Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cyclohexanols”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,243 records · Page 69Linked to original sources
PubMed2002

Facile syntheses of all possible diastereomers of conduritol and various derivatives of inositol stereoisomers in high enantiopurity from myo-inositol.

Phosphoinositide-based signaling processes are crucially important in intracellular signal transduction events. Inositol phosphate analogues have been useful in probing the structure-activity relationships between inositol phosphates and biomacromolecules, and in studying biological functions of newly found inositol phosphates. Thus, a systematic and ready access to inositol stereoisomers is highly desirable. And practical and convenient syntheses of conduritols and related compounds are also important because of their biological activities and their synthetic utilities in the preparation of other bioactive molecules. We herein report the first syntheses of all possible diastereomers of conduritol and various derivatives of eight inositol stereoisomers in high enantiopurity from myo-inositol, which involve efficient enzymatic resolution of the intermediates conduritol B and C derivatives, followed by oxidation-reduction or the Mitsunobu reaction, and cis-dihydroxylation in stereo- and regioselective manners.

Candida↗
PubMed2005

A short synthesis of (+)-cyclophellitol.

[reaction: see text] A new synthesis of (+)-cyclophellitol, a potent beta-glucosidase inhibitor, has been completed in nine steps from D-xylose. The key transformations involve a zinc-mediated fragmentation of benzyl-protected methyl 5-deoxy-5-iodo-xylofuranoside followed by a highly diastereoselective indium-mediated coupling with ethyl 4-bromocrotonate. Subsequent ring-closing olefin metathesis, ester reduction, olefin epoxidation, and deprotection then afford the natural product. This constitutes the shortest synthesis of (+)-cyclophellitol reported to date.

Cyclohexanols↗
PubMed2006

A convenient approach for access to both carbapentofuranoses and carbahexopyranoses. Stereocontrolled synthesis of enantiopure carba-D-ribofuranoses, carba-D-arabinofuranoses and carba-L-gulopyranose.

A new approach to carbasugars in enantiomerically pure form is reported. The key step involves ring-closing metathesis of dienols 6 derived from a (R)-(+)-glyceraldehyde derivative 4 to form the substituted cyclopentenol 9 and cyclohexenol 34a. Stereocontrolled addition of hydroxyl groups followed by conversion of the ketal unit to hydroxymethyl group in these intermediates led to carbapentoses and -hexoses. Stereoselectivity during introduction of hydroxyl groups arises through the steric hindrance posed by the allylic substituents. A remarkable feature of the present approach is the accessibility of both d- and l-series of carbapentoses as illustrated by the synthesis of beta-D- and beta-L-carbaribofuranoses 17 and 20, respectively. Carba-alpha-D-ribofuranose 25, the biosynthetic intermediate to the antibiotic aristeromycin, has also been synthesized from the same cyclopentenol 9. Functional group manipulation in the cyclopentenol 9a also enabled access to carbaarabinofuranose 32. The present synthetic strategy can be extended for the synthesis of carbahexopyranose, as illustrated by the synthesis of carba-alpha-L-gulopyranose 40b.

Cyclohexanols↗
PubMed2007

Single enantiomer epoxides by bromomandelation of prochiral alkenes.

A combination of mandelic acid and N-bromosuccinimide efficiently converts prochiral alkenes into a readily separable 1:1 mixture of the bromomandelates. The diastereomerically pure bromomandelates are then converted into a variety of enantiomerically pure products. Terminal alkenes are converted into enantiomerically pure epoxides. Cyclohexene is converted into enantiomerically pure cis-2-azidocyclohexanol and cis-2-phenylthiocyclohexanol.

Alkenes↗
PubMed2005

Antibiotic terpenoid chloro-dihydroquinones from a new marine actinomycete.

As part of our continuing interest in exploring the chemistry of actinomycete bacteria uniquely adapted for survival in ocean sediments, we encountered several new strains, which by 16S rDNA sequence-based phylogenetic analysis were recognized as members of a new genus (tentatively called MAR4) within the family Streptomycetaceae. We report here the isolation and structure elucidation of three new chlorinated dihydroquinones (1-3) and one previously reported analogue, 4, from our strain CNQ-525, isolated from ocean sediments collected at a depth of 152 m near La Jolla, California. The compounds formally possess new carbon skeletons, but are related to several previously reported metabolites of the napyradiomycin class. The structures of the new molecules, which possess significant antibiotic properties and cancer cell cytotoxicities, were assigned by comprehensive spectral measurements and by comparison with NMR and other spectral data from the antibiotic A80915C (5), the full stereostructure of which was recently assigned by X-ray diffraction methods.

