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In this paper the presence of selected prenylated and unprenylated phenylpropanoids, namely ferulic acid 1 , boropinic acid 2 , 4′-geranyloxyferulic acid 3 , umbelliferone 4 , 7-isopentenyloxycoumarin 5 , and auraptene 6 , have been determined in Italian raw propolis after having been extracted with different methodologies. An aqueous solution of β-cyclodextrin was the best extraction method for ferulic acid 1 , treatment with indifferently EtOH or aqueous β-cyclodextrin were the most effective one for umbelliferone 4 , boropinic acid 2 gave the best yields either with H 2 O/β-cyclodextrin or olive oil treatment or in biphasic systems, maceration with biphasic mixtures of aqueous β-cyclodextrin and olive oil was seen to be the most effective procedure for 7-isopentenyloxycoumarin 5 , the only method providing significant quantities of 4′-geranyloxyferulic acid 3 was the maceration of raw propolis with olive oil, and finally auraptene 4 was best extracted with absolute EtOH. “Classic” maceration in general performed better than ultrasound-assisted one. [ABSTRACT FROM AUTHOR]

Assessing the effects of glutathione peroxidase (GPx)-like catalytic activities of natural, semi-synthetic, and synthetic compounds is nowadays well recognized of importance for the preliminary screening of potential anti-inflammatory, neuroprotective, and anti-cancer agents. To this aim the Iwaoka's assay, relying on 1H NMR data recording, has been the most exploited test. In this short communication we propose an efficient and easy to perform methodology to accomplish the same process based on the application of hyphenated techniques like gas-chromatography coupled to mass spectrometry (GC-MS) and high-performance liquid chromatography with diode array detection (HPLC-DAD). The assay consisted in monitoring and quantifying the oxidation at different times of 1,4-dithiothreitol to 4,5-dihydroxy-1,2-dithiane in the presence of H 2 O 2 and 2-phenyl-1,2-benzoselenazol-3(2 H)-one (Ebselen) as the catalyst in EtOAc or MeOH as the solvents. The results we recorded by the application of both GC-MS and HPLC-DAD, showed that the GPx-like activity of Ebselen, used as the reference compound, can be effectively monitored in a time-course manner, and compare favorably to the NMR-based test. • A novel version of the Iwaoka's assay has been established. • Successful application of GC/MS and HPLC/DAD. • Application of an effective and reliable test. • Potential for a rapid screening of a wide panel of chemicals. [ABSTRACT FROM AUTHOR]

• Sorbents used for the adsorption of amarogentin from Gentiana lutea root extract. • Mg-based materials adsorbed amarogentin in virtual quantitative yield. • Percentages of adsorbed phytochemicals were evaluated by HPLC analysis. • An amarogentin-based blend as a novel food addictive was obtained. Amarogentin is well known to be among the most bitter naturally occurring compound. Either as an individual one or extracts, amarogentin is used as a food additive and as a dietary supplement. The aim of the present investigation is to set-up a convenient process to selectively isolate amarogentin from the ethanolic roots extract of Gentiana lutea. The process consisted in the treatment of an aqueous suspension of such an extract with a panel of 21 solid inorganic / organic sorbents followed by filtration, desorption, and high performance liquid chromatography (HPLC) analyses. Among the solid materials tested, those containing Mg+2 in the frame of a lamellar structure provided very good adsorption yields in the range 86.4% − 99.9% (p < 0.05 at Student's t -test). The method we set up could be in principle useful to obtain a pure nature-derived food additive to provide bitter taste to foods and beverages. [ABSTRACT FROM AUTHOR]

