Nonaqueous capillary electrophoresis (NACE) using methanol (MeOH) as a solvent of the BGEs and quantum mechanical density functional theory (DFT) have been applied to determine the thermodynamic acidity (ionization) constants (pKa ) of mono- and diaza[5]helicenes, mono- and diaza[6]helicenes, and their dibenzo derivatives in MeOH and water. First, the mixed acidity constants, pKa,MeOHmix${\rm{p}}K_{{\rm{a,MeOH}}}^{{\rm{mix}}}$ , of ionogenic pyridinium groups of azahelicenes and their derivatives in MeOH were obtained by nonlinear regression analysis of pH dependence of their effective electrophoretic mobilities. The effective mobilities were measured by NACE in a large series of methanolic BGEs within a wide conventional pH range (pHMeOH 1.6-12.0) and at ambient temperature (21-26°C) in a home-made CE device. Prior to mixed acidity constant calculation, the effective mobilities were corrected to reference temperature (25°C) and constant ionic strength (25 mM). Then, the mixed acidity constants were recalculated to the thermodynamic acidity constants pKa,MeOH by the Debye-Hückel theory of nonideality of electrolyte solutions. Finally, from the methanolic thermodynamic pKa,MeOH values, the aqueous thermodynamic pKa,H2O${\rm{p}}{K_{{\rm{a,}}{{\rm{H}}_{\rm{2}}}{\rm{O}}}}$ constants were estimated using the empirical relations between methanolic and aqueous acidity constants derived for structurally related pyridine derivatives. Depending on the number and position of the nitrogen atoms in their molecules, the analyzed azahelicenes were found to be weak to moderate bases with methanolic pKa,MeOH in the range 2.01-8.75 and with aqueous pKa,H2O${\rm{p}}{K_{{\rm{a,}}{{\rm{H}}_{\rm{2}}}{\rm{O}}}}$ in the range 1.67-8.28. The thermodynamic pKa,MeOH obtained by the DFT calculations were in a good agreement with those determined experimentally by NACE.
Mebendazole (MBZ) was developed as a broad-spectrum anthelmintic but has recently shown efficacy as an anticancer agent. The use of MBZ for cancer, however, is challenging due to its poor solubility leading to poor bioavailability. Herein, we developed a prodrug approach with various N-linked promoieties including acyloxymethyl, aminoacyloxymethyl, and substituted phosphonooxymethyl in attempt to improve these characteristics. Compound 12, containing an (((((isopropoxycarbonyl)oxy)methoxy)phosphoryl)oxy)methyl promoiety, showed a >10 000-fold improvement in aqueous solubility. When evaluated in mice, 12 displayed a 2.2-fold higher plasma AUC0- t and a 1.7-fold improvement in brain AUC0- t with a calculated oral bioavailability of 52%, as compared to 24% for MBZ-polymorph C (MBZ-C), the most bioavailable polymorph. In dogs, 12 showed a 3.8-fold higher plasma AUC0- t with oral bioavailability of 41% compared to 11% for MBZ-C. In summary, we have identified a prodrug of MBZ with better physicochemical properties and enhanced bioavailability in both mice and dog.
- MeSH
- anthelmintika metabolismus MeSH
- aplikace orální MeSH
- biologická dostupnost MeSH
- dusík chemie MeSH
- mebendazol metabolismus MeSH
- myši MeSH
- prekurzory léčiv aplikace a dávkování chemie metabolismus farmakokinetika MeSH
- psi MeSH
- rozpustnost MeSH
- stabilita léku MeSH
- tkáňová distribuce MeSH
- voda chemie MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
2-(Phosphonomethyl)pentanedioic acid (2-PMPA) is a potent and selective inhibitor of glutamate carboxypeptidase-II (GCPII) with efficacy in multiple neurological and psychiatric disease models, but its clinical utility is hampered by low brain penetration due to the inclusion of multiple acidic functionalities. We recently reported an improvement in the brain-to-plasma ratio of 2-PMPA after intranasal (IN) dosing in both rodents and primates. Herein, we describe the synthesis of several 2-PMPA prodrugs with further improved brain delivery of 2-PMPA after IN administration by masking of the γ-carboxylate. When compared to IN 2-PMPA in rats at 1 h post dose, γ-(4-acetoxybenzyl)-2-PMPA (compound 1) resulted in significantly higher 2-PMPA delivery to both plasma (4.1-fold) and brain (11-fold). Subsequent time-dependent evaluation of 1 also showed high brain as well as plasma 2-PMPA exposures with brain-to-plasma ratios of 2.2, 0.48, and 0.26 for olfactory bulb, cortex, and cerebellum, respectively, as well as an improved sciatic nerve to plasma ratio of 0.84. In contrast, IV administration of compound 1 resulted in similar plasma exposure of 2-PMPA versus the IN route (AUCIV: 76 ± 9 h·nmol/mL versus AUCIN: 99 ± 24 h·nmol/mL); but significantly lower nerve and brain tissue exposures with tissue-to-plasma ratios of 0.21, 0.03, 0.04, and 0.04 in nerve, olfactory bulb, cortex, and cerebellum, respectively. In primates, IN administration of 1 more than doubled 2-PMPA concentrations in the cerebrospinal fluid relative to previously reported levels following IN 2-PMPA. The results of these experiments provide a promising strategy for testing GCPII inhibition in neurological and psychiatric disorders.
