Non vitamin coenzyme is :

Lipoic acid is a coenzyme (required for Pyruvate Dehydrogenase and Alpha-Ketoglutarate Dehydrogenase) but it is not a Vitamin (Option 3). Niacin is Vitamin B3 work as coenzyme in its active form Nicotinamide adenine dinucleotide (NAD) for a number of dehydrogenase enzymes in metabolism (Option 1). Coenzyme A is a derivative of Vitamin B5 - Pantothenic acid and works in acyi group transfer reaction (Option 2). SAM - is S-Adenosyl Methionine, which is a methyl donor. It is neither a Coenzyme, nor a Vitamin (Option 4). Extra information: Another Non-vitamin coenzyme is Tetrahydrobiopterin derived from guanosine triphosphate. Vitamin K is the only fat soluble vitamin which acts as coenzyme