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Abstract: A simple method for the stereocontrolled synthesis of both α and β pseudo-anomers of a thio-functionalized C-glycoside is described. A 2,3:4,6-di-O-isopropylidene manno scaffold is employed to allow a strict control of the diastereoselectivity of the base-catalyzed intramolecular hetero-Michael addition of an alcohol to a vinyl sulfone, by simply changing the temperature of the reaction. [Copyright &y& Elsevier]

Reaction of methyl- and phenylthiomethylidene phosphoranes 1 and 2 with a variety of reducing sugars has been explored. Furano-type carbohydrates afforded with good yields the corresponding open-chain vinyl sulfides, whereas pyrano derivatives produced elimination compounds together with the expected vinyl sulfides, depending on the nature of the protective groups. [Copyright &y& Elsevier]

The glucose transporter 5 (GLUT5)—a specific d-fructose transporter—belongs to a family of facilitating sugar transporters recently enlarged by the human genome sequencing. Prompted by the need to develop specific photolabels of these isoforms, we have studied the interaction of conformationally locked d-fructose and l-sorbose derived 1,3-oxazolidin-2-thiones and 1,3-oxazolidin-2-ones to provide a rational basis for an interaction model. The inhibition properties of the d-fructose transporter GLUT5 by glyco-1,3-oxazolidin-2-thiones and glyco-1,3-oxazolidin-2-ones is now reported. In vitro, the fused-rings systems tested showed an efficient inhibition of GLUT5, thus bringing new insights on the interaction of d-fructose with GLUT5. [Copyright &y& Elsevier]

Abstract: A regio- and stereoselective iodination has been performed on vicinal diols located on ketopyranose templates using the controlled- Garegg conditions. 3-O-Benzyl-1,2-O-isopropylidene-β-d-fructo- or psicopyranoses (1 or 4) were selectively iodinated, respectively, at C-5 or C-4 of the ketoses to afford the l-sorbo or d-sorbo iodohydrins. [ABSTRACT FROM AUTHOR]

Abstract: Diphenylphoshinoylethyne reacts with diols under basic conditions to produce cycloacetalic phosphine oxides. The reaction appears to be general and particularly effective with carbohydrate derivatives. The 2-(diphenylphoshinoyl)ethylidene (DPE) acetals produced are stable in acidic media while they can be cleaved under reductive and/or basic conditions: base-catalyzed transacetalization is a method of choice for their mild and effective deprotection. [Copyright &y& Elsevier]

The reaction of hydroxylated thiols with 1,2-bis-phenylsulfonylethylene was investigated: in contrast with diols, a more complex reaction was observed and application to carbohydrate-derived PSE oxathianes was envisaged. [Copyright &y& Elsevier]

A 5a-carba-analogue 4 of glucotropaeolin 2 was synthesized in racemic form and showed a good inhibiting power against myrosinase. [Copyright &y& Elsevier]

The phenylsulfonylethylidene (PSE) acetal is a relatively new protecting group in carbohydrate chemistry. However, carbohydrate-derived phenylsulfonylethylidene (PSE) acetals show a different behavior in reductive desulfonylation than simple symmetrical acetals. Here we have investigated various SET-type reaction conditions in order to open PSE acetals regioselectively and to produce chiral ω-hydroxyethenyl ethers. Whereas sodium amalgam leads to a mixture of regioisomeric vinyl ethers besides the ethylidene acetal, samarium iodide is suited for regioselective ring opening. This is shown with seven different carbohydrate PSE acetals, both of the 1,3-dioxane and the 1,3-dioxolane type. [ABSTRACT FROM AUTHOR]

Abstract: Retro-Michael type reactions applied to PSE acetals protecting monosaccharides led either to complete removal or to ring-cleavage. In protic medium, application of standard basic conditions resulted in acetal deprotection, while the use of butyl lithium in aprotic medium allowed controlled ring-cleavage. A regio- and stereoselective C- over O-alkylation was observed during the process. Furthermore, depending on the substrates and the reaction conditions involved, new carbohydrate-derived β-alkoxyvinyl sulfones were obtained with varying regioselectivity. [Copyright &y& Elsevier]

Abstract: Clamped by the acid-resistant phenylsulfonylethylidene (PSE) acetal, d-glucal privileged the additive pathway over the Ferrier I rearrangement when confronted with protic nucleophiles. [Copyright &y& Elsevier]

Abstract: Selected ulofuranosides and ulopyranosides react with thiocyanic acid to give good yields of stable carbohydrate-fused hemiaminal 1,3-oxazolidine-2-thiones. [Copyright &y& Elsevier]

Abstract: E-1-Phenylsulfinyl-2-phenylsulfanylethylene (E-SOSE) reacts with O-nucleophiles generated by means of t-BuOK via an addition–elimination mechanism, thus affording the product of substitution of the phenylsulfanyl group in a stereo-conservative process. When used alone, the strongly basic and hindered tert-butoxide brings about elimination of either the phenylthiolate or phenylsulfinate groups. Z-SOSE is much more prone to elimination: either with t-BuOK alone or with other O-nucleophiles generated by t-BuOK, it always leads to products derived from elimination. Other alkaline tert-butoxides or other bases appear not as effective in generating species nucleophilic enough to react with E-SOSE. [Copyright &y& Elsevier]

