Carotenoids: separation methods applicable to biological samples

Total Sialic Acid, Antioxidant Enzyme Activities, Trace Elements, and Vitamin Status Before and After Surgery in Women with Uterine Myoma and Endometrial Cancer

The objective of present study was to examine endometrial tissue Be, As, Cr, Mo, Sr, Ti, Tl, Cu, Co, Se, Zn, Mn, Fe, Cd, Pb, Mg, P, erythrocytes CAT, SOD, GSH-Px, GSH, MDA, serum retinol, cholecalciferol, phylloquinone, TSA, LSA, TOS, and TAS status and to evaluate the relationships between the variables. The study had 110 participants; of these, 50 were women with uterine myoma (UM), 10 were women with endometrial cancer (EC), and 50 were healthy female subjects. In the study, vitamin analyses by HPLC and element analyses were determined using ICP-OES method. It was observed that EC group was significantly lower than healthy group in terms of levels of cholecalciferol (p < 0.05), phylloquinone (p < 0.01), GSH (p < 0.05), Fe (p < 0.05), and had a significant rise in Mg/Fe (p < 0.01) and Zn/Fe (p < 0.05) in preoperative period. UM group had significantly lower retinol (p < 0.05), phylloquinone (p < 0.001), GSH-Px (p < 0.01), GSH (p < 0.01), Cr (p < 0.01), Cu (p < 0.05), Mg (p < 0.01), and Zn (p < 0.01) levels than control group in preoperative period and significantly higher levels of MDA (p < 0.01), TSA (p < 0.01), and LSA (p < 0.01) than control group. It was found that significant associations were observed between Cu-CA 15-3 (r = 0.558, p = 0.016), Mn-CA 15-3 (r = 0.511, p = 0.030), P-CA 15-3(r =  - 0.502, p = 0.034) and with UM, also between GSH-CA-125 (r =  - 0.825, p = 0.022) and with EC group. The results of correlation analysis observed that concentrations of Cu, Mn, P, and GSH together with CA 15-3 and CA-125 levels might be important for monitoring patients with UM and EC before surgery.

Plasma Carotenoids and Polyphenols and Their Association with MetS: The Need for Nutritional Interventions

Metabolic syndrome (MetS) is characterized by increased pro-oxidative stress and a chronic inflammation state and their consequent alterations. Several studies have highlighted the protective effect of carotenoids and polyphenols in MetS patients. This study aimed to evaluate the plasma level of selected carotenoids and polyphenols and to determine their relationship with MetS severity, MetS components, and inflammatory markers in Polish adults with metabolic disorders. It was designed as a cross-sectional study. The final study group comprised 275 adults, including 158 women and 117 men. Data were collected on the frequency of consumption of selected food groups. Anthropometric measurements and blood samples were taken to determine the concentration of carotenoids, polyphenols, and indicators (parameters) of metabolic disorders. Plasma concentrations of selected carotenoids and polyphenols were low in adults with MetS. The highest concentrations of carotenoids and polyphenols in the blood were observed for lutein and phenolic acids (including gallic and p-coumaric acids). Nevertheless, a correlation was found between the individual bioactive compounds and MetS components. In terms of the lipid profile, our study showed that the plasma of the selected carotenoids and polyphenols positively correlated with HDL cholesterol (zeaxanthin; total carotenoids), LDL cholesterol (chlorogenic acid), triglycerides (lycopene), and the total cholesterol (kaempferol). We found that the level of CRP as a marker of inflammation negatively correlated with the concentration of zeaxanthin. In our study group, no relationship was found between the dietary antioxidant intensity and the variables studied, which may be attributed to the low frequency of consumption of the sources of bioactive compounds, such as carotenoids and polyphenols, but also to the metabolic disorders. Further research is needed to determine whether these associations are causally related to the metabolic syndrome or are a result of the pathologies of the syndrome or improper diet with a low intake of vegetables and fruit.

Metabolomics of Chlorophylls and Carotenoids: Analytical Methods and Metabolome-Based Studies

Chlorophylls and carotenoids are two families of antioxidants present in daily ingested foods, whose recognition as added-value ingredients runs in parallel with the increasing number of demonstrated functional properties. Both groups include a complex and vast number of compounds, and extraction and analysis methods evolved recently to a modern protocol. New methodologies are more potent, precise, and accurate, but their application requires a better understanding of the technical and biological context. Therefore, the present review compiles the basic knowledge and recent advances of the metabolomics of chlorophylls and carotenoids, including the interrelation with the primary metabolism. The study includes material preparation and extraction protocols, the instrumental techniques for the acquisition of spectroscopic and spectrometric properties, the workflows and software tools for data pre-processing and analysis, and the application of mass spectrometry to pigment metabolomics. In addition, the review encompasses a critical description of studies where metabolomics analyses of chlorophylls and carotenoids were developed as an approach to analyzing the effects of biotic and abiotic stressors on living organisms.

