Kunitomo Adachi

Design, synthesis, and structure-activity relationships of 2-substituted-2-amino-1,3-propanediols: Discovery of a novel immunosuppressant, FTY720

FTY720 (2-amino-2-[2-(4-octylphenyl)ethyl]-1,3-propanediol hydrochloride), a novel synthetic immunosuppressant led by modification of ISP-I (myriocin, thermozymocidin) displayed potent immunosuppressive activity both in vitro and in vivo.

Simple compounds, 2-alkyl-2-amino-1,3-propanediols have potent immunosuppressive activity

Abstract ISP-I (myriocin, thermozymocidin) was structurally simplified to give 2-amino-2-alkyl-1,3-propanediols that were also potent immunosuppressants. Among the series, 2-amino-2-pentadecyl-1,3-propanediol most actively prolonged rat skin allograft survival and was more effective than ciclosporin.

Synthesis and biological evaluation of 2,2-disubstituted 2-aminoethanols: analogues of FTY720

Desymmerization of symmetric FTY720 by substitution of different alkyl groups for one of the prochiral hydroxymethyl groups was performed. The size of the alkyl groups and the absolute configuration at quaternary carbon were important on immunosuppressive activity.

Synthetic studies on biologically active natural products by a chemicoenzymatic approach: Enantioselective synthesis of C- and N-nucleosides, showdomycin, 6-azapseudouridine and cordycepin

Abstract An efficient synthesis of C- and N-nucleosides has been developed in an enantioselective and stereocontrolled manner starting from Diels-Alder adduct of furan and dimethyl acetylenedicarboxylate by chemicoenzymatic strategy. The symmetric unsaturated dimethyl esters 2 and 3 were almost quantitatively hydrolysed with pig liver esterase to yield half-esters 4 and 5 with reasonably high optical yields. Decarboxylative ozonolysis of the chiral half-esters 4 followed by chemical transformation afforded methyl L -riboside 12, but after the enantiomer conversion (4 to 13 and 5 to 28) the methyl D -riboside (17), ( + )-showdomycin (22), and ( − )-6-azapseudouridine (27), were obtained from 13, and ( − )-cordycepin (32) was obtained from 28.

FTY720 Story. Its Discovery and the Following Accelerated Development of Sphingosine 1-Phosphate Receptor Agonists as Immunomodulators Based on Reverse Pharmacology

