Determination of glycine and threonine in topical dermatological preparations

In the present study, a single HPLCmethod was developed for the determination of glycine and threonine in cicatrizants. Two different preparations of a cream and an ointment, and the corresponding bandages, onto which the formulations were applied, were studied. The method involved matrix solubilisation with dichloromethane, liquid–liquid isolation of gly and thr with aqueous 1N NaOH, and derivatization with phenylisothiocyanate. Reversed-phase HPLC separation was carried out by gradient elution with 20mM aqueous NaClO4 and acetonitrile (from 90% to 30% aqueous NaClO4 in 10 min) on a LiChrospher® 100 RP-18 cartridge (125mm×4.6 mm). Analytes were determined with a UV detector set at 245 nm. Quantitation was accomplished by internal standardization with methionine. Linearity was studied in the range 60–120% of the concentrations expected for gly and thr (viz. for gly from 200 to 400gml−1, and for thr from 100 to 200gml−1). In reference aqueous samples, linear correlation (r) was better than 0.99 for gly and thr, while in spiked matrix samples r ranged from 0.97 to 0.98. Recoveries were in the 95–105% interval, and precision (CV%, N= 6)was better than 5% for both analytes either in cream, ointment or bandages. The method was successfully used for the quality control of topical dermatological preparations

Application of NIR spectroscopy and Luff-Schoorl methods for determining the sugar content of commercial plant milk

The present study reports on the use of near infrared (NIR) spectroscopy for the control of sugar content of plant milk. Total glucose content was selected as parameter for building the calibration set for the instrument. Thirty six plant milk samples were purchased from local supermarkets and included milk obtained from soy (15 samples), rice (11 samples), oats (6 samples), kamut (1), spelt (1), almond (1), Quinoa (1). In all samples total glucose was determined applying the Luff-Schoorl method. The apparatus was a Bruker NIR Multi Purpose Analyzer equipped with a Liquid Sampling Module, operated in an interval of frequencies ranging from 10000 to 4000 cm-1 with a resolution of 16 cm-1. On every sample 32 scans were carried out, at 40°C, with a thermostat time of 30 sec. Results of the Luff-Schoorl glucose determination were compared with the respective data obtained from the NIR instrument. All data were processed by the software included in the instrument proprietary computer program. The quality of the calibration model obtained was good (R2>0,996; RMSEE=0.18) and it was confirmed by a good cross-validation model (cross-validation R2> 0.98; RMSECV=0.34). Therefore the model was applied and fully validated on an independent test set of samples which confirmed the excellent prediction of the model. The NIR measurements proved to be reliable with high accuracy and the comparison of the Luff-Schoorl method and NIR evidenced that the actual sugar content of the purchased products can be slightly different from what is reported on the product label. From the data presented in this study it can be concluded that NIR spectroscopy can be applied successfully for the control of sugar content in plant milk products obtained from a wide variety of plant sources. Considered the practicability, the speed, and the low cost of the NIR measurements, the spectroscopic technique can be applied in in-line and on-line quality control of plant milk production. The NIR instrument appears superior under all aspects of reliability, robustness, precision and speed in comparison with the impractical, laborious, and non-robust classical Luff-Scoorl method

Polyphenolic profile of green/red spotted Italian Cichorium intybus salads by RP-HPLC-PDA-ESI-MSn

Today the consumption of fresh vegetables is highly recommended not only for the intake of nutrients, but also for the healthy properties of secondary metabolites involved in the prevention of many disorders. In the present work, phenolic acids and flavonoids extracted from four green (Cichorium intybus var. sativus and var. foliosum) and a red spotted (a cross between C. intybus var. silvestre cv “Treviso” and C. endivia var. foliosum) salads were characterized by high-performance liquid chromatography–electrospray ionization/mass spectrometry. Among the 76 compounds detected in this work, five organic acids (two malic acid derivatives, two pyroglutamic hexoside isomers, and cis-aconitic acid), ten hydroxycinnamic acid derivatives (ferulic, malonyl caffeoylquinic, and caffeoylmethylglutaroylquinic acids, cinnamoyl- and caffeoyl-malate, coumaroyl, sinapoyl, feruloyl, and coumaroylcaffeoyl glycosides, dicaffeoyl lactone, 3-O-caffeoyl-4-O-(3-hydroxyglutaroylquinic acid), four flavonols (quercetin-di-O-glucoside, quercetin-3-O-malonylhexosyl-7-O-hexoside, myricetin-3-O-glucoside, and isorhamnetin-3-O-glucoside), and cyanidin-3-O-glucuronyl-5-O-hexoside have been identified in chicory salads for the first time. These data, together with the results obtained in our previous investigations on Cichorium genus Italian salads, provide a contribution to a more exhaustive identification of the secondary metabolites profile of each considered plant, that could be also useful in building/selecting hybrids with agronomic and peculiar healthy features, even using traditional methods of cultivation