Alpinetin Chemical Identity
Alpinetin (7-hydroxy-5-methoxyflavanone, C16H14O4, molecular weight 270.28) is a flavanone: a chromanone ring closed between a phenolic A ring and a phenyl B ring, with a saturated bond between carbons 2 and 3. It has one stereocenter at carbon 2. Unlike a flavone, the saturated ring breaks the full conjugation, which is why the powder is pale instead of yellow.
The raw material is the seed of Alpinia katsumadai Hayata (Zingiberaceae), the spice-like seed mass used in Chinese herbal practice; other Alpinia species such as A. oxyphylla are different raw materials. Alpinetin is closely related to pinocembrin, which is 5,7-dihydroxyflavanone, and to cardamonin, the chalcone that can cyclize into alpinetin and carries the same formula C16H14O4.
Related products include Cardamonin 98%, Pinocembrin 98% and Alpinia katsumadai extract powder. Chalcone and flavanone are isomers with the same mass, so the CAS number 1090-65-9 and the InChIKey in the table fix the identity.
Several names circulate for the same seed constituents, which makes searches noisy. Alpinetin is sometimes listed under its systematic name 7-hydroxy-5-methoxyflavanone, and cardamonin appears as alpinetin chalcone. A purchase specification that quotes the CAS number 1090-65-9 and the HPLC grade identifies the flavanone and excludes the chalcone isomer.