Ginseng is an increasingly popular ingredient in supplements for healthcare products and traditional medicine. Heat-processed ginsengs, such as red ginseng or black ginseng, are regarded as more valuable for medicinal use when compared to white ginseng due to some unique less polar ginsenosides that are produced during heat-treatment. Although ginseng leaf contains abundant ginsenosides, attention has mostly focused on ginseng root; relatively few publications have focused on ginseng leaf. Raw ginseng leaf was steamed nine times to make black ginseng leaf using a process that is similar to that used to produce black ginseng root. Sixteen ginsenosides were analyzed during each steaming while using high-performance liquid chromatography (HPLC). The contents of ginsenosides Rd and Re decreased and the less polar ginsenosides (F2, Rg3, Rk2, Rk3, Rh3, Rh4, and protopanaxatriol) enriched during steam treatment. After nine cycles of steaming, the contents of the less polar ginsenosides F2, Rg3, and Rk2 increased by 12.9-fold, 8.6-fold, and 2.6-fold, respectively. Further, we found that the polar protopanaxadiol (PPD) -type ginsenosides are more likely to be converted from ginsenoside Rg3 to ginsenosides Rk1 and Rg5 via dehydration from Rg3, and from ginsenoside Rh2 to ginsenosides Rk2 and Rh3 through losing an H2O molecule than to be completely degraded to the aglycones PPD during the heat process. This study suggests that ginseng leaves can be used to produce less polar ginsenosides through heat processes, such as steaming. [ABSTRACT FROM AUTHOR]

Roots and leaves of Carlina acaulis L. are still used in ethnomedicine in many European countries; however, the limited occurrence of the plants and protection of this species necessitate a search for alternative ways for obtaining this plant material. In this study, in vitro cultures, hydroponic cultures, and field cultivation were applied to obtain the C. acaulis plant material. Its quality was evaluated using antioxidant activity tests and high performance liquid chromatography analysis. Our study showed that the antioxidant activity and the content of chlorogenic and 3,5-di-caffeoylquinic acid in roots of plants cultivated in hydroponics and field conditions were comparable. However, the amount of carlina oxide was significantly higher in plants from the field. The flavonoid content in leaves obtained from both cultivation systems was at the same level; however, the antioxidant activity and the content of the investigated metabolites were higher in the soil cultivation system. The callus line exhibited high differentiation in phytochemical compositions depending on the treatments and medium compositions. [ABSTRACT FROM AUTHOR]

Two additional oxyprenylated phenylpropanoids in Citrus paradisi Macfad. seeds extract • The isolation of novel O- prenylpropanoids from grapefruit is described. • Novel phytochemicals have been characterized by HPLC/DAD. • Novel phytochemicals have been isolated for the first time within the Rutaceae family. [ABSTRACT FROM AUTHOR]

Umbelliprenin has recently been shown to have great potential as a skin whitening agent. Wishing to investigate the same effect in plant species known to biosynthesize this coumarin, three plants belonging to the Apiaceae family, namely Anethum graveolens L. (dill), Pimpinella anisum L. (anise), and Ferulago campestris (Besser) Grecescu (field ferula) were screened by HPLC analysis for their respective content of umbelliprenin in extracts obtained with different solvent mixtures and by maceration and ultrasound-assisted processes. EtOH was shown to be the best solvent, providing umbelliprenin yields ranging from 1.7% to 14.4% (with respect to the total amount of extract obtained). Extracts with the highest content of this farnesyloxycoumarin were then assayed as modulators of melanogenesis in cultured murine Melan A cells employing the same umbelliprenin obtained by chemical synthesis as the reference. A parallelism between the content of the coumarin and the recorded depigmenting effect (60% for the EtOH extract of F. campestris as the best value) was revealed for all plants extracts when applied at a dose of 100 μg/mL. Our results demonstrate that the same potential of umbelliprenin can be ascribed also to umbelliprenin-enriched plant extracts which reinforces enforce the widespread use of phyto-preparations for cosmetic purposes (e.g., A. graveolens). [ABSTRACT FROM AUTHOR]

A high performance liquid chromatography (HPLC) method was developed for the simultaneous isolation, on a semi-preparative scale, of chavibetol and methyleugenol from the crude essential oil of P. pseudocaryophyllus leaves. The purity of the isolated compounds and their quantifications were developed using GC/FID. Chavibetol was isolated with high purity (98.7%) and mass recovery (94.6%). The mass recovery (86.4%) and purity (85.3%) of methyleugenol were lower than those of chavibetol. Both compounds were identified on the basis of spectral analysis. The results suggest that the method can provide chavibetol with high purity, mass recovery, and productivity from crude essential, which will be used in bioassays against stored insect pests. [ABSTRACT FROM AUTHOR]

