1．赤小豆 含糖類，三萜皂甙（triterpenoidsaponin)。每百克含蛋白質(zhì)20.7g，脂肪0.5g，碳水化物58g，粗纖維4.9灰分3.3g，鈣67mg，磷305mg，鐵5.2mg，硫胺素（thiamine)0.3lmg，核黃素（riboflavine)0.11mg，煙酸（nicotinicacid)2.7mg等。

2．從赤豆中分離得到3-呋喃甲醇-β-D-吡喃葡萄糖甙（3-fu-ranmethanol-β-D-hlucopyranoside)，右旋兒茶精-7-O-β-D吡喃葡萄糖甙（catechin-7-O-β-D-glucopyranoside)和1D-5-O-（a-D-吡喃半乳糖基)-4-O-甲基肌醇[1D-5-O（a-D-galactopyranosyl)-4-O-methyl-myoinositol]。還分離得到6個齊墩果烯低聚糖甙（oleanene-oligoglycosides)：赤豆皂甙（azukisaponin)Ⅰ，即是3-O-[β-D-吡喃葡萄糖基（1→2)-β-D-吡喃葡萄糖醛酸基]槐花二醇{3-O-[β-D-glucopyranosyl（1→2)-β-D-glucuronopyranosyl] sophoradiol}；赤豆皂甙Ⅱ，即是3-O-[β-D-吡喃葡萄糖基（1→2)-β-D-吡喃葡萄糖醛酸基]大豆皂醇B{3-O[β-D-glucopyranosyl（1→2)-β-D-glucuronopyranosyl]soyasapogenol B}；赤豆皂甙Ⅲ，即是3-O-[β-D-吡喃葡萄糖基（1→2)-β-D-吡喃葡萄糖醛酸基]赤豆皂醇{3-O-[β-D-glucopyranosyl（l→2)-β-D-glucuronopyranosyl]azukisa-pogenol}；赤豆皂甙Ⅳ，即是3-O[β-D-吡喃葡萄糖基-28-O-吡喃葡萄糖基（l→6)-β-D-吡喃葡萄糖基]刺葉絲石竹酸{3-O-（β-D-glucopyranosyl)28-D-glucopyranosyl（1→6)-β-D-glucopyranosyl] gypsogenic acid}；赤豆皂甙Ⅴ，即是3-O-[a-L-吡喃鼠李糖基（l→2)-β-D-吡喃葡萄糖基（1→2)-β-D-吡喃葡萄糖醛酸基]大豆皂醇B{3-O-[a-L-rhamnopyranosyl（1→2)-β-D-glucopyra-nosyl（l→2)-β-D-glucuronopyranosyl]-soyasapogenol B}和赤豆皂甙Ⅵ，即是3-O-[β-D吡喃葡萄糖基（1→2)β-D-吡喃葡萄糖醋酸基]-29-O-[β-D-吡喃葡萄糖基（1→6)-β-D-吡喃葡萄糖基]赤豆皂醇{3-O-[β-D-glucopyranosyl（1→2)β-D-glucuropyranosyl]-29-O-[β-D-glucopyranosyl（1→6)-β-D-glucopyranosyl]azukisapogenol}。

從赤豆的熱水提取物中還得到三種黃烷醇鞣質(zhì)（flavanoltannins)：D-兒茶精（D-catechin)、D-兒茶精（D-epicatechin)和表沒食子兒茶精（epigallocatechin)。從新鮮種子中分離到原矢車菊素（procyanidin)B1和B3。

具抑菌，利尿作用。