3d image of tetrahydrobiopterin skeletal formula

tetrahydrobiopterin bh4 thb sapropterin cofactor aromatic amino acid hydroxylase phenylalanine biosynthesis neurotransmitters serotonin melatonin dopamine norepinephrine noradrenaline epinephrine adrenaline enzyme coenzyme biosynthesis autism neuroprotection prenatal hypoxia programmed cell death depression metabolite metabolism cycle mechanism pathway catabolism biosynthetic intermediate biogenesis substrate precursor synthesis derivative bioprecursor metabolic endogenous contractor molecule molecular formula skeletal structural structure 3d