烟酰胺腺嘌呤二核苷酸磷酸(nicotinamide adenine dinucleotide phosphate)缩写NADP，曾称为三磷酸吡啶核苷酸（TPN）或辅脱氢酶Ⅱ或辅酶Ⅱ。它是一种辅酶，是烟酸酰胺腺嘌呤二核苷酸与一个磷酸分子以酯键结合的物质，广泛存在生物界。化学性质、吸收光谱、氧化还原形式等均类似NAD。它通过6-磷酸葡萄糖脱氢酶（EC．1．1．1．49），6-磷酸葡萄糖酸脱氢酶（EC．1．1．1．44）等，可被许多脱氢酶进行可逆的还原。但是与很多利用NAD的脱氢酶不一定能进行反应，也不能呼吸链直接氧化。在好氧生物的细胞中与NAD不同，它主要以还原态存在。氧化型辅酶Ⅱ二钠（NADP,disodium salt）用作各种诊断检测中的辅助因子。 

Formula: C₂₁H₂₆N₇O₁₇P₃Na₂
Molecular weight: 787.4 D (NADP: 743.4 D)
Appearance: White to yellowish amorphous powder
Solubility: Clear, colorless solution in water (c=50 mg/ml)
NADP, Na-salt (from value found enzymatically, based on dry weight): ≥97%
NADP (enzymatically, A₃₄₀, ε=6.3 [l x mmol^-1 x cm^-1]): ≥85%
NADP (A₂₆₀, ε=18 [l x mmol^-1 x cm^-1]): ≥85%
Na (flame photometric): 4.5±0.5%
Water (K. Fischer): ≤6%
NAD (enzymatically): ≤0.5%
Methanol (GC): ≤3%
A₃₆₀ (c=10 mg/ml water, against water): ≤0.600
A₃₄₀ (c=0.01 mg/ml phosphate buffer, pH 7.0): ≤0.005
Stability: At +2 to +8°C within specification range for 24 months.Store dry.