The screening of Chinese crude drugs for Ca2+ antagonist activity: identification of active principles from the aerial part of Pogostemon cablin and the fruits of Prunus mume

Hot aqueous extracts of 134 Chinese crude drugs were subjected to screening for inhibitory activity on K+ contracture of guinea pig taenia coli, and significant activity was observed in 17 crude drugs. Chemical investigations of two crude drugs, Kakko and Ubai, which originate from Pogostemon cablin and Prunus mume, respectively, were undertaken, and patchouli alcohol (I) and 5-(hydroxymethyl)-2-furaldehyde (II) were identified as their active principles, respectively.