Compounds that are mammalian metabolites of an agonist of G-protein-coupled receptor 1.39 (GPR139), intermediates used in the synthesis of such metabolites, pharmaceutical compositions comprising such metabolites, and the use of such metabolites as biomarkers and agents in the treatment of schizophrenia, for example, negative and/or cognitive symptoms of schizophrenia, disorders associated with social and cognitive dysfunction, as well as several other disorders related to modulated of GPR139.

##STR00001##

A polymer of structure (A) with two end group R.sub.3p, and R.sub.4p, and a polymer chain (R) which has either repeat units of structures (Ip) or (IIp). R.sub.3p, is either a C-1 to C-8 alkyl, a moiety of structure (IIIp), or a moiety of structure (IIIpI). R.sub.3p is a C-1 to C-8 alkyl if the repeat unit is (IIp). R.sub.3p is structure (IIIp) or structure (IIIp1) if the repeat unit has (Ip). R4p is either a terminating moiety such as H, a moiety of structure (IVp), a moiety of structure (IVp1), or a moiety of structure (IVp2). R.sub.3p and R.sub.4p cannot respectively, both simultaneously, be moieties of structure (IIIp) and (IVp), simultaneously be moieties of structure (IIIp) and (IVp1), or simultaneously be moieties of structure (IIIp) and (IVp2). The polymer of structure (A) must contain, one grafting end group moiety selected from structures (IIIp), (IVp), (IVp1) or (IVp2). Composition of this with a solvent are used in DSA processing.