Vanillin
[CAS# 121-33-5]

Identification

• Classification: API >> Nervous system medication >> Antiepileptic and anticonvulsant
• Name: Vanillin
• Synonyms: 4-Hydroxy-3-methoxybenzaldehyde
• Molecular Formula: C₈H₈O₃
• Molecular Weight: 152.14
• CAS Registry Number: 121-33-5
• EC Number: 204-465-2
• SMILES: COC1=C(C=CC(=C1)C=O)O

Properties

• Density: 1.056 g/mL (20 °C) (Expl.)
• Melting point: 81-84 °C (Expl.)
• Boiling point: 170 °C (15 mmHg) (Expl.)
• Flash point: 147 °C (Expl.)
• Water solubility: 10 g/L (25 °C)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H317-H319
• Safety Statements: P261-P264+P265-P272-P273-P280-P302+P352-P305+P351+P338-P321-P333+P317-P337+P317-P362+P364-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin sensitization	Skin Sens.	1	H317
Acute toxicity	Acute Tox.	4	H302
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2A	H319
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	5	H303
Reproductive toxicity	Repr.	2	H361
Germ cell mutagenicity	Muta.	2	H341
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400

Discovery and Applications

Vanillin is a widely used aromatic compound known for its characteristic vanilla flavor and fragrance. It is a key component of vanilla bean extract and has been extensively utilized in the food, fragrance, and pharmaceutical industries. Structurally, vanillin is a phenolic aldehyde with the chemical formula C8H8O3, featuring hydroxyl, methoxy, and aldehyde functional groups that contribute to its distinct sensory properties and chemical reactivity.

The discovery of vanillin dates back to the 19th century when it was first isolated from vanilla beans. However, due to the high cost and limited supply of natural vanilla, scientists developed synthetic methods to produce vanillin from alternative sources. In the late 19th century, the first synthetic vanillin was derived from coniferin, a glucoside found in pine bark. Later, more efficient production routes were established using lignin, a byproduct of the paper industry, and guaiacol, a petrochemical derivative. These advancements made vanillin widely available and affordable, leading to its extensive use across multiple industries.

In the food industry, vanillin serves as a primary flavoring agent in a variety of products, including baked goods, confectionery, beverages, and dairy products. Its pleasant aroma and taste enhance the sensory appeal of food items, making it a fundamental ingredient in the global flavor industry. Additionally, vanillin is used as a masking agent to suppress undesirable flavors in processed foods and pharmaceuticals.

Beyond its role in flavoring, vanillin exhibits significant biological activity. Studies have demonstrated its antioxidant, antimicrobial, and anti-inflammatory properties, leading to its exploration in pharmaceutical and cosmetic formulations. It has been investigated for potential therapeutic applications, including neuroprotection, anti-cancer activity, and cardiovascular health benefits.

Vanillin also plays an important role in the fragrance and personal care industries, where it is used in perfumes, soaps, and lotions. Its warm, sweet scent contributes to various aromatic compositions, often blended with other compounds to create complex fragrances. Furthermore, vanillin is employed in chemical synthesis as an intermediate for producing fine chemicals, agrochemicals, and pharmaceuticals.

With growing demand for sustainable and eco-friendly products, the production of bio-based vanillin has gained increasing attention. Microbial fermentation using engineered microorganisms offers a renewable alternative to petrochemical-derived vanillin, reducing the environmental impact of its synthesis. Advances in biotechnology continue to improve the efficiency and scalability of bio-based vanillin production, aligning with global sustainability goals.

Vanillin remains an essential compound with diverse applications spanning multiple industries. Its unique combination of flavor, fragrance, and bioactivity ensures its continued significance in food science, medicine, and material chemistry. Ongoing research aims to explore new derivatives and applications, further expanding the versatility of this widely used aromatic aldehyde.

References

2025. Production, extraction, and authentication of natural and non-natural vanillin. A comprehensive review and economic future biotechnology perspectives. Food Chemistry, 463.
DOI: 10.1016/j.foodchem.2024.142249

2024. Metabolic engineering of Escherichia coli for upcycling of polyethylene terephthalate waste to vanillin. The Science of the Total Environment, 953.
DOI: 10.1016/j.scitotenv.2024.177544

2025. Highly selective and visual detection of vanillin based on fluorescence Cd-MOF sensor in milk powders. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 325.
DOI: 10.1016/j.saa.2024.124958