Pseudoceratina purea

Crews et al. proposed a biogenetic pathway, based on the isolation of prep-sammaplin A (155), to rationalize the formation of psammaplin A (152) and other bromotyrosine derivatives isolated from Pseudoceratina purea by his group (110, 112). A straightforward dimerization of a rearranged cysteine (Cys = HS-CH2-CH2-NHCOOMe) could generate prepsammaplin A (155). Condensation of the dimer... 

The Okinawan sponge Psammaplysilla purea that contains purealidins M-0 (2004-2006) also yields purealidins J (2078), K (2079), L (2080), P (2081), Q (2082), and R (2083) (1835). Purealidin J (2078) is the antipode of pseudocer-atinine A (2089). The Indian sponge Psammaplysilla purpurea, which is the source of purpurealidins F-H (2018-2020) and other bromotyrosines (vide supra), also contains purpurealidins A (2084), B (2085), C (2086), and D (2087) (1842). A Caribbean Pseudoceratina sponge has afforded the simple carboxylic acid 2088 (1868). The New Caledonian sponge Pseudoceratina verrucosa, which is the source of pseudoceratinine B (1990), also contains pseudo-ceratinines A (2089) and C (2090), the absolute configurations of which are shown (1829). 

Psammaplysilla purea and was named as purealidin R (79). Alkaloid 98 was isolated from a Caribbean sponge Pseudoceratina sp. as a major brominated metabolite (80). 

Purealidin C (192) was isolated from the Okinawan sponge P. purea, which exhibited cytotoxic, antifungal, and antimicrobial activities ( 4), Tokaradines A (193) and B (194), isolated from Pseudoceratina purpurea, are rare examples of marine bromotyrosine-derived metabolites containing an A-substituted pyridinium group. 

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