1-(3-Mercaptopropionic acid)-8-D-arginine vasopression monoacetate 16679-58-6 62288-83-9 DDAVP Demopressin acetate Desmopressin acetate Desmopressin acetate anhydrous Desmopressin monoacetate Octostim Vasopressin, 1-(3-mercaptopropanoic acid)-8-D-arginine-, monoacetate (salt)