Nephroprotective effect of Ferulago angulata flowers on N-nitrosodimethylamine-induced nephrotoxicity in rats and its phytochemical profile

The present study was designed to assess the phytochemical content of Ferulago angulata (FA) and possible in vivo nephroprotective effect of FA administration on trace elements, minerals, MDA and GSH in kidney and liver tissue samples, serum vitamin (α-tocopherol, retinol, cholecalciferol, phylloquinone), TSA, and LSA in a rat model of DMN-induced nephrotoxicity. In the study, Wistar albino rats were assigned to six groups: Control (0.9% NaCl), (DMN 10 mg/kg), (FA 150 mg/kg), (DMN + FA 150 mg/kg), (FA 300 mg/kg), and (DMN + FA 300 mg/kg). Rats were intraperitoneally given DMN for the first 7 days. Renal injury caused by DMN was proved by the histopathological alterations. The FA (300 mg/kg) treatment significantly normalized Se, Cr, Ca levels in liver and Co level in kidney tissue samples. These observed positive effects are due to the phytochemical content of the plant. The flower extract of FA (300 mg/kg) can be used for the prevention of kidney damage. PRACTICAL APPLICATIONS: Ferulago angulata flowers are used in traditional medicine for treat kidney and liver digestive system diseases. This species is endemic taxa of the family Apiaceae, which has been used both as food and therapeutics because of their phytochemical composition. In this study, the phenolic characterization of FA flower was used to a new RP-HPLC method, as well as the biological activity of FA flower and possible in vivo nephroprotective effect of FA flowers on trace elements, minerals, MDA and GSH in kidney and liver tissue samples and vitamins, TSA, and LSA in serum samples a rat model of DMN-induced nephrotoxicity. It was found that high level of phenolic compounds (chlorogenic acid, vanillic acid, 2-hydroxycinnamic acid) present in the flower extract of F. angulata has positive effects and antioxidant properties. Due to its phenolic content, FA flower extract could protect for kidney damage and can be used as antioxidants in the food additive and pharmaceutical industry.

The role of trace element, mineral, vitamin and total antioxidant status in women with habitual abortion

OBJECTIVE

In this study, women with habitual abortus (HA) and healthy control groups were determined for zinc (Zn), copper (Cu), manganese (Mn), selenium (Se), iron (Fe), cobalt (Co), chromium (Cr), nickel (Ni), lead (Pb), magnesium (Mg), calcium (Ca), sodium (Na), potassium (K), retinol, cholecalciferol, α-tocopherol, phylloquinone, total antioxidant (TAS) and total oxidation status (TOS) levels, also, and the relationships of these variables with HA were evaluated.

MATERIAL AND METHODS

The study included 39 women with HA and 39 healthy control subjects. In this study, trace element and mineral analyses by ICP-OES and vitamin analyses were determined using HPLC method.

RESULTS

Statistical analysis found that in the HA group was significantly lower than the control group with regarding cholecalciferol, phylloquinone, TAS, Se, Zn, Cu, Mg, K and Na levels (p < .05, p < .01, p < .01, p < .001, p < .05, p < .05, p < .01, p < .01 and p < .05). However, HA group was also significantly higher than control group regards to TOS, OSI and Ca⁄Mg levels (p < .05, p < .001, p < .05). In the HA group, significantly positive correlations were observed between phylloquinone and Ca (r = 0.495; p = .027), also, indicates negative significant correlation between cholecalciferol and Co (r = -0.598; p = .031).

CONCLUSION

Our findings indicate that the results could be helpful in the monitoring of women with HA in terms of deficiency. It is important that in terms of the evaluation of phylloquinone, cholecalciferol Se, Zn, Cu, Mg and Ca/Mg ratio is required to consider.

Assessment of antioxidant enzymes, total sialic acid, lipid bound sialic acid, vitamins and selected amino acids in children with phenylketonuria

BACKGROUND

In this study, children with phenylketonuria and healthy control subjects were assessed for glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) activity, malondialdehyde (MDA), glutathione (GSH), retinol, cholecalciferol, α-tocopherol, phylloquinone, total sialic acid (TSA), lipid bound sialic acid (LSA), total antioxidant (TAS), total oxidation (TOS), and amino acid levels, and the relationships of these variables with phenylketonuria were evaluated.

METHODS

The study included 60 children with phenylketonuria and 30 control subjects. Children with phenylketonuria were divided into hyperphenylalaninemia (HPA) and amino acid mixture (AAM) groups.

