The efficiency of protein chemical modification on tyrosine residues with N-methylluminol derivatives was drastically improved by using horseradish peroxidase (HRP). In the previous method, based on ...the use of hemin and H
O
, oxidative side reactions such as cysteine oxidation were problematic for functionalization of proteins selectively on tyrosine residues. Oxidative activation of N-methylluminol derivatives with a minimum amount of H
O
prevented the occurrence of oxidative side reactions under HRP-catalyzed conditions. As probes for HRP-catalyzed protein modification, N-methylluminol derivatives showed much higher efficiency than tyramide without inducing oligomerization of probe molecules. Tyrosine modification also proceeded in the presence of β-nicotinamide adenine dinucleotide (NADH, H
O
-free conditions).
A direct functionalization of unsubstituted isoxazole (1) was achieved by generation of 4‐isoxazolyl anion species (3). An efficient 4‐iodination of isoxazole and halogen–metal exchange reaction ...using a turbo Grignard reagent (iPrMgCl⋅ LiCl) were essential for the generation of 3, which reacted with various electrophiles to give 4‐functionalized isoxazoles in good to high yields. Isoxazolyl boronate, boronic acid, and stannane were also synthesized as useful building blocks from 1. The current methods enabled us to synthesize multi‐functionalized isoxazoles by introducing each substituent into the desired positions. Furthermore, total synthesis of triumferol, which was isolated from Triumfetta rhomboidea, was achieved from 1 in only three steps.
Taking position: Preparation of a 4‐isoxazolyl anion species from 4‐iodoisoxazole using iPrMgCl⋅LiCl enabled introduction of a wide variety of functional groups into the 4‐position of the isoxazole ring in good to excellent yields. This approach provides various isoxazolyl metal species which can be used for multifunctionalization of isoxazoles. The step‐by‐step synthesis of 3,4,5‐trisubstituted isoxazoles was achieved by using the this 4‐isoxazolyl anion method.
Serum albumin has attracted significant attention as a drug‐delivery carrier to tumor tissue. We previously reported boron neutron capture therapy (BNCT), an effective method that uses ...maleimide‐functionalized closo‐dodecaborate albumin conjugates (MID‐ACs). MID can form covalent bonds with the free thiol group of Cys34 and with lysine residues in albumin. In this study, we synthesized tyrosyl‐radical‐trapping‐moiety‐functionalized closo‐dodecaborates (TRT‐DBs), which were expected to form covalent bonds with tyrosine residues. N′‐Acetyl‐N,N‐dimethylphenylenediamine was chosen as the TRT moiety to bind to closo‐dodecaborate through an amide linker (TRT‐DB 1) and an ammonium linker (TRT‐DB 2). TRT‐DB 1 more efficiently conjugated to bovine serum albumin (BSA) than 2: approximately 2.4 molecules of 1 were bound to each BSA if BSA (10 µm) was treated with 1 (1 mm) in the presence of Ru(bpy)3 (1 mm; bpy = 2,2′‐bipyridyl) and ammonium persulfate (1 mm) under light irradiation for 1 min. Furthermore, double modification of BSA with 1 and MID increased the boron density in BSA for efficient boron delivery to tumors. Western blot analysis using the anti‐B12 cluster antibody revealed that closo‐dodecaborate‐conjugated BSAs were taken up by colon 26 cells.
Tyrosyl‐radical‐trapping‐moiety‐functionalized closo‐dodecaborate (TRT‐DB) 1 is conjugated to bovine serum albumin (BSA). Approximately 2.4 molecules of 1 are bound to each BSA if BSA (10 µm) is treated with 1 (1 mm) in the presence of Ru(bpy)3 (1 mm; bpy = 2,2′‐bipyridyl) and ammonium persulfate (APS; 1 mm) under light irradiation for 1 min.
