M5U m5u dimethyl 2,2'-((12Z,122Z,4S,6Z,8E,10E,15S,17Z,19E,21E)-2,13-dioxo-3,14-dioxa-1(4,2),12(2,4)-dioxazolacyclodocosaphane-6,8,10,17,19,21-hexaene-4,15-diyl)(2S,2'S,3S,3'S,4E,4'E)-bis(3-hydroxyhex-4-enoate) M5U