Abstract: Based on the vinyl bis-sulfone methodology previously developed to synthesize PSE acetals, an original approach to homochiral carbohydrate-derived PSE 1,3-oxathianes is described. The ready formation of intermediate phenylsulfonylvinyl sulfides, which have a synthetic potential of their own, emphasizes the versatility of the method. [Copyright &y& Elsevier]

Unprotected carbohydrates can readily be converted into base-modified nucleosides and deoxynucleosides through a short sequence involving the condensation of anthranilic acid derivatives with a suitably protected sugar-derived 2-alkylthio-1,3-oxazoline. [Copyright &y& Elsevier]

The recently devised route to ethenyl ethers—i.e. 1,2-bis(phenylsulfonyl)ethylene (BPSE)-mediated conversion of alcohols into β-alkoxyvinyl sulfones followed by reductive desulfonylation—has been applied in the carbohydrate field to the synthesis of a number of vinyl-functionalised monosaccharides, a number of which had not been prepared via alternative routes. [Copyright &y& Elsevier]

Selected sugar-based ethenyl ethers have been employed in 1,3-dipolar cycloaddition with nitrile oxides. In the d-fructo series, high diastereoselectivity was observed as compared with the 3-epimeric d-psico series. [Copyright &y& Elsevier]

Glycerol carbonate and tri- O -acetyl-D-glucal were used for the synthesis of glycero-functionalized carbohydrates. Ferrier reaction between the two partners afforded the O -glucoside in 84% yield. Spontaneous crystallization yielded 28% of a pure diastereoisomer with the S configuration as determined by X-ray crystallography. Then, the azido-glycerosugar was prepared in two steps: ring opening of the cyclic carbonate with sodium azide and per-acetylation with an excellent yield of 94%. A library of glycoconjugates were prepared using a 1,3-dipolar cycloaddition in yields ranging from 64 to 99%. [ABSTRACT FROM AUTHOR]

A series of several new isoniazid derivatives, isonicotinic acid 2-(2-hydroxy-8-substituted-tricyclo[7.3.1.0 2.7 ]tridec-13-ylidene)-hydrazides, were synthesized and fully characterized. These new isoniazid derivatives were studied regarding their antibacterial activity and cytotoxicity, as well as their influences on some metabolizing enzymes. The best anti-mycobacterial activity was observed in the case of compounds containing alkyl side chains in the 8 position of tricyclo[7.3.1.0 2.7 ]tridec-13-ylidene group. On contrary, the antimicrobial activity of these new compounds against various non-tuberculosis strains showed the best activity to be with the phenyl side chain of compound 6 . It proved also to be the most toxic, inducing apoptosis and blocking the cell cycle in G0/G1 phase. The cell cycle was blocked in G0/G1 phase also by compound 3 , but this compound did not show any toxicity. All compounds induced the expression of NAT1 and NAT2 genes in HT-29 cell line, and the expression of CYP1A1 in HT-29 and HCT-8 cell lines. The expression level of CYP3A4 was increased by compounds 1 , 6 and 7 in HCT-8 cells. These results indicated that the activation of other metabolizing pathways, apart from those of isoniazid, take place. It might also point out the possibility of an increased isoniazid acetylation ratio by co-administration with new compounds in slow acetylators. [ABSTRACT FROM AUTHOR]

A convenient strategy for a 'one-pot' synthesis of neoglycoproteins (NGP) was developed using the myrosinase-glucosinolate couple, a natural enzyme-substrate system. This enzymatic reaction allowed us to generate an isothiocyanate in situ which then reacted with the lysine residues of bovine serum albumin protein (BSA) to produce multivalent neoglycoproteins. Using two models, glucomoringin which is a natural glucosinolate bearing a l -rhamnose unit, and an artificial glucosinolate specifically designed for mannose type lectins, an average of up to 17.8 and 28.7 carbohydrate residues could be respectively grafted onto the BSA protein. This process is comparable to commercial approaches using BSA-Man C without the disadvantage of handling harmful chemical reagents. Lectin binding screening (GLYcoPROFILE®) showed that among all NGPs synthesized, BSA-Man 16 gave similar and in some cases better affinities in comparison with commercial BSA-Man c towards various mannose-specific lectins. [Display omitted] • Enzymatically induced isothiocyanate formation through a Lossen rearrangement. • A natural myrosinase-glucosinolate/enzyme-substrate system used for bioconjugation. • A one-pot strategy for the preparation of neoglycoproteins without isothiocyanate handling. [ABSTRACT FROM AUTHOR]

