Pdf rational drug design, synthesis and biological. Mycobacterial dihydrofolate reductase inhibitors identified. Dihydrofolate reductase inhibitors for use as antimicrobial. Trimethoprim and other nonclassical antifolates an. Dihydrofolate reductase inhibitors as potential drugs wiley online. Antifolates available as inhibitors of dhfrs contain the 2,4diamino1,3diaza pharmacophore. Formation acid, potent inhibitor dihydrofolate reductase. The present paper demonstrates that liver slices, when incubated with 14cfa, accumulate 10formyl fa. Theeffect ofthe antifolate inhibitor pyrimethamine wasassayedin duplicate after cultivating asynchronous parasites in. Design, synthesis and biological evaluation of 6substituted pyrrolo2,3 d pyrimidines as dihydrofolate reductase inhibitors and potential antiopportunistic infection agents. Inhibitors of multiple mutants of plasmodium falciparum. When the simulations were checked for the naphthyl group the same interactions were seen as that of pteridyl ring for the ligands 23, 24, and 25 of greatest interest. Dihydrofolate reductase inhibitors are an important class of drugs, as evidenced by their use as antibacterial, antimalarial, antifungal, and anticancer agents.
A dihydrofolate reductase inhibitor dhfr inhibitor is a molecule that inhibits the function of dihydrofolate reductase, and is a type of antifolate since folate is needed by rapidly dividing cells to make thymine, this effect may be used to therapeutic advantage. Dihydrofolate reductase as a therapeutic target federation of. Isoniazid has the potential to be this alternative drug. Cambridge, ma january 7, 2016 spero therapeutics, llc, a biopharmaceutical company founded to develop novel therapies for the treatment of bacterial infections, today announced it has entered into a license agreement with promiliad biopharma for access to its dihydrofolate reductase dhfr inhibitors that target grampositive and negative bacteria, fungi and protists. Screeningcharacterizing dihydrofolate reductase inhibitors iii. Dihydrofolate reductase thymidylate synthase 1071 figure 1 substrates and cofactors of dihydrofolate reductase dhfr dihydrofolate dhf and nicotinamide adenine dinucleotide phosphate nadp, respectively and. Inhibition of the enzyme dihydrofolate reductase dhfr depletes the available tetra hydrofolate and blocks the formation of thymidylate, purines, the amino. Dihydrofolate reductase dhfr was discovered in the late 1950s by investigators searching for folatedependent enzymes involved in 1carbon metabolism, with its already known application as anti. The manifestations of methotrexate toxicity depend of the route of administration, dose.
Designing dihydrofolate reductase inhibitors as xray. For example, methotrexate is used as cancer chemotherapy because it can prevent neoplastic cells from dividing. Cavallito jc, nichol ca, brenckman wd jr, deangelis rl, stickney dr, simmons ws, sigel cw 1978 lipid soluble inhibitors of dihydrofolate reductase. Dihydrofolