From carbohydrate-derived ketene dithioacetals to 1--thioglycals: a synthetic and theoretical insight.

A strategy for the synthesis of 1--substituted thioglycals was developed from cyclic carbohydrate-derived ketene dithioacetals in a four-step sequence. The corresponding thioglycals, in two carbohydrate series, were first obtained by removal of the exocyclic glycosyl sulfoxide, followed by treatment with an organolithium reagent. Various electrophilic groups were introduced onto the thioglycal double bond after deprotonation and formation of a glycosyl lithium intermediate.

Synthesis of 4-(Phenylamino)quinazoline-2(1H)-thiones Using Green Solvents.

Given the importance of quinazolines and quinazolinethiones in therapeutic and Food and Drug Administration (FDA)-approved molecules, we thought interesting to consider their synthesis in green solvents. We have shown that obtain 4-(arylamino)quinazoline-2-(1H)-thiones and 4-(arylamino)pteridine-2-(1H)-thiones analogues was efficient in green solvents derived from biomass, especially eucalyptol. Although reaction times are somewhat long to achieve good yields, the products were obtained by simple filtration.

Synthetic Modifications of Andrographolide Targeting New Potential Anticancer Drug Candidates: A Comprehensive Overview.

This review collects the synthetic modifications performed on andrographolide, a natural molecule derived from , for oncology applications. Various pharmacomodulations were carried out, and the products were tested on different cancer cell lines. The impact of these modifications was analyzed with the aim of mapping the positions essential for activity to facilitate future research in this field.

Sabinene: A New Green Solvent Used in the Synthesis of Thiazolo[5,4-]pyridines by Thermal or Microwave Activation.

Following the work already carried out in our laboratory on eucalyptol, a new green solvent derived from biomass, we are now looking at sabinene as another new green solvent. Sabinene is also derived from biomass, has no known toxicity and can be recycled by distillation. We have shown that it can be used as it is or distilled to synthesize thiazolo[5,4-]pyridine heterocycles by thermal activation or microwave irradiation.

Protecting-group free synthesis of glycoconjugates displaying dual fungicidal and plant defense-eliciting activities.

A straightforward synthesis of carbohydrate templated isoxazolidines is described, by reaction of unprotected glycosylhydroxylamines (operating as 1,3-dipoles) with methyl acrylate using microwave activation. Rhamno- and erythro-isoxazolidines are recognized by plant cells, resulting in a strong ROS-production as a plant immune response, and exert a high antifungal activity against Botrytis cinerea.

Antioxidant Effects of Catechins (EGCG), Andrographolide, and Curcuminoids Compounds for Skin Protection, Cosmetics, and Dermatological Uses: An Update.

Here we have chosen to highlight the main natural molecules extracted from , , and that may possess antioxidant activities of interest for skin protection. The molecules involved in the antioxidant process are, respectively, catechins derivatives, in particular, EGCG, andrographolide, and its derivatives, as well as various curcuminoids. These plants are generally used as beverages for (tea tree), as dietary supplements, or as spices.

Broadening the reaction scope of unprotected aldoses via their corresponding nitrones: 1,3-dipolar cycloadditions with alkenes.

Condensation reactions of unprotected tetroses and pentoses with hydroxylamines afforded nitrones, which were easily converted to densely functionalized isoxazolidines in the presence of electron-poor alkenes. The 1,3-dipolar cycloaddition occurred with good facial discrimination of the chiral nitrone but under rather low endo/exo control. Stereochemistry of isomers was ascertained by chemical correlation with known derivatives from the literature.

Regiospecific formation of sugar-derived ketonitrone towards unconventional C-branched pyrrolizidines and indolizidines.

The synthesis of unprecedented branched pyrrolizidines and indolizidines was accomplished via nitrone chemistry. The required ketonitrone, a known intermediate usually obtained as a mixture of regioisomers, was prepared in a pure form from d-arabinose by a sequence of oximation/reduction/oxidation steps. Nucleophilic vinylation or allylation followed by ring-closing metathesis of the corresponding N-allylpyrrolidines furnished the targeted iminosugars, which proved potent and selective inhibitors of alpha-glucosidase from rice (GH31 family).