Camosic acid extraction

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... 

Since the ancient times, spices have been added to different types of food to improve their flavor and to enhance their storage stability. The intake of herbs and spices is regulated by themselves by means of the flavor intensity of the essential oil. However, antioxidant extracts with high contents of phenolic diterpenes do not necessarily contain essential oils. Particularly, plant material from essential oil production for cosmetic or pharmaceutical products is an interesting side product to be used for the preparation of antioxidative extracts. However, data published by Richheimer et al. (1996) indicated that the deoiled biomass contains markedly less camosic acid than the dried, nondeoiled plant material. 

FIGURE 6.4 HPLC chromatogram of phenolic diterpenes in commercial rosemary extracts (ISO isorosmanol ROS rosmanol CAR camosic acid CA camosol DMIR dimethyl -isorosmanol and MCA 12-O-methylcamosic acid). 

Mace and colleagues have examined the ability of camosol and camosic acid from rosemary as well as the synthetic dithiolethione, oltipraz, to block the formation of DNA adducts, and their effects on the expression of phase I and phase II enzymes. It was found that both rosemary extracts and oltipraz inhibited BaP- or aflatoxin Bi-induced DNA adduct formation by efficiently inhibiting CYP activities and inducing the expression of GST. Treatment of female CD-I mice with a 2% methanol extract of rosemary in AIN-76A diet for 3 weeks increased the liver microsomal 2-hydroxylation of estradiol and estrone by approximately 150%, increased their 6-hydroxylation by approximately 30%, and inhibited the 16a-hydroxylation of estradiol by approximately 50%. The same treatment of rosemary also stimulated the liver microsomal glucuronidation of estradiol and estrone by 54 to 67% and 37 to 56%, respectively. In additional studies, feeding 2% rosemary diet to ovariectomized CD-I mice for 3 weeks inhibited the uterotropic action of estradiol and estrone by 35 to 50% compared with animals fed a control diet. 

Hops resin 150 mg hops aipha acids (from hops [humulus lupulus, ieaves, flowers] extract) 10 iU naturai Vitamin E (from 8 mg d-aipha tocopheroi acetate) 0.5 mg astaxanthin (from Haematococcus pluvialis aigai extract) 1.5 mg camosic acid (from rosemary [Rosemarinus officinalis, ieaves, flowers] extract) 100 mg olive oil... 

Frankel, E.N. et al.. Antioxidant activity of a rosemary extract and its constituents, camosic acid, camo-sol, and rosemarin add, in bulk oil and oU-in-water emulsion, J. Agric. Food. Chem., 44, 131, 1996. 

In bulk com oil, the rosemary extract, camosic acid, rosmarinic acid and a-tocopherol were significantly more achve than carnosol (Table 9.11). In contrast, in com oil-in-water emulsion, carnosol was significantly more achve than in bulk oil, whereas the rosemary extract and camosic acid were less achve... 

Table 9.11. Antioxidant activity of a rosemary extract, camosic acid, camosol and rosmarinic acid in stripped com oil and emulsified com oil at 60°C (% inhibition) ...

The antioxidant activities of rosemary extracts, carnosol and camosic acid were also significantly influenced by the oil substrates and the type of system tested, bulk oils versus oil-in-water emulsions, the methods used to measure oxidation and the concentration of test compounds. The rosemary extracts, carnosol and camosic acid effectively inhibited hydroperoxide formation in com oil, soybean oil, peanut oil and fish oil, when tested in bulk (Table 9.12). The rosemary extract and pure constituents were more active antioxidants in bulk corn, peanut and fish oils than in bulk soybean oil. This difference may be attributed to the relatively higher concentrations of tocopherols in soybean oil that are known to have a negative effect on the antioxidant activity of rosemary constituents. Test compounds also inhibited hexanal formation in bulk vegetable oils, and propanal and pentenal formation in bulk fish oils. In marked contrast, these test compounds were either inactive or promoted oxidation in the corresponding vegetable oil-in-water emulsions. In fish oil emulsions, however, the rosemary compounds inhibited conjugated diene and pentenal formation, but not propanal. 

Interfacial phenomena may explain these differences in activities. Rosemary extracts, carnosol and camosic acid behaved like other hydrophilic antioxidants such as ascorbic acid and Trolox in being more effective in bulk oil than in oil-in-water emulsion systems. In the bulk oil systems where oil is the main phase, the hydrophilic rosemary antioxidants may be more protective by being oriented in the air-oil interface. In contrast, in the oil-in-water emulsion systems, where water is the main phase, the hydrophilic rosemary antioxidants remain in the water and are less effective in the oil-water interface where oxidation takes place (Chapter 10). The higher antioxidant activities of rosemary antioxidants observed in fish oil emulsions than in vegetable oil emulsions may be explained by their greater affinity toward the more polar oil interface with the water of the fish oil systems. 

Table 9.12. Percent inhibition of hydroperoxide formation by rosemary extracts (R-E), camosol and camosic acid in bulk oils and oil-in water emulsions ...

