鲜蒜嫩鳞被中半胱氨酸肽的制备及其对豆类铁锌生物利用率的影响

离子交换层析结合制备液相方法从鲜蒜嫩鳞被中制备2种半胱氨酸肽(γ-GCPs):(SC2RC7)-γ-L-谷氨酰-S-烯丙基-L-半胱氨酸(1)和(SC2RC7)-γ-L-谷氨酰-S-丙基-L-半胱氨酸(2)。产物结构经HPLC-MS,CD和1H NMR,13C NMR分析并与标准品比对确定。利用体外模拟胃、肠消化实验检测其对豆类铁锌生物利用率的影响。结果表明,5 g豆粉中添加0.01 mmol的化合物1和化合物2分别使黄豆铁生物利用率从1.88%提高到6.73%和4.42%,绿豆铁生物利用率从2.52%提高到12.04%和9.38%;使黄豆锌生物利用率从13.37%提高到23.95%和20.58%,绿豆锌生物利用率从15.98%提高到28.44%和27.05%。

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

Two γ-glutamyl-cysteine peptides (γ-GCPs), (SC2RC7)-γ-L-glutamyl-S-allyl-L-cysteine (1) and (SC2RC7)-γ-L-glutamyl-S-propyl-L-cysteine (2) were isolated from fresh garlic scales using ion-exchange chromatography and preparative HPLC. Their molecular structures were identified by HPLC-MS, CD, ¹H NMR, ¹³C NMR, and specific rotation, and confirmed by using 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, at the level of 0.01 mmol/5 g of legume respectively. The enhancing effect of the two γ-GCPs on bioavailability 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 bioavailability of zinc from the food legume, with the extent of increase 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%. Obviously, both 1 and 2 had a promoting effect 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.