Pteridine from Mexico
Pteridine is a fused heterocyclic system containing pyrimidine and pyrazine rings, essential for biochemical research and vitamin synthesis. Classified under HTS 2934.99.44.00 as an aromatic heterocyclic compound not elsewhere specified. Used in folate and flavin coenzyme production.
Duty Rate — Mexico → United States
100%
Rate breakdown
9903.04.6093.5%Pharmaceuticals Annex IV: patented pharma articles — 100% floor rate
9903.05.900%Articles already subject to Section 232 (steel/aluminum/copper + derivatives, autos + parts, wood, medium/heavy vehicles + parts, semiconductors, patented pharma) — U.S. note 52(f)
Import Tips
• Include NMR or HPLC analysis confirming aromatic heterocyclic structure for customs classification
• Declare intended research use to avoid pharmaceutical classification under Chapter 30
• Package with stabilizers if required for air transport per chapter note 2(f)