WC.Dumlap et al I Methods 42(2007)358-376 lated from Ircinia ramosa.Chondropsin C(77)was similarly isolated ported as a minor compo occurring in the original NSW Chondropsis sp.collection ins A-D (65-68 from a class,the 33-membered ring macrolide poecillastrin A (80),was isolated from a Caribbean deep-water collection ue() (77)Chondropsin C R -H 人 ()B(6)C()and 7-dexychoodropin (7) fuscol (72 oosin D(79 及：Conversely, the potent anti-proliferative sponge metabo￾lites chondropsins A (75) and B (76) were first isolated from an Australian (New South Wales) collection of Chondropsis sp. [100], followed by the discovery of chondropsin A (75) and 73-deoxychondropsin (78) in the Queensland sponge Ircinia ramosa. Chondropsin C (77) was similarly isolated from a Philippines specimen of Ircinia sp. [101], and chon￾dropsin D (79), containing a 37- instead of a 35-membered ring macrocycle, was later reported as a minor component occurring in the original NSW Chondropsis sp. collection [102]. Chondropsin macrolide lactams have also been iso￾lated from a New Caledonian sponge of the genus Psam￾moclemma [103]. An additional member of this structural class, the 33-membered ring macrolide poecillastrin A (80), was isolated from a Caribbean deep-water collection of Poecillastra sp. having similar anti-proliferative proper￾ties of the chondropsins [104]. O HN HO O OH O O OH OH OR OH HN O OH OH OH HO O H O N O OH O O OH R= O OH OH O chondropsin D (79) H OH O R3O R2O R1O O (65) Pseudopterosin A R1 = H, R2 = H, R3 = H (66) Pseudopterosin B R1 = Ac, R2 = H, R3 = H (67) Pseudopterosin C R1 = H, R2 = Ac, R3 = H (68) Pseudopterosin D R1 = H, R2 = H, R3 = Ac pseudopterosins A-D (65-68) H H elisabethatriene (69) O OH O OH OAc H OH H fuscoside (70) O O OH OH O manoalide (71) H H OH fuscol (72) O OR O OCOMe O OH OH O O N N R = Me; eleutherobin (73) R = H; desmethyleleutherobin (74) O H N O HO O OH O O OH OH OH R3O OH HN O HO OH H N OH R2 OH O O R1 (75) Chondropsin A R1 = R2 = OH R3 = (76) Chondropsin B R1 = R2 = OH R3 = H (77) Chondropsin C R1 = H R2 = H R3 = (78) 73-deoxychondropsin R1 = R2 = H R3 = OMe O OMe O OMe O O OH OH O O OH OH O O OH OH O chondropsins A (75), B (76), C (77) and 73-deoxychondropsin (78) 368 W.C. Dunlap et al. / Methods 42 (2007) 358–376