RESUMO
Apple pomace has been considered as a sustainable source for antioxidant phenolic compounds. Previous reports show extraction of total phenolic contents (TPC) by following various conventional and non-conventional techniques; however, a comparative study has not been reported. In the present work, conventional extraction was compared with several non-conventional extraction methods including ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), high-speed homogenization (HH). Moreover, efficacy of combined treatments, including high-speed homogenization coupled with MAE and ultrasound-assisted enzymatic extraction (UAEE) was evaluated for the recovery of TPC. The results revealed that UAEE results in the highest TPC (4.62 mg GAE/g), moreover, it simultaneously enabled the recovery of low methoxy pectins with the degree of methylation ranging from 14.03- 28.85%. The LC-Q-Tof analysis revealed the presence of various phenolic acids and flavonoids. The DPPH radical scavenging assay showed that the phenolic rich extracts had IC50 values ranging from 27.1 to 54.6, depending on the extraction parameters. This article is protected by copyright. All rights reserved.
RESUMO
3 Starting from 2-methyl-4-nitro-imidazole, new 5-(2-methyl- 4-nitro-1-imidazomethyl)-1,3,4-oxadiazole-2-thione () was synthesized and was subjected to Mannich reaction with appropriate amines to yield a new series of 3-substituted aminomethyl-5-(2-methyl-4-nitro-1-imidazomethyl)- 1,3,4-oxadiazole-2-thiones (4a-j). The structure of the title compounds was elucidated by elemental analysis and spectral data. The newly synthesized Mannich bases were screened for their antibacterial and antifungal activity. Many of these compounds exhibited potent antifungal activity.
