Pentagalloyl-glucose (PGG) occurs in many plants and possesses several therapeutic properties, including anti-diabetic ones. Based on the latter, the inhibitory action of PGG on α-amylases was investigated. PGG inhibited both the pancreatic and the salivary α-amylases. With starch as the substrate, complexation with the free enzyme form either predominates (pancreatic enzyme) or is the only complexation that is effectively allowed (salivary enzyme; competitive inhibition). This contrasts with a previous report on the salivary enzyme showing non-competitive inhibition when a synthetic substrate was used. PGG was less effective than acarbose as an inhibitor of α-amylases and presented a different binding pattern in terms of the aminoacyl residues involved. Finally, PGG also diminished the hyperglycemic excursion normally caused by starch administration when it was given to rats simultaneously to the polysaccharide. This suggests that PGG or foods and infusions rich in PGG could be helpful as adjuvants for maintaining normal glycemia.

戊糖基葡萄糖（PGG）存在于许多植物中，并具有多种治疗特性，包括抗糖尿病特性。基于后者，研究了PGG对α-淀粉酶的抑制作用。PGG同时抑制胰腺和唾液中的α-淀粉酶。以淀粉为底物，与游离酶的复合要么占主导地位（胰腺酶），要么是唯一被有效允许的复合（唾液酶；竞争性抑制）。这与先前关于唾液酶的报道相反，当使用合成底物时唾液酶显示出非竞争性抑制作用。PGG作为α-淀粉酶抑制剂的效果不如阿卡波糖，并且在涉及的氨酰基残基方面表现出不同的结合模式。最后，当PGG同时给予大鼠多糖时，PGG还减少了通常由淀粉给药引起的高血糖偏移。这表明PGG或富含PGG的食物和输注液可作为维持正常血糖的佐剂。