RESULTS

The HPA group had significantly lower levels of GSH-Px, CAT, GSH, TAS, α-aminobutyric acid, and taurine levels (p < 0.01, p < 0.05, p < 0.05, p < 0.001, p < 0.01, p < 0.05, respectively) than the control group. Additionally, the AAM group had significantly lower levels of CAT, TAS, and phylloquinones (p < 0.05, p < 0.05, p < 0.05, respectively) than the control group. It was observed in our study that in the HPA group, a significantly strong positive linear correlation was observed between phenylalanine and α-aminoadipic acid (r = 0.777; p = 0.002).

CONCLUSIONS

It was concluded that the levels of α-aminoadipic acid and phylloquinone might be an appropriate choice for the determination of phenylketonuria in parallel with the levels of phenylalanine. α-aminobutyric acid and phylloquinone as a supplement can decrease HPA damage.

Development of an Improved Carotenoid Extraction Method to Characterize the Carotenoid Composition under Oxidative Stress and Cold Temperature in the Rock Inhabiting Fungus Knufia petricola A95

Black yeasts are a highly specified group of fungi, which are characterized by a high resistance against stress factors. There are several factors enabling the cells to survive harsh environmental conditions. One aspect is the pigmentation, the melanin black yeasts often display a highly diverse carotenoid spectrum. Determination and characterization of carotenoids depend on an efficient extraction and separation, especially for black yeast, which is characterized by thick cell walls. Therefore, specific protocols are needed to ensure reliable analyses regarding stress responses in these fungi. Here we present both. First, we present a method to extract and analyze carotenoids and secondly we present the unusual carotenoid composition of the black yeast Knufia petricola A95. Mechanical treatment combined with an acetonitrile extraction gave us very good extraction rates with a high reproducibility. The presented extraction and elution protocol separates the main carotenoids (7) in K. petricola A95 and can be extended for the detection of additional carotenoids in other species. K. petricola A95 displays an unusual carotenoid composition, with mainly didehydrolycopene, torulene, and lycopene. The pigment composition varied in dependency to oxidative stress but remained relatively constant if the cells were cultivated under low temperature. Future experiments have to be carried out to determine if didehydrolycopene functions as a protective agent itself or if it serves as a precursor for antioxidative pigments like torulene and torularhodin, which could be produced after induction under stress conditions. Black yeasts are a promising source for carotenoid production and other substances. To unravel the potential of these fungi, new methods and studies are needed. The established protocol allows the determination of carotenoid composition in black yeasts.

Antioxidant properties of Ferulago angulata and its hepatoprotective effect against N-nitrosodimethylamine-induced oxidative stress in rats

CONTEXT

Ferulago angulata (Schlecht.) Boiss. (Apiaceae) (FASB) is used to treat liver diseases and has been used both as food and therapeutics by many cultures for thousands of years because of the natural antioxidant compounds.

OBJECTIVE

This study determines antioxidant properties of FASB flowers, the levels of minerals and vitamins, and also, evaluates the hepatoprotective effect of flowers against N-nitrosodimethylamine (NDMA) induced on liver tissue by assessing antioxidant enzymes and histopathological parameters in Wistar albino rats.

MATERIALS AND METHODS

In the study, the rats were divided into six groups of ten. Control, untreated animals were given 0.9% NaCl. Rats were intraperitoneally given NDMA (10 mg/kg) for the first 7 days. FASB methanol extract (150 and 300 mg/kg) was administered orally for 21 days.

RESULTS

α-Tocopherol, retinol, ascorbic acid, total antioxidant activity, phenolic and flavonoid contents of FASB were 0.70 ± 0.13, 0.29 ± 0.03 μg/g, 139.32 ± 7.06 μg/100 g, 171.61 ± 6.05 mM ascorbic acid/g, 90.47 ± 4.11 mg GA/g and 37.39 ± 2.85 mg QE/g. DPPH and hydroxyl radical scavenging activity was obtained IC₅₀ 67.34 ± 4.14 and 64.87 ± 4.68 μg/mL, respectively.

DISCUSSION AND CONCLUSION

The results of the study indicated that FASB flowers contain high levels of vitamins, minerals, total antioxidant activity, phenolics and flavonoids. Due to the positive effect on significant changes in antioxidant enzymes of liver tissue and histopathological examination, it is thought that the plant could be used as a hepatoprotective.