Xanthine oxidase, an enzyme present in significant levels in the intestine and liver, metabolizes hypoxanthine to xanthine and xanthine to uric acid in the purine catabolic pathway. An inhibitory compound acting against xanthine oxidase was isolated from sweet white clover (Melilotus albus) by bioassay and high-performance liquid chromatography guided separation. It was identified as tricin by spectroscopic analysis. Tricin possessed a potent xanthine oxidase inhibitory activity with an IC50 value of 4.13 μM. Further inhibition kinetics data indicated it to be a mixed-type inhibitor and Ki and KI values were determined to be 0.47 μM and 4.41 μM. To find a rich source of tricin, the distribution of tricin in seven different tissues from four Gramineae species was investigated by high-performance liquid chromatography analysis. The highest amount (1925.05 mg/kg dry materials) was found in the straw of wheat, which is considered as a potentially valuable source of natural tricin. [ABSTRACT FROM AUTHOR]

Highlights • UPLC method set up for the quantification of minor nutraceuticals in spinach, goji, and quinoa. • Prenyloxyphenylpropanoids have been disclosed for the first time. • Widening of the nutraceutical pool knowledge in Amaranthaceae and Solanaceae plants. Abstract Spinach leaves, goji berries and quinoa seeds are claimed to have a great nutraceutical potential due to their high content of compounds providing benefits for human health, such as amino acids, polyunsaturated fatty acids, carotenoids, betaine, vitamins, fibre, minerals and polyphenols. Samples of these plants were extracted with different solvent mixtures (e.g. EtOH, H 2 O/EtOH 3:7 and H 2 O/EtOH 7:3) and extractions were accomplished using a microwave apparatus. Subsequent UHPLC analysis and photodiode array detection were employed for the quantification of biologically active compounds like 7-isopentenyloxycoumarin, auraptene, umbelliprenin, boropinic acid and 4′-geranyloxyferulic acid. EtOH was found to be the best solvent in terms of extractive yields and the above-mentioned phytochemicals were recorded in the concentration range 2.01–49.22 µg/g dry extract. The findings depicted herein revealed that spinach, goji and quinoa are good sources of oxyprenylated umbelliferone and ferulic acid derivatives. [ABSTRACT FROM AUTHOR]

An efficient analytical strategy based on different extraction methods of biologically active naturally occurring oxyprenylated umbelliferone and ferulic acid derivatives 7-isopentenyloxycoumarin, auraptene, umbelliprenin, boropinic acid, and 4′-geranyloxyferulic acid and quantification by UHPLC with spectrophotometric (UV/Vis) detection from Tea tree oil is reported. Absorption of the pure oil on Al 2 O 3 (Brockmann activity II) prior washing the resulting solid with MeOH and treatment of this latter with CH 2 Cl 2 resulted the best extraction methodology in terms of yields of oxyprenylated secondary metabolites. Among the five O -prenylphenylpropanoids herein under investigation auraptene and umbelliprenin were never detected while 4′-geranyloxyferulic acid was the most abundant compound resulting from all the three extraction methods employed. The UHPLC analytical methodology set up in the present study resulted to be an effective and versatile technique for the simultaneous characterization and quantification of prenyloxyphenylpropanoids in Tea tree oil and applicable to other complex matrices from the plant kingdom. [ABSTRACT FROM AUTHOR]

A green dispersive liquid-liquid microextraction (DLLME) using deep eutectic solvent (DES) as the extracting solvent has been developed and applied for the simultaneous quantification of ferulic acid, umbelliferone, boropinic acid, 7-isopentenyloxycoumarin, 4′-geranyloxyferulic acid (GOFA), and auraptene in some vegetable oils using ultra high performance liquid chromatography (UHPLC) with photodiode array detection (PDA). All parameters in the extraction step, including selection and loading of both extracting and dispersing solvents, amount of both extractant and disperser solvent were investigated and optimized. PhAA/TMG DES achieved higher recovery and enrichment factor compared to other DESs. The validated method showed good linearity with correlation coefficients, r 2 > 0.9990 for all the analytes. Furthermore, this is the first time that eco-friendly solvents are used for the extraction of oxyprenylated phenylpropanoids and the corresponding extract analyzed with ultra high performance liquid chromatography with photodiode array detection. [ABSTRACT FROM AUTHOR]

