Nitro-fatty acids (NO2FAs) are endogenously produced electrophiles and NRF2 activators with therapeutic potential. We developed a synthetic protocol combining a Henry reaction and base-promoted β-elimination, yielding ultrapure regio/stereoisomers of nitro-stearic (NO2SA), nitro-oleic (NO2OA), and conjugated/bis-allylic nitro-linoleic (NO2LA) acids. These were tested for NRF2 pathway activation in bone marrow cells under different oxygen conditions. We observed that 9- and 10-NO2OA, and 10-NO2LA increased NRF2 stabilization under hypoxia, while 9- and 10-NO2OA significantly upregulated Hmox1 and Gclm at all oxygen levels. 9- and 10-NO2OA enhanced HO-1 and GCLM proteins independently of oxygen, while 10-NO2LA was oxygen-dependent, boosting HO-1 under hypoxia and GCLM under ambient conditions. Moreover, 10-NO2OA and 10-NO2LA induced NRF2 nuclear translocation. In contrast, the saturated 10-NO2SA, which has lower electron-acceptor ability, was inactive. In summary, these findings suggest the biological activity of NO2FAs is dependent on oxygen level, which could be used in future research of other oxidative stress-dependent pathways.
- MeSH
- Nitro Compounds * pharmacology chemical synthesis chemistry MeSH
- NF-E2-Related Factor 2 * metabolism MeSH
- Heme Oxygenase-1 metabolism MeSH
- Cell Hypoxia MeSH
- Linoleic Acids chemical synthesis chemistry pharmacology MeSH
- Oxygen metabolism MeSH
- Fatty Acids * pharmacology chemical synthesis chemistry MeSH
- Mice MeSH
- Signal Transduction drug effects MeSH
- Stereoisomerism MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
DC-SIGN, a C-type lectin receptor expressed on immune cells, is considered a promising target for immunomodulatory and antiviral therapies. While mannose-based glycomimetics have been extensively studied as DC-SIGN ligands, fucose-based strategies remain underexplored. This study explores the fucosylation of linear alcohols and sugars using eight different fucosyl donors, aiming at designing strategies for the development of fucose-based glycomimetics targeting DC-SIGN. Four types of leaving groups and two different acyl-based protecting groups on the donors were tested. The glycosylation of 3-azidopropan-1-ol exclusively yielded the β-anomer, demonstrating high stereoselectivity. The azido group in the product is versatile, allowing for direct click chemistry reactions or reduction to an amine for further functionalization. Both types of reactions were demonstrated in a model reaction. In the glycosylation of a sugar, a disaccharide moiety of Lewis X antigen was selected as a target molecule. Only one of the eight tested fucosyl donors worked well in this reaction and provided the product in a reasonable yield. The disaccharide was also equipped with the 3-azidopropyl linker, facilitating future modifications. Finally, NMR studies confirmed compatibility of the linker with canonical Ca2+-dependent carbohydrate binding to DC-SIGN, suggesting potential for further development of fucose-based glycomimetics targeting this C-type lectin receptor.
- MeSH
- Fucose * chemistry MeSH
- Glycosides * chemistry chemical synthesis pharmacology metabolism MeSH
- Glycosylation MeSH
- Lectins, C-Type * metabolism antagonists & inhibitors MeSH
- Humans MeSH
- Molecular Structure MeSH
- Cell Adhesion Molecules * metabolism antagonists & inhibitors MeSH
- Receptors, Cell Surface * metabolism antagonists & inhibitors MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
The synthesis of axially chiral benzimidazoles with a peri-substituted naphthalene and a dimethylamino group at positions 1 and 2, respectively, was developed. We evaluated these compounds in the desymmetrization reaction of cis-tetrahydrophthalic anhydride with benzyl alcohol, as the nucleophilic sp2 imidazole nitrogen atom is able to catalyze the acyl-transfer reaction. The prepared benzimidazoles demonstrated catalytic activity and showed that their axial chirality impacts stereoselectivity.
- Publication type
- Journal Article MeSH
Stereoselective synthesis of spirocyclic compounds containing heterocyclic motifs represents a formidable challenge in enantioselective synthesis. Here, we present a cascade reaction between α,β-unsaturated aldehydes and isoxazolones under synergistic catalysis of a chiral secondary amine and a palladium(0) catalyst. This strategy allows access to chiral spiroisoxazolone derivatives with a large substrate scope tolerance and high levels of diastereoselectivity (dr up to 20:1) and enantioselectivity (up to 99% ee). Furthermore, the utility of this methodology is showcased by the transformation of chiral spiroisoxazolones into structurally attractive and enantiomerically enriched cyclopentene carboxylic acids with two stereogenic centers.
