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Bromopyrrole alkaloids comprise a typical class of marine natural products, frequently encountered as secondary metabolites of marine sponges of various species.1 During our studies on bioactive substances from Okinawan marine organisms,1 2 we have examined the extracts of numerous marine sponges and isolated several bromopyrrole alkaloids, which were found to be pharmacologically useful as «-adrenoceptor blockers,3 antagonists of serotonergic receptor,4 and actomyosin ATPase activators.5 Recently, we investigated bioactive constituents of another Okinawan sponge Hymeniacidon sp. and isolated three novel compounds, named manzacidins A-C (1-3), belonging to an unprecedented class of bromopyrrole alkaloids with an unusual 3,4,5,6-tetrahydropyrimidine ring. Here, we describe the isolation and structure elucidation of 1-3.The sponge Hymeniacidon sp., collected at Manza Beach, Okinawa, was extracted with methanol. The

According to the traditional usage of the plant for antiinflammation and analgesia, Leucas aspera was tested for its prostaglandin (PG) inhibitory and antioxidant activities. The extract showed both activities, i.e., inhibition at 3 x 10(-4) g/ml against PGE(1)- and PGE(2)-induced contractions in guinea pig ileum and a 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect. The separation guided by the activities in these dual assay methods provided eight lignans and four flavonoids, LA-1- -12, among which LA-1- -7 and LA-10- -12 were identified as nectandrin B, meso-dihydroguaiaretic acid, macelignan, acacetin, apigenin 7-O-[6"-O-(p-coumaroyl)-beta-D-glucoside], chrysoeriol, apigenin, erythro-2-(4-allyl-2, 6-dimethoxyphenoxy)-1-(4-hydroxy-3-methoxyphenyl)propan-1-ol, myristargenol B, and machilin C, respectively. LA-8 was determined to be (-)-chicanine, the new antipode of the (+) compound, by spectroscopic methods including CD and ORD. Chiral-HPLC analysis of LA-9 showed that it was a mixture of two enantiomers, (7R, 8R)- and (7S, 8S)-licarin A. All of these components were first isolated from L. aspera. PG inhibition was observed in LA-1, LA-2, and LA-5, and antioxidant activity in LA-1- -3 and LA-8- -12.