Development of an Advanced HPLC-MS/MS Method for the Determination of Carotenoids and Fat-Soluble Vitamins in Human Plasma

The concentration of carotenoids and fat-soluble vitamins in human plasma may play a significant role in numerous chronic diseases such as age-related macular degeneration and some types of cancer. Although these compounds are of utmost interest for human health, methods for their simultaneous determination are scarce. A new high pressure liquid chromatography (HPLC)-tandem mass spectrometry (MS/MS) method for the quantification of selected carotenoids and fat-soluble vitamins in human plasma was developed, validated, and then applied in a pilot dietary intervention study with healthy volunteers. In 50 min, 16 analytes were separated with an excellent resolution and suitable MS signal intensity. The proposed HPLC-MS/MS method led to improvements in the limits of detection (LOD) and quantification (LOQ) for all analyzed compounds compared to the most often used HPLC-DAD methods, in some cases being more than 100-fold lower. LOD values were between 0.001 and 0.422 µg/mL and LOQ values ranged from 0.003 to 1.406 µg/mL, according to the analyte. The accuracy, precision, and stability met with the acceptance criteria of the AOAC (Association of Official Analytical Chemists) International. According to these results, the described HPLC-MS/MS method is adequately sensitive, repeatable and suitable for the large-scale analysis of compounds in biological fluids.

Development of an Advanced HPLC-MS/MS Method for the Determination of Carotenoids and Fat-Soluble Vitamins in Human Plasma

The concentration of carotenoids and fat-soluble vitamins in human plasma may play a significant role in numerous chronic diseases such as age-related macular degeneration and some types of cancer. Although these compounds are of utmost interest for human health, methods for their simultaneous determination are scarce. A new high pressure liquid chromatography (HPLC)-tandem mass spectrometry (MS/MS) method for the quantification of selected carotenoids and fat-soluble vitamins in human plasma was developed, validated, and then applied in a pilot dietary intervention study with healthy volunteers. In 50 min, 16 analytes were separated with an excellent resolution and suitable MS signal intensity. The proposed HPLC-MS/MS method led to improvements in the limits of detection (LOD) and quantification (LOQ) for all analyzed compounds compared to the most often used HPLC-DAD methods, in some cases being more than 100-fold lower. LOD values were between 0.001 and 0.422 µg/mL and LOQ values ranged from 0.003 to 1.406 µg/mL, according to the analyte. The accuracy, precision, and stability met with the acceptance criteria of the AOAC (Association of Official Analytical Chemists) International. According to these results, the described HPLC-MS/MS method is adequately sensitive, repeatable and suitable for the large-scale analysis of compounds in biological fluids.

Formulation and Physicochemical Characterization of Lycopene-Loaded Solid Lipid Nanoparticles

PURPOSE

Lycopene belongs to the carotenoids that shows good pharmacological properties including antioxidant, anti-inflammatory and anticancer. However, as a result of very low aqueous solubility, it has a limited systemic absorption, following oral administration.

METHODS

Here, we prepared a stable lycopene-loaded solid lipid nanoparticles using Precirol® ATO5, Compritol 888 ATO and myristic acid by hot homogenization method with some modification. The size and morphological characteristics of nanoparticles were evaluated using Scanning Electron Microscopy (SEM). Moreover, zeta potential and dispersity index (DI) were measured using zeta sizer. In addition, encapsulation efficiency (EE%), drug loading (DL) and cumulative drug release were quantified.

RESULTS

The results showed that the size and DI of particles was generally smaller in the case of SLNs prepared with precirol when compared to SLNs prepared with compritol. Scanning electron microscopy (SEM) and particle size analyses showed spherical SLNs (125 ± 3.89 nm), monodispersed distribution, and zeta potential of -10.06 ± 0.08 mV. High EE (98.4 ± 0.5 %) and DL (44.8 ± 0.46 mg/g) were achieved in the case of nanoparticles prepared by precirol. The stability study of the lycopene-SLNs in aqueous medium (4 °C) was showed that after 2 months there is no significant differences seen in size and DI compared with the fresh formulation.

CONCLUSION

Conclusively, in this investigation we prepared a stable lycopene-SLNs with good physicochemical characteristic which candidate it for the future in vivo trials in nutraceutical industries.

Structures and Analysis of Carotenoid Molecules

Modifications of the usual C40 linear and symmetrical carotenoid skeleton give rise to a wide array of structures of carotenes and xanthophylls in plant tissues. These include acyclic, monocyclic and dicyclic carotenoids, along with hydroxy and epoxy xanthophylls and apocarotenoids. Carotenols can be unesterified or esterified (monoester) in one or two (diester) hydroxyl groups with fatty acids. E-Z isomerization increases the array of possible plant carotenoids even further. Screening and especially quantitative analysis are being carried out worldwide. Visible absorption spectrometry and near infrared reflectance spectroscopy have been used for the initial estimation of the total carotenoid content or the principal carotenoid content when large numbers of samples needed to be analyzed within a short time, as would be the case in breeding programs. Although inherently difficult, quantitative analysis of the individual carotenoids is essential. Knowledge of the sources of errors and means to avoid them has led to a large body of reliable quantitative compositional data on carotenoids. Reverse-phase HPLC with a photodiode array detector has been the preferred analytical technique, but UHPLC is increasingly employed. HPLC-MS has been used mainly for identification and NMR has been useful in unequivocally identifying geometric isomers.