- Publication type
- Journal Article MeSH
Our previously reported HDAC6 inhibitor (HDAC6i) Marbostat-100 (4) has provided many arguments for further clinical evaluation. By the substitution of the acidic hydrogen of 4 for different carbon residues, we were able to generate an all-carbon stereocenter, which significantly improves the hydrolytic stability of the inhibitor. Further asymmetric synthesis has shown that the (S)-configured inhibitors preferentially bind to HDAC6. This led to the highly selective and potent methyl-substituted derivative S-29b, which elicited a long-lasting tubulin hyperacetylation in MV4-11 cells. Finally, a crystal structure of the HDAC6/S-29b complex provided mechanistic explanation for the high potency and stereoselectivity of synthesized compound series.
- MeSH
- Histone Deacetylase 6 * antagonists & inhibitors metabolism MeSH
- Histone Deacetylase Inhibitors * chemistry pharmacology chemical synthesis MeSH
- Carbolines * chemistry pharmacology chemical synthesis MeSH
- Crystallography, X-Ray MeSH
- Humans MeSH
- Models, Molecular MeSH
- Molecular Structure MeSH
- Morpholines chemical synthesis chemistry pharmacology MeSH
- Cell Line, Tumor MeSH
- Dose-Response Relationship, Drug MeSH
- Structure-Activity Relationship MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
V oblasti celkových inhalačných prchavých anestetík od použitia oxidu dusného, dietyléteru, chloroformu a cyklopropánu nastal vďaka zavedeniu fluórovaných anestetík a s nimi spojených chirálnych technológií pokrok, v dôsledku ktorého došlo pri anestézii k zníženiu úmrtnosti. Z fluórovaných chirálnych prchavých anestetík sa do oblasti anestézie dostali halotan (Fluotan®), izoflurán (Foran®), dezflurán (Supran®) a enflurán (Ehran®). Z nechirálnych sa používajú metoxyflurán (Penthrox®) a sevoflurán (Sevoran®). Chirálne anestetiká majú v svojej štruktúre stereogénne centrum a existujú vo forme dvoch enantiomérov (S)-(+) a (R)-(–). Hoci sa tieto chirálne anestetiká používajú vo forme racemátov, z hľadiska účinnosti a bezpečnosti je u nich dôležité študovať okrem biologickej aktivity racemátov i biologickú aktivitu ako i ďalšie vlastnosti jednotlivých enantiomérov. V predloženom prehľade je pozornosť venovaná skupine liečiv známych ako inhalačné anestetiká vo vzťahu k ich chirálnym aspektom. Boli u nich zistené významné rozdiely (R) a (S)-enantiomérov vo farmakodynamickej, farmakokinetickej aktivite, ako i v toxicite. Na rozdelenie jednotlivých racemátov na enantioméry sa využíva hlavne plynová chromatografia (GC). V prehľade sú uvedené jednotlivé chirálne fázy, resp. selektory využívané pri ich enantioseparácii, ako i pri farmakokinetických štúdiách. Príprava jednotlivých enantiomérov okrem preparatívnej GC je možná aj pomocou metód stereoselektívnej syntézy.
Since the advent of nitric oxide, diethyl ether, chloroform and cyclopropane, the greatest advancement in the area of general inhalational anesthetics has been achieved by the introduction of fluorinated anesthetics and the relevant chiral techniques. This progress led to marked decrease in mortality rates in anesthesia. In the group of chiral fluorinated compounds, halothane (Fluotan®), isoflurane (Foran®), desflurane (Supran®) and enflurane (Ehran®) are deployed as volatile anesthetics. Chiral anesthetics possess a stereogenic center in their molecules and thus exist as two enantiomers (S)-(+) and (R)-(–). Although these chiral anesthetics are used as racemates, it is crucial to study besides the bioactivities of the racemic compounds also the biological activity and other properties of the particular enantiomers. The present survey discusses the drug category known as inhalational anesthetics in regard to their chiral aspects. These compounds exhibit marked differences between the (R) and (S)-enantiomers in their pharmacodynamics, pharmacokinetics and toxicity. The main analytical technique employed in the enantioseparation of these compounds is gas chromatography (GC). This review lists the individual chiral phases (chiral selectors) used in the enantioseparation as well as in pharmacokinetic studies. The possibilities of preparation of these compounds in their enantiomerically pure form by means of stereoselective synthesis are also mentioned.
- MeSH
- Anesthetics, General * pharmacokinetics pharmacology MeSH
- Anesthetics, Inhalation * pharmacokinetics pharmacology MeSH
- Humans MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
In recent years, a number of drugs targeting the prostate-specific membrane antigen (PSMA) have become important tools in the diagnosis and treatment of prostate cancer. In the present work, we report on the synthesis and preclinical evaluation of a series of 18F-labeled PSMA ligands for diagnostic application based on the theragnostic ligand PSMA-617. By applying modifications to the linker structure, insight into the structure-activity relationship could be gained, highlighting the importance of hydrophilicity and stereoselectivity on interaction with PSMA and hence the biodistribution. Selected compounds were co-crystallized with the PSMA protein and analyzed by X-rays with mixed results. Among these, PSMA-1007 (compound 5) showed the best interaction with the PSMA protein. The respective radiotracer [18F]PSMA-1007 was translated into the clinic and is, in the meantime, subject of advanced clinical trials.