Abstract: Tosylated glycerol carbonate was used for N-glyceryl functionalization of diverse aza-aromatic systems. Depending on the pK a of the aza-heterocycle and the reaction conditions applied, original N-alkylated or N-acylated aza-heterocyclic derivatives were obtained. Those compounds carry an electrophilic appendage—either carbonate or epoxide—which allows further useful transformations. [Copyright &y& Elsevier]

Abstract: Glucosinolates (GLs) present in root, seed, and leaf extracts of Pentadiplandra brazzeana Baillon were characterized and quantified according to the ISO 9167-1 method based on the HPLC analysis of desulfo-GLs. The analyses were complemented by GC–MS analyses of the isothiocyanates (ITCs) generated from GL degradation by myrosinase. Glucotropaeolin (1a), glucolimnanthin (2a), and glucoaubrietin (3a) were shown to be present in the root extract, whereas the seed mainly contained 3a. 3,4-Dimethoxybenzyl GL (4a), glucobrassicin (5a) and traces of 1a were detected in the leaf extract. The products were fully characterized as their desulfo-counterparts by spectroscopic techniques. [Copyright &y& Elsevier]

Abstract: The reactivity of tosylated glycerol carbonate 2 toward nucleophiles has been exploited to generate glycidol analogues protected with carbonate or carbamate groups. The activated glycerol 2 is a reasonable linking agent with thiol and alcohol nucleophiles and an excellent and selective one with primary amines, allowing efficient bis-functionalizations of glycerol. [Copyright &y& Elsevier]

Abstract: New non-hydrolyzable analogues of glucosinolates have been prepared. Myrosinase inhibition was observed with modified aglycon moieties, even bulky phenothiazine analogue 6 gave reasonable inhibition. The simplest structure 8 derived from dimethylaminoethanethiol has shown to be the most potent inhibitor with an IC50 of 3.32μM. [Copyright &y& Elsevier]

Abstract: 1,3-Oxazoline- (OXT) and 1,3-oxazolidine-2-thiones (OZT) can undergo direct Stille and Suzuki cross-coupling reactions under microwave activation to produce 2-aryloxazoles and 2-aryloxazolines in reasonable to good yields. [Copyright &y& Elsevier]

Abstract: Enzymatic desulfation of stable glucoraphenin affords desulfoglucoraphenin, which unexpectedly undergoes further transformations into cyclic nitrone-type derivatives. [Copyright &y& Elsevier]

Abstract: An efficient chemoselective ligation approach using an oxime bond was developed for the synthesis of amino acid derivatives of virginiamycin M1, a highly sensitive streptogramin antibiotic. [Copyright &y& Elsevier]

A total of forty-three compounds were synthesized, including thirty-two new ones. Among those compounds, seventeen were selected and tested on human tumor cell lines: PC-3 (prostate adenocarcinoma), HCT-116 (colorectal tumor), NCIH-460 (lung carcinoma), SKMEL-103 (melanoma) and AGP-01 (gastric tumor). Alkynylated 1,2,4-oxadiazoles 2m , 3g and 3k exhibited antiproliferative activities against NCIH-460 in culture. Alkynylated N -cyclohexyl-1,2,4-oxadiazoles 3a-m and bis-heterocycle glucoglycero-1,2,3-triazole- N -cyclohexyl-1,2,4-oxadiazole derivatives 5a-k and 6 – 11 were evaluated for their in vitro efficacy towards Mycobacterium tuberculosis (Mtb) H 37 Ra and H 37 Rv strains. In general, glycerosugars conjugated to 1,2,4-oxadiazole via a 1,2,3-triazole linkage (5a , 5e , 5j , 5k , and 7) showed in vitro inhibitory activity against Mtb (H 37 Rv). The largest molecules bis-triazoles 10 and 11 , proved inactive against TB. Probably, the absence of the N -cyclohexyl group in compound 8 and 1,2,4-oxadiazole nucleus in compound 9 were responsible for its low activity. Glucoglycero-triazole-oxadiazole derivatives 5e (10 μM) and 7 (23.9 μM) were the most promising antitubercular compounds, showing a better selective index than when tested against RAW 264.7 and HepG2 cells. Vero cell were used to investigate cytotoxicity of compounds 5a , 5h , 5j , 5k , and these compounds showed good cell viability. Further, in silico studies were performed for most active compounds (5e and 7) with potential drug targets, DprE1 and InhA of Mtb to understand possible interactions aided with molecular dynamic simulation (100ns). [Display omitted] • Forty-one compounds were synthesized and tested for human tumor cell lines and/or tuberculosis (H 37 Ra and H 37 Rv strains). • Alkynylated 1,2,4-oxadiazoles were effective as antiproliferative agents (lung carcinoma, NCIH-460) with IC50 = 3–17 μM. • Glucoglycero-triazole-oxadiazoles, mainly the compounds 5a,j,k , 5e and 7 (10-47 µM), were the most active against TB. • In silico studies supported the anti-TB compounds complexed with proteins DprE1 and InhA have stable association. [ABSTRACT FROM AUTHOR]