I have a bunch of metabolites that are differentially expressed between populations (~800+). The data was generated using untargeted metabolomics and were annotated using classyFire annotations. One of my colleagues wants to know how many of these differentially expressed metabolites are (putatively) involved in primary metabolism vs secondary metabolism. I am quite new to metabolomics and my training is largely in statistical genomics, so I have little knowledge of the metabolomics databases or the function of these metabolites. I am hoping to find some resource that will allow me to enter the InChIKeys (or something similar) and determine whether these metabolites are involved in primary or secondary metabolism. I have an inclination that such a resource does not exist and the definition of primary or secondary metabolism may be dependent on the organism. Does anyone have some insight on how to easily classify 800 compounds into primary or secondary metabolites? I'm working within the cereal/grass family if that matters.