Oxyprenylated natural products were shown to exert in vitro and in vivo remarkable anti-cancer and anti-inflammatory effects. This paper describes a rapid, selective, and sensitive HPLC method with fluorescence detection for determination of 4'-geranyloxyferulic acid (GOFA) and its conjugate with l -nitroarginine methyl ester (GOFA-L-NAME) in mononuclear cells. Analytes were extracted from cells using methanol and eluted on a GraceSmart RP 18 analytical column (250 × 4.6 mm i.d., 5 μm particle size) kept at 25 °C. A mixture of formic acid 1% in water (A) and methanol (B) were used as mobile phase, at a flow-rate of 1.2 mL/min in gradient elution. A fluorescence detector (excitation/emission wavelength of 319/398 nm for GOFA and GOFA-L-NAME), was used for the two analytes. Calibration curves of GOFA and GOFA-L-NAME were linear over the concentration range of 1.0–50 μg/mL, with correlation coefficients ( r 2 ) ≥ 0.9995. Intra- and inter-assay precision do not exceed 6.8%. The accuracy was from 94% to 105% for quality control samples (2.0, 25.0 and 40 μg/mL). The mean (RSD%) extraction recoveries (n = 5) for GOFA and GOFA-L-NAME from spiked cells at 2.0, 25.0 and 40.0 μg/mL were 92.4 ± 1.5%, 94.7 ± 0.9% and 93.8 ± 1.1%, for GOFA and 95.3 ± 1.2%, 94.8 ± 1.0% and 93.9 ± 1.3%, for GOFA-L-NAME. The limits of detection and quantification were 0.3 μg/mL and 1.0 μg/mL for GOFA and GOFA-L-NAME. This method was successfully applied to measure GOFA and GOFA-L-NAME concentrations in a mononuclear cells. [ABSTRACT FROM AUTHOR]

Natural honey has been employed as a nutraceutical agent with benefits and therapeutic promises for humans for many centuries. It has been largely used as food and medicine by all generations, traditions, and civilizations, both ancient and modern. Several chemicals having beneficial effects for human health have been reported as components of natural honey and these include sugars, organic acids, aminoacids, minerals, and vitamins. Also some important phytochemicals have been described and these comprise tannins, flavonoids, terpenes, saponins, and alkaloids. In this note it is described the successful application of a RP HPLC-UV–vis method for the separation and quantification of 4′-geranyloxyferulic acid (GOFA) in four honey samples of different origin. Concentration values showed a great variation between the four samples tested, being chestnut honey the one richest in GOFA (7.87 mg/g). The findings described herein represent the first example reported in the literature of the characterization of an oxyprenylated phenylpropanoid in honey. [ABSTRACT FROM AUTHOR]

Abstract: Rhamnus spp. is known to contain biologically active anthraquinone secondary metabolites but the presence of oxyprenylated ones is not reported. To this aim, a new simple, and accurate analytical method was developed to reveal chemical fingerprint of these analytes in plant extracts. Plant samples were analysed after extraction with n-hexane (first step) and methanol (second step) using a C18 column with a mobile phase composed of 35% of water:65% of methanol (both with 1% formic acid, v/v) at 0.7mLmin−1 flow rate in gradient elution mode. For quantitative analyses, selective detection was performed at 435nm. The limit of quantification (LOQ) was 0.5μM, with the only exception of 3-geranyloxyemodin for which the LOQ value was 5.0μM, and external matrix-matched standard curves showed linearity up to 125μM. The within- and between-batch precision (RSD%) values ranged from 0.2% to 12.9% while within- and between-batch trueness (bias%) values ranged from 12.2% to 12.7%. The method was applied to evaluate for the first time the presence and the quantities of oxyprenylated anthraquinones in Rhamnus spp. barks as well as the anthraquinone profile of Rhamnus pumila Turra. The proposed method could be directly applied to the selective quantification of these analytes in natural sources. [Copyright &y& Elsevier]