Synthesis,Anticancer Activity,Structure-Activity Relationship and Mechanistic Investigations of Falcarindiol Analogues

Forty samples of optically active falcarindiol analogues are synthesized by using the easily available C2 symmetric (R)- and (S)-1,1’-binaphth-2-ol (BINOL) in combination with Ti(OⁱPr)₄, Zn powder and EtI. Their anticancer activities on Hccc-9810, HepG2, MDA-MB-231, Hela, MG-63 and H460 cells are assayed to elucidate their structure-activity relationships. These results showed that the falcarindiol analogue (3R,8S)- 2 i with the terminal double bond has the most potent anti-proliferation effect on Hccc-9810 cells with IC₅₀ value of 0.46 μM. The falcarindiol analogue (3R,8S)- 2 i can induce obvious Hccc-9810 cell apoptosis in a concentration-dependent manner by Hoechst staining and flow cytometry analysis. The proposed mechanism suggests that the falcarindiol analogue (3R,8S)- 2 i increases LDH release and MDA content, and reduces the levels of SOD activity, which lead to the accumulation of oxidative stress and induce apoptosis in Hccc-9810 cells.     

我国桑叶食品开发研究进展

桑树是我国一种重要的经济作物,桑叶被广泛用于生产各种功能性食品。桑叶含有丰富的蛋白质、多酚类、生物碱类、多糖类、γ-氨基丁酸和植物甾醇等营养和活性成分,具有抗氧化、降血糖、降血脂、抗炎等功效。目前桑叶食品主要有桑叶茶、桑叶菜和桑叶粉(浆)系列食品。不同工艺(绿茶、红茶和乌龙茶)加工而成的桑叶茶各有特色。相对于传统的桑叶茶,桑叶菜或桑叶粉(浆)能更好地进行桑叶的全食物利用,但目前没有专用的菜用桑品种和合适的评判桑叶菜品质的标准。在复杂的食品体系中,食品加工工序以及桑叶与其他食品材料的组分相互作用,都会导致桑叶理化性质及品质功能的改变。本文介绍桑叶原料特性及其在食品领域的开发现状,指出了现有研究的不足之处,以期为更合理、更科学地开发桑叶食品或其他类似食品提供依据。     

金线莲的化学成分及生物活性研究进展

金线莲(Anoectochilus roxburghii(will.)Lind.),为兰科开唇兰属多年生草本植物,别名金丝线、金耳环、乌人参、金线虎头蕉、金线入骨消、金钱草等,分布于福建、浙江和广西等地区,其株型小巧,叶片金黄色,叶脉呈网状方式排列,极具观赏价值。金线莲还作为"药食同源"植物在民间被长期广泛使用,其味平、甘,临床上可用于糖尿病、咯血、急性肝炎、支气管炎和肿瘤等症,且无毒副作用,使用安全,越来越受到研发人员的关注。化学解析表明,金线莲化学成分结构类型丰富,包括黄酮、挥发油、多糖、生物碱、甾体等;现代药理研究提示,金线莲具有降血糖、心血管保护、抗感染和抗肿瘤等功效;本文系统综述金线莲物质基础和生物活性,为药食两用金线莲新型天然保健产品的开发提供参考依据。     

采前氯吡脲处理对‘秦美’猕猴桃贮藏期间果实硬度及细胞壁降解的影响

以‘秦美’猕猴桃果实为试材,于盛花期后28 d分别采用0(对照,清水)、5、10、20 mg/L 4个质量浓度的氯吡脲(1-(2-chloropyridin-4-yl)-3-phenylurea,CPPU)溶液进行蘸果处理,蘸果时间3～5 s,研究采前CPPU处理对‘秦美’猕猴桃贮藏期间果实硬度及细胞壁降解酶活力的影响。结果表明:CPPU处理加速了果实硬度、原果胶和纤维素质量分数的下降,提高了可溶性果胶质量分数及多聚半乳糖醛酸酶(polygalacturonase,PG)、果胶甲酯酶(pectin methylesterase,PME)、纤维素酶(cellulase,Cx)和β-半乳糖苷酶(β-D-galaetosidase,β-Gal)细胞壁降解活力。各处理组果实硬度与可溶性果胶质量分数和PG、Cx活力呈极显著负相关(P0.01),与原果胶、纤维素质量分数呈极显著正相关(P0.01);20 mg/L CPPU处理组果实的β-Gal活力与硬度呈显著负相关(P0.05)。CPPU处理提高了果实细胞壁降解酶的活力,促进了细胞壁的降解,加速了贮藏期间果实的软化,降低了果实的耐贮藏性。为维持猕猴桃采后果实硬度,延长贮藏期,生产中不宜使用CPPU处理,或使用的质量浓度不宜超过5 mg/L。     

Antioxidant activities of enzymatic‐hydrolysed proteins of dromedary (Camelus dromedarius) colostrum

This work investigated the antioxidant activities of dromedary colostrum proteins before and after hydrolysis by pepsin, trypsin, α‐chymotrypsin, pancreatin and papain. The enzymatic hydrolysis affected the degrees of hydrolysis, electrophoretic profiles, molecular weight distribution and hydrophobic/hydrophilic properties of the generated peptides. The antioxidant activities were evaluated using four antioxidant assays, including 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) radical‐scavenging activities, ferric reducing power and ferrous ion chelating activity. Interestingly, the antioxidant activities of dromedary colostrum proteins were enhanced after enzymatic hydrolysis. The highest antioxidant potential was obtained by pancreatic hydrolysates (P ≤ 0.05). These results suggest that dromedary colostrum protein hydrolysates are an important source of natural antioxidant peptides.     

鲣鱼蛋白肽谱效关系研究

采用鲣鱼为原料,以蛋白质回收率为指标,酶解制备不同工艺条件的样品。通过测定其黄嘌呤氧化酶(XOD)抑制活性、ORAC值、分子质量分布图谱和总氨基酸含量,构建鲣鱼蛋白肽体外化学活性与其分子质量分布图谱、总氨基酸含量图谱之间的谱效关系。结合超高效液相-质谱联用(LC-MS/MS)方法研究其降尿酸肽和抗氧化肽的分布。研究表明,鲣鱼蛋白肽的XOD抑制活性与其ORAC值具有显著的相关性。由多肽分子质量<1ku所占含量的分布区段和脂肪族氨基酸的含量可初步预测鲣鱼蛋白肽的化学活性。质谱分析表明,纯化组分的质谱基峰图在不同时间段的信号强度与鲣鱼蛋白肽的降尿酸活性和抗氧化活性具有明显的相关性。