Hi there,
I have a set of 13 metabolites. I want to do pathway or enrichment analysis. For 10/13 metabolites I found their HMDB ID, and for 3/13 their PubChem ID (since they do not have HMDB ID). However, when performing enrichment or pathway analysis, half of the metabolites are not matched against the library set (which is either KEGG or SMPDB). It seem like they are not found there. Those metabolites are:
CE(17:1) → 131769811 (PubChem ID)
Cer(d16:1/24:1) → HMDB0011694
FA(8:0)-2OH → 5312790 (PubChem ID)
5alpha-Pregnan-3beta,20alpha-diol disulfate → HMDB0094650
PC(O-16:0/16:0) → 145911 (PubChem ID)
PC(P-16:0/16:1) → HMDB0011206
Because they are not found, they are not taken into account in the enrichemnt/pathway analysis. How can I solve this problem?
Thank you!
PD. Also, what’s the difference between pathway and enrichment analysis?