Identification of novel nucleotides found in the red seaweed Porphyra umbilicalis

Extracts of the red seaweed Porphyra umbilicalis are a valuable constituent of herbal medicines. The nucleotide complement of such an extract was purified and compounds identified by chromatographic behaviour, UV absorbance/pH profile, base-to-phosphate ratio, acid hydrolysis, and by fast-atom bombardment mass spectrometry with mass-analysed ion kinetic energy spectrum scanning. In addition to eighteen common nucleotides, and two cyclic nucleotides, fifteen novel nucleotides were identified, comprising eight deoxynucleotides and two cyclic deoxynucleotides, ten aminoacylnucleotides and two nucleoside trisphosphates together with 2'-phosphoadenosine-3',5'-cyclic pyrophosphate, 5'-phosphoadenosine-2',3'-cyclic monophosphate and N6,N6-dimethyladenosine-5'-monophosphate. The possible origin and potential actions of these novel compounds are discussed.