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

Rosemary is composed of various phenolics such as rosmarinic acid, the flavonoid hesperidin, and the terpenoids camosic acid, camasol, and rosmanol (Al-Sereiti et al. 1999). Rosemary is well known for antioxidant and antimicrobial activity (Naghibi et al. 2005). Multiple extracts and bioactive constituents of rosemary were evaluated for in vitro effect on human cancer cells (Yesil-Celiktas etal. 2010). These included human small cell lung, prostate, liver, breast, and myeloid leukemia, all rosemary extracts and finctionated compounds were toxic to the cell lines at low doses but camosic acid was most effective (Yesil-Celiktas et al. 2010). Bakirel etal. reported in 2007 that ethanol extracts of rosemary reduced blood glucose, and increased insulin levels of rabbits with induced diabetes. They also noted increased levels of the antioxidants SOD and CAT in these animals. 

Yesil-Celiktas, O., Sevimli, C., Bedir, E., and Vardar-Sukan, F. 2010. Inhibitory effects of rosemary extracts, camosic acid and rosmarinic acid on the growth of various human cancer cell... 

Frankel, E.N., Huang, S.W., Aeschbach, R., and Prior, E. 1996. Antioxidant Activity of a Rosemary Extract and Its Constituents, Camosic Acid, Camosol, and Rosmarinic Acid, in Bulk Oil and Oil-in-Water Emulsion. Journal of Agricultural and Food Chemistry, 44(1), 131-135. 

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. 

Extract of rosemary is currently approved in the EU as a natural antioxidant (E392). Camosic acid has a typical o-diphenol structure and is easily oxidised. The antioxidation mechanism is based on a coupling reaction with the peroxyl radical at the 12- or 14-position of camosic acid and subsequent transformation reactions of intermediates to an o-quinone and a hydroxy p-quinone (Figure 10.13). 

Extracts of sweet maijoram have antioxidant/ free radical scavenging properties that are in part due to labiatic, ursolic and camosic acids, and camosol and phenolic compounds. The antioxidant activity is reflected in the ability of the volatile oil and different maijoram extracts to act as liver and kidney chemopreventive agents against lead acetate toxicity in mice. ... 

Rosemary extracts have antioxidative properties comparable to those of butylated hydroxyanisole (BHA) and butylated hydro-xytoluene (BHT) camosic acid and labiatic acid are reported as active components (see sage)P As such, rosemary constituents and extracts show potential as chemo-preventive, radioprotective, neuroprotective, antimutagenic, antihepatotoxic, and antiul-cerogenic agents. ... 

Cuvelier et al. (1996) assessed the antioxidant activity of 24 pilot-plant and commercial rosemary extracts and identified 22 different compounds for investigation. These included diterpenes, flavonoids, and phenolic acids. There was no apparent correlation between antioxidant activity and extract composition but the most effective extracts contained camosol, rosmarinic acid, and camosic acid and, to a lesser extent, caffeic acid, rosmanol, rosmadial, cirsimaritin, and genkwanin. Camosol was a component of all 24 extracts while rosmarinic and camosic acids were found in 83% and 71% of the extracts, respectively (Cuvelier et al, 1996). Richheimer et al. (1996) also evaluated the antioxidant components in a variety of plant and commercial rosemary products. In the commercial products, camosol and camosic acid were the predominant forms with low levels of methyl camosate. No clear relationship between the type of commercial rosemary extract and antioxidant composition was established. These investigators found that 7-methoxy-rosmanol was present in the commercial extracts but not in extracts obtained... 

Frankel et al. (1996a) also observed that camosol and camosic acid were significantly more active antioxidants in oil-in-water emulsions buffered at pH 4 or 5 than at pH 7. Hopia et al. (1996) reported that camosic acid was a better antioxidant than camosol in methyl linoleate, but that the reverse was tme in linoleic acid. In methyl linoleate or linoleic acid, camosic acid and camosol were more active than a-tocopherol. However, a-tocopherol was more active in bulk corn oil triacylglycerols, followed by camosic acid and camosol. The oxidative stability of rapeseed oil treated with rosemary extracts correlated well with the content of camosic acid, but not with content of camosol (Trojakova et al, 2001). In all emulsified systems, a-tocopherol exhibited more antioxidant activity than camosol or camosic acid (Hopia et al., 1996). In bulk com oil, the addition of camosol to a-tocopherol had a negative impact on the antioxidant activity of a-tocopherol, whereas camosic acid enhanced a-tocopherol activity (Hopia et al, 1996). Both camosic acid and camosol disappeared from the test system more quickly than a-tocopherol (Hopia et al, 1996). 

Bailey, D, Richheimwr, S, Bank, V and King, B (1999) High purity camosic acid from rosemary and sage extracts by pH-controlled precipitation. US Patent 5,859,293. 

Tena et al (1997) reported that extracts obtained with SC-CO had the highest average camosic acid concentration (35.7 mg/g), followed by acetone (26.2 mg/g), methanol (15.9 mg/g), dichloromethane (7.9 mg/g) and hexane (1.9 mg/g) extracts. An added advantage of SC-CO was that the extract was... 

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