Abstract
1. Serotonin O-sulfate was synthesized and its infrared spectrum, ultraviolet spec-trum and paper chromatographic properties were investigated.
2. On rat small intestine the contraction (or stimulating) activity of serotonin O-sul-fate was, if any, less than one hundredth of serotonin.
3. Serotonin O-sulfate was hydrolyzed by sulfatase of Charonia lampas (Tritonalia sauliae), but not measurably by the extracts of mammalian organs.
The authors are very grateful to Prof. S. Ebashi and Dr. F. Ebashi for the pharmacological studies and to Dr. G. Chihara for infrared spec-troscopy. A part of expense of this study was defrayed by a grant from the Ministry of Education and from Seikagaku-Kenkyusho Ltd., to which our thanks are due.
