Has acyl-CoA dehydrogenase activity on a number of substrates. N-octanoyl-CoA is the best tested, but n-lauroyl-CoA, n-palmitoyl-CoA and isovaleryl-CoA were also used. A + a 2,3-saturated acyl-CoA = a 2,3-dehydroacyl-CoA + AH2 Belongs to the acyl-CoA dehydrogenase family.