Electrospray Ionization Multiple Mass Spectrometry Research Articles

Isolation of Anthocyanins by High-Speed Countercurrent Chromatography and Application of the Color Activity Concept to Different Varieties of Red Grape Pomace from Macedonia

Anthocyanins of Macedonian grape pomace from three varieties “Pinot noir”, “Merlot” and “Vranec” were isolated by high speed countercurrent chromatography. After purification of the fractions by means of preparative high performance liquid chromatography the structures of isolated pigments were elucidated by electrospray ionization multiple mass spectrometry (ESI-MSn) and nuclear magnetic resonance (NMR) spectroscopy. The major anthocyanin malvidin-3-glucoside and the minor pigments delphinidin-3-glucoside, cyaniding-3-glucoside, petunidin-3-glucoside, and malvidin-3-p-coumarоyl-glucoside were isolated. The “Color activity concept” was applied and visual detection thresholds of isolated anthocyanins were determined. The results of the “color activity value” of the isolated pigments and their detection thresholds were in good agreement with the color shade of the different varieties of red grape pomace.

Anthocyanin Composition of Black Carrot (Daucus carota ssp. sativus var. atrorubens Alef.) Cultivars Antonina, Beta Sweet, Deep Purple, and Purple Haze

This study aimed to identify the pigment composition of black carrot (Daucus carota ssp. sativus var. atrorubens Alef.) cultivars Antonina, Beta Sweet, Deep Purple, and Purple Haze. Cyanidin 3-xylosyl(glucosyl)galactosides acylated with sinapic acid, ferulic acid, and coumaric acid were detected as major anthocyanins by high-performance liquid chromatography with diode array detection (HPLC-DAD) and with electrospray ionization multiple mass spectrometry (HPLC-ESI-MS(n)) analyses. The preparative isolation of these pigments was carried out by means of high-speed countercurrent chromatography (HSCCC). The color activity concept was applied to the isolated anthocyanins at three pH values. Cyanidin 3-xylosyl(sinapoylglucosyl)galactoside was found to exhibit a lower visual detection threshold and a higher pH stability than cyanidin 3-xylosyl(feruloylglucosyl)galactoside and cyanidin 3-xylosyl(coumaroylglucosyl)galactoside. The color parameters of the fresh roots of the four cultivars were described by the CIELab coordinates L* (lightness), C* (chroma), and h(ab) (hue angles). Total phenolics varied among the cultivars and ranged from 17.9 to 97.9 mg gallic acid equivalents (GAE)/100 g fresh weight (fw). For the content of monomeric anthocyanins, values between 1.5 and 17.7 mg/100 g fw were determined.

Multi-analyte approach for the determination of ng L−1 levels of steroid hormones in unidentified aqueous samples

Since the 1970s, many analytical methods for the detection of illegal growth promoters, such as thyreostats, anabolics, β-agonists and corticosteroids have been developed for a wide range of matrices of animal origin, including meat, fat, organ tissue, urine and faeces.The aim of this study was to develop an analytical method for the determination of ngL−1 levels of estrogens, gestagens, androgens (EGAs) and corticosteroids in aqueous preparations (i.e. drinking water, drinking water supplements), commercially available on the ‘black’ market. For this, extraction was performed with Bakerbond C18 speedisk, a technique commonly used in environmental analysis. After fractionation, four fractions were collected using a methanol:water gradient program. Gas chromatography coupled to electron impact multiple mass spectrometry (GC–EI-MS2) screening for the EGAs was carried out on the derivatized extracts. For the detection of corticosteroids, gas chromatography coupled to negative chemical ionization mass spectrometry (GC–NCI-MS) was used after oxidation of the extracts. Confirmation was done by liquid chromatography coupled to electrospray ionization multiple mass spectrometry (LC–ESI-MS2). The combined use of GC and LC coupled to MS enabled the identification and quantification of anabolics and corticosteroids at the low ngL−1 level. This study demonstrated the occurrence of both androgens and corticosteroids in different commercial aqueous samples.

Characterization of Anthocyanins and Pyranoanthocyanins from Blood Orange [Citrus sinensis (L.) Osbeck] Juice

Anthocyanins from blood orange [Citrus sinensis (L.) Osbeck] juices were isolated and purified by means of high-speed countercurrent chromatography and preparative high-performance liquid chromatography. Structures of the pigments were then elucidated by electrospray ionization multiple mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy. The major anthocyanins of the juice were characterized as cyanidin 3-glucoside and cyanidin 3-(6"-malonylglucoside). Furthermore, six minor anthocyanins were detected and identified as cyanidin 3,5-diglucoside, delphinidin 3-glucoside, cyanidin 3-sophoroside, delphinidin 3-(6"-malonylglucoside), peonidin 3-(6"-malonylglucoside), and cyanidin 3-(6"-dioxalylglucoside). The occurrence of the latter compound in blood oranges is reported here for the first time, together with full NMR spectroscopic data. Further investigations revealed the presence of four anthocyanin-derived pigments, which are formed through a direct reaction between anthocyanins and hydroxycinnamic acids during prolonged storage of the juice. These novel pyranoanthocyanins were identified as the 4-vinylphenol, 4-vinylcatechol, 4-vinylguaiacol, and 4-vinylsyringol adducts of cyanidin 3-glucoside through comparison of their mass spectrometric and chromatographic properties with those of synthesized reference compounds.

Preparative counter-current chromatography isolation of liensinine and its analogues from embryo of the seed of Nelumbo nucifera GAERTN. using upright coil planet centrifuge with four multilayer coils connected in series

Preparative counter-current chromatography (CCC) isolation of liensinine and its analogues, isoliensinine and neferine from embryo of the seed of Nelumbo nucifera GAERTN. has been successfully performed for the first time using upright coil planet centrifuge with four multilayer coils connected in series with 1600 mL capacity. Two kinds of two-phase solvent systems were applied to preparative CCC isolation. The first was the system composed of light petroleum (b.p. 60–90 °C)–ethyl acetate–tetrachloromethane–chloroform–methanol–water (1:1:4:4:6:2, v/v) which was very suitable for fast and small-scale CCC isolation. The second was the system composed of ethyl acetate–tetrachloromethane–methanol–water (1:6:4:1, v/v), which was the optimum for large-scale CCC isolation. Using the first system, 1102 mg of the crude alkaloid was purified in one-step separation of 150 min, yielding 350 mg neferine, 100 mg isoliensinine and 95 mg liensinine with over 95% purity. While using the second solvent system, 5850 mg of the crude alkaloid was purified in one-step separation of 9 h, yielding 2545 mg neferine, 698 mg isoliensinine and 650 mg liensinine with over 97% purity. Structures of the compounds were identified by electrospray ionization multiple mass spectrometry, one- and two-dimensional NMR.

Preparation of Mevinolinic Acid from Monascus purpureus Using High‐Speed Countercurrent Chromatography (HSCCC)

High‐speed countercurrent chromatography (HSCCC) was applied for the separation of a crude Monascus purpureus extract. The separation was carried out using a two‐phase solvent system composed of n‐hexane/ethyl acetate/methanol/water (1/1/1/1, v/v) at a flow rate of 1.0 mL/min. From 250 mg of the alkaline treated extract the method yielded 40 mg of mevinolinic acid with a purity of 99% in each separation. The product was confirmed as mevinolinic acid by electrospray ionization multiple mass spectrometry (ESI‐MS) and NMR analysis.