Showing papers on "Carnosic acid published in 2004"
TL;DR: As part of a project to characterise plant-derived natural products that modulate bacterial multidrug resistance (MDR), bioassay-guided fractionation of a chloroform extract of the aerial parts of Rosmarinus officinalis led to the characterisation of the known abietane diterpenes carnosic acid, carnosol and 12-methoxy-trans-carnosic Acid.
375 citations
TL;DR: Ultrasound was used to increase the extraction efficiency of carnosic acid from the herb Rosmarinus officinalis using butanone, ethyl acetate and ethanol as solvents and reduced the solvent effect so that ethanol reached a similar level of extraction efficiency to the other two when sonicated.
302 citations
TL;DR: Carnosic acid significantly inhibited triglyceride elevation in olive oil-loaded mice at doses of 5-20 mg/kg (p.o.) and reduced the gain of body weight and the accumulation of epididymal fat weight in high fat diet-fed mice after 14 days.
214 citations
TL;DR: Methods were developed to identify and select accessions of rosemary, Rosmarinus officinalis, producing optimum antioxidant activity, and the variation of carnosic acid concentrations in extracts of 29 accessions, grown in field trials at three sites in England was determined.
Abstract: Methods were developed to identify and select accessions of rosemary, Rosmarinus officinalis (L.), producing optimum antioxidant activity. Extracts from 12 different rosemary accessions, using three solvents of varying polarity, were assayed for their antioxidant activity, and their major antioxidant compounds were identified and quantified by high-performance liquid chromatography (HPLC). Carnosic acid concentrations were correlated with (i) the free radical scavenging activity of these extracts, as measured by the 2,2-diphenyl-1-picrylhydrazyl assay (adjusted R2 = 77.3%) and (ii) their inhibition of linoleic acid oxidation, as measured by the β-carotene assay (adjusted R2 = 44.1%). The correlation was broadly confirmed by the production of volatile aldehydes as measured by the hexanal assay. The variation of carnosic acid concentrations in extracts of 29 accessions, grown in field trials at three sites in England, was determined. Keywords: Antioxidants; β-carotene; carnosic acid; DPPH•; rosemary; rosmar...
120 citations
TL;DR: A fast and accurate method to calculate molar absorption coefficients (epsilon) of carnosic acid, by using HPLC, has been tested on standard polyphenols and caffeine, and should be widely adapted for standardless quantitative analysis.
52 citations
TL;DR: Immortalized human microvascular endothelial cells (HMEC-1) were utilized to assess anti-endothelial effects of 10 novel potential cancer chemopreventive compounds from various sources and data indicate that inhibition of endothelial cell function contributes to various extents to the chemopleventive or anti-angiogenic potential of these lead compounds.
51 citations
TL;DR: In this article, a more applicable technique using a 10% to 100% methanol with 2% acetic acid mobile phase and a citric acid-sodium citrate buffered methanolic 1,1-diphenyl2-picrylhydrazyl free radical reagent is presented, whereby free radical scavengers can be detected within crude extracts of variable polarity without special considerations.
Abstract: The importance of natural antioxidants principally relates to their health-promoting properties. The discovery of new sources of established compounds or more potent compounds is a costly exercise and any technique capable of aiding this procedure would be highly significant. An approach combining chromatographic separation, component analysis and post-column identification of free radical scavenging has been reported. However, its effectiveness is dependent upon various factors and the number of samples analyzed without operator intervention is restricted. A more applicable technique using a 10% to 100% methanol with 2% acetic acid mobile phase and a citric acid-sodium citrate buffered methanolic 1,1-diphenyl2-picrylhydrazyl free radical reagent is presented, whereby free radical scavengers can be detected within crude extracts of variable polarity without special considerations. As an illustration, acetone, 70% (aq.) methanol and acetonitrile-soluble extracts were prepared from sage (Salvia officinalis L.) for extraction of polar and non-polar radical scavengers and analyzed. Radical scavenging components were identified as carnosic, caffeic and rosmarinic acids and luteolin-7-O-glycoside. Others radical scavengers were tentatively identified as benzoic and hydroxycinnamic acid derivatives, flavonoids and diterpenoids. Through the application of this technique, carnosic acid and rosmarinic acid were identified as the principal free radical scavengers.
33 citations
TL;DR: In this paper, the supercritical CO 2 extraction of crude rosemary extracts was performed at pressures 10 and 20 MPa and temperatures 35 and 60 °C. The antioxidative efficiency of extracts was determined by measuring peroxide value.
Abstract: In present work, the purification of crude rosemary extract with supercritical fluids is presented. Carbon dioxide was used as a solvent. The crude extract was prepared from rosemary with conventional extraction process. The supercritical CO 2 extraction of crude extracts was performed at pressures 10 and 20 MPa and temperatures 35 and 60 °C. The best results were obtained at pressure 10 MPa and temperature 35 °C. The content of carnosic acid in the samples before and after high pressure extraction was identified by high performance liquid chromatography. The content of carnosic acid in purified extract is higher compared to crude extract. The antioxidative efficiency of extracts was determined by measuring peroxide value. Activity of purified rosemary extracts is higher compared to crude extracts.
29 citations
1 citations
TL;DR: A review of the literature dealing with the synthesis of some bioactive diterpenes can be found in this paper, where the authors describe the biological activity and synthesis of only four diterphenes: pisiferic acid, carnosic acid and triptolide and miltirone.
Abstract: This article reviews the literature published dealing with the synthesis of some bioactive diterpenes. It describes the biological activity and synthesis of only four diterpenes: pisiferic acid, carnosic acid, triptolide and miltirone. This review excludes the discussions of Taxodione, a bioactive diterpene, because it has already been reviewed [85] . The utility of several reagents in the total synthesis of terpenoid compounds has been documented. It can be observed that several routes have been developed for the synthesis of a single diterpene.