Actinobacteria↗
PubMed1994

Apiosporamide, a new antifungal agent from the coprophilous fungus Apiospora montagnei.

Bioassay-guided fractionation of an EtOAc extract from the mycelium of the coprophilous fungus Apiospora montagnei has furnished a new antifungal metabolite, named apiosporamide [1], and the known dihydroisocoumarin cis-(3R,4R)-4-hydroxymellein [4]. The structure of 1 was assigned on the basis of HMBC, HMQC, NOESY, and hrms data. Elucidation of the structure was complicated by the fact that several nmr signals appeared only under certain conditions.

Acetylation↗
PubMed1998

Total synthesis and biological activities of (+)- and (-)-boscialin and their 1'-epimers.

Natural (-)-boscialin [(-)-1] has recently been described as one of the constituents of various medicinal plants. To obtain more material for investigations of its biological activities, we carried out the synthesis of (-)-1 and its isomers. Starting from the chiral building block 2, the key steps of the synthesis involved a regioselective reduction and a nucleophilic addition. The enantiomer of the natural product, (+)-boscialin [(+)-1], could be obtained via acid-catalyzed epimerization of hydroxyketone 4 to (+)-3. Starting the synthesis with (-)-3 led to (-)-boscialin [(-)-1] with the natural absolute configuration. In addition to (+)- and (-)-boscialin, the corresponding 1'-epimers (+)- and (-)-epiboscialin were also obtained. In vitro assays with (-)-boscialin [(-)-1] and its three stereoisomers were carried out to test for activity against microbes, parasites, and human fibroblasts. The investigations revealed activity against various microbes and against Trypanosoma brucei rhodesiense and also revealed cytotoxicity against human cancer cells.

Animals↗
PubMed2001

A new asymmetric synthesis of trans-hydroisoquinolones.

[reaction: see text]. A convenient enantioselective synthesis of trans-hydroisoquinolones is described. This synthesis capitalizes on the ready availability of enantioenriched 2-substituted cyclohexenols by exploiting the asymmetry of an allylic carbon-oxygen sigma bond to control carbon-carbon bond formation in pinacol-terminated cyclizations of N-acyliminium cations.

Carbon↗
PubMed2003

DISAL glycosyl donors for the synthesis of a linear hexasaccharide under mild conditions.

[reaction: see text] The new class of glycosyl donors with a methyl 3,5-dinitrosalicylate (DISAL) anomeric leaving group has proved efficient for glycosylation under strictly neutral, mildly basic, or mildly acidic conditions. Here, we report the synthesis of novel DISAL disaccharide glycosyl donors prepared by easy nucleophilic aromatic substitution. These DISAL donors proved efficient in the synthesis of a starch-related hexasaccharide under very mild conditions. Glycosylations proceeded with alpha-selectivity and were compatible with Trt protecting groups.

Carbohydrate Sequence↗
PubMed2003

Common-intermediate strategy for synthesis of conduritols and inositols via beta-hydroxy cyclohexenylsilanes.

[reaction: see text] Syntheses of conduritols B-D and F and d-(+)-chiro- and neo-inositols from cyclohexenylsilane intermediates are described. The key cyclohexylsilane intermediates 5 and 14 were synthesized by stereoselective olefin dihydroxylation of the corresponding cyclohexenylsilanes. Selective Peterson elimination reactions and Fleming-Tamao oxidations of 5 and 14 then delivered the targeted cyclitol derivatives.

Cyclization↗
PubMed2005

Expedient synthesis of potent cannabinoid receptor agonist (-)-CP55,940.

[reaction: see text] A stereocontrolled synthesis of (-)-CP55,940, a potent cannabinoid receptor agonist, has been attained using a novel aldolization/retro-aldolization interconversion strategy, in which a temporarily generated chiral aldol motif plays essential roles.

Cannabinoid Receptor Agonists↗
PubMed2006

Stereodivergent syntheses of conduramines and aminocyclitols.

