Effect of an anti-ulcer drug, plaunotol, and its metabolites on NAD+ dependent 15-hydroxyprostaglandin dehydrogenase from gastric mucosa

15-Hydroxyprostaglandin dehydrogenase was partially purified from hog gastric mucosa by about 1000-fold with a 13.5% yield. Its molecular weight was estimated to be 32,000 daltons by gel filtration. The enzyme was inhibited by some metabolites of plaunotol [(2E, 6Z, 10E)-7-hydroxymethyl-3,11,15-trimethyl-2,6,10,14-hexadecatetrae n-1- ol], a new anti-ulcer drug. The inhibition patterns for substrates, prostaglandin E1 and NAD+ were both uncompetitive with Ki values of 7.8 and 19.7 microM, respectively.