Calmodulin inhibitors from the bitter mushroom Naematoloma fasciculare (Fr.) Karst. (Strophariaceae) and absolute configuration of fasciculols.

Calmodulin inhibitors were found in the bitter poisonous mushroom Naematoloma fasciculare (Fr.) KARST. (Strophariaceae). The active compounds, fasciculols B, C, and F, were isolated by droplet counter-current chromatography and identified on the basis of various physical and spectral data. Application of the dibenzoate chirality method to a p-bromobenzoate derivative of fasciculol C allowed the absolute configurations at the C-2 and C-3 positions to be determined as (R) and (S), respectively.