A total of 42 trisubstituted carboranes categorised into five scaffolds were systematically designed and synthesized by exploiting the different reactivities of the twelve vertices of o-, m-, and ...p-carboranes to cover all directions in chemical space. Significant inhibitors of hypoxia inducible factor transcriptional activitay were mainly observed among scaffold V compounds (e.g., Vi-m, and Vo), whereas anti-rabies virus activity was observed among scaffold V (Va-h), scaffold II (IIb-g), and scaffold IV (IVb) compounds. The pharmacophore model predicted from compounds with scaffold V, which exhibited significant anti-rabies virus activity, agreed well with compounds IIb-g with scaffold II and compound IVb with scaffold IV. Normalized principal moment of inertia analysis indicated that carboranes with scaffolds I-V cover all regions in the chemical space. Furthermore, the first compounds shown to stimulate the proliferation of the rabies virus were found among scaffold V carboranes.
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Chiral sp3-rich bicyclo3.3.1nonane scaffolds 10–12 were synthesized as single diastereomers from aldehyde 9, which was prepared from 4,4-dimethoxycyclohexa-2,5-dienone through a ...copper-catalyzed enantioselective reduction. Three different types of intramolecular addition reactions were studied: SmI2-mediated reductive cyclization, base-promoted aldol reaction, and one-pot Mannich reaction. We succeeded in introducing three side-chains to scaffold 11 and construct an sp3-rich compound library in both enantiomeric variants by simply changing the chirality of the ligands. The biological evaluation revealed that all synthesized compounds exhibited a concentration-dependent inhibition of hypoxia-inducible factor-1 (HIF-1) transcriptional activity, with IC50 values in the range of 17.2–31.7 µM, whereas their effects on cell viability were varied (IC50 = 3.5 to > 100 µM). The most active compound 16f inhibits the accumulation of HIF-1α protein and mRNA in hypoxia, indicating that it has a mechanism of action distinctly different from other known compounds bearing the common bicyclo3.3.1nonane skeleton.
Epstein-Barr virus (EBV) is involved in the pathogenesis of various lymphomas and carcinomas, whereas Kaposi's sarcoma-associated herpesvirus (KSHV) participates in the pathogenesis of endothelial ...sarcoma and lymphomas. EBV and KSHV are responsible for 120,000 and 44,000 annual new cases of cancer, respectively. Despite this clinical importance, no chemotherapies or vaccines have been developed for virus-specific treatment and prevention of these viruses. Humans are the only natural host for both EBV and KSHV, and only a limited species of laboratory animals are susceptible to their experimental infection; this strict host tropism has hampered the development of their animal models and thereby impeded the study of therapeutic and prophylactic strategies. To overcome this difficulty, three main approaches have been used to develop animal models for human gammaherpesvirus infections. The first is experimental infection of laboratory animals with EBV or KSHV. New-world non-human primates (NHPs) and rabbits have been mainly used in this approach. The second is experimental infection of laboratory animals with their own inherent gammaherpesviruses. NHPs and mice have been mainly used here. The third, a recent trend, employs experimental infection of EBV or KSHV or both to immunodeficient mice reconstituted with human immune system components (humanized mice). This review will discuss how these three approaches have been used to reproduce human clinical conditions associated with gammaherpesviruses and to analyze the mechanisms of their pathogenesis.
To describe the longterm safety and efficacy profile of tofacitinib in patients with moderate to severe active rheumatoid arthritis (RA).
Data were pooled from 2 open-label studies (NCT00413699, ...NCT00661661) involving patients who had participated in qualifying phase I, II, or III index studies of tofacitinib. Safety data included over 60 months of observation; efficacy data are reported up to Month 48. Treatment was initiated with tofacitinib 5 or 10 mg twice daily. Primary endpoints were adverse events (AE) and laboratory safety data. Secondary endpoints included American College of Rheumatology (ACR) response rates, and Disease Activity Score (28 joints) (DAS28)-4erythrocyte sedimentation rate (ESR) and Health Assessment Questionnaire-Disability Index (HAQ-DI) assessments.
Overall, 4102 patients were treated for 5963 patient-years; mean (maximum) treatment duration was 531 (1844) days; 20.8% of patients discontinued treatment over 60 months. The most common AE were nasopharyngitis (12.7%) and upper respiratory tract infection (10.5%). Serious AE were reported in 15.4% of patients with an exposure-estimated incidence rate of 11.1 events/100 patient-years. Serious infections were reported in 4.5% of patients with an exposure-estimated incidence rate of 3.1 events/100 patient-years (95% CI: 2.66-3.55). Mean values for laboratory variables were stable over time and consistent with phase II and III studies. Persistent efficacy was demonstrated through Month 48, as measured by ACR response rate (ACR20/50/70) DAS28-4-ESR, and HAQ-DI. Safety and efficacy were similar for patients receiving tofacitinib as monotherapy or with background nonbiologic disease-modifying antirheumatic drugs.
