Flavonoid biosynthesis

Flavonoids are synthesized by the phenylpropanoid metabolic pathway in which the amino acid phenylalanine is used to produce 4-coumaroyl-CoA. This can be combined with malonyl-CoA to yield the true backbone of flavonoids, a group of compounds called chalcones, which contain two phenyl rings. Conjugate ring-closure of chalcones results in the familiar form of flavonoids, the three-ringed structure of a flavone. The metabolic pathway continues through a series of enzymatic modifications to yield flavanones → dihydroflavonols → anthocyanins. Along this pathway, many products can be formed, including the flavonols, flavan-3-ols, proanthocyanidins (tannins) and a host of other various polyphenolics.

A study showed that men receiving saw palmetto had moderate response to the treatment versus men receiving finasteride. Even though the finasteride effect was higher, the study concluded that the saw palmetto induced suppression was statistically significant. (Marks et al.,2001)

Another study (Rossi et al., 2012) was conducted to determine how effective saw palmetto was for hair loss prevention and compared its effects with finasteride. The researchers used 100 male patients that were diagnosed with mild to moderate androgenetic alopecia. The patients were split into two groups, one received saw palmetto(320 mg) and the other received finasteride (1mg).

Flavanoids can possess chiral carbons. Methods of analysis should take this element into account especially regarding bioactivity or enzyme stereospecificity.

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