Rhein, also known as cassic acid, is a substance in the anthraquinone group obtained from rhubarb. Like all such substances, rhein is a cathartic. Rhein is commonly found as a glycoside such as rhein-8-glucoside or glucorhein. Rhein was first isolated in 1895. It is found in rhubarb species like Rheum undulatum and Rheum palmatum as well as in Cassia reticulata.

CAS：478-43-3
中文别名：1,8-二羟基-3-羧基蒽醌;9,10-二氢-4,5-二羟基-9,10-二氧代-2-蒽羧酸;4,5-二羟基蒽醌-2-羧酸;4,5-二羟蒽醌-2-羧酸;
英文别名：1,8-dihydroxy-3-carboxy-9,10-anthraquinone;4,5-Dihydroxy-9,10-dioxo-9,10-dihydroanthracene-2-carboxylic acid;Cassic acid;2-Anthracenecarboxylic acid, 9,10-dihydro-4,5-dihydroxy-9,10-dioxo-;Rheic acid;Rhubarb Yellow;1,8-dihydroxyanthraquinone-3-carboxylic acid;4,5-dihydroxyanthraquinone-2-carboxylic acid;1,8-dihydroxy-3-carboxyanthraquinone;9,10-Dihydro-4,5-dihydroxy-9,10-dioxo-2-anthracenecarboxylic acid;Monorhein;4,5-Dihydroxyanthraquinone-2-carboxylic acid;9,10-dihydro-4,5-dihydroxy-9,10-dioxoanthracene-2-carboxylic acid;Rheic Acid;Chrysazin-3-carboxylic acid;
分子式：C15H8O6
分子量：284.22
精确质量：284.032
Psa：111.9
Logp：1.5714

MDL号：MFCD00009618

外观与性状：为咖啡色针晶，升华后为黄色针晶。熔点 321-322℃，水溶性<0.1g/100mL
熔点：≥300°C(lit.)
储存条件：2-8°C

RTECS号：CA9516000
安全说明：S26; S37/39
危险类别码：R36/37/38
WGK Germany：2
海关编码：2918990090
危险品标志：Xi
危险标志：GHS07
信号词：Warning
危险性描述：H315; H319; H335
危险性防范说明：P261; P305 + P351 + P338

用途
蛋白酶抑制剂。医药。