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151.
Exudates (DE) secreted from two shiitake mushroom mycelia (strains 1358 and L5458) were evaluated for their antioxidative properties and phenolic content. 1358DE and L5458DE showed distinct antioxidant activity in different in vitro assays, including scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, hydroxyl radical, superoxide anions and hydrogen peroxide; the ability to chelate ferrous ions; reducing power; hemolysis inhibition activity in rat erythrocyte; and lipid peroxidation inhibition (IC50 values of 1358DE and L5458DE were 3.3 and 132.6; 44.5 and > 1000; 26.9 and 53.7; 153.6 and > 175.0; 176.0 and 521.0; 26.7 and 746.4; 47.8 and 736.9; and 3.1 and > 1000 microg/mL, respectively). Their total phenolic content was 237.33 and 24.08 mg gallic acid equivalent (GAE)/g of dry DE, respectively. Overall, these results show that 1358DE generally possesses better antioxidant properties than L5458DE, possibly due to its larger total phenolic content. Shiitake mushroom mycelial exudates, particularly of 1358DE, could be a good source of natural antioxidants. 相似文献
152.
Prevention of Enzymatic Browning by Natural Extracts and Genome-Editing: A Review on Recent Progress
Norfadilah Hamdan Chia Hau Lee Syie Luing Wong Che Ellysa Nurshafika Che Ahmad Fauzi Nur Mirza Aqilah Zamri Ting Hun Lee 《Molecules (Basel, Switzerland)》2022,27(3)
Fresh fruits and vegetable products are easily perishable during postharvest handling due to enzymatic browning reactions. This phenomenon has contributed to a significant loss of food quality and appearance. Thus, a safe and effective alternative method from natural sources is needed to tackle enzymatic browning prevention. The capabilities of natural anti-browning agents derived from plant- and animal-based resources in inhibiting enzymatic activity have been demonstrated in the literature. Some also possess strong antioxidants properties. This review aims to summarize a recent investigation regarding the use of natural anti-browning extracts from different sources for controlling the browning. The potential applications of genome-editing in preventing browning activity and improving postharvest quality is also discussed. Moreover, the patents on the anti-browning extract from natural sources is also presented in this review. The information reviewed here could provide new insights, contributing to the development of natural anti-browning extracts and genome-editing techniques for the prevention of food browning. 相似文献
153.
Andreas C. Hans Patrick M. Becker Johanna Haußmann Simon Suhr Daniel M. Wanner Vera Lederer Dr. Felix Willig Dr. Wolfgang Frey Prof. Dr. Biprajit Sarkar Prof. Dr. Johannes Kästner Prof. Dr. René Peters 《Angewandte Chemie (International ed. in English)》2023,62(13):e202217519
A catalyst type is disclosed allowing for exceptional efficiency in direct 1,4-additions. The catalyst is a zwitterionic entity, in which acetate binds to CuII, which is formally negatively charged and serving as counterion for benzimidazolium. All 3 functionalities are involved in the catalytic activation. For maleimides productivity was increased by a factor >300 compared to literature (TONs up to 6700). High stereoselectivity and productivity was attained for a broad range of other Michael acceptors as well. The polyfunctional catalyst is accessible in only 4 steps from N-Ph-benzimidazole with an overall yield of 96 % and robust during catalysis. This allowed to reuse the same catalyst multiple times with nearly constant efficiency. Mechanistic studies, in particular by DFT, give a detailed picture how the catalyst operates. The benzimidazolium unit stabilizes the coordinated enolate nucleophile and prevents that acetate/acetic acid dissociate from the catalyst. 相似文献