- MeSH
- Antigens, Surface MeSH
- Glutamate Carboxypeptidase II antagonists & inhibitors MeSH
- Humans MeSH
- Ligands MeSH
- Prostatic Neoplasms diagnostic imaging MeSH
- Niacinamide analogs & derivatives chemistry pharmacology MeSH
- Oligopeptides chemistry pharmacology MeSH
- Positron-Emission Tomography MeSH
- Radiopharmaceuticals pharmacology MeSH
- Fluorine Radioisotopes chemistry MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
β-N-Acetylhexosaminidases (EC 3.2.1.52) are a unique family of glycoside hydrolases with dual substrate specificity and a particular reaction mechanism. Though hydrolytic enzymes per se, their good stability, easy recombinant production, absolute stereoselectivity, and a broad substrate specificity predestine these enzymes for challenging applications in carbohydrate synthesis. This mini-review aims to demonstrate the catalytic potential of β-N-acetylhexosaminidases in a range of unusual reactions, processing of unnatural substrates, formation of unexpected products, and demanding reaction designs. The use of unconventional media can considerably alter the progress of transglycosylation reactions. By means of site-directed mutagenesis, novel catalytic machineries can be constructed. Glycosylation of difficult substrates such as sugar nucleotides was accomplished, and the range of afforded glycosidic bonds comprises unique non-reducing sugars. Specific functional groups may be tolerated in the substrate molecule, which makes β-N-acetylhexosaminidases invaluable allies in difficult synthetic problems.
Bark beetles kill apparently vigorous conifers during epidemics by means of pheromone-mediated aggregation. During non-endemic conditions the beetles are limited to use trees with poor defense, like wind-thrown. To find olfactory cues that help beetles to distinguish between trees with strong or weak defense, we collected volatiles from the bark surface of healthy felled or standing Picea abies trees. Furthermore, living trees were treated with methyl jasmonate in order to induce defense responses. Volatiles were analyzed by combined gas chromatography and electroantennographic detection (GC-EAD) on Ips typographus antennae. Compounds eliciting antennal responses were characterized by single sensillum recording for identification of specific olfactory sensory neurons (OSN). Release of monoterpene hydrocarbons decreased, while oxygenated compounds increased, from spring to early summer in felled trees. In both beetle sexes particular strong EAD activity was elicited by trace amounts of terpene alcohols and ketones. 4-Thujanol gave a very strong response and the absolute configuration of the tested natural product was assigned to be (+)-trans-(1R,4S,5S)-thujanol by stereoselective synthesis and enantioselective gas chromatography. One type of OSN responded to all ketones and five other OSN were characterized by the type of compounds that elicited responses. Three new OSN classes were found. Of the eight EAD-active compounds found in methyl jasmonate-treated bark, the known anti-attractant 1,8-cineole was the one most strongly induced. Our data support the hypothesis that highly active oxygenated host volatiles could serve as positive or negative cues for host selection in I. typographus and in other bark beetles.
- MeSH
- Acetates pharmacology MeSH
- Coleoptera physiology MeSH
- Cyclopentanes pharmacology MeSH
- Electrophysiological Phenomena drug effects MeSH
- Plant Bark chemistry drug effects metabolism MeSH
- Monoterpenes chemical synthesis chemistry pharmacology MeSH
- Oxylipins pharmacology MeSH
- Gas Chromatography-Mass Spectrometry MeSH
- Picea chemistry metabolism MeSH
- Stereoisomerism MeSH
- Styrene chemistry pharmacology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
An enzymatic alternative to the chemical synthesis of chiral gem-difluorinated alcohols has been developed. The method is highly effective and stereoselective, feasible at laboratory temperature, avoiding the use of toxic heavy metal catalysts which is an important benefit in medicinal chemistry including the synthesis of drugs and drug precursors. Candida antarctica lipases A and B were applied for the enantioselective resolution of side-chain modified gem-difluorinated alcohols, (R)- and (S)-3-benzyloxy-1,1-difluoropropan-2-ols (1a and 1b), compounds serving as chiral building blocks in the synthesis of various bioactive molecules bearing a gem-difluorinated grouping. The catalytic activity of these lipases was investigated for the chiral acetylation of 1a and 1b in non-polar solvents using vinyl acetate as an acetyl donor. The dependence of the reaction course on various substrate and enzyme concentrations, reaction time, and temperature was monitored by chiral capillary electrophoresis (CE) using sulfobutyl ether β-cyclodextrin as a stereoselective additive of the aqueous background electrolyte. The application of CE, NMR, and MS methods has proved that the complex enzyme effect of Candida antarctica lipase B leads to the thermodynamically stable (S)-enantiomer 1b instead of the expected acetylated derivatives. In contrast, the enantioselective acetylation of racemic alcohol 1 was observed as a kinetically controlled process, where (R)-enantiomer 1a was formed as the main product. This process was followed by enzymatic hydrolysis and chiral isomerisation. Finally, single pure enantiomers 1a and 1b were isolated and their absolute configurations were assigned from NMR analysis after esterification with Mosher's acids.
