Proline Physical Properties and Description

What is Proline?

Proline carries a solid reputation among amino acids, holding the unique position of being a secondary amine and forming a ring structure with its side chain. In daily chemical and industrial spaces, this non-essential amino acid rises above many other building blocks for its robust cyclic structure, which impacts protein folding and molecular stability. In natural biological settings, proline helps stabilize key proteins and supports osmotic stress resistance in plants, showing up across food, feed, and pharmaceutical materials. Its solid presence in raw materials, especially in biochemistry and synthetic chemistry, keeps it in demand for both large-scale and specialized manufacturing.

Product Appearance and Material Forms

Commercially, Proline comes as a colorless or white crystalline solid, sometimes appearing as odorless flakes or fine powder. Its texture can shift to pearl-like granules, which aid in handling bulk raw materials. Anyone working with Proline powder will notice its smooth, grainy consistency, making it simple to measure, dissolve, or blend for solution preparation. Crystal forms show a distinct transparency under bright light, and the material maintains stability at regular room conditions. Whether in solid, powder, granular, or crystalline form, Proline avoids clumping and shows minimal dust generation. Density hovers near 1.35 grams per cubic centimeter, and the material dissolves quickly in water to form a clear, stable solution suitable for lab and industrial applications.

Chemical Structure and Molecular Formula

Proline stands apart with the molecular formula C₅H₉NO₂, and a molar mass of 115.13 grams per mole. Unlike almost every other amino acid, the side chain loops back and bonds to the main amine group, forming a five-membered ring. Chemists recognize this structure for the way it restricts free rotation, playing a strong role in protein conformations, especially collagen. The molecule features a carboxylic acid group, an imino group, and its own unique geometry, making it resistant to some enzymatic processes but ideal for certain synthetic strategies. Under standard temperature and pressure, Proline remains stable and shows no tendency to react violently with common solvents.

Specifications and Safety Information

For most supply chains, Proline packs with a purity of above 98% and low moisture content to ensure consistent reactivity. The chemical lands under HS Code 292249, which covers amino-acid derivatives, supporting import and export classifications internationally. Packaging options include tightly sealed bags or drums to shield the flakes or powder from moisture and contamination. No vapor pressure hazard arises under ambient conditions, and solutions can be prepared up to about 20% concentration by volume with ease.

Proline ranks as non-hazardous for typical handling and is not considered harmful by oral, dermal, or inhalation exposure in small amounts. Lab experience proves that basic protective gear, such as gloves and dust masks, offers adequate safety during use. Spillage poses minimal threat compared to more reactive or toxic raw materials, and Proline does not generate dust explosions or toxic fumes under normal use. In cases where pure powder enters the eyes or respiratory tract, simple water rinse or fresh air restores comfort. Chemical stability extends to most common reagents, except for strong oxidizers, so storage with standard dry, cool, and well-ventilated room provisions keeps the material in safe condition.

Proline in Industrial and Raw Material Applications

In industry, Proline supports peptide synthesis, protein engineering, pharmaceuticals, and even cosmetic formulations. My experience using Proline in peptide synthesis shows a reliable performance, where the ring structure cuts down on racemization and boosts final yield during solid-phase synthesis. Pharmaceutical developers rely on Proline as an essential ingredient in making collagen-related medicines and, in some regions, as a food supplement for protein drinks and amino acid infusions. Companies working with raw chemical production leverage Proline’s thermal stability and non-hygroscopicity to ship in bulk with little worry about product loss or degradation. Powder and crystal forms fit liquid solution preparation, research, and routine blending for feed or bioprocessing, with nearly no loss in quality or consistency.

Potential Hazards and Handling Recommendations

From a safety perspective, Proline stands far less risky than caustic or volatile organic chemicals. Its handling hazard level matches table salt or sugar in most settings, so basic industrial hygiene controls suffice. Large storage containers call for labeling that reflects its identity as an amino acid, and inventory control prevents product confusion with more hazardous substances. Disposal needs meet typical organic waste streams, passing most environmental regulations for solid chemical disposal or water dilution. Handling in the lab or production areas means scooping, weighing, and mixing under standard ventilation, with PPE limited to standard gloves and eye protection. Companies concerned with material safety will find Proline easy to integrate into green chemistry protocols, reducing risk of operator exposure and downstream environmental impact.

Environmental and Regulatory Considerations

Regulatory status for Proline ensures wide acceptance as a food or feed additive, permitted in many countries within accepted daily intake guidelines. It does not fall under hazardous transportation regulations, but product labeling carries the Chemical Abstracts Service (CAS) number 147-85-3, which aids in regulatory reporting. For disposal or accidental release, water rinsing or collection in closed containers minimizes environmental impact since the material shows low aquatic toxicity and does not persist or bioaccumulate. Experience in plant operations makes it clear that Proline brings fewer complications during routine inspections compared to many other chemical raw materials.

Summary of Key Properties

Colorless to white powder, flake, or crystal, Proline has a density near 1.35 g/cm³. Molecular formula C₅H₉NO₂; molar mass 115.13 g/mol. It dissolves easily in water, stable under normal storage, and can be handled as a bulk raw material or solution for various industries. Limited hazard profile, minimal environmental risk, and broad acceptance as a food, feed, and pharmaceutical ingredient put Proline among the most straightforward and usable amino acid-based raw materials on the market.