The acid-base dissociation constant (pKa) of a drug is a key physicochemical parameter influencing many biopharmaceutical characteristics. While this has been well established, the overall proportion of non-ionizable and ionizable compounds for drug-like substances is not well known. Even less well known is the overall distribution of acid and base pKa values. The current study has reviewed the literature with regard to both the proportion of ionizable substances and pKa distributions. Further to this a set of 582 drugs with associated pKa data was thoroughly examined to provide a representative set of observations. This was further enhanced by delineating the compounds into CNS and non-CNS drugs to investigate where differences exist. Interestingly, the distribution of pKa values for single acids differed remarkably between CNS and non-CNS substances with only one CNS compound having an acid pKa below 6.1. The distribution of basic substances in the CNS set also showed a marked cut off with no compounds ...Fingolimod (FTY720) is the first of a novel class: sphingosine 1-phosphate (S1P) receptor modulator and is currently in phase 3 clinical trials for multiple sclerosis (MS). FTY720 was first synthesized in 1992 by chemical modification of an immunosuppressive natural product, ISP-I (myriocin). ISP-I was isolated from the culture broth of Isaria sinclairii, a type of vegetative wasp that was an ‘eternal youth’ nostrum in traditional Chinese medicine. ISP-I is an amino acid having three successive asymmetric centers and some functionalities. We simplified the structure drastically to find a nonchiral symmetric 2-substitued-2-aminopropane-1,3-diol framework for an in vivo immunosuppressive activity (inhibition of rat skin allograft rejection test or prolonging effect on rat skin allograft survival) and finally discovered FTY720. During the course of the lead optimization process, we encountered an unexpected dramatic change of the mechanism of action with an in vivo output unchanged. Since it proved that FTY720 did not inhibit serine palmitoyltransferase that is the target enzyme of ISP-I, reverse pharmacological approaches have been preformed to elucidate that FTY720 is mainly phosphorylated by sphingosine kinease 2 in vivo and the phosphorylated drug acts as a potent agonist of four of the five G protein coupled receptors for S1P: S1P1, S1P3, S1P4 and S1P5. Evidence has accumulated that immunomodulation by FTY720-P is based on agonism at the S1P1 receptor. Medicinal chemistry targeting S1P1 receptor agonists is currently in progress. The FTY720 story provides a methodology where in vivo screens rather than in vitro screens play important roles in the lead optimization. Unlike recent drug discovery methodologies, such a strategy as adopted by the FTY720 program would more likely meet serendipity.Aggressive carcinomas ferment glucose to lactate even in the presence of oxygen. This particular metabolism, termed aerobic glycolysis, the glycolytic phenotype, or the Warburg effect, was discovered by Nobel laureate Otto Warburg in the 1920s. Since these times, controversial discussions about the relevance of the fermentation of glucose by tumours took place; however, a majority of cancer researchers considered the Warburg effect as a non-causative epiphenomenon. Recent research demonstrated, that several common oncogenic events favour the expression of the glycolytic phenotype. Moreover, a suppression of the phenotypic features by either substrate limitation, pharmacological intervention, or genetic manipulation was found to mediate potent tumour-suppressive effects. The discovery of the transketolase-like 1 (TKTL1) enzyme in aggressive cancers may deliver a missing link in the interpretation of the Warburg effect. TKTL1-activity could be the basis for a rapid fermentation of glucose in aggressive carcinoma cells via the pentose phosphate pathway, which leads to matrix acidification, invasive growth, and ultimately metastasis. TKTL1 expression in certain non-cancerous tissues correlates with aerobic formation of lactate and rapid fermentation of glucose, which may be required for the prevention of advanced glycation end products and the suppression of reactive oxygen species. There is evidence, that the activity of this enzyme and the Warburg effect can be both protective or destructive for the organism. These results place glucose metabolism to the centre of pathogenesis of several civilisation related diseases and raise concerns about the high glycaemic index of various food components commonly consumed in western diets.Photodynamic therapy (PDT) is a clinical treatment that combines the effects of visible light irradiation with subsequent biochemical events that arise from the presence of a photosensitising drug (possessing no dark toxicity) to cause destruction of selected cells. Today, the most common agent used in dermatological PDT is 5-aminolevulinic acid (ALA). As a result of its hydrophilic character, ALA penetrates skin lesions poorly when applied topically. Its systemic bioavailability is limited and it is known to cause significant side effects when given orally or intravenously. Numerous chemical derivatives of ALA have been synthesised with the aims of either improving topical penetration or enhancing systemic bioavailability, while reducing side effects. In vitro cell culture experiments with ALA derivatives have yielded promising results. However, if ALA derivatives are to demonstrate meaningful clinical benefits, a rational approach to topical formulation design is required, along with a systematic study aimed at uncovering the true potential of ALA derivatives in photodynamic therapy. With respect to systemic ALA delivery, more study is required in the developing area of ALA-containing dendrons and dendrimers.Pseudomonas tolaasii, P. reactans and Burkholderia gladioli pv. agaricicola, are responsible of diseases on some species of cultivated mushrooms. The main bioactive metabolites produced by