Silychristin

Silychristin (also known as silichristin) is a natural product and one of the constituents of silymarin, the standardized, active extract of the fruit of milk thistle, Silybum marianum. It is the second most abundant constituent in silymarin, after silybin. Silychristin is a flavonolignan, along with many other silymarin constituents (such as silybin, isosilybin, silydianin, etc.), meaning it is composed up of a flavonoid and a lignan. It is estimated that up to 65–80% of silymarin extract is made up of flavonolignans, like silychristin, which give silymarin its well known potent antioxidant and hepatoprotective properties. Silychristin can exist as two stereoisomers, silychristin A (2R, 3S) and silychristin B (2S, 3R). The marianum variety of S. marianum (purple corollas) includes silychristin A as a major flavonolignan constituent, while the lesser known and studied albiflorum variety (white corollas) includes unique flavonolignans, including silyhermin, (–)-silandrin, and (+)-silymonin.