(5Z,9alpha,11alpha,13E,15S)-9,11,15-Trihydroxy-16,16-dimethylprosta-5,13-dien-1-oic acid 16,16-Dimethyl PGF2 alpha 16,16-Dimethyl-pgf2alpha 16,16-Dimethylprostaglandin F2alpha 39746-23-1