both Pseudomonas strains are the lipodepsipeptides (LDPs) tolaasin I and II and the so called White Line Inducing Principle (WLIP), respectively, LDPs which have been extensively studied for their role in the disease process and for their biological properties. In particular, their antimicrobial activity and the alteration of biological and model membranes (red blood cell and liposomes) was established. In the case of tolaasin I interaction with membranes was also related to the tridimensional structure in solution as determined by NMR combined with molecular dynamic calculation techniques. Recently, five news minor tolaasins, tolaasins A–E, were isolated from the culture filtrates of P. tolaasii and their chemical structure was determined by extensive use of NMR and MS spectroscopy. Furthermore, their antimicrobial activity was evaluated on target micro-organisms (fungi—including the cultivated mushrooms Agaricus bisporus, Lentinus edodes, and Pleurotus spp.—chromista, yeast and bacteria). The Gram positive bacteria resulted the most sensible and a significant structure-activity relationships was apparent. The isolation and structure determination of bioactive metabolites produced by B. gladioli pv. agaricicola are still in progress but preliminary results indicate their peptide nature. Furthermore, the exopolysaccharide (EPS) from the culture filtrates of B. gladioli pv. agaricicola, as well as the O-chain and lipid A, from the lipopolysaccharide (LPS) of the three bacteria, were isolated and the structures determined.The heterogeneity of symptoms and disease progression observed in synucleinopathies, of which Parkinson’s disease (PD) is the most common representative, poses large problems for the discovery of novel therapeutics. The molecular basis for pathology is currently unclear, both in familial and in sporadic cases. While the therapeutic effects of L-DOPA and dopamine receptor agonists constitute good options for symptomatic treatment in PD, the development of neuroprotective and/or neurorestorative treatments for PD and other synucleinopathies faces significant challenges due to the poor knowledge of the putative targets. Recent experimental evidence strongly suggests a central role for neurotoxic α-synuclein oligomeric species in neurodegeneration. The events leading to protein oligomerization, as well as the oligomeric species themselves, are likely amenable to modulation by small molecules, which are beginning to emerge in high throughput compound screens in a variety of model organisms. The therapeutic potential of small molecule modulators of oligomer formation demands further exploration and validation in cellular and animal disease models in order to accelerate human drug development.Introduction A large number of antiepileptic drugs (AEDs) are available today, but they may not be satisfactory regarding clinical efficacy, tolerance, toxicity or pharmacokinetic properties. The purpose of this review is to focus upon the rationale behind the chemical modifications of several recently marketed AEDs or drugs in development and to categorize them according to the main purposes for the improvements: better efficacy or tolerability accompanied by improved pharmacokinetic properties. Material and Method AEDs that have been chemically modified to new derivatives during the last years are reviewed based on recent publications and PubMed-searches. Results and Discussion Improvement in pharmacokinetic parameters may affect both tolerability and efficacy. Modifications to improve tolerability include various valproate analogues, divided into aliphatic amides, cyclic derivatives or amino acid conjugates. Furthermore, there are the carbamazepine analogues oxcarbazepine and eslicarbazepine, the felbamate analogues fluorofelbamate and carisbamate (RWJ 33369), and the lamotrigine analogue JZP-4. The levetiracetam analogues brivaracetam and seletracetam and the derivatives of gabapentin, pregabalin and XP13512, have improved selectivity compared to their parent compounds. Other new drugs have new mechanisms of action related to GABA and glutamate receptors; the glutamate antagonists like topiramate (talampanel and NS-1209), and GABAA receptor agonists, benzodiazepine or progesterone analogues (ELB-139 and ganaxolone). Conclusion Further challenges for development of new AEDs include investigations of target molecules affected by pathophysiological processes and detailed structure-activity relationships with focus on stereoselectivity. These potential drugs may become of importance in future drug therapy in epilepsy and other CNS disorders.Lead optimization using drug metabolism and pharmacokinetics (DMPK) parameters has become one of the primary focuses of research organizations involved in drug discovery in the last decade. Using a combination of rapid in vivo and in vitro DMPK screening procedures on a large array of compounds during the lead optimization process has resulted in development of compounds that have acceptable DMPK properties. In this review, we present a general screening paradigm that is currently being used as part of drug discovery at Schering-Plough and we describe a case study using the Hepatitis C Virus (HCV) protease inhibitor program as an example. By using the DMPK optimization tools, a potent HCV protease inhibitor, SCH 503034, was selected for development as a candidate drug.Integrins have been reported to mediate cell survival, proliferation, differentiation, and migration programs. For this reason, the past few years have seen an increased interest in the implications of integrin receptors in cancer biology and tumor cell aggression. This review considers the potential role of integrins in cancer and also addresses why integrins are present attractive targets for drug design. It discusses of the several properties of the integrin-based chemotherapeutic agents currently under consideration clinically and provides an insight into cancer drug development using integrin as a target.

