Sofia D. Koulocheri

Pomegranate juice consumption increases GSH levels and reduces lipid and protein oxidation in human blood.

The aim of the present study was the assessment of the antioxidant effects of pomegranate juice (PJ) consumption in humans. Thus, 14 healthy volunteers consumed PJ daily for a period of 15days and the changes of oxidative stress markers in their blood were assessed at four different time points, immediately before the experiment (T1), after 15days of juice administration (T2), one (T3) and three weeks (T4) after the interruption of PJ administration. The markers studied were total antioxidant capacity (TAC), levels of malondialdehyde (MDA), and protein carbonyls (CARB) measured in plasma, as well as reduced glutathione (GSH), and catalase activity (CAT) measured in erythrocytes. The MDA was reduced by 24.4% at T3 and CARB were reduced by 19.6% and 17.7% at T2 and T3, respectively, supporting the evidence that PJ consumption enhances the antioxidant status in humans by decreasing lipid peroxidation and protein oxidation. Moreover, GSH levels were significantly increased (22.6%) at T2, indicating that PJ consumption improves the antioxidant mechanisms in erythrocytes by increasing GSH levels. Finally, it was shown that even a week after stopping PJ consumption some of its beneficial effects on antioxidant status still remained in the organism.

Asymmetric total synthesis of (−)-prosophylline

Abstract The asymmetric total synthesis of (−)-prosophylline from d -glucal via (2 S )-hydroxymethyl-dihydropyridone 6 by a 17-step synthesis and 12% overall yield is presented.

Asymmetric synthesis of (2R,3S)-3-hydroxypipecolic acid δ-lactam derivatives

Abstract A practical synthetic scheme that incorporates an amide functionality into the rigid framework of (2 S ,3 R )-3-hydroxypipecolic acid to produce novel hydroxylated δ-lactam derivatives is reported. The reaction sequence includes the transformation of chiral furanylazide to a 2 S -hydroxymethyldihydro pyridone, which was reduced diasteroselectively, protected and oxidized to two corresponding δ-lactam derivatives. Asymmetric dihydroxylation and oxidation of the latter compounds afforded two chiral (2 R ,3 S )-3-hydroxypipecolic acid δ-lactam derivatives.

Stereoselective Michael Addition of Thiophenols, Amino Acids and Hydrazoic Acid to (2S)-Hydroxymethyl-dihydropyridone as a Convenient Route to Novel Azasugar Derivatives

Abstract The outcome and stereochemical aspects of 1,4-conjugate addition of thiophenols, α-aminoacid derivatives and hydrazoic acid to chiral (2S)-hydroxymethyl-dihydropyridone 3 is presented. Subsequent reduction with NaBH4 provided predominantly the kinetically favored axial 3-piperidinol adducts. The stereochemistry of the products, which depends on electrostatic interaction and steric hindrance, was revealed by 1H NMR and 2D NOESY spectroscopic analysis.

A Fast Entry to Furanoditerpenoid-Based Hedgehog Signaling Inhibitors: Identifying Essential Structural Features

New, small molecule Hedgehog (Hh) pathway inhibitors, such as the furanoditerpenoid taepeenin D, are of high medicinal importance. To establish key structure-activity relationships (SARs) for this lead, a synthetic sequence has been developed for the expedient preparation of several derivatives and their evaluation as Hh inhibitors exploiting its structural similarity to abietic acid. While C(14) substitution is not essential for biological activity, the presence of a hydrogen bond acceptor at C(6) and an intact benzofuran moiety are.

1,4‐Reductive Addition of Hydrazoic Acid to γ‐Oxo‐α,β‐unsaturated δ‐Lactones and ‐Lactams: A Convenient Route to α‐Amino‐γ‐oxo‐α,β‐unsaturated δ‐Lactones and ‐Lactams

γ-Oxo-α,β-unsaturated δ-lactones and lactams, which are easily accessible from their corresponding 2-furylcarbinols, were used as substrates for the 1,4-reductive addition of hydrazoic acid. The outcome of the reaction is the formation, in high yields, of the corresponding α-amino-γ-oxo-α,β-unsaturated δ-lactones and -lactams, compounds of great biological and synthetic interest.

Resistance-Trained Individuals Are Less Susceptible to Oxidative Damage after Eccentric Exercise

It has been proposed that exercise-induced oxidative stress and adaptations are dependent on training status. In this study, we examined the effects of training background on free radical generation and adaptations after eccentric exercise. Forty volunteers were divided into two groups (trained and untrained) and were asked to perform eccentric exercise. Then, their blood samples were collected pre, 24, 48, and 72 hours postexercise. Biomarkers indicating oxidative damage and the antioxidant profiles of the participants were measured in plasma and erythrocyte lysate both spectrophotometrically and chromatographically. The results revealed that the untrained group depicted more severe oxidative damage (protein carbonyls, malondialdehyde), weaker antioxidant status (reduced glutathione, static and capacity oxidation-reduction potential), and weaker radical-scavenging activity (superoxide radical scavenging and reducing power) compared to the trained participants. Our findings show that trained individuals are less susceptible to oxidative damage and suggest that generalized nutritional recommendations regarding recovery after exercise should be avoided.

An Expedient Asymmetric Synthesis of a Calystegine B4 Analogue

A convenient, high-yielding synthetic route to polyhydroxylated 6-oxa-nor-tropanes that mimic the structural framework of calystegine B 4 is reported.