Gajera H P, Gevariya Shila N, Hirpara Darshna G, Patel S V, Golakiya B A
Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, Gujarat 362 001 India.
J Food Sci Technol. 2017 Sep;54(10):3180-3191. doi: 10.1007/s13197-017-2756-8. Epub 2017 Aug 22.
Fruit phenolics are important dietary antioxidant and antidiabetic constituents. The fruit parts (pulp, seed, seed coat, kernel) of underutilized indigenous six black jamun landraces ( L.), found in Gir forest region of India and differed in their fruit size, shape and weight, are evaluated and correlated with antidiabetic, DPPH radical scavenging and phenolic constituents. The α-amylase inhibitors propose an efficient antidiabetic strategy and the levels of postprandial hyperglycemia were lowered by restraining starch breakdown. The sequential solvent systems with ascending polarity-petroleum ether, ethyl acetate, methanol and water were performed for soxhlet extraction by hot percolation method and extractive yield was found maximum with methanolic fruit part extracts of six landraces. The methanolic extracts of fruit parts also evidenced higher antidiabetic activity and hence utilized for further characterization. Among the six landraces, pulp and kernel of BJLR-6 (very small, oblong fruits) evidenced maximum 53.8 and 98.2% inhibition of α-amylase activity, respectively. The seed attained inhibitory activity mostly contributed by the kernel fraction. The inhibition of DPPH radical scavenging activity was positively correlated with phenol constituents. An HPLC-PDA technique was used to quantify the seven individual phenolics. The seed and kernel of BJLR-6 exhibited higher individual phenolics-gallic, catechin, ellagic, ferulic acids and quercetin, whereas pulp evidenced higher with gallic acid and catechin as α-amylase inhibitors. The IC value indicates concentration of fruit extracts exhibiting ≥50% inhibition on porcine pancreatic α-amylase (PPA) activity. The kernel fraction of BJLR6 evidenced lowest (8.3 µg ml) IC value followed by seed (12.9 µg ml), seed coat (50.8 µg ml) and pulp (270 µg ml). The seed and kernel of BJLR-6 inhibited PPA at much lower concentrations than standard acarbose (24.7 µg ml) considering good candidates for antidiabetic herbal formulations.
水果中的酚类物质是重要的膳食抗氧化剂和抗糖尿病成分。对印度吉尔森林地区发现的6个未充分利用的本土黑醋栗地方品种的果实部分（果肉、种子、种皮、果仁）进行了评估，这些品种在果实大小、形状和重量上存在差异，并将其与抗糖尿病、DPPH自由基清除能力和酚类成分进行了关联分析。α-淀粉酶抑制剂提出了一种有效的抗糖尿病策略，通过抑制淀粉分解降低餐后高血糖水平。采用极性递增的顺序溶剂系统——石油醚、乙酸乙酯、甲醇和水，通过热渗滤法进行索氏提取，发现6个地方品种的果实部分甲醇提取物的提取率最高。果实部分的甲醇提取物也显示出较高的抗糖尿病活性，因此用于进一步表征。在这6个地方品种中，BJLR-6（果实非常小，呈长方形）的果肉和果仁对α-淀粉酶活性的抑制率分别最高，为53.8%和98.2%。种子的抑制活性主要由果仁部分贡献。DPPH自由基清除活性的抑制与酚类成分呈正相关。采用HPLC-PDA技术对7种单一酚类物质进行定量。BJLR-6的种子和果仁表现出较高的单一酚类物质——没食子酸、儿茶素、鞣花酸、阿魏酸和槲皮素，而果肉中没食子酸和儿茶素作为α-淀粉酶抑制剂的含量较高。IC值表示对猪胰腺α-淀粉酶（PPA）活性表现出≥50%抑制作用的水果提取物浓度。BJLR6的果仁部分IC值最低（8.3μg/ml），其次是种子（12.9μg/ml）、种皮（50.8μg/ml）和果肉（270μg/ml）。考虑到BJLR-6的种子和果仁是抗糖尿病草药配方的良好候选者，它们对PPA的抑制浓度远低于标准阿卡波糖（24.7μg/ml）。
