A HPTLC-densitometric method was developed in order to obtain a reliable procedure for routine analysis of cephalexin in pharmaceutical formulations. Optimization of TLC conditions for the densitometric scanning was reached by eluting HPTLC silica gel plates in an horizontal developing chamber. Quantitation of cephalexin was performed in single beam reflectance mode by using a computer-controlled densitometric scanner and applying a five-point calibration. A linear regression has been found in the 200–1000 ng range. The setup method is precise, reproducible and accurate. Recovery was also assessed by comparison with the HPLC USP XXIII alternate method. In this case HPTLC-densitometry appears worth of consideration as being relatively inexpensive and time-saving (up to 12 samples can be determined simultaneously in less than 15 min with a solvent consumption of about 15 ml). The results suggest that the proposed method may be used in place of HPLC for the routine quantitation of cephalexin in both pure and dosage forms.

The antioxidant activities of some polyphenolic fractions of grapes and wines have been tested using in vitro and ex vivo tests. Polyphenolic fractions were obtained applying a liquid/liquid extraction method and analyzed by using HPLC/DAD, Ion Spray HPLC/MS and Electrospray MS. Some tannin/anthocyan interaction compounds were also extracted and analyzed from wines. EPR spectroscopy, TRAP assay, 2-deoxyribose assay and a platelet aggregation inhibition test were performed to test antioxidant activities of polyphenolic fractions. Results showed that the anthocyans fraction and the fraction containing procyanidins were very effective in antioxidant activity.

Self‐rooted olive ( Olea europaea L.) plants were grown in hydroponics at various NaCl concentrations (from 0 to 200m M ) for 28 to 32 days followed by 28 to 30 days of relief from salinity over two growing seasons. Olive leaves accumulated both glucose and mannitol during the period of salinity stress. The concentrations of fructose, myo ‐inositol, galactose, galactinol, sucrose, raffinose, and stachyose were not significantly affected by salinity. Starch content was decreased by salinity. The mannitol/glucose and mannitol/soluble carbohydrates ratios increased as the external NaCl concentration was increased, but returned to the control levels during the relief period. The increase in mannitol or glucose molar concentrations, expressed on a leaf tissue water basis, was partially due to a reduction in leaf tissue water content under salinity stress. However, an increase in mannitol concentration was also observed when expressed on a dry weight basis. The accumulation of mannitol in leaf tissue preceded any reduction in leaf area rate or net assimilation rate. The increase in leaf mannitol or glucose concentration was positively correlated with the increasing level of salinity at the root zone, but not with the accumulation of Na + in the shoot. The role of mannitol. a potential osmoregulator in leaf mesophyll during salinity stress, is discussed in relation to the complex carbohydrate composition of olive leaves.

Liquid-liquid (LLE) and liquid-solid extraction (LSE) procedures were developed to identify polyphenols in phillyrea (Phillyrea angustifolia L.) leaves. The liquidsolid extraction, carried out by using two serial Bond-Elut® CH and Bond-Elut® SAX cartridges allowed the collection of both polyphenols and soluble carbohydrates during a single extraction of leaf. This method seems to be suitable for both phytochemical and physiological study of the species, allowing the identification of two classes of organic compounds which have a central role in the metabolism of phillyrea plants. A method of isolation and concentration of polyphenols for further molecular characterization, using centrifuge chromatography, was also developed. Molecular characterization, carried out by UV-Vis spectrophotometry and mass spectrometry, demonstrated the presence of compounds with interesting biological activity, i.e. flavonoids and oleuropein derivatives. The soluble carbohydrate composition of phillyrea leaves did not substantially differ from that ofOlea europaea L. leaves, except for a higher mannitol/glucose ratio. This carbohydrate distribution may be linked to the evolution pattern of this species which usually grows in severely stressed environments.

An HPLC/MS application to anthocyanic compounds of Vitis vinifera L. is described. A series of liquid-liquid and liquid-solid extractions yielded an extract containing anthocyanic compounds only. This extract was analyzed by HPLC/DAD and HPLC/MS, and UV-vis and MS spectra of each compound were obtained. An API ion-spray interface allowed coupling between the chromatographic system and a mass spectrometer. This interface allowed application of the chromatographic conditions normally used in the HPLC analysis of anthocyanic compounds, which led to the identification of the 3-glucosides, the 3-acetylglucosides, and the 3-p-coumaroylglucosides of delphinidin, cyanidin, petunidin, peonidin, and malvidin, already known in the literature. Two 3-caffeoylglucoside derivatives were identified too, and it has been possible to identify, for the first time, some 3,5-diglucosides that are known to be present in Vitis sp. but not in Vitis vinifera L. The investigated cultivars showed the same anthocyanic profile but dramatic quantitative differences.

Negative-ion fast-atom bombardment mass spectrometry together with precursor and product-ion spectroscopies has been validly employed in the identification of six flavonol glycosides present in the juice of Sedum telephium leaves. The proposed technique proved to be a valuable alternative to the combination of high performance liquid chromatography and mass spectrometry in the analysis of the complex polyphenol mixtures present in some medicinal plants.

Two new flavonol glycosides, kaempferol 3-O-β-neohesperidoside-7-O-α-rhamnoside and quercetin 3-O-β-neohesperidoside-7-O-α-rhamnoside were identified in the fresh leaves of Sedum telephium ssp. maximum. The known compounds, quercetin, kaempferol and their 3-glucosides, 7-rhamnosides and 3,7-dirhamnosides were also identified. All compounds were characterized by means of chemical and spectroscopic methods. NOE experiments were performed to detect the glycosidic bond at the 7-hydroxyl of the aglycone molecules.

Qualitative and quantitative analyses of carbohydrates in olive (Olea europaea L.) tissues have been carried out by HPLC-RI. Sample purification was by two successive solid-liquid extractions to remove completely plant phenolics and pigments. Five carbohydrate peaks; sucrose (stachyose + raffinose + sucrose), glucose, galactose, fructose (fructose + myo-inositol) and mannitol were detected when plant extracts were run on a Sugar SC 1011 column operating at 75°C, using water as eluent 0.5 ml min−1. The use of two serial Sugar SC 1011 columns operating at 90°C and eluting the plant extracts with H2O−CH3CN (95/5 v/v) enables identification and quantification of nine carbohydrates, including tetra and tri-saccharides.