Discovery of fingolimod, the sphingosine 1-phosphate receptor modulator and its application for the therapy of multiple sclerosis

Fingolimod (FTY720) is a first-in-class, orally active, sphingosine 1-phosphate (S1P)-receptor modulator with a structure closely related to sphingosine. The compound was discovered by chemical modification of a natural product, myriocin. Phosphorylated form of FTY720 acts as a functional antagonist at S1P receptor type 1 (S1P(1)), inhibits lymphocyte egress from secondary lymphoid organs and shows immunomodulating effects. Phase III studies in multiple sclerosis demonstrated that oral FTY720 had superior efficacy compared with intramuscular IFN-β1a (AVONEX(®)) with regard to reducing the rate of relapse and the number of inflammatory lesions in the CNS. FTY720 has been approved as a new therapeutic drug for multiple sclerosis in more than 50 countries, including the USA, Japan and some of those in the EU.

A novel anti-rheumatic drug suppresses tumor necrosis factor-α and augments interleukin-10 in adjuvant arthritic rats

Tumor necrosis factor-alpha (TNF-alpha) plays an important role in the pathology of rheumatoid arthritis. When N-[1-(4-¿[4-(pyrimidin-2-yl)piperazin-1-yl]methyl¿phenyl)cycloprop yl] acetamide (Y-39041) (3-30 mg/kg) was orally administered to rats with established arthritis from day 15 to day 20, hindpaw volume was significantly reduced. This inhibitory activity of Y-39041 was kept up after administration was stopped. On day 17 Y-39041 suppressed lipopolysaccharide-induced TNF-alpha and interleukin-6 production in serum at doses of 3-30 mg/kg, and augmented interleukin-10 production at doses of 10 and 30 mg/kg. The finding that Y-39041 suppresses TNF-alpha and interleukin-6 production and augments interleukin-10 production could be beneficial in the therapy of chronic inflammatory diseases.

A novel dual regulator of tumor necrosis factor-α and interleukin-10 protects mice from endotoxin-induced shock

A pyrimidylpiperazine derivative, N-[1-(4-¿[4-(pyrimidin-2-yl)piperazin-1-yl]methyl¿phenyl)cycloprop yl] acetamide (Y-39041), is a dual cytokine regulator of tumor necrosis factor (TNF)-alpha and interleukin-10 production. Lipopolysaccharide-induced TNF-alpha release in BALB/c mice was inhibited by the oral treatment with the compound at 10-100 mg/kg (about 80% suppression) while interleukin-10 release was augmented (about 10-fold increase at 30 mg/kg). In addition, Y-39041 (30 mg/kg, p.o.) completely protected mice from lipopolysaccharide-induced death by the treatment before and after lipopolysaccharide injection. The finding that Y-39041 suppresses TNF-alpha production and stimulates interleukin-10 production at the same time provides new insights for the treatment of septic shock, rheumatoid arthritis and Crohns diseases.

Novel DMARDs on the basis of a new concept of dual cytokine regulation, TNF-α suppression and IL-10 augmentation

A series of arylpiperazine derivatives was synthesized to obtain agents showing apparent therapeutic effects in a chronic inflammatory animal model, starting from a lead possessing potent dual cytokine regulatory activity in vivo. We found a pyrimidylpiperazine derivative 17c showing the dual regulatory activity and an excellent therapeutic effect in an adjuvant-induced arthritis model.

Sphingosine 1-Phosphate Receptor 1 as a Useful Target for Treatment of Multiple Sclerosis

Sphingosine 1-phosphate (S1P), a lysophospholipid mediator, is generated from sphingosine by sphingosine kinases and binds five known cell surface receptors. S1P receptor 1 (S1P1) plays an essential role in lymphocyte egress from secondary lymphoid organs (SLO), as evinced by the inability of lymphocytes to exit from the SLO in mice lacking lymphocytic S1P1. Fingolimod hydrochloride (FTY720) is a first-in-class, orally active, S1P receptor modulator with a structure closely related to sphingosine. FTY720 was first synthesized by chemical modification of a natural product, myriocin. FTY720 is effectively converted to an active metabolite, FTY720 phosphate (FTY720-P) by sphingosine kinases. FTY720-P shows high affinity to 4 of the S1P receptors (S1P1, S1P3, S1P4, and S1P5). In particular, FTY720-P strongly induces internalization and degradation of S1P1, inhibits S1P responsiveness of lymphocytes in the SLO, and acts as a functional antagonist at lymphocytic S1P1. Consequently, FTY720 inhibits S1P1-dependent lymphocyte egress from the SLO to decrease circulation of lymphocytes including autoreactive Th17 cells and is highly effective in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Because FTY720 shows a superior efficacy in relapsing remitting MS patients compared to intramuscular interferon-β-1a (Avonex®), S1P1 is presumed to be a useful target for the therapy of MS.