Phosphorylation of D-glucose, D-galactose, D-fructose, glycerol and xylitol acetals with diethoxyor diphenoxy(thiono)phosphoryl chloride gave the corresponding esters. A novel method of partially and fully deprotecting these compounds, which we have called "autocatalytic cleavage", was effected by simply refluxing in water. Antifungal and insecticidal properties of these compounds are presented.

This paper describes the separation of the four sets of stereoisomers of nucleoside analogs, new potential antiviral agents by direct analytical HPLC methods using derivatized cellulose and amylose chiral stationary phases. The resolution was made using normal-phase methodology with a mobile phase consisting of n-hexane-alcohol (ethanol or 2-propanol) in various percentages, and a silica-based cellulose tris-3,5-dimethylphenylcarbamate (Chiralcel OD-H), or tris-methylbenzoate (Chiralcel OJ) and a silica-based amylose tris-3,5-dimethylphenylcarbamate (Chiralpak AD) or tris-(S)-1-phenylethylcarbamate (Chiralpak AS). The effects of structural features on the extent of discrimination between the stereoisomers were examined through the retention, the selectivity and the resolution factors as well as the elution order. Baseline separation (Rs>1.5) was easily obtained in many cases. The resolution results were complementary between the different columns.

Anomeric spirohydantoin derivatives from monosaccharides are known for various biological properties. We describe herein the synthesis of the 3-spirohydantoin derivatives of D-allose and D-ribose. The key step is the stereoselective glyco-alpha-aminonitrile formation from ulose derivatives of D-glucose and D-xylose using titanium tetra-isopropoxide as a mild and efficient catalyst. Target compounds were synthesized from these intermediates. The glucidic moiety was partially or totally deprotected under acidic conditions. These new heterocyclic monosaccharidic derivatives are potent glycogen phosphorylase inhibitors.

BACKGROUND & AIMS:Butyrate, produced in the colon lumen, maintains mucosal cell homeostasis. Poorly diffusible, its access is compromised in growing colon cancers and absent in distant metastases. Butyrate regulates DNA synthesis. We postulated that systemic administration of butyrate should reduce colon cancer growth and enhance 5-fluorouracil (5-FU) efficacy.METHODS:A stable derivative of butyrate (3n-But) was used. The antitumoral efficacy of 5-FU and 3n-But, alone or combined, was evaluated in human colorectal cancers (hCRCs) subcutaneously, orthotopically, or intrasplenically grafted into nude mice. Thymidylate synthase (TS) and thymidine kinase (TK) mRNA expression, proliferation, apoptosis, and cell cycle alterations were studied.RESULTS:In vivo, 5-FU alone inhibited growth of only 3 of the 12 hCRCs tested and 3n-But alone had no effect; the 5-FU/3n-But combination inhibited growth of all 16 hCRCs tested. The hCRCs differed in their p53 and microsatellite instability status. 5-FU/3n-But decreased TK and TS mRNA expression by 20- and 40-fold, respectively, and TS activity by 75%, stopped cell proliferation without affecting cell differentiation, and significantly enhanced apoptosis. 3n-But potentiated the efficacy of Tomudex and methotrexate, 2 TS inhibitors, but not that of oxaliplatin. In vitro, 5-FU/3n-But inhibited [3H]thymidine but not bromodeoxyuridine incorporation and induced apoptosis in hCRC cell lines. Cells treated with 5-FU/3n-But did not accumulate in G1 nor in S phase of the cell cycle, while 5-FU and 3n-But arrested the cycle in S and in G1 phase, respectively. 3n-But prevented the cell rescue from 5-FU-induced cytotoxicity by uridine or thymidine.CONCLUSIONS:3n-But and TS inhibitors acted synergistically against colorectal cancers, independently of the genetic alterations of the hCRCs. The mechanism of action of 5-FU/3n-But could be enhanced reduction of TS and prevention of thymidine salvage in DNA synthesis.

Regioselective carbamoylation of 3-S-(N,N-diethyldithiocarbamate) derivative of D-glucose gave the corresponding 6-O-(N,N-diethylcarbamate)-3-S-(N,N-diethyldithiocarbamate) as main product in yield of 43%. Transcarbamoylation was formed during the esterification in basic media and one of the by-product contained three different carbamic esters: O-carbamic, S-carbamic and O-thiocarbamic esters. The identification of each carbamate derivatives was realized by NMR analysis.

The synthesis of 3-spirohydantoin derivatives of d-allose and d-ribose is reported. The key step is the stereoselective conversion of glyco-α-aminonitriles from ulose derivatives of d-glucose and d-xylose using titanium(IV) isopropoxide as a mild and efficient catalyst. Cyclisation of the glyco-α-aminonitriles give the target spirohydantoins.

2',3'-Dideoxy-2',3'-didehydronucleosides and azasaccharides are known to possess antiviral activity. The synthesized 1-methoxyisoindoline system (10), which is related to the above nucleosides, is potentially stable in-vivo. The 1-methoxyisoindoline was synthesized from the achiral phthalaldehyde in 10 steps via an enantiomerically pure diol obtained by Sharpless asymmetric dihydroxylation. The new heterocyclic compound is an azosaccharide mimic which provides an access to a new series of nucleoside analogues with potential as antiretroviral agents (anti-HIV) and as glycosidase inhibitors.

