Extraction carnosic acid

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. 

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. 

The comparison of six commercial extracts (Figure 6.3) showed that C02 extraction results in the highest proportion of carnosic acid among the phenolic diterpenes (Schwarz and Temes, 1992b). Extraction solvents used for the extracts shown in Figure 6.3 were ethanol (extract 1) hexane and acetone (extract 2) ethanol (extract 3) methanol (extract 4) hexane, ethanol and methanol (extract 5) and super critical C02 (extract 6). 

Schwarz et al. (1992), Cuvelier et al. (1994), and Richheimer et al. (1996) showed that carnosic acid degrades in solvents at ambient conditions, forming camosol, 7-epirosmanol, rosmanol and methyl carnosic acid. Bracco et al. (1981) and Aeschbach et al. (1994) have explored mechanical extraction using medium-chain triglycerides... 

Dapkevicius et al. (1998) compared yields and antioxidant activities of four different extracts from rosemary and sage leaves an acetone, a water extract (both from deodorized plant material), and an acetone and SFC C02 extract (both from nondeodorized plant material). The yields (g per kg dry matter) ranged from 50.2 for the SFC C02 to 90.8 for the water extract from deodorized plant material. High antioxidant activity was found for the SFC C02 and the acetone extracts, but low activity was determined for all water extracts. This emphasizes the importance of camosol and carnosic acid that are extracted from leaves with water-ethanol solvent... 

The use of extracts from rosemary as food preservatives is well established [25] the phenolic compounds obtained from this source have been shown to act as antioxidants in vitro and reduce the oxidation of dietary lipids in a dose-dependant manner [26]. The constituents of rosemary considered responsible for the majority of this antioxidant activity are rosmarinic acid, carnosol, and carnosic acid [14]. 

Common sage and rosemary (see Table 8.32), plants of the Lami-aceae family, contain the diterpenes camosic acid, also known as rosmaricin (8-259), derived from ent-caurene, and bitter carnosol (picrosalvin, 8-260), which are potent antioxidants. Carnosic acid is a major component of fresh rosemary tops (1-2%), but is unstable and is enzymatically transformed into carnosol. These two diterpenoids represent about 15% w/w of plants haulm extracts and exhibit about 90% of extract antioxidant activity. Other transformation products of carnosic acid are rosmanol (7a-hydroxy derivative, 8-261), epirosmanol (7P-isomer, 8-262) and similar compounds. 

Mint plants (Lamiaceae), for example in common thyme (ThymtAS vulgaris), contain substituted biphenyls derived from monoter-penic alcohol thymol, their o-quinones (10-178) or p-quinones (10-179), which exhibit marked antioxidant activities. Among the most active natural antioxidants with anti-inflammatory effects is carnosic acid, also known as rosmaricine (10-180), which is accompanied by carnosol (picrosalvin, 10-181). These two antioxidants represent about 15% by weight of commercial extracts of rosemary... 

Carnosic acid is unstable and is transformed into carnosol. Other active products are rosmanol (7a-isomer, 10-182), epirosmanol (7p-isomer) and 7-methylepirosmanol (10-183). Other minority compounds of rosemary extracts are isorosmanol (10-184), rosmariquinone (10-185) and rosmaridiphenol (10-186), which... 

Frankel, E. N., S. H. Huang, E. Prior, and R. Aeschbach. 1996. Evaluation of antioxidant activity of rosemary extracts, carnosol and carnosic acid in bulk vegetable oils and fish oil and their emulsions. /. Sci. Food Agric. 72(2) 201-208. 

Sage extracts, like those of rosemary, have strong antioxidant activities in vitro and in vivo labiatic acid, carnosic acid, and the phenolic acids are reported to be the active compounds (see rosemary). Sage oil displayed chemopreventive activity against... 

A variety of health benefits including cancer prevention, anti-inflammatory, antiviral, and anti-tumor activities have been claimed for carnosic acid, carnosol, and rosmarinic acid. Mirmunni et al. (1992) found that a rosemary extract containing 8.8% carnosic acid and 1.2% carnosol had antimutagenic activity in... 

The major rosemary phytochemicals including camosol, carnosic acid, ursolic acid and rosmarinic acid (Figure 1) were separated by HPLC as described in Materials and Methods and illustrated in Figure 2. The retention time of these compounds were carnosic acid, 19.5 min camosol, 7.7 min ursolic acid, 13 min and rosmarinic acid, 2-12 min. It seemed that rosmarinic acid was not resolved well in this system. The relative amounts of these compounds in rosemary extracts were similar to previous findings (5) as 16.5-19.2% ursolic acid 3.8-4.6% camosol 0.1-0.5% carnosic acid and trace amount of rosmarinic acid, respectively. 

Herbs and spices often contain high amount of phenolic compounds. For example, rosemary contains carnosic acid, camosol, and rosmarinic acid. Crude rosemary extracts are a commercially important source of natural phenolic antioxidant additives in foods meats, bulk oils, lipid emulsions, and beverages. 

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