Tofacitinib demonstrated consistent safety and persistent efficacy over 48 months in patients with RA.
Niemann-Pick disease type C (NPC) is caused by a loss of function of either NPC1 or NPC2 protein, resulting in the accumulation of unesterified, free-cholesterol (free-C) in cells/tissues and thus ...leading to cell/tissue damage. In the brain of patients/animals with NPC, as a consequence of the accumulation of free-C in late endosomes/lysosomes (LE/LY) in cells, multiple lipids including complex sphingolipids are accumulated, and almost all patients/animals ultimately develop progressive/fatal neurodegeneration. Several reagents that are considered to act in the brain show beneficial effects on NPC-model animals. In the present study, we investigated the effects of antiepileptic drugs, such as primidone and valproic acid, on the accumulation of free-C in NPC1-null CHO cells and NPC1* fibroblasts, human fibroblasts established from a patient with NPC1 mutation. Like valproic acid, treatment with primidone reduced free-C levels in LE/LY in NPC1-null/mutant cells. Down-regulation of cholesterol ester levels in NPC1-null cells and up-regulation of HMG-CoA reductase and low-density lipoprotein receptor mRNA levels in NPC1* cells were partially recovered by primidone treatment. Thus, primidone was suggested to enhance free-C trafficking from LE/LY to endoplasmic reticulum in NPC1-null/mutant cells. In NPC1-null mice, oral application of primidone (100 mg/kg/day) extended lifespan by approximately 5 days, although the first days showing ataxia, a typical symptom of neuromotor dysfunction, were not affected. Our findings suggest the potential of primidone for the treatment of NPC.
•Primidone reduced free-cholesterol (free-C) levels in NPC1-null cells.•Primidone enhanced free-C trafficking from LE/LY to ER in NPC1-null cells.•Oral treatment with primidone extended lifespan in NPC1-null mice.
Sphingosine kinases (SphKs) and ceramide kinase (CerK) phosphorylate sphingosine to sphingosine‐1‐phosphate (S1P) and ceramide to ceramide‐1‐phosphate (C1P), respectively. S1P and C1P are bioactive ...lipids that regulate cell fate/function and human health/diseases. The translocation and activity of SphK1 are regulated by its phosphorylation of Ser
225 and by anionic lipids such as phosphatidic acid and phosphatidylserine. However, the roles of another anionic lipid C1P on SphK1 functions have not yet been elucidated, thus, we here investigated the regulation of SphK1 by CerK/C1P. C1P concentration dependently bound with and activated recombinant human SphK1. The inhibition of CerK reduced the phorbol 12‐myristate 13‐acetate‐induced translocation of SphK1 to the plasma membrane (PM) and activation of the enzyme in membrane fractions of cells. A treatment with C1P translocated wild‐type SphK1, but not the SphK1‐S225A mutant, to the PM without affecting phosphorylation signaling. A cationic RxRH sequence is proposed to be a C1P‐binding motif in α‐type cytosolic phospholipase A
2 and tumor necrosis factor α‐converting enzyme. The mutation of four cationic amino acids to Ala in the 56‐RRNHAR‐61 domain in SphK1 reduced the phorbol 12‐myristate 13‐acetate‐ and C1P‐induced translocation of SphK1 to the PM, however, the capacity of C1P to bind with and activate SphK1 was not affected by this mutation. In conclusion, C1P modulates SphK1 functions by interacting with multiple sites in SphK1.
Sphingosine kinases (SphKs) and ceramide kinase (CerK) phosphorylate sphingosine to sphingosine‐1‐phosphate (S1P) and ceramide to ceramide‐1‐phosphate (C1P), respectively. In the current study, we found that C1P modulates SphK1 functions by interacting with multiple sites in SphK1.
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