Abstract
The unsaponifiable matter from the marine red alga Porphyra tenera (asakusa-nori) did not show such stimulation as observed previously with hiziki (brown alga Hizikia fusiformis), but rather a slight inhibition on the porcine pancreatic carboxylesterase activity toward triacetin in vitro. Nine fractions obtained from the unsaponifiable matter by thin-layer chromatography were found to be divisible into two groups: an activator group and a non-activator group, which was not detected in hiziki. The addition of a non-activator fraction to an activator fraction abolished the activation activity. In addition, one of the active principles in the activator fraction of the purple laver was identified as phytol, as is the case with hiziki. These findings suggest that non-stimulation by the whole unsaponifiable matter must be due to masking of the activity of the activators by the nonactivators.