Two novel quinoline-2-carboxylic acid derivatives, perspicamides A (2) and B (3), were isolated from the Australian ascidian Botrylloides perspicuum. Extraction of the freeze-dried ascidian with methanol and purification of the extract by C18 MPLC followed by repeated C18 HPLC yielded the new compounds 2 and 3 as well as the known compounds botryllamides A-C (4-6). The structures of 2 and 3 were determined from analysis of 2D NMR spectra. 2-Quinolinecarboxylic acid derivatives are relatively uncommon in nature. Simple quinolinecarboxylic acids have been isolated from a variety of insects including cockroaches, flies, and butterflies. Xanthurenic acid, or 4,8 dihydroxy-2-quinolinecarboxylic acid, a metabolite of tryptophan, is present in urine in cases of vitamin B6 deficiency. The 8-methoxy derivative of xanthurenic acid is a possible endogenous carcinogen. Only four quinolinecarboxylic acid deriviatives have been reported from marine organisms: xanthurenic acid and its derivatives, tridemnic acids A (1) and B, which have been isolated from the ascidian Trididemnum sp. from British Columbia, and 4,5,8-trihydroxyquinolinecarboxylic acid, which has been isolated from the Antarctic sponge Dendrilla membranosa. This paper reports the structures of two xanthurenic acid derivatives, perspicamides A (2) and B (3), which we have isolated from the Australian ascidian Botrylloides persipicuum Herdman 1886 (Styelidae). The ascidian also contained the enamide derivatives botrylamides A-C (4- 6), which have been isolated previously from Botryllus schlosseri from the Great Barrier Reef and Botryllus sp. from the Philippines.