Theonezolide

The theonezolides are 37-membered macrocycles, consisting of fatty acid chains with attached functionalities such as a sulfate ester and a thiazole [22]. Theonezolide A (610) is a cytotoxic metabolite of Theonella sp. from Okinawa. The structure was reported without stereochemical details [489]. The structures of theonezolides B (611) and C (612) from a Japanese Theonella sp. were determined by spectroscopic methods but without stereochemistry, except at one centre [490]. 

The theonezolides A-C (431-433) were isolated from the sponge Theonella sp. They are 37-membered macrocyclic compounds consisting of two principal fatty acid chains with various functionalities such as a sulfate ester, an oxazole, and a thiazole [336, 337]. Compounds 431-433 displayed cytotoxic activity against L1210 and KB cells and were found to have a unique bioactivity in terms of induction of rabbit platelet shape change and aggregation [338]. 

Rho, M.-C., Park, Y.-H., Sasaki, S., Ishibashi, M., Kondo, K., Kobayashi, J., and Ohizumi, Y. (1996). The mode of rabbit platelet shape change and aggregation induced by theonezolide-A, a novel polyketide macroUde, isolated from the Okinawan marine sponge Theonella sp. Can. J. Physiol. Pharmacol. 74,193-199. 

Two additional macrolides, theonezolides B (127) and C (128), were also isolated from the same Okinawan marine sponge Theonella sp., and their structures were elucidated on the basis of spectroscopic data as well as chemical degradation experiments [77]. Altihough the H NMR spectra of theonezolides B (127) and C (128) appeared almost indistinguishable to... 

Subsequently we studied the stereochemistry of the C-4 C-17 fragment (123), which were commonly obtained by ozonolysis of the three macrolides, theonezolides A (121), B (127), and C (128). This fragment (123) contains 4 chiral centers which comprise two 1,3-diol type moieties (14-OAc/16-OMe and 8-OAc/lO-OAc) the numberings of the carbons for compound 123 and the following model compounds described... 

Theonezolides A-C are cytotoxic macrolides containing an oxazole and a sulfate group in the lactone ring with 37 members the configurations of 23 chiral centers are not yet fully determined (Kobayashi et al, 1993c Kondo, Ishibashi, and Kobayashi, 1994). 

T. (1993c) Theonezolide A a novel polyketide natural product from... 

Kondo, K., Ishibashi, M., and Kobayashi, J. (1994) Isolation and structures of theonezolides B and C from the Okinawan marine sponge TheoneUa sp. Tetrahedron, 50,8355-8362. 

---