A New Method to Simultaneously Quantify the Antioxidants: Carotenes, Xanthophylls, and Vitamin A in Human Plasma

A simple and accurate reversed phase high-performance liquid chromatography coupled with diode array detector (HPLC-DAD) method for simultaneously determining and quantifying the antioxidants carotenes, xanthophylls, and retinol in human plasma is presented in this paper. Compounds were extracted with hexane, a C30 column, and a mobile phase of methanol, methyl tert-butyl ether, and water were used for the separation of the compounds. A total of 8 carotenoids, 3 Z-β-carotene isomers, and 1 fat-soluble vitamin (retinol) were resolved within 72 min at a flow rate of 0.6 mL/min. Detection was achieved at 450 nm for carotenoids and 330 nm for retinol. To evaluate the effectiveness of themethod, it has been applied to an intervention study conducted on eight volunteers. Results. Limits of detection were between 0.1 μg/mL for lycopene and astaxanthin and 1.3 μg/mL for 15-Z-β-carotene. Recoveries were ranged between 89% and 113% for α-carotene and astaxanthin, respectively. Accuracy was between 90.7% and 112.2% and precision was between 1% and 15% RSD. In human plasma samples compounds studied were identified besides three lycopene isomers, demonstrated to be suitable for application in dietary intervention studies. Conclusions. Due to its accuracy, precision, selectivity, and reproducibility, this method is suitable to dietary habits and/or antioxidants status studies.

A rapid and sensitive method for determination of carotenoids in plant tissues by high performance liquid chromatography

BACKGROUND

The dietary carotenoids serve as precursor for vitamin A and prevent several chronic-degenerative diseases. The carotenoid profiling is necessary to understand their importance on human health. However, the available high-performance liquid chromatography (HPLC) methods to resolve the major carotenoids require longer analysis times and do not adequately resolve the violaxanthin and neoxanthin.

RESULTS

A fast and sensitive HPLC method was developed using a C30 column at 20°C with a gradient consisting of methanol, methyl-tert-butyl ether and water. A total of 15 major carotenoids, including 14 all-trans forms and one cis form were resolved within 20 min. The method also distinctly resolved violaxanthin and neoxanthin present in green tissues. Additionally this method also resolved geometrical isomers of the carotenoids.

CONCLUSION

The HPLC coupled with C30 column efficiently resolved fifteen carotenoids and their isomers in shorter runtime of 20 min. Application of this method to diverse matrices such as tomato fruits and leaves, Arabidopsis leaves and green pepper fruits showed the versatility and robustness of the method. The method would be useful for high throughput analysis of large number of samples.

Improving Method Reliability in Carotenoid Analysis through Selective Removal of Glycerolipid Interferences by Lipase Treatment

Saponification is most often used to hydrolyze glycerolipid interferences during carotenoid analysis. Ester bonds of other plant metabolites such as carotenoids are, however, also hydrolyzed during saponification, thus altering the natural carotenoid composition. A straightforward and selective cleanup procedure was therefore developed involving the enzymatic hydrolysis of matrix glycerolipids. The optimized procedure (100 μL of extracted vegetable or algal oil in 20 mL of 50:50 phosphate buffer/methanol with 25 μL of sodium n-octyl sulfate, 30 mg of bile salts, and 250 μL of NaCl solution (5 mM), magnetic stirring for 2 h at 40 °C with 1 mL of Lipozyme TL 100 L and 1 mL of Lipozyme CALB L) removed the greater part of triglycerides (94.8-100.0%) and diglycerides (88.2-99.8%) while preserving the natural carotenoid composition.

Study of RP HPLC Retention Behaviours in Analysis of Carotenoids

For determination of selected carotenoids, various types of columns for high-performance liquid chromatography (HPLC) with different properties have been used. The characteristics of the laboratory-used packing material containing monomeric alkyl-bonded phases (C18, C30) and phenyl as well as phenyl-hexyl stationary phases were studied. The retention data of the examined compounds were used to determine the hydrophobicity and silanol activity of stationary phases applied in the study. The presence of the polar and carboxyl groups in the structure of the bonded ligand strongly influences the polarity of the stationary phase. Columns were compared according to methylene selectivity using a series of benzene homologues. The measurements were done using a methanol-water mobile phase. Knowledge of the properties of the applied stationary phase provided the possibility to predict the RP HPLC retention behaviours in analysis of carotenoids including lutein, lycopene and β-carotene. The composition of the mobile phase, the addition of triethylamine and the type of stationary phase had been taken into account in designing the method of carotenoid identification. Also a monolithic column characterised by low hydrodynamic resistance, high porosity and high permeability was applied. The presented results show that the coverage density of the bonded ligands on silica gel packings and length of the linkage strongly influence the carotenoid retention behaviours. In our study, the highest retention parameters for lutein, lycopene and β-carotene were observed for C30 and C18 stationary phase. This effect corresponds with pore size of column packing greater than 100 Å and carbon content higher than 11 %.

