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This work deals with the chemical synthesis of simple analogs of anthocyanins, the main class of watersoluble natural pigments. Flavylium ions with hydroxyl, methoxyl and b-D-glucopyranosyloxyl substituents at positions 4 0 and 7 have been prepared by straightforward chemical procedures. Moreover, the two 3-deoxyanthocyanidins of red sorghum apigeninidin (4 0 ,5,7-trihydroxyflavylium) and luteolinidin (3 0 ,4 0 ,5,7-tetrahydroxyflavylium) were synthesized in a one-step protocol. Attempts to synthesize luteolinidin O-b-D-glucosides resulted in a mixture of the 5-O-and 7-O-regioisomers in low yield. A preliminary study of the 4 0-b-D-glucopyranosyloxy-7-hydroxyflavylium and 7-b-D-glucopyranosyloxy-4 0hydroxy-flavylium ions shows that simply changing the glucosidation site can profoundly affect the color intensity and stability.

The grape juice by-product obtained from grape traditional press was extracted by Microwave Hydrodiffusion and Gravity (MHG); a green extraction technique preliminarily optimized at 1 W/g. The MHG extract (MHGE) was analyzed by HPLC for identification and quantification of anthocyanins and other phenolic compounds. Then, MHGE was added to the natural juice (NJ) to produce an innovative grape juice (IJ). These three juices were evaluated for their total polyphenol content (TPC), total anthocyanin content (TAC) in addition to their sensorial characteristics. MHGE showed the highest values of TPC (21.41±0.04 mg GAE/g DW), TAC (4.49±0.01 μg MVGE/g DW). Moreover, IJ (grape juice enriched with MHGE) was richer in TPC (6.70±0.0 1mg GAE/g DW) and TAC (3.96±0.01 μg MVGE/g DW) than NJ (2.90±0.02 mg GAE/g DW and 3.63±0.06 μg MVGE/g DW, respectively).

. Both pigments inhibit heme-induced lipid peroxidation in mildly acidic conditions (a model of postprandial oxidative stress in the stomach), the colorless (chalcone) forms being more potent than the colored forms. Finally, P1 and P2 are moderate ligands of human serum albumin (HSA), their likely carrier in the blood circulation, with chalcones having a higher affinity for HSA than the corresponding colored forms.