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1.
In the present study, the phenolic composition analysis of seven red varieties of propolis, collected in different regions of Cuba, was evaluated by gas chromatography/mass spectrometry (GC-MS). Seventeen compounds were identified in all samples by the interpretation of their mass spectra. This appears to be the first report on the GC-MS analysis of isoflavonoids in the propolis. The results confirmed the presence of the main isoflavonoids isolated previously and suggested the general structure for the other five isoflavonoids. Vestitol, 7-O-methylvestitol, and medicarpin were present in high amounts in all propolis samples analyzed. This result indicates that propolis samples rich in isoflavonoids are not exclusively found in Pinar del Rio province and proves that GC-MS technique is a useful and alternative tool for the chemical analysis of tropical red propolis.  相似文献   

2.
Isoflavonoids isolated from Cuban propolis   总被引：3，自引：0，他引：3  
Chemical investigation of a red-type Cuban propolis sample has led to the isolation of 11 isoflavonoids (2 isoflavones, 3 isoflavans, and 6 pterocarpans), together with gallic acid, isoliquiritigenin, and (-)-liquiritigenin. Structural determination, including the absolute stereochemistry, was accomplished by spectroscopic analysis, particularly CD and 2D NMR techniques. The fragmentation behavior of pterocarpans was studied by electrospray ionization (ESI) tandem mass spectrometry (MS/MS) using an ion-trap analyzer, and a generalized fragmentation pathway, useful in the identification and structural characterization of pterocarpans, is proposed. Isoflavonoids are reported for the first time from propolis samples.  相似文献   

3.
Suppressive effects of ethanolic extracts prepared from propolis group 12 and its main botanical origin (leaf bud of Baccharis dracunculifolia) on transformation of the aryl hydrocarbon receptor (AhR), the initial action of dioxin toxicity, were investigated. It was found that suppressive effects of propolis on AhR transformation were relatively higher than those of resins of its botanical origin in cell-free system and in Hepa-1c1c7 cells. When the composition of chemical ingredients was measured, propolis contained slightly higher amounts of flavonoid aglycones as compared with its botanical origin with the same characteristics. Moreover, antiradical activity, one of the typical biological activities of flavonoids, in propolis was also slightly higher than that in its botanical origin. These results indicate that not only propolis but also its botanical origin contains high amounts of flavonoid aglycones and that both of them are useful dietary sources for flavonoids with a potency to prevent dioxin toxicity.  相似文献   

4.
Sixty-five samples of propolis were collected from eleven regions of Cuba; methanolic extracts of propolis were prepared from all samples, and a classification method was developed using a combination of NMR, HPLC-PDA, and HPLC-ESI/MS techniques. The analysis of (1)H and (13)C NMR spectra and chromatographic profiles of all propolis extracts allowed the definition of three main types of Cuban propolis directly related to their secondary metabolite classes: brown Cuban propolis (BCP), rich in polyisoprenylated benzophenones, red Cuban propolis (RCP), containing isoflavonoids as the main constituents, and yellow Cuban propolis (YCP), probably with aliphatic compounds. Subsequently, the principal compounds of the brown and red types were characterized by HPLC-ESI/MS analysis. Instrumental techniques used are complementary; NMR was shown to be a quick and informative tool for the rapid analysis of crude propolis polar extracts and allowed the identification of the main class of secondary metabolites, while LC-PDA and LC-MS techniques were useful tools for qualitative and quantitative analysis of marker compounds of Cuban propolis.  相似文献   