Simultaneous analysis of circulating 25-hydroxy-vitamin D3, 25-hydroxy-vitamin D2, retinol, tocopherols, carotenoids, and oxidized and reduced coenzyme Q10 by high performance liquid chromatography with photo diode-array detection using C18 and C30 columns alone or in combination

Circulating lipid-phase micronutrients (LPM) such as 25-hydroxylated D vitamers, retinol, tocopherols, carotenoids including their isomers, and coenzyme Q10 play important roles in health maintenance and disease prevention and can serve as useful biomarkers. We developed fast, affordable, and accurate HPLC assays that simultaneously measured all above LPM in a single run using UV/VIS detection at 265nm, 295nm, and 480nm with (1) a C18 column alone; (2) a C30 column alone; or (3) each of these columns connected in series. The C18 column alone could separate all major LPM of interest in less than 17min but insufficiently resolved the lycopene isomers, the 25-hydroxylated D vitamers, lutein from zeaxanthin and β- from γ-tocopherol. The C30 column alone separated all LPM of interest including many isomeric analytes but failed to resolve the Q10 compounds, which co-eluted with carotenoids. Connecting the C18 and C30 columns in series with a detector after the C30 column and a pressure resistant detector between the columns resulted in ideal resolution and accurate quantitation of all LPM of interest but required software capable of processing the acquired data from both detectors. Connecting the C18 and C30 columns in series with exclusively one detector after the C30 column resulted in carotenoid-Q10 interferences, however, this was remedied by heart-cutting 2D-LC with a 6-port valve between the columns, which resolved all analytes in 42min. Faster run times led to some analytes not being resolved. Many variations of these methods are possible to meet the needs of individual requirements while minimizing sample material and turn-around-times.

Analysis of circulating lipid-phase micronutrients in humans by HPLC: review and overview of new developments

Retinol, tocopherols, coenzyme Q10, carotenoids, and vitamin D are lipophilic compounds shown to function as important health-protective agents by mitigating the damaging effects of oxidative and other injury. Scientific interest in evaluating these compounds has resurfaced in recent years, particularly in the nutritional, clinical and epidemiologic fields, and has precipitated the development of a multitude of new analytical techniques. This review considers recent developments in HPLC-based assays since 2007 for the simultaneous determination of these lipid-phase compounds utilizing exclusively serum or plasma as these matrices are mostly used in clinical and epidemiological investigations. We also provide an overview of blood measurements for selected carotenoids, tocopherols, coenzyme Q10 and retinol from the last 15years of healthy umbilical cord blood, children, and adults.

Unravelling ionization and fragmentation pathways of carotenoids using orbitrap technology: a first step towards identification of unknowns

Vegetables are a major source of carotenoids and carotenoids are identified as potentially important natural antioxidants that may aid in the prevention of several human chronic degenerative diseases. Characterization of carotenoids in organic biological matrices is a crucial step in any research valorization trajectory. This study reports for the first time the use of high mass resolution and exact mass orbitrap technology for the elucidation of carotenoid fragmentation pathways. This contributes to the generation of new tools for identifying unknown carotenoids based on fragmentation patterns. Two different chromatographic methods making use of different mobile phases resulted in the generation of different ion species because of the large influence of the mobile phase solvent composition on ionization. It was shown that depending on the molecular ion species that are generated (protonated ions or radical molecular ions), different fragments are formed when applying higher energy collisional dissociation. Fragmentation and the abundance of fragments provide valuable structural information on the type of functional groups, the polyene backbone and the location of double bonds in ring structures of carotenoids. Furthermore, coherence between specific substructures in the molecules and characteristic fragmentation patterns was observed allowing the assignment of fragmentation patterns for carotenoid substructures that can theoretically be extrapolated to carotenoids with similar (sub)structures. Differentiation between isomeric carotenoids by compound specific fragments could however not be made for all the isomeric groups under study. As a wide variety of isomeric forms of carotenoids exist in nature, the combination of good chromatographic separation with high resolution mass spectrometry and other complementary qualitative structure elucidation techniques such as a photo diode array detector and/or nuclear magnetic resonance spectroscopy are indispensable for unambiguous identification of unknown carotenoids.

