Pteridine from Mexico
Pteridine is a fused pyrimido-pyrimidine heterocyclic system used in biochemical research and as a precursor for folate derivatives. It falls under HTS 2934.99.90.01 as other heterocyclic compounds not specifically named elsewhere in heading 2934.
Duty Rate — Mexico → United States
110%
Rate breakdown
9903.04.6093.5%Except as provided in heading 9903.04.61, patented pharmaceutical articles as provided for in subdivisions (c) and (d) of U.S. note 40 to this subchapter
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
Import Tips
• Include NMR and mass spectrometry data in import documentation to confirm heterocyclic structure
• Declare CAS number (91-18-9) accurately to match tariff database entries
• Obtain prior FDA notification if destined for biological research applications