- MeSH
- aplikace intranazální MeSH
- estery analýza chemie farmakologie MeSH
- glutamátkarboxypeptidasa II antagonisté a inhibitory MeSH
- hematoencefalická bariéra účinky léků MeSH
- intravenózní podání MeSH
- krysa rodu rattus MeSH
- Macaca mulatta MeSH
- mozek účinky léků MeSH
- mozkomíšní mok účinky léků MeSH
- neuroprotektivní látky analýza chemie farmakologie MeSH
- organofosforové sloučeniny analýza chemie farmakologie MeSH
- potkani Wistar MeSH
- prekurzory léčiv analýza chemie farmakologie MeSH
- tkáňová distribuce MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Aberrant excitatory neurotransmission associated with overproduction of glutamate has been implicated in the development of HIV-associated neurocognitive disorders (HAND). The glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON, 14) attenuates glutamate synthesis in HIV-infected microglia/macrophages, offering therapeutic potential for HAND. We show that 14 prevents manifestation of spatial memory deficits in chimeric EcoHIV-infected mice, a model of HAND. 14 is not clinically available, however, because its development was hampered by peripheral toxicities. We describe the synthesis of several substituted N-(pivaloyloxy)alkoxy-carbonyl prodrugs of 14 designed to circulate inert in plasma and be taken up and biotransformed to 14 in the brain. The lead prodrug, isopropyl 6-diazo-5-oxo-2-(((phenyl(pivaloyloxy)methoxy)carbonyl)amino)hexanoate (13d), was stable in swine and human plasma but liberated 14 in swine brain homogenate. When dosed systemically in swine, 13d provided a 15-fold enhanced CSF-to-plasma ratio and a 9-fold enhanced brain-to-plasma ratio relative to 14, opening a possible clinical path for the treatment of HAND.
- MeSH
- aminokapronáty aplikace a dávkování chemická syntéza farmakologie MeSH
- azosloučeniny aplikace a dávkování chemická syntéza farmakologie MeSH
- diazooxonorleucin aplikace a dávkování farmakologie MeSH
- glutaminasa antagonisté a inhibitory MeSH
- HIV infekce komplikace MeSH
- krev metabolismus MeSH
- kyselina glutamová metabolismus MeSH
- lidé MeSH
- mozek metabolismus MeSH
- myši inbrední C57BL MeSH
- neurokognitivní poruchy farmakoterapie etiologie MeSH
- nootropní látky aplikace a dávkování chemická syntéza farmakologie MeSH
- prasata MeSH
- prekurzory léčiv aplikace a dávkování chemická syntéza farmakologie MeSH
- stabilita léku MeSH
- virová nálož účinky léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The aliphatic nitroalkene (E)-1-nitropentadec-1-ene (NPD), reported in early seventies in soldiers of the termite genus Prorhinotermes, was the first documented nitro compound produced by insects. Yet, its biosynthetic origin has long remained unknown. Here, we investigated in detail the biosynthesis of NPD in P. simplex soldiers. First, we track the dynamics in major metabolic pathways during soldier ontogeny, with emphasis on likely NPD precursors and intermediates. Second, we propose a hypothesis of NPD formation and verify its individual steps using in vivo incubations of putative precursors and intermediates. Third, we use a de novo assembled RNA-Seq profiles of workers and soldiers to identify putative enzymes underlying NPD formation. And fourth, we describe the caste- and age-specific expression dynamics of candidate initial genes of the proposed biosynthetic pathway. Our observations provide a strong support to the following biosynthetic scenario of NPD formation, representing an analogy of the sphingolipid pathway starting with the condensation of tetradecanoic acid with l-serine and leading to the formation of a C16 sphinganine. The C16 sphinganine is then oxidized at the terminal carbon to give rise to 2-amino-3-hydroxyhexadecanoic acid, further oxidized to 2-amino-3-oxohexadecanoic acid. Subsequent decarboxylation yields 1-aminopentadecan-2-one, which then proceeds through six-electron oxidation of the amino moiety to give rise to 1-nitropentadecan-2-one. Keto group reduction and hydroxyl moiety elimination lead to NPD. The proposed biosynthetic sequence has been constructed from age-related quantitative dynamics of individual intermediates and confirmed by the detection of labeled products downstream of the administered labeled intermediates. Comparative RNA-Seq analyses followed by qRT-PCR validation identified orthologs of serine palmitoyltransferase and 3-ketodihydrosphingosine reductase genes as highly expressed in the NPD production site, i.e. the frontal gland of soldiers. A dramatic onset of expression of the two genes in the first days of soldier's life coincides with the start of NPD biosynthesis, giving further support to the proposed biosynthetic hypothesis.