Effects of extraction and high-performance liquid chromatographic conditions on the determination of lutein in spinach

A major factor in the direct determination of lutein in spinach extracts proved to be obtaining reproducible and stable chromatography of lutein. This was achieved on a C30 column with the mobile phase acetone-0.1M triethylammonium acetate (TEAA) buffer (pH 7) 9:1 (v/v). Extraction of 10mg of lyophilized spinach with 10 mL of extraction solvent (ethanol, acetone, ethanol-ethyl acetate 1:1 (v/v), methanol-THF 1:1 (v/v)) for 15 min with magnetic stirring under nitrogen resulted in equal yields of lutein. The yields were enhanced by addition of 15% of 1M TEAA buffer pH 7 to all four extraction solvents. As confirmed by recovery experiments, no loss of lutein occurred during the extraction. The relative standard deviation from triplicate extractions was less than 5%. The addition of 15% TEAA pH 7 to acetone enhanced the extraction yield of lutein also from unlyophilized spinach. The content of lutein in different spinach samples ranged from 5 to 15 mg/100g of fresh weight. The first separation is reported of all the carotenoids and chlorophylls on a C18 core-shell column and the addition of 15% of 1M TEAA buffer pH 7 to acetone also enhanced the extraction yield of β-carotene compared to the yield produced by pure acetone.

Influence of sample processing on the analysis of carotenoids in maize

We performed a number of tests with the aim to develop an effective extraction method for the analysis of carotenoid content in maize seed. Mixtures of methanol–ethyl acetate (6:4, v/v) and methanol–tetrahydrofuran (1:1, v/v) were the most effective solvent systems for carotenoid extraction from maize endosperm under the conditions assayed. In addition, we also addressed sample preparation prior to the analysis of carotenoids by liquid chromatography (LC). The LC response of extracted carotenoids and standards in several solvents was evaluated and results were related to the degree of solubility of these pigments. Three key factors were found to be important when selecting a suitable injection solvent: compatibility between the mobile phase and injection solvent, carotenoid polarity and content in the matrix.

Evaluation of the suitability of low hazard surfactants for the separation of phenols and carotenoids from red-flesh orange juice and olive mill wastewater using cloud point extraction

Natural antioxidants derived from plant sources attract considerable scientific interest. While classic extraction methods consume high volumes of toxic organic solvents, cloud point extraction requires surfactant not exceeding 15% of the waste volume. In preliminary tests, the suitability of various low hazard surfactants (Span 20, PEG 400, Tween 80 and 20) was explored for separation of phenols and carotenoids from olive mill wastewater and red-flesh orange juice. Tween 80 showed the highest recovery and further applied to the next experiments. The most appropriate surfactant concentrations were 5% (for olive mill wastewater) and 7% (for orange juice) as indicated by recovery % and the rest cloud point extraction parameters (analyte concentration, concentration factor, and phase volume ratio). A double step CPE with 5% + 5% of Tween 80 recovered up to 94.4% of the total phenols from olive mill wastewater, while a 7% + 7% of Tween 80 recovered up to 72.4% of the total carotenoids from orange juice. Evaluation of the final effects and extraction efficiency of single and double step cloud point extraction shows that double step scheme seems to be preferable in both cases. Finally, phenols and carotenoids recovered by Tween 80 maintained high antiradical activity (DPPH test).

β-Carotene and lycopene affect endothelial response to TNF-α reducing nitro-oxidative stress and interaction with monocytes

SCOPE

Cardiovascular disease (CVD) is associated with vascular oxidative imbalance and inflammation. Increased reactive oxygen species (ROS) generation is associated with a functional inactivation of nitric oxide (NO) due to the reaction with O₂⁻, leading to peroxynitrite (ONOO⁻) formation and subsequent reduction in the beneficial effect of vascular NO bioavailability. Carotenoids'-rich diets have been associated with decreased risk of CVD, but the underlying mechanism is still unknown.

METHODS AND RESULTS

In human umbilical vein endothelial cells (HUVECs), both β-carotene (BC) or lycopene (Lyc) significantly affected tumor necrosis factor-α (TNF-α)-induced inflammation, being associated with a significant decrease in the generation of ROS (spectrofluorometry) and nitrotyrosine (an index of ONOO⁻ formation, cytofluorimetry), an increased NO/cGMP (cyclic guanosine monophosphate) levels (EIA), and a down-regulation of NF-κB-dependent adhesion molecule expression (Western blot and EMSA) and monocyte-HUVEC interaction (adhesion assay). Our results indicate that BC or Lyc treatment reduce the inflammatory response in TNF-α-treated HUVECs. This is due to the redox balance protection and to the maintenance of NO bioavailability.

CONCLUSION

Our observations provide background for a novel mechanism for carotenoids' anti-inflammatory activity in the vasculature and may contribute to a better understanding of the protective effects of carotenoid-rich diets against CVD risk.

Pressurized liquid extraction as a green approach in food and herbal plants extraction: A review

Pressurized liquid extraction is a "green" technology for the extraction of nutraceuticals from foods and herbal plants. This review discusses the extraction principles and the optimization of the extraction parameters that improves the extraction efficiency. The use of different solvent mixtures and other extraction additives to enhance the efficiency of the extraction are discussed. Dynamic mode of extraction in Pressurized liquid extraction, and the use of combined and hyphenated sample preparation and analytical techniques are presented. This work discusses how different studies used Pressurized liquid extraction to enrich phenolic compounds, lignans, carotenoids, oils and lipids, essential oils and other nutraceuticals from foods and herbal plants.

