Degradation Study of Carnosic Acid, Carnosol, Rosmarinic Acid, and Rosemary Extract (Rosmarinus officinalis L.) Assessed Using HPLC

• Published in: Journal of agricultural and food chemistry Vol. 60; no. 36; pp. 9305 - 9314
• Main Authors: Zhang, Ying, Smuts, Jonathan P, Dodbiba, Edra, Rangarajan, Rekha, Lang, John C, Armstrong, Daniel W
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Washington, DC American Chemical Society 12-09-2012
• Subjects: Abietanes - chemistry; Antioxidants - chemistry; Aroma and flavouring agent industries; Biological and medical sciences; Chromatography, High Pressure Liquid - methods; Cinnamates - chemistry; Depsides - chemistry; Food industries; Fundamental and applied biological sciences. Psychology; Kinetics; Plant Extracts - chemistry; Rosmarinic Acid; Rosmarinus - chemistry; Temperature; carnosol; rosmarinic acid; HPLC analysis; degradation study; rosemary extract in fish oil; carnosic acid; Spice; HPLC chromatography; Degradation; Acids; Labiatae; Dicotyledones; Angiospermae; Rosmarinus officinalis; Rosemary; Spermatophyta; Fish extract
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf302179c

Rosemary, whose major caffeoyl-derived and diterpenoid ingredients are rosmarinic acid, carnosol, and carnosic acid, is an important source of natural antioxidants and is being recognized increasingly as a useful preservative, protectant, and even as a potential medicinal agent. Understanding the stability of these components and their mode of interaction in mixtures is important if they are to be utilized to greatest effect. A study of the degradation of rosmarinic acid, carnosol, carnosic acid, and a mixture of the three was conducted in ethanolic solutions at different temperatures and light exposure. As expected, degradation increased with temperature. Some unique degradation products were formed with exposure to light. Several degradation products were reported for the first time. The degradation products were identified by HPLC/MS/MS, UV, and NMR. The degradation of rosemary extract in fish oil also was investigated, and much slower rates of degradation were observed for carnosic acid. In the mixture of the three antioxidants, carnosic acid serves to maintain levels of carnosol, though it does so at least in part at the cost of its own degradation.