[reaction: see text] The diastereomers of 6-amino-cyclohex-3-ene-1,2-diols 1 (4-deoxy-3-conduramines), key building blocks for the syntheses of a large range of natural products, have been enantioselectively prepared. Diastereoselective dihydroxylation of the compounds provided a new family of aminocyclitols 2 (deoxyinosamines). The key reactions of our syntheses are Sharpless catalytic asymmetric epoxidation, diastereoselective addition of vinylmetal reagents to the aldehydes, and ring-closing metathesis (RCM).

Cyclohexanols↗
PubMed1997

Penicillium discolor, a new species from cheese, nuts and vegetables.

The new species Penicillium discolor, frequently isolated from nuts, vegetables and cheese is described. It is characterised by rough, dark green conidia, synnemateous growth on malt agar and the production of the secondary metabolites chaetoglobosins A, B and C, palitantin, cyclopenin, cyclopenol, cyclopeptin, dehydrocyclopeptin, viridicatin and viridicatol. It also produces the mouldy smelling compounds geosmin and 2-methyl-isoborneol, and a series of specific orange to red pigments on yeast extract sucrose agar, hence the epithet discolor. P. discolor resembles P. echinulatum morphologically but on basis of the secondary metabolites is also related to P. expansum, P. solitum and P. crustosum.

Benzodiazepinones↗
PubMed2001

1,8-cineol, a food flavoring agent, prevents ethanol-induced gastric injury in rats.

This study investigated the gastroptrotective effect of 1,8-cineole (cineole) on ethanol-induced gastric mucosal damage in rats and the possible mechanisms involved. 1,8-Cineole (50-200 mg/kg), given orally 1 hr before administration of 1 ml of absolute ethanol significantly attenuated the ethanol-induced gastric injury in a manner similar to nordihydroguairetic acid, a known lipoxygenase inhibitor. 1,8-Cineole showed a tendency to restore the ethanol-associated decreases in nonprotein sulfhydryls, suggesting a possible antioxidant effect. In gastric secretion studies, 1,8-cineole, similar to cimetidine, a known histamine-2 receptor antagonist, demonstrated significant inhibitions of both gastric juice volume as well as total acid output. The protection offered by 1,8-cineole was found to be unaltered by 8-phenyltheophylline or L-NAME, indicating that its effect is not mediated by endogenous adenosine or nitric oxide. These results, taken together with the earlier reports, suggest that the antioxidant and lipoxygenase inhibitory actions of 1,8-cineole are of prime importance in affording gastroprotection against ethanol injury in the rat.

Administration, Oral↗
PubMed1998

Identification and characterization of a novel synthetic cannabinoid CP 55,940 binder in rat brain cytosol.

We have detected the presence of a specific [3H] CP 55,940 binder in the cytosol of rat cerebral cortex. Competition studies showed that only cold CP 55,940 and to a lesser extent delta9THC was able to compete with [3H] CP 55,940; little competition was observed with either delta8THC or anandamide. Scatchard analysis of the data indicate the presence of two distinct binding components having affinity constants (Kd) of 0.97 +/- 0.03 nM, 5.83 +/- 0.08 nM, and Bmax of 3.31 +/- 0.06 pmol/mg protein, 22.2 +/- 1.2 pmol/mg protein respectively. The cytosolic CP 55,940 binder was heat stable up to 30 degrees C. Besides the brain cytosol, lesser amounts of binding were also detected in the spleen, and testis. Liver, kidney and muscle cytosol preparations were found to be devoid of this binder. Unlike the previously characterized brain membrane cannabinoid receptor, this binder was found to be salt, sulfhydryl blocking reagents and nucleotide resistant. Interestingly, dithiothreitol (DTT), a protein-disulfide group reducing agent, inhibited the binding of [3H] CP-55,940 to the receptor and approximately 80% binding inhibition was obtained at a 5 mM concentration. Western blot analysis using anti-receptor antibody reveal the presence of a 95-110, 50 and 38 kDa band in the brain, spleen and testis cytosolic preparations. In conclusion, we have identified the presence of a novel CP 55,940 binder in rat cerebral cortex cytosol possessing biochemical properties distinct from those previously observed using rat cerebral cortex membrane cannabinoid receptor.

Animals↗
PubMed2000

Reduced testosterone level in a venlafaxine treated patient.

We report on a patient with a low testosterone level which occurred during treatment with venlafaxine. The testosterone level increased when the medication was discontinued. Possible clinical correlation with amelioration of paraphilia is discussed.

Adult↗