Preparation and Functional Exploration of Cysteine Peptides from Fresh Garlic Scales for Improving Bioavailability of Food Legume Iron and Zinc / 分析化学

ABSTRACT

Two γ-glutamyl-cysteine peptides (γ-GCPs ) , ( SC2 RC7 )-γ-L-glutamyl-S-allyl-L-cysteine ( 1 ) and ( SC2 RC7 )-γ-L-glutamyl-S-propyl-L-cysteine ( 2 ) have been isolated from fresh garlic scales using ion-exchange chromatography and pre-HPLC. Their molecular structures were identified by HPLC-MS, CD, 1 H NMR, 13 C NMR, specific rotation and confirmed by the corresponding standard compounds. The influence of exogenously adding 1 and 2 on the bioavailability of iron and zinc from food legume was examined with soybean and mung bean, in the level of 0. 01 mmol/5 g of legume respectively. The enhancing effect of the two γ-GCPs of compound 1 and 2 on bioaccessibility of iron was generally evidenced in the case of soybean ( from 1 . 88% to 6 . 73% and 4 . 42%) and mung bean ( from 2 . 52% to 12 . 04% and 9 . 38%) . The two γ-GCPs similarly enhanced the bioaccessibility of zinc from the food legume, in soybean ranging from 13. 37% to 23. 95% and 20. 58%, and in mung bean from 15. 98% to 28. 44% and 27. 05%. Thus, both compounds 1 and 2 obviously had a promoting influence on the bioavailability of iron and zinc from food legumes. These findings are of practical value in a food-based strategy to enhance the bioavailability of trace minerals for human health.