3 methoxy tyramine hydrochloride

Gallic acid (GA), trans-caffeic acid (CA) and its methylated products (3-hydroxy-4-methoxycinnamic acid (trans), trans-ferulic acid), 3,4-dihydrobenzaldehyde (DHA) and its methylated products (vanillin, iso-vanillin), protocatechuic acid (PCA), dopamine hydrochloride and its methylated products (3-hydroxy-4-methoxy-phenethylamine hydrochloride, 3-methoxy-tyramine hydrochloride), quercetin, and luteolin were obtained from Sigma-Aldrich (USA). Two major methylated products of GA (3,4-dihydroxy-5-methoxybenzoic acid (5OMeBA), 3,5-dihydroxy-4-methoxybenzoic acid), methylated products of 5OMeBA (5-hydroxyveratric acid, syringic acid), methylated products of PCA (3-hydroxy-4-methoxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid), 5-hydroxyuridine (ho⁵U) and the methylated product 5-methoxyuridine (mo⁵U) were purchased from Carbosynth (UK).

Animals aged 15 to 30 weeks were used for LC–MS/MS experiments. The chemicals and reagents were purchased as follows: 2-phenylethylamine hydrochloride was obtained from Tokyo Chemical Industry (Tokyo, Japan). l-(−)-norepinephrine (+)-bitartrate salt monohydrate, dopamine hydrochloride, 5-hydroxytryptamine creatinine sulfate monohydrate, 3-methoxytyramine hydrochloride, 5-hydroxyindole-3-acetic acid, and 3,4-dihydroxybenzylamine hydrobromide were obtained from Sigma-Aldrich. Dihydroxybenzylamine (DHBA) was used as an internal standard. LC–MS-grade formic acid (FA) and acetonitrile (ACN) were purchased from Fujifilm Wako Pure Chemical Corporation (Osaka, Japan). Ascorbic acid (AA) was purchased from Tokyo Chemical Industry.