Biotin (S)-sulfoxide is an inactive metabolite of the coenzyme biotin .1,2It has also been found inE. coliand is reduced by the biotin sulfoxide reduction system as a source of biotin.3 1.Denkel, L.A., Rhen, M., and Bange, F.-C.Biotin sulfoxide reductase contributes to oxidative stress tolerance and virulence in Salmonella enterica serovar TyphimuriumMicrobiology (Reading)159(Pt 7)1447-1458(2013) 2.Carling, R.S., and Turner, C.Methods for assessment of biotin (Vitamin B7)Laboratory assessment of vitamin status193-217(2019) 3.del Campillo-Campbell, A., Dykhuizen, D., and Clearly, P.P.Enzymic reduction of d-biotin d-sulfoxide to d-biotinMethods Enzymol.62379-385(1979)
Coenzyme Q10 is a component of the electron transport chain and participates in aerobic cellular respiration, generating energy in the form of ATP. In its reduced form, it acts as an antioxidant. Coenzyme Q2 is a precursor of coenzyme Q10 that has 2, rather than 10, isoprenoid units on the ubiquinone base. It can act as an electron acceptor for bacterial Complex I. In mammalian cells, exogenous coenzyme Q2 prevents the production of reactive oxygen species associated with Complex I activity. Forms of coenzyme Q with shorter isoprenoid chains, including coenzyme Q2, induce p53-dependent apoptosis in human B-cell acute lymphoblastoid leukemia BALL-1 cells.