4-Amino-5-H-2,3-dihydroisothiazole-1,1-dioxide ring was attached to a monosaccharide ring system by carbanion-mediated sulfonate intramolecular cyclisation (CSIC) of either secondary or tertiary aminonitrilesulfonamide carbohydrate derivatives using NaH, Cs2CO3 or BuLi as a base. These new bicyclic systems were used as glycone precursors of aza analogues of TSAO RT inhibitors. We report the first synthesis of an aza analogue of TSAO-m3T.

1,2-O-Isopropylidene-α-d-xylofuranose has been used to protect one aldehyde group of o-phthalaldehyde. This chiral protecting group acts as a resolving agent and this leads to separable diastereoisomers when a new stereogenic centre is created by the conversion of the second aldehyde group to a benzyloxyhydroxyethyl chain. These separated diastereoisomers were cyclised to 1,3-dihydrobenzo[c]furans with retention of chiral integrity at the C3 site thus allowing further elaboration to enantiomerically pure nucleoside analogues.

Novel carbamic esters possessing a carbohydrate moiety derived from glycerol or D-glucose with two N,N-diethyldithiocarbamoyl groups and a series of bisdithiocarbamic esters having a ketone or an alkyl ester have been synthesized. The in vitro activity of these new compounds was evaluated against Fusarium oxysporum f. sp. lini. Some of the compounds [bis[1,3-S-(N,N-diethyldithiocarbamoyl)]-1, 3-dideoxyglycerol) and diethyl N,N'-(1,3-dideoxyglycer-1, 3-diyl)bis(dithiocarbamate)] were more active for inhibiting vegetative mycelium growth than, respectively, the commercial N, N-diethyldithiocarbamic acid sodium salt and Maneb. The structure activity of these new compounds is discussed.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

α-Aminonitriles have been stereoselectively introduced at non-anomeric positions of monosaccharides, in which the carbon C-α is one of the atoms of the sugar ring. Target compounds were prepared from various ulose derivatives and amines using titanium(IV) isopropoxide as a mild and effective Lewis acid.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ABSTRACT Phosphorylation of D-glucose, D-galactose, D-fructose, glycerol and xylitol acetals with diethoxy- or diphenoxy(thiono)phosphoryl chloride gave the corresponding esters. A novel method of partially and fully deprotecting these compounds, which we have called “autocatalytic cleavage”, was effected by simply refluxing in water. Antifungal and insecticidal properties of these compounds are presented.

Two novel ribofuranose cyclonucleoside analogues have been synthesised by a route using 5-azido-5-deoxy-1,2-O-isopropylidene-α-d-ribofuranose as the starting material. This derivative was converted into two azole-reversed nucleosides, which were cyclised regiospecifically and stereospecifically by formation of a pentofuranosylamine. An alternative route, starting from a methyl β-d-ribofuranoside, was much less efficient, reflecting the need for the correct anomeric configuration in the cyclisation step.

1,2-O-Isopropylidene-3,5-O-propylidene-α-d-glucofuranose (3) was synthesized by conversion of 3-O-allyl-1,2-O-isopropylidene-α-d-glucofuranose (1) into its 3-O-prop-1-enyl isomer (2), followed by rapid acid-catalysed intramolecular acetalation in an aprotic solvent. The diacetal 3 was used as the precursor of 6-O-alkyl and 6-O-glucidyl-d-glucose amphiphiles, which show thermotropic and lyotropic liquid-crystalline properties.

Regiospecific synthesis of 12 novel n-butyric and phenylalkylcarboxylic monoesters of mannose and xylitol was achieved. The strategy adopted, avoided a tedious intramolecular transesterification step, previously described for the synthesis of analogous compounds and permitted the facile synthesis of a new generation of stable derivatives. The general tolerance of the drugs has been assayed after intravenous administration of a bolus dose into mice. Monobutyric esters showed a low toxicity commensurate with the requirements for future development. A relationship was observed between chain length and toxicity. In contrast, phenylacetic, 3-phenylpropionic and 4-phenylbutyric esters were found to be toxic. Phenylbutyric esters induced marked and specific neuromuscular damage. Preliminary biological investigations of the new series of monobutyric esters showed them to retain the benificial biological properties of butyric acid whilst remaining relatively non toxic. They induced an inhibition of in vitro proliferation of 10 human cases of de novo acute myeloid leukemia (AML) primary cultures and AML established cell lines. AML blasts growth appeared to be blocked and cell differentiation was established. Transcription and expression of maturation markers and finally apoptosis were observed. Moreover, human γ-chain hemoglobin (HbF) synthesis in erythroleukemia cells was stimulated by monobutyric esters. Mannose and xylitol butyric derivatives would appear to have exciting potential in treatment of β-Hemoglobinopathies, sickle cell anemia and cancer.