p1-185 p1-185 p1-185, also known as progesterone 3-o-(l-valine)-e-oxime or as pregn-4-ene-3,20-dione 3-o-(l-valine)-e-oxime, is a synthetic progestogen and neurosteroid and an oxime ester analogue and prodrug of progesterone (and by extension of allopregnanolone). it was developed as an improved water-soluble version of progesterone such that it could be formulated as an aqueous preparation and easily and rapidly administered intravenously as a potential therapy for traumatic brain injury. however, the chemical synthesis of p1-185 was described as somewhat challenging, so oxime conjugates of progesterone of the c20 instead of c3 position, such as eidd-1723 and eidd-036, have since been developed. p1-185clinical dataother names(3e)-3-(imino)pregn-4-en-20-onedrug classprogestogen; neurosteroididentifiers iupac name phenanthren-3-ylidene]amino] (2s)-2-amino-3-methylbutanoate cas number1185297-01-1pubchem cid44219330chemspider25052147chemblchembl565873chemical and physical dataformulac26h40n2o3molar mass428.617 g·mol−13d model (jsmol)interactive image smiles cc(c)(c(=o)o/n=c/1\cc2(3cc4((3ccc2=c1)cc4c(=o)c)c)c)n inchi inchi=1s/c26h40n2o3/c1-15(2)23(27)24(30)31-28-18-10-12-25(4)17(14-18)6-7-19-21-9-8-20(16(3)29)26(21,5)13-11-22(19)25/h14-15,19-23h,6-13,27h2,1-5h3/b28-18+/t19-,20+,21-,22-,23-,25-,26+/m0/skey:jfipywocxpcafx-nprmjfgvsa-n