規格:1g 產地:愛爾蘭 含量:>95% 外觀 粉末 比重 不適用 溶于水 pH值 6.0 無異味 形態: 粉末 穩定性 穩定 超過5年（冰箱） 配料: 名稱 比例 硝基苯-Oligosacchairides 100％ p-Nitrophenyl maltopentaose Purity > 95% Catalogue Number: O-PNPG5 Content: 1 gram Appearance Powder Specific Gravity Not applicable Solubility in Water Readily soluble pH Value 6.0 Odour None Form Powder Stability Stable in a freezer for more than 5 years. Ingredients Name CAS Proportion Nitrophenyl-Oligosacchairides 100% DESCRIPTION: p-Nitrophenyl maltopentaoside （PNPG5; MW = 950.1） contains an alpha-linked p-nitrophenyl group at the reducing end of maltopentaose. This oligomer is a substrate for enzymes such as amyloglucosidase, a-glucosidase or ß-amylase. The substrate as supplied is > 95% pure with very minor contamination with p-nitrophenyl maltotetraoside and p-nitrophenyl maltohexaoside. ASSAY OF b-AMYLASE USING PNPG5: PNPG5 is used in combination with yeast a-glucosidase （“Betamyl b-amylase assay reagent”） for the assay of cereal b-amylases. However this reagent is also hydrolysed by microbial amyloglucosidase and some a-glucosidases. Consequently, it cannot be used to selectively measure b-amylase in the presence of these other enzymes. Yeast a-glucosidase has little action on PNPG5, but rapidly hydrolyses p-nitrophenyl maltotrioside （PNPG3）.