- MeSH
- alkoholoxidoreduktasy metabolismus MeSH
- aminokyseliny metabolismus MeSH
- hmyzí proteiny metabolismus MeSH
- Isoptera metabolismus MeSH
- ketony metabolismus MeSH
- mastné kyseliny metabolismus MeSH
- metabolom MeSH
- nitroparafiny metabolismus MeSH
- serin-C-palmitoyltransferasa metabolismus MeSH
- sfingolipidy metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Termite nests often are referred to as the most elaborate constructions of animals. However, some termite species do not build a nest at all and instead found colonies inside the nests of other termites. Since these so-called inquilines do not need to be in direct contact with the host population, the two colonies usually live in separate parts of the nest. Adaptations of both the inquiline and its host are likely to occur to maintain the spatial exclusion and reduce the costs of potential conflicts. Among them, mutual avoidance, based on chemical cues, is expected. We investigated chemical aspects of cohabitation between Constrictotermes cavifrons (Nasutitermitinae) and its obligatory inquiline Inquilinitermes inquilinus (Termitinae). Inquiline soldiers produce in their frontal glands a blend of wax esters, consisting of the C12 alcohols (3Z)-dodec enol, (3Z,6Z)-dodecadienol, and dodecanol, esterified with different fatty acids. The C12 alcohols appear to be cleaved gradually from the wax esters, and they occur in the frontal gland, in soldier headspace, and in the walls of the inquiline part of the nest. Electrophysiological experiments revealed that (3Z)-dodecenol and (3Z,6Z)-dodecadienol are perceived by workers of both species. Bioassays indicated that inquiline soldier heads, as well as the two synthetic compounds, are attractive to conspecific workers and elicit an arresting behavior, while host soldiers and workers avoid these chemicals at biologically relevant amounts. These observations support the hypothesis that chemically mediated spatial separation of the host and the inquiline is an element of a conflict-avoidance strategy in these species.
- MeSH
- alkoholy metabolismus MeSH
- čich MeSH
- esterifikace MeSH
- estery metabolismus MeSH
- feromony metabolismus MeSH
- hnízdění * MeSH
- Isoptera fyziologie MeSH
- komunikace zvířat MeSH
- úniková reakce MeSH
- vosky metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON, 1) has shown robust anticancer efficacy in preclinical and clinical studies, but its development was halted due to marked systemic toxicities. Herein we demonstrate that DON inhibits glutamine metabolism and provides antitumor efficacy in a murine model of glioblastoma, although toxicity was observed. To enhance DON's therapeutic index, we utilized a prodrug strategy to increase its brain delivery and limit systemic exposure. Unexpectedly, simple alkyl ester-based prodrugs were ineffective due to chemical instability cyclizing to form a unique diazo-imine. However, masking both DON's amine and carboxylate functionalities imparted sufficient chemical stability for biological testing. While these dual moiety prodrugs exhibited rapid metabolism in mouse plasma, several provided excellent stability in monkey and human plasma. The most stable compound (5c, methyl-POM-DON-isopropyl-ester) was evaluated in monkeys, where it achieved 10-fold enhanced cerebrospinal fluid to plasma ratio versus DON. This strategy may provide a path to DON utilization in glioblastoma multiforme patients.
