Citral
[CAS# 5392-40-5]

Identification

• Classification: Flavors and spices >> Synthetic spice >> Aldehyde fragrance >> Nonenal
• Name: Citral
• Synonyms: 3,7-Dimethyl-2,6-octadienal; Geranial; Neral
• Molecular Formula: C₁₀H₁₆O
• Molecular Weight: 152.23
• CAS Registry Number: 5392-40-5
• EC Number: 226-394-6
• FEMA: 2303
• SMILES: CC(=CCC/C(=C/C=O)/C)C

Properties

• Density: 0.889
• Boiling point: 229 °C
• Refractive index: 1.486-1.49
• Flash point: 101 °C
• Water solubility: PRACTICALLY INSOLUBLE

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H317-H319-H401
• Safety Statements: P261-P264-P272-P273-P280-P302+P352-P305+P351+P338-P333+P313-P337+P313-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Skin sensitization	Skin Sens.	1	H317
Eye irritation	Eye Irrit.	2	H319
Skin sensitization	Skin Sens.	1B	H317
Aspiration hazard	Asp. Tox.	1	H304
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Specific target organ toxicity - single exposure	STOT SE	2	H371
Specific target organ toxicity - repeated exposure	STOT RE	2	H373

Discovery and Applications

Citral was first isolated in the early 20th century from the essential oils of lemongrass and other citrus fruits. Its unique citrus aroma and chemical structure—a mixture of geranial and neral—intrigued chemists. The discovery of this compound marked a pivotal moment in the study of natural fragrances and essential oils, prompting further exploration of its properties and potential applications.

Citral’s aromatic properties have direct applications in the perfume and flavor industry. It is a key ingredient in perfumes, cosmetics, and food additives, giving off a fresh citrus aroma and flavor. Its ability to mimic the scent of lemons and other citrus fruits makes it valuable in creating a desirable sensory experience for consumer products.

In addition to its aromatic properties, citral exhibits biological activity, which has sparked interest in pharmaceutical and medical research. It has antimicrobial properties against a variety of pathogens, making it a candidate for antimicrobial agents and treatments. In addition, studies have shown citral to have potential anti-inflammatory and antioxidant effects, paving the way for research into its therapeutic applications.

In industrial chemistry, citral is a precursor for the synthesis of a wide range of compounds. Its versatile chemical structure enables it to be derived as a valuable intermediate for the production of vitamins, flavors, and agrochemicals. Controlled synthesis of citral derivatives continues to drive innovation in chemical manufacturing and product development.

Citral’s role extends to agriculture and horticulture, where it is a natural insecticide and repellent. Its application helps protect crops from pests while minimizing environmental impact, in line with sustainable agricultural practices. Additionally, its use in plant growth regulators highlights its utility in improving crop yield and quality.

As global industry shifts toward sustainability, citral’s natural origin and biodegradability position it favorably in green chemistry projects. Its incorporation into eco-friendly formulations and processes highlights its potential to contribute to a more sustainable future, reduce reliance on synthetic chemicals, and lighten its environmental footprint.

Looking ahead, ongoing research will continue to explore new applications and increase citral production through biotechnological and enzymatic approaches. Advances in biocatalysis and metabolic engineering are expected to optimize production efficiency and expand its application in diverse industries, from healthcare to renewable energy.

References

2025. Citral: A potent inhibitor of advanced glycation end products. Food Chemistry.
DOI: 10.1016/j.foodchem.2024.141247

2024. Development of essential oils inclusion complexes: a nanotechnology approach with enhanced thermal and light stability. Discover Nano.
DOI: 10.1186/s11671-024-04158-7

2024. Aroma Alchemy: Uridine diphosphate-dependent glycosyltransferases mediated regulation of fruit aroma and flavor biosynthesis. Phytochemistry Reviews.
DOI: 10.1007/s11101-024-10049-7