Multicenter evaluation of use of dried blood spot compared to conventional plasma in measurements of globotriaosylsphingosine (LysoGb3) concentration in 104 Fabry patients.

Abstract Objectives Fabry disease (FD) is an X-linked lysosomal storage disorder, resulting from a deficiency of the enzyme α-galactosidase A, responsible for breaking down glycolipids such as globotriaosylceramide and its deacylated derivative, globotriaosylsphingosine (LysoGb3). Here, we compare the levels of LysoGb3 in dried blood spots (DBS) and plasma in patients with classic and late-onset phenotypes. Methods LysoGb3 measurements were performed in 104 FD patients, 39 males and 65 females. Venous blood was collected. A portion was spotted onto filter paper and another portion separated to obtain plasma. The LysoGb3 concentrations in DBS and plasma were determined by highly sensitive electrospray ionization liquid chromatography tandem mass spectrometry. Agreement between different matrices was assessed using linear regression and Bland Altman analysis. Results The method on DBS was validated by evaluating its precision, accuracy, matrix effect, recovery, and stability. The analytical performances were verified by comparison of a total of 104 paired DBS and plasma samples from as many FD patients (representing 46 GLA variants). There was a strong correlation between plasma and the corresponding DBS LysoGb3 concentrations, with few exceptions. Discrepancies were observed in anemic patients with typically low hematocrit levels compared to the normal range. Conclusions The method proved to be efficient for the rapid analysis of LysoGb3. DBS provides a convenient, sensitive, and reproducible method for measuring LysoGb3 levels for diagnosis, initial phenotypic assignment, and therapeutic monitoring in patients with FD

Nervous system and Fabry disease, from symptoms to diagnosis: damage evaluation and follow-up in adult patients, enzyme replacement, and support therapy

The X-linked genetic Fabry disease causes multiorgan lesions due to intracellular storage of the substrate globotriaosylceramide. Neurological involvement ranges from painful, small fiber neuropathy to cerebrovascular disorders to multifocal aggressive forms. Disease identification through proper differential diagnosis and timely assessment of organ damage should guide a careful treatment planning. Mainstay treatment, include enzyme replacement and support therapy. Neurologists have a pivotal role in early instrumental and clinical detection of organ damage. A panel of experts has developed a set of consensus recommendations to guide the approach of neurologists to Fabry disease

Synthesis of (E)-8-(3-Chlorostyryl)caffeine Analogues Leading to 9-Deazaxanthine Derivatives as Dual A2AAntagonists/MAO-B Inhibitors

A systematic modification of the caffeinyl core and substituents of the reference compound (E)-8-(3-chlorostyryl)caffeine led to the 9-deazaxanthine derivative (E)-6-(4-chlorostyryl)-1,3,5,-trimethyl-1H-pyrrolo[3,2-d]pyrimidine-2,4-(3H,5H)-dione (17f), which acts as a dual human A2a antagonist/MAO-B inhibitor (Ki(A2A) = 260 nM; IC50(MAO-B) = 200 nM; IC50(MAO-A) = 10 μM) and dose dependently counteracts haloperidol-induced catalepsy in mice from 30 mg/kg by the oral route. The compound is the best balanced A2A antagonist/MAO-B inhibitor reported to date, and it could be considered as a new lead in the field of anti-Parkinson’s agents. A number of analogues of 17f were synthesized and qualitative SARs are discussed. Two analogues of 17f, namely 18b and 19a, inhibit MAO-B with IC50 of 68 and 48 nM, respectively, being 5–7-fold more potent than the prototypical MAO-B inhibitor deprenyl (IC50 = 334 nM)

Identification of a novel arylpiperazine scaffold for fatty acid amide hydrolase inhibition with improved drug disposition properties

We herein describe the systematic approach used to develop new analogues of compound 2, recently identified as a potent and selective fatty acid amide hydrolase (FAAH) inhibitor. Aiming at identifying new scaffolds endowed with improved drug disposition properties with respect to the phenylpyrrole-based lead, we subjected it to two different structural modification strategies. This process allowed the identification of derivatives 4b and 5c as potent, reversible and non-competitive FAAH inhibitors

Synthesis and Biological Evaluation of Metabolites of 2‑<i>n</i>‑Butyl-9-methyl-8-[1,2,3]triazol-2-yl‑9<i>H</i>‑purin-6-ylamine (ST1535), A Potent Antagonist of the A_2A Adenosine Receptor for the Treatment of Parkinson’s Disease

The synthesis and preliminary in vitro evaluation of five metabolites of the A_2A antagonist ST1535 (<b>1</b>) are reported. The metabolites, originating in vivo from enzymatic oxidation of the 2-butyl group of the parent compound, were synthesized from 6-chloro-2-iodo-9-methyl-9<i>H</i>-purine (<b>2</b>) by selective C–C bond formation via halogen/magnesium exchange reaction and/or palladium-catalyzed reactions. The metabolites behaved in vitro as antagonist ligands of cloned human A_2A receptor with affinities (<i>K</i>_i 7.5–53 nM) comparable to that of compound <b>1</b> (<i>K</i>_i 10.7 nM), thus showing that the long duration of action of <b>1</b> could be in part due to its metabolites. General behavior after oral administration in mice was also analyzed

Potent, Metabolically Stable 2-Alkyl-8-(2H-1,2,3-triazol-2-yl)-9H-adenines as Adenosine A2A Receptor Ligands

Inhibition of adenosine A2A receptors has been shown to elicit a therapeutic response in preclinical animal models of Parkinson's disease (PD). We previously identified the triazolo-9H-purine, ST1535, as a potent A2A R antagonist. Studies revealed that ST1535 is extensively hydroxylated at the ω-1 position of the butyl side chain. Here, we describe the synthesis and evaluation of derivatives in which the ω-1 position has been substituted (F, Me, OH) in order to block metabolism. The stability of the compounds was evaluated in human liver microsomes (HLM), and the affinity for A2A R was determined. Two compounds, (2-(3,3-dimethylbutyl)-9-methyl-8-(2H-1,2,3-triazol-2-yl)-9H-purin-6-amine (3 b) and 4-(6-amino-9-methyl-8-(2H-1,2,3-triazol-2-yl)-9H-purin-2-yl)-2-methylbutan-2-ol (3 c), exhibited good affinity against A2A R (Ki =0.4 nM and 2 nM, respectively) and high in vitro metabolic stability (89.5 % and 95.3 % recovery, respectively, after incubation with HLM for two hours)