Absolute Configuration of Symbiodinolactone A

The absolute configurations at five stereogenic centers in symbiodinolactone A, a 12-membered macrolide isolated from the symbiotic marine dinoflagellate <i>Symbiodinium</i> sp. associated with an acoelomorpha <i>Amphiscolops</i> sp., were determined to be 7<i>R</i>,11<i>R</i>,12<i>R</i>,13<i>R</i>,14<i>R</i>. A combination of different techniques was applied in this regard such as Rychnovsky's method, Kishi's universal NMR databases, the modified Mosher's method, and comparison of the NMR data of the bis(<i>S</i>)-MTPA ester of a degradation product of symbiodinolactone A with those of synthesized reference compounds. In addition, symbiodinolactone A was found to exhibit cytotoxicity against L1210 murine leukemia cells.