285.2012.01360.x

Microwave-assisted Synthesis and Bioevaluation of Some Semicarbazones

Pharmaceutical Sciences—1968. A Literature Review of Pharmaceutics

This study involves the evaluation of the effect of certain stabilizers, that is, citric acid (CT), tartaric acid (TA) and boric acid (BA) on the degradation of ascorbic acid (AH(2) ) in oil-in-water cream formulations exposed to the UV light and stored in the dark. The apparent first-order rate constants (0.34-0.95 × 10(-3) min(-1) in light, 0.38-1.24 × 10(-2) day(-1) in dark) for the degradation reactions in the presence of the stabilizers have been determined. These rate constants have been used to derive the second-order rate constants (0.26-1.45 × 10(-2) M(-1) min(-1) in light, 3.75-8.50 × 10(-3) M(-1) day(-1) in dark) for the interaction of AH(2) and the individual stabilizers. These stabilizers are effective in causing the inhibition of the rate of degradation of AH(2) both in the light and in the dark. The inhibitory effect of the stabilizers is in the order of CT > TA > BA. The rate of degradation of AH(2) in the presence of these stabilizers in the light is about 120 times higher than that in the dark. This could be explained on the basis of the deactivation of AH(2) -excited triplet state by CT and TA and by the inhibition of AH(2) degradation through complex formation with BA. AH(2) leads to the formation of dehydroascorbic acid (A) by chemical and photooxidation in cream formulations.

C.L. Hwang

Papers

Studies on the Effect of Gallate on the Oxidation of Aldehydes Dispersed in Cetomacrogol Solutions

Antioxidant solubility and efficiency.

Effect of Synergists on Activity of Gallates