5.
Previously, it was reported that one group of propolis (Group 12) was identified in southeastern Brazil, and the botanical origin of the propolis was Baccharis dracunculifolia resinous exudates. It was also observed that honeybee (Africanized Apis mellifera) mainly visited the leaf buds or unexpanded leaves of B. dracunculifolia but rarely expanded leaves. B. dracunculifolia is dioecious with male and female inflorescences, and RPHPLC of the ethanolic extracts of the respective male and female bud resinous exudates showed the same profiles. RPHPLC profiles of propolis G12 leaf buds and unexpanded and expanded leaves of B. dracunculifolia showed similarity, but unexpanded leaves quantitatively decreased in chemical constituents as compared with leaf buds. In the case of expanded leaves, all chemical constituents were severely decreased or disappeared. Artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) was also identified in both propolis and resinous exudates, and both ethanolic extracts contained the highest concentrations of this compound as compared with the rest of the chemical constituents.  相似文献   

6.
The valorization of extracts from Brazilian vetiver (Vetiveria zizanioides (L.) Nash ex Small) roots was studied. This study took into account the extraction method, the chemical composition of the extracts, their sensorial characteristics, and the possibility of chemical transformations of the product. The performed extraction methods were hydrodistillation and extraction with supercritical carbon dioxide. Some pretreatment methods were tested on the vetiver roots and evaluated in terms of extraction yield, process time, chemical composition, and sensorial properties. Supercritical carbon dioxide extraction resulted in high yield (3.2%) in significantly less time than the other methods. The chemical compositions of the extracts obtained by the different methods were also compared to those of commercial vetiver oils from other sources, showing that Brazilian samples had a greater acid amount. An extraction in basic medium from Brazilian vetiver oil was done to remove its main acid (zizanoic acid), which was chemically transformed into an alcohol (khusimol) of desirable sensorial properties. Sensory evaluation indicated that the Brazilian volatile oil without acid could be used in perfumery and the extract obtained with supercritical carbon dioxide could have application in food.  相似文献   

7.
The objective of this work was to evaluate the adsorption of macronutrients calcium, potassium, magnesium, nitrogen, and phosphorus in two Brazilian tropical peat samples, investigating the effect of pH and determining the kinetics of the adsorption process. Two different Brazilian tropical peat samples were characterized using FTIR, TG, and SEM techniques. Different pH conditions were tested, as well as different mass concentrations of the peats. Differences in the chemical structures of the peat samples directly influenced the adsorptive capacities for the macronutrients. The adsorptive capacity for nitrogen was highest at pH 3, while the best adsorption of calcium and potassium was obtained at pH 6. The best fit to the data was provided by the pseudo-second-order model, which confirmed the rapid adsorption of calcium by both peats.  相似文献   

8.
The antioxidant capacity of propolis from the southern region of Uruguay was evaluated using in vitro as well as cellular assays. Free radical scavenging capacity was assessed by ORAC, obtaining values significantly higher than those of other natural products (8000 μmol Trolox equiv/g propolis). ORAC values correlated well with total polyphenol content (determined by Folin-Ciocalteu method) and UV absorption. Total polyphenol content (150 mg gallic acid equiv/g propolis) and flavonoids (45 mg quercetin equiv/g propolis) were similar to values reported for southern Brazilian (group 3) and Argentinean propolis. Flavonoid composition determined by RP-HPLC indicates a strong poplar-tree origin. Samples high in polyphenols efficiently inhibit low-density lipoprotein lipoperoxidation and tyrosine nitration. In addition, Uruguayan propolis was found to induce the expression of endothelial nitric oxide synthase and inhibit endothelial NADPH oxidase, suggesting a potential cardiovascular benefit by increasing nitric oxide bioavailability in the endothelium.  相似文献   