- MeSH
- antimetabolity antitumorózní terapeutické užití MeSH
- diazooxonorleucin terapeutické užití MeSH
- glioblastom farmakoterapie metabolismus MeSH
- glutamin metabolismus MeSH
- Haplorrhini MeSH
- lidé MeSH
- myši nahé MeSH
- myši MeSH
- nádory mozku farmakoterapie metabolismus MeSH
- prekurzory léčiv farmakokinetika terapeutické užití MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Inhibition of glutamate carboxypeptidase II (GCPII) is effective in preclinical models of neurological disorders associated with excessive activation of glutamatergic systems. Here we report synthesis, structural characterization, and biological activity of new hydroxamic acid-based inhibitors with nanomolar affinity for human GCPII. Crystal structures of GCPII/hydroxamate complexes revealed an unprecedented binding mode in which the putative P1' glutarate occupies the spacious entrance funnel rather than the conserved glutamate-binding S1' pocket. This unique binding mode provides a mechanistic explanation for the structure-activity relationship data, most notably the lack of enantiospecificity and the tolerance for bulky/hydrophobic functions as substituents of a canonical glutarate moiety. The in vivo pharmacokinetics profile of one of the inhibitors will be presented along with analgesic efficacy data from the rat chronic constrictive injury model of neuropathic pain.
- MeSH
- antigeny povrchové metabolismus MeSH
- glutamátkarboxypeptidasa II antagonisté a inhibitory metabolismus MeSH
- inhibitory enzymů chemická syntéza chemie farmakologie MeSH
- kyseliny hydroxamové chemická syntéza chemie farmakologie MeSH
- lidé MeSH
- molekulární modely MeSH
- molekulární struktura MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
2-Phosphonomethylpentanedioic acid (1, 2-PMPA) is a potent inhibitor of glutamate carboxypeptidase II which has demonstrated robust neuroprotective efficacy in many neurological disease models. However, 1 is highly polar containing a phosphonate and two carboxylates, severely limiting its oral bioavailability. We strategized to mask the polar groups via a prodrug approach, increasing the likelihood of passive oral absorption. Our initial strategy was to cover the phosphonate with hydrophobic moieties such as pivaloyloxymethyl (POM) and isopropyloxycarbonyloxymethyl (POC) while keeping the α- and γ-carboxylates unsubstituted. This attempt was unsuccessful due to the chemical instability of the bis-POC/POM derivatives. Addition of α,γ-diesters and α-monoesters enhanced chemical stability and provided excellent oral exposure in mice, but these mixed esters were too stable in vivo, resulting in minimal release of 1. By introducing POC groups on both the phosphonate and α-carboxylate, we synthesized Tris-POC-2-PMPA (21b), which afforded excellent release of 1 following oral administration in both mice and dog.
- MeSH
- antigeny povrchové MeSH
- aplikace orální MeSH
- biologická dostupnost MeSH
- glutamátkarboxypeptidasa II antagonisté a inhibitory MeSH
- inhibitory proteas chemie farmakologie MeSH
- jaterní mikrozomy MeSH
- lidé MeSH
- myši MeSH
- neuroprotektivní látky chemická syntéza farmakologie MeSH
- objevování léků MeSH
- prekurzory léčiv chemická syntéza farmakologie MeSH
- psi MeSH
- techniky in vitro MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
We present here a structure-aided design of inhibitors targeting the active site as well as exosites of glutamate carboxypeptidase II (GCPII), a prostate cancer marker, preparing potent and selective inhibitors that are more than 1000-fold more active toward GCPII than its closest human homologue, glutamate carboxypeptidase III (GCPIII). Additionally, we demonstrate that the prepared inhibitor conjugate can be used for sensitive and selective imaging of GCPII in mammalian cells.
- MeSH
- glutamátkarboxypeptidasa II antagonisté a inhibitory chemie metabolismus MeSH
- HEK293 buňky účinky léků MeSH
- inhibitory enzymů chemie metabolismus farmakologie MeSH
- konformace proteinů MeSH
- lidé MeSH
- močovina chemie MeSH
- molekulární struktura MeSH
- preklinické hodnocení léčiv metody MeSH
- racionální návrh léčiv MeSH
- techniky syntetické chemie MeSH
- vazebná místa MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH