Procyanidins are natural compounds with good biological activity.However,due to a large number of phenolic hydroxyl groups in the structure,they have high polarity and low bioavailability.The preparation of A-type pro...Procyanidins are natural compounds with good biological activity.However,due to a large number of phenolic hydroxyl groups in the structure,they have high polarity and low bioavailability.The preparation of A-type proanthocyanidin derivatives is an effective way to change their polarity and biological activity.In this paper,a series of A-type procyanidin derivatives were designed and synthesized by two practical and safe methods,and two new dimeric A-type procyanidin derivatives,procyanidin A1-acetone conjugate(6)and procyanidin A2-cystein conjugate(9)were obtained and reported for the first time.Their structures were characterized and confirmed by ^(1)H NMR,^(13)C NMR,HMBC,^(1)H-^(1)H COSY and MS.All the compounds showed strong DPPH scavenging activities.Compound 6 showed inhibitory effects onα-glucosidase with an IC_(50) value of 8.7μg/mL,while its parental compound,procyanidin A1,had no inhibitory effects.Degradation of procyanidins from peanut skin by L-cystein was studied.The results showed that the main structural unit of procyanidins in peanut skin was A-type proanthocyanidins dimer.展开更多
文摘目的寻找能将氨基酸侧链的羟基、巯基与二元羧酸连接成酯的方法。方法分别以L 丝氨酸和L 半胱氨酸为起始物 ,采用叔丁氧羰基、苄酯或二苯甲酯形式保护 ,分别与丁二酸单苄酯、草酸单苄酯、丁二酸单叔丁酯缩合成酯 ,合成了 3个未见文献报道的化合物O (4 苄氧丁二酰基 ) N 叔丁氧羰基 L 丝氨酸苄酯 (4 )、O (2 苄氧草酰基 ) N 叔丁氧羰基 L 丝氨酸苄酯 (8)、S (4 叔丁氧丁二酰基 ) N 叔丁氧羰基 L 半胱氨酸二苯甲酯 (12 )。化合物 4经氢解合成未见文献报道的化合物O 丁二酰基 N 叔丁氧羰基 L 丝氨酸 (5 )。化合物 5经酸解得到O 丁二酰基 L 丝氨酸(6)。结果与结论目标化合物的结构经光谱确证。通过这种方法二元羧酸能与氨基酸的羟基。
基金National Natural Science Foundation of China(Grant No.81860688)College Students Innovation and Entrepreneurship Project of Inner Mongolia(Grant No.202010132013)the Scientific Research Project of introductory high-level talents in Inner Mongolia。
文摘Procyanidins are natural compounds with good biological activity.However,due to a large number of phenolic hydroxyl groups in the structure,they have high polarity and low bioavailability.The preparation of A-type proanthocyanidin derivatives is an effective way to change their polarity and biological activity.In this paper,a series of A-type procyanidin derivatives were designed and synthesized by two practical and safe methods,and two new dimeric A-type procyanidin derivatives,procyanidin A1-acetone conjugate(6)and procyanidin A2-cystein conjugate(9)were obtained and reported for the first time.Their structures were characterized and confirmed by ^(1)H NMR,^(13)C NMR,HMBC,^(1)H-^(1)H COSY and MS.All the compounds showed strong DPPH scavenging activities.Compound 6 showed inhibitory effects onα-glucosidase with an IC_(50) value of 8.7μg/mL,while its parental compound,procyanidin A1,had no inhibitory effects.Degradation of procyanidins from peanut skin by L-cystein was studied.The results showed that the main structural unit of procyanidins in peanut skin was A-type proanthocyanidins dimer.
