Abstract
In general, it is difficult to distinguish between sulfate and phosphate groups in natural products, because these groups are found only in trace amounts in natural products. We have devised a hydrogen/deuterium (H/D) exchange method using the liquid chromatography mass spectrometry technique for establishing a general methodology to distinguish between sulfated and phosphorylated compounds. Sulfate- or phosphate-containing compounds were differentiated by the H/D exchange method based on the number of exchangeable hydrogen in deuterated sulfate (-SO3D) and phosphate (-PO3D2), respectively. In this paper, we describe an application of this method to a natural product and in particular to Watasenia oxyluciferin that is found in the firefly squids (Hotaru-ika in Japanese) for the purpose of identifying coelenteramide disulfate.