A nitromethane-based HPLC system alternative to acetonitrile for carotenoid analysis of fruit and vegetables

Acetonitrile-based HPLC systems are the most commonly used for carotenoid analysis from different plant tissues. Because of the acetonitrile shortage, an HPLC system for the separation of carotenoids on C(18) reversed-phase columns was developed in which an acetonitrile-alcohol-based mobile phase was replaced by nitromethane. This solvent comes closest to acetonitrile with respect to its elutrophic property. Our criterion was to obtain similar separation and retention times for a range of differently structured carotenoids. This was achieved by further increase in the lipophilicity with ethylacetate. For all the carotenoids which we tested, we found co-elution only of β-cryptoxanthin and lycopene. By addition of 1% of water, separation of this pair of carotenoids was also achieved. The final recommended mobile phase consisted of nitromethane : 2-propanol : ethyl acetate : water (79 : 10 : 10 : 1, by volume). On Nucleosil C(18) columns and related ones like Hypersil C(18), we obtained separation of carotenes, hydroxyl, epoxy and keto derivatives, which resembles the excellent separation properties of acetonitrile-based mobile phases on C(18) reversed phase columns. We successfully applied the newly developed HPLC system to the separation of carotenoids from different vegetables and fruit.

Revealing the power of the natural red pigment lycopene

By-products derived from food processing are attractive source for their valuable bioactive components and color pigments. These by-products are useful for development as functional foods, nutraceuticals, food ingredients, additives, and also as cosmetic products. Lycopene is a bioactive red colored pigment naturally occurring in plants. Industrial by-products obtained from the plants are the good sources of lycopene. Interest in lycopene is increasing due to increasing evidence proving its preventive properties toward numerous diseases. In vitro, in vivo and ex vivo studies have demonstrated that lycopene-rich foods are inversely associated to diseases such as cancers, cardiovascular diseases, diabetes, and others. This paper also reviews the properties, absorption, transportation, and distribution of lycopene and its by-products in human body. The mechanism of action and interaction of lycopene with other bioactive compounds are also discussed, because these are the crucial features for beneficial role of lycopene. However, information on the effect of food processing on lycopene stability and availability was discussed for better understanding of its characteristics.

Simultaneous determination of retinol, retinyl palmitate and β-carotene in rat serum treated with 7,12-dimethylbenz[a]anthracene and Hypericum Perforatum L. by high-performance liquid chromatography with diode-array detection

A new and simple high-performance liquid chromatography method was developed and validated for the simultaneous determination of retinol, retinyl palmitate and β-carotene in rat serum treated with Hypericum Perforatum L. and 7,12-dimethylbenz[a]anthracene. Furthermore, vitamin C was determined spectrophotometrically. High-performance liquid chromatography analysis was performed utilizing an Inertsil ODS3 reversed phase column with methanol-acetonitrile-tetrahydrofuran (65:30:5, v/v/v) as mobile phase, at a flow rate of 1.5 mL min−1 and 40°C. Diode-array detection was conducted at 325 and 450 nm for retinol and retinyl palmitate, and β-carotene, respectively with a running time of 26 min. The high-performance liquid chromatography assay and extraction procedure proposed are simple, rapid, sensitive and accurate. This method was then applied to determine the amounts of retinol, retinyl palmitate and β-carotene in rat serum. Results of this study demonstrated that at 60th day in the 7,12-dimethylbenz[a]anthracene-treated group there was a significant decrease (pa] anthracene + Hypericum Perforatum L. treated group compared to the control group..

Dereplication of bioactive constituents of the genus hypericum using LC-(+,-)-ESI-MS and LC-PDA techniques: Hypericum triquterifolium as a case study

Utilizing liquid chromatography-electro spray ionization-mass spectrometry (LC-(+,-)-ESI-MS) and liquid chromatography-photodiode array detection (LC-PDA) techniques, a dereplication strategy for the analysis of the secondary metabolites constituents of the genus Hypericum has been developed. From the crude methanolic extract of the aerial parts of H. triquetrifolium (leaves, stems, and flowers) and on the basis of their UV-profiles, chromatographic retention times and (+,-)-ESI-MS (TIC and SIM) mass spectral data, seven known (1-7) compounds were dereplicated fairly rapidly. The compounds were classified into three structural classes: phloroglucinols: hyperfirin and adhyperfirin; naphthodianthrones: hypericin, pseudo-hypericin, proto-hypericin, and protopseudo-hypericin; and the flavonoid rutin.