9.
Sitka spruce (Picea sitchensis) samples (491) from 50 different clones as well as 24 different tropical hardwoods and 20 Scots pine (Pinus sylvestris) samples were used to construct diffuse reflectance mid-infrared Fourier transform (DRIFT-MIR) based partial least squares (PLS) calibrations on lignin, cellulose, and wood resin contents and densities. Calibrations for density, lignin, and cellulose were established for all wood species combined into one data set as well as for the separate Sitka spruce data set. Relationships between wood resin and MIR data were constructed for the Sitka spruce data set as well as the combined Scots pine and Sitka spruce data sets. Calibrations containing only five wavenumbers instead of spectral ranges 4000-2800 and 1800-700 cm(-1) were also established. In addition, chemical factors contributing to wood density were studied. Chemical composition and density assessed from DRIFT-MIR calibrations had R2 and Q2 values in the ranges of 0.6-0.9 and 0.6-0.8, respectively. The PLS models gave residual mean squares error of prediction (RMSEP) values of 1.6-1.9, 2.8-3.7, and 0.4 for lignin, cellulose, and wood resin contents, respectively. Density test sets had RMSEP values ranging from 50 to 56. Reduced amount of wavenumbers can be utilized to predict the chemical composition and density of a wood, which should allow measurements of these properties using a hand-held device. MIR spectral data indicated that low-density samples had somewhat higher lignin contents than high-density samples. Correspondingly, high-density samples contained slightly more polysaccharides than low-density samples. This observation was consistent with the wet chemical data.  相似文献   

10.
Cyclic polyalcohol composition of 80 natural wood samples from different botanical species, with the majority of them used in the oenology industry for aging purposes, has been studied by gas chromatography-mass spectrometry (GC-MS) after its conversion into their trimethylsilyloxime derivatives. Each botanical species showed a different and specific cyclic polyalcohol profile. Oak wood samples were characterized by the richness in deoxyinositols, especially proto-quercitol. Meanwhile, other botanical species showed a very low content of cyclic polyalcohols. The qualitative and quantitative study of cyclic polyalcohols was a useful tool to characterize and differentiate woods of different botanical origin to guarantee the authenticity of chips used in the wine-aging process. Monosaccharide composition was also analyzed, showing some quantitative differences among species, but cyclic polyalcohols were the compounds that revealed the main differentiation power.  相似文献   

11.
Botanical origin and chemical composition of Brazilian propolis   总被引：11，自引：0，他引：11  
Brazilian propolis has been classified into 12 groups based on physicochemical characteristics: five in the southern Brazil group (group 3), one in the southeastern Brazil group (group 12), and six in the northeastern Brazil group (group 6). The plant origins of these groups were investigated using reversed-phase high-performance thin-layer chromatography (RPHPTLC), reversed-phase high-performance liquid chromatography (RPHPLC), and gas chromatography-mass spectrometry (GC-MS). It was concluded that the origins of propolis group 3, group 6, and group 12 are resins of the poplar tree, Hyptis divaricata, and Baccharis dracunculifolia, respectively.  相似文献   

12.
We have investigated the capability of direct infusion electrospray ionization mass spectrometry in the negative ion mode, ESI(-)-MS, to differentiate representative samples of artisan cacha?a, a Brazilian sugar cane distillate of large production, aged in four different types of wood casks: amburana (Amburana cearensis), jequitibA (Cariniana estrellensis), balm (Myroxylon peruiferum), and oak (Quercus rubra). The ESI(-)-MS were found to be very characteristic, showing sets of diagnostic ions for each of the four types of samples: amburana (m/z 271, 313, 377), jequitibA (m/z 143, 171, 255), balm (m/z 137, 269, 283, 297), and oak (m/z 197, 301, 307). Furthermore, principal component (PCA) and hierarchical cluster analysis (HCA), applied to the ESI(-)-MS data, divided these samples into four definite categories. The influence of the aging time on the ESI(-)-MS fingerprints of the cacha?a samples stored in oak casks was also established. An inversion in the relative intensity of the diagnostic ions of m/z 307 and 301 is detected in the ESI(-)-MS as the aging time increased from 1 to 2 years. The chemical structures of the major cacha?a components were proposed on the basis of the following: (a) the comparison of the ESI(-)-MS/MS of the diagnostic anions with those of the authentic anions or (b) the interpretation of the fragmentation patterns of the previously unknown diagnostic anions. Hence, direct infusion ESI(-)-MS allows not only a rapid, simple, and accurate way to distinguish among cacha?a samples stored in different wood casks but also monitoring changes in their chemical composition according to the aging time.  相似文献   

13.
The present study investigated the chemical composition and antioxidant activity of the water extract of propolis (WEP) collected from 26 locations in China. Spectrophotometry was used to determine the physicochemical properties and the chemical constituents of WEP. Phenolic compounds in WEP were identified by RP-HPLC-DAD with reference standards. The antioxidant activities [characterized by reducing power and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability] of WEP were also measured. Results show that epicatechin, p-coumaric acid, morin, 3,4-dimethoxycinnamic acid, naringenin, ferulic acid, cinnamic acid, pinocembrin, and chrysin are the major functional phenolic compounds in Chinese WEPs. Furthermore, most WEPs show strong antioxidant activities, which are significantly correlated with E(1cm)(1%), an index for the estimation of the quality of WEP. WEPs also contain many more active constituents than ethanol extracts of propolis.  相似文献   

14.
Sixteen red rice accessions from the southern United States were studied for their physical, milling, pasting, and thermal properties, chemical composition, and starch fine structure relative to cultivated medium- and long-grain rice varieties. All red rice samples were medium-grain, but their physicochemical properties were different from those of Bengal, a cultivated medium-grain rice. Their apparent amylose and crude protein contents were generally higher, and their amylopectin structure consisted of a higher percentage of the shorter branch chains (DP6-24) and a lower percentage of the longer branch chains (DP25-65). Red rice starch pasting and thermal properties were similar to those of Wells, a long-grain rice cultivar. The red rice samples can be classified into two major clusters according to their kernel properties by hierarchical cluster analysis: one cluster with more resemblance to Wells and another cluster with more resemblance to Bengal. Starch structure and kernel physicochemical properties may offer an alternative way of classifying red rice in addition to phenotypic and genetic indices.  相似文献   

15.
Twenty-five samples of propolis were collected from seven different regions in northern Argentina; ethanolic extracts of propolis were prepared from all samples, and the respective samples were examined for UV absorption spectra, RPHPTLC, RPHPLC, antimicrobial activity, antiradical activity, and total phenolic content. It was found that 16 of the 25 samples showed a phenolic profile similar to that found in samples from southern Brazil and corresponding to poplar-based propolis and that the rest of the samples showed a different profile and higher antimicrobial and antiradical activities.  相似文献   

16.
R.F. Isbell  J.B.F. Field 《Geoderma》1977,18(3):155-175
Red and yellow earths are kaolinitic and generally sesquioxidic soils having massive B horizons with porous, earthy fabrics and weak profile differentiation but usually displaying a gradual increase in clay content with depth. They are widespread in tropical Queensland and northeast Brazil where comparable climates prevail although the vegetation is markedly different. Their parent materials are mostly quartzitic sedimentary rocks or unconsolidated sediments and the soils occur in a wide variety of topographic and geomorphic situations. In both regions it is probable that many of the soils have not formed under the present climatic conditions.Profile morphology, drainage, silt and clay contents, clay mineralogy, and soil chemistry have been compared and contrasted between the red and yellow earths within and between the two regions. Canonical variate analysis has shown that, on the basis of surface soil chemical attributes, the red earths can be separated from the yellow earths within each region and that the Queensland soils can be separated from the Brazilian soils.  相似文献   

17.
The objective of this work was to quantify the flavonoids present in foods most commonly consumed by the Brazilian population. The predominant flavonoids found in largest abundance in all of the analyzed vegetables were glycosides of quercetin. In lettuce, a small amount of luteolin was also detected. In sweet pepper, quercetin and luteolin were both present. White onion [48-56 mg/100 g of fresh weight (FW), expressed as aglycon], red onion (40-100 mg/100 g of FW), red lettuce (67-67.2 mg/100 g of FW), arugula (41-118 mg/100 g of FW), and chicory (18-38 mg/100 g of FW) were highest in total flavonoids. In fruits, the highest concentrations of flavonoids were found in the peel (125-170 mg/100 g of FW) and pulp (35-44 mg/100 g of FW) of oranges and in some apple varieties (14-36 mg/100 g of FW). Variability in flavonoid content due to time of harvesting was high for leafy vegetables and red onions. The estimated ingestion by Brazilian population ranged from 60 to 106 mg/day.  相似文献   

18.
The composition and antioxidant activity of Italian poplar propolis obtained using three harvesting methods and extracted with different solvents were evaluated. Waxes, balsams, and resins contents were determined. Flavones and flavonols, flavanones and dihydroflavonols, and total phenolics were also analyzed. To characterize the phenolic composition, the presence of 15 compounds was verified through HPLC-MS/MS. The antioxidant activity was evaluated through 1,1-diphenyl-2-picrylhydrazyl radical and reducing power assays. The ability of propolis to inhibit lipid oxidation was monitored by analyzing hydroperoxide and TBARS formation in lipids incorporated into an oil-in-water (O/W) emulsion. Acetone shows the highest extraction capacity. Wedge propolis has the highest concentration of active phenolic compounds (TP = 359.1 ± 16.3 GAEs/g; TFF = 5.83 ± 0.42%; TFD = 7.34 ± 1.8%) and seems to be the most promising for obtaining high-value propolis more suitable to prepare high-quality dietary supplements (TBARS = 0.012 ± 0.009 mmol std/g; RP = 0.77 ± 0.07 TEs/g).  相似文献   

19.
In this paper four rice samples and purified starch thereof characterized by different genetic background, amylose content, and gelatinization behavior were considered. They were examined with respect to chemical composition and pasting properties. To explain differences observed in the Rapid Visco Analyzer (RVA) curves, Fourier transform infrared spectroscopy (FTIR) was also used to characterize the rice and starch samples. Double two‐dimensional correlation analysis (D2DCORR), a powerful chemometric tool not commonly used in food analysis, was applied to FTIR spectra to support the interpretation of FTIR results. Finally, a study by FTIR spectroscopy was performed to characterize the lipid components extracted from some rice and starch samples. Rice samples showed different pasting properties owing to genetic characteristics, although these differences were mostly evident in the samples of starch thereof. However, the most interesting differences among samples were evidenced in the lipid component related to lipid–carbohydrate interactions, as resulted from the FTIR spectra and D2DCORR analysis.  相似文献   

20.
The use of organic matter (OM) amendments is widespread in tropical countries and may be beneficial for soil carbon storage. Interactions between earthworms and OM amendments in tropical soils are largely unknown. The aim of this study was to investigate the effect of bioturbation on the quantity and chemical composition of OM in soil amended with compost and vermicompost. Our approach included comparison of soil samples amended with compost, vermicompost or chemical fertilizers in the presence or absence of earthworms during a one-year greenhouse experiment. The soils were submitted to a regular cultivation cycle. After one year, we analysed bulk samples for soil OM elemental composition and characterised its lignin and non-cellulosic carbohydrate components.Our results showed a decrease of the carbon and nitrogen content in soil amended with chemical fertilizers. Vermicompost amendment led to unchanged OC content, whereas the compost amendment increased the soils OC content compared to initial soil. The addition of earthworms reduced OC and N content in soils with organic amendments. This is in contrast to soil amended with mineral fertilizer only, where the presence of earthworms did not have any effect. Bioturbation influenced the lignin signature of the soils, and to a lesser extent the non-cellulosic carbohydrate signature. In conclusion, compost amendment combined with bioturbation influenced the quality and quantity of SOM and as result carbon storage and its biogeochemical cycling in tropical soils. Implications for soil fertility remain to be elucidated.  相似文献   

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