Carnosol

Frankel, E.N., Huang, S.W., Aeschbach, R., and Prior, E. 1996 Antioxidant activity of a rosemary extract and its constituents, carnosic acid, carnosol and rosmaric acid in bulk oil and oil-in-water emulsion. J. Agric. Food Chem. 44 131 -136. 

From the Diterpene Carnosol to the Benzodiazepine Agonist Miltirone... 

The abundant diterpene carnosol 1 can be converted easily into the ester 2 in 90% total yield by the sequence shown in the Scheme. 

Rosemary (Rosmarinus officinalis, Labiatae) is native to southern Europe. Rosemary acts as a mild analgesic and antimicrobial agent in traditional herbal use [95]. The relative amount of carnosol (Di25) in dried rosemary leaves is 3.8-4.6%. Among the antioxidant compounds in rosemary leaves, 90% of the antioxidant activity can be attributed to Di25 and carnosic acid (ll,12-dihydroxy-8,ll,13-abietatrien-20-oic acid)... 

Abietane diterpenes (C61C61C6 with varying degrees of unsaturation) include the 5-LOX inhibitor abietane, the GABA(A) receptor antagonist taxodione and the bitter tastant carnosol. 

Carnosol Rosmarinus officinalis, Salvia GABAA-R chloride channel... 

Figure 6.4 Chemical structures of carnosol, perillyl alcohol, and other polyphenols.

Extensive studies (139, 140) on rosemary extracts containing carnosol, camosic acid, and rosmarinic acid have shown that the activities of these natural antioxidants are system-dependent and that their effectiveness in different food systems is difficult to predict. In bulk vegetable oils (corn, soybean and peanut) and fish oils, carnosol and camosic acid are effective antioxidants. It has been hypothesized that this... 

One important trend in the food industry is the increased demand for natural food ingredients free of chemicals. Therefore, special attention has been paid to alternative processes directed toward extraction solvents and techniques with both GRAS and GMP labels (Ibanez et al., 1999). Supercritical C02-extraction (SFC C02) has been used (Weinreich, 1989 Nguyen et al., 1991 Nguyen et al., 1994 Ibanez et al., 1999). Tena et al. (1997) noted that extracts from rosemary obtained by SFC C02 (35 bar at 100°C) were the cleanest extracts and provided the highest recovery of carnosic acid compared to solvent extracts (acetone, hexane, dichlor-methane and methanol) after bleaching with active carbon. Bicchi et al. (2000) reported a fractionated SFC C02 method to selectively isolate carnosol and carnosic acid at 250 atm and 60°C in the second fraction. The authors used 5% methanol to modify the dissolution power of SFC C02. 

Pukl, M., Umek, A., Paris, A., Strukelj, B., Renko, M., Korant, B.D. and Turk, V. 1992. Inhibitory effect of carnosolic acid on HIV-1 protease. Planta Medica. 58 A632. 

Singletary, K.W. 1996. Rosemary extract and carnosol stimulate rat liver glutathione-S-transferase and quinone reductase activities. Cancer Lett. 100 139-144. 

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