2937.90.45.00 - Other

This HTS category, 2937.90.45.00, encompasses "Other" amino-acid derivatives used as hormones, prostaglandins, thromboxanes, leukotrienes, or their structural analogues. Following the broader classification of hormones and their synthetic counterparts, this specific subheading captures those amino-acid derivatives that do not fall under more specialized headings within Chapter 29. The key determinant for classification here is the functional use of the compound as a hormone or a related signaling molecule, whether derived from natural sources or synthesized.

This category is distinguished from its sibling, 2937.90.40.00, which specifically covers l-Thyroxine (Levothyroxine) and its sodium salt. Therefore, any amino-acid derivative that functions hormonally but is not l-Thyroxine or its sodium salt would be classified under this "Other" subheading. The focus remains on the hormonal or analogous biological activity of these compounds.

As this node represents a leaf category, there are no further subcategories. Classification under 2937.90.45.00 relies on the process of elimination: if an amino-acid derivative meets the general description of hormonal activity within the scope of heading 2937, and is not specifically enumerated in a preceding subheading, it will be classified here. Documentation supporting the intended use as a hormone is crucial for accurate classification.