W.C.Dumlap et al.I Methods 4(2007)358-370 R1-CHMOERCMCE a=L D=D X( aB(64 fied to be the dinoflagellate Symbiodinium sp.partner [89]. mide 1-5 (54-58)and ulicyelamide alhotehcpucdtyndcrnve atrine (ine Tpohcrmainetdcednonsteroidalantinnammao r0203 0 marine sponge Luffariella rariabilis 94.95 As with the ins,it has bee hat fusco agea inL tariabilis,which lacks resident phytosymbionts,is an IC (10-15 nM)similar to that of paclitaxel 97 Eleutherobin,together with several related derivatives was later disc hin i ch dive taxa,although unproven,argues strongly that this pharma 99)tha eleuthe extraction of the natural C4 hemiacetal precursor,des- methyleleutherobin(74). to secondary metabolites of unambiguous istramide B(63) are likely to be derived from dietary sources or from com nensal microbiota residing within an host te-spe amides (4t-43) (44 which are the potent anti-inflammatory pseudopterosins nd Peloruside (5 Newald Myclo A-D(6568)isolated from the gorgonian (sea whip)cora thae and are the Estee thetic source of these diterpene glycosides has been identi- possibly involving commensal cyanobacteria 76] NH S O N N N NH O S N NH O R2 O R1 O X (54) Lissoclinamide 1 R1=CHMe2 R2=CHMeEt a=L b=D X=thiazole (Δ) (55) Lissoclinamide 2 R1=CHMeEt R2=CHMe2 a=D b=D X=thiazoline (56) Lissoclinamide 3 R1=CHMeEt R2=CHMe2 a=D b=L X=thiazoline (57) Lissoclinamide 4 R1=CHMe2 R2=CH2Ph a=L b=D X=thiazoline (58) Lissoclinamide 5 R1=CHMe2 R2=CH2Ph a=L b=D X=thiazole (Δ) (59) Ulicyclamide R1=CHMeEt R2=Me a=L b=D X=thiazole (Δ) a b Δ lissoclinamide 1-5 (54-58) and ulicyclamide (59) N N S O N N N O S N O O Δ A = thiazoline B = thiazole (Δ) bistratamide A (60) and B (61) O N N O O HO OH O O O bistratene (bistramide) A (62) O N N O O O O OH O OH bistramide B (63) Soft corals are known to be the ‘‘producers’’ of pharma￾cologically important terpenes, the most developed of which are the potent anti-inflammatory pseudopterosins A–D (65–68) isolated from the gorgonian (sea whip) coral Pseudopterogorgia elisabethae and are used in the Estee Lauder’s Resilience skin care products [88]. The biosyn￾thetic source of these diterpene glycosides has been identi- fied to be the dinoflagellate Symbiodinium sp. partner [89], although reputedly derived from bacteria associated with the Symbiodinium endosymbiont [10]. Recently the full bio￾synthetic pathway has been elucidated for the pseudoptero￾sins with elisabethatriene (69) as a key intermediate [90,91]. Two other marine-derived non-steroidal anti-inflammatory terpenoids are the 5-lipoxygenase inhibitor fuscoside (70) from the Caribbean soft coral Eunicea fusca [92,93] and the phospholipase A2 inhibitor manoalide (71) from the marine sponge Luffariella variabilis [94,95]. As with the pseudopterosins, it has been demonstrated that fuscol (72) from E. fusca is biosynthesised by its dinoflagellate partner [96], whereas the biosynthetic origin of manoalide in L. variabilis, which lacks resident phytosymbionts, is uncertain. The diterpene glycoside eleutherobin (73) iso￾lated from the soft coral Eleutherobia sp. from Western Australia is a potent antimitotic cancer cell inhibitor with an IC50 (10–15 nM) similar to that of paclitaxel [97]. Eleutherobin, together with several related derivatives, was later discovered in the encrusting coral Erythropodium caribaeorum inhabiting waters of South Florida and the Caribbean [98]. The finding of eleutherobin in such diverse taxa, although unproven, argues strongly that this pharma￾cophore is produced by a microbial symbiont common to both corals. It should be noted that eleutherobin, however, is an isolation artefact [99] that occurs from methanol extraction of the natural C-4 hemiacetal precursor, des￾methyleleutherobin (74). 6. Targeting phytosymbiont selection in drug bioprospecting using molecular discrimination As discussed previously, MNPs that co-occur in unre￾lated genera of marine organisms, or are closely related to secondary metabolites of unambiguous microbial origin, are likely to be derived from dietary sources or from com￾mensal microbiota residing within an invertebrate host. The remarkable site-specific divergence in metabolite bio￾synthesis of the mycalamides (41–43), pateamine (44), and peloruside (45) by New Zealand Mycale conspecifics [75], although yet to be substantiated, argues strongly that the sponge residing under different abiotic conditions sus￾tains different chemotypic populations of endosymbionts, possibly involving commensal cyanobacteria [76]. NH OH O O O O HN O N O N Me OMe O O O N H O Me N O N O OH didemnin B (64) W.C. Dunlap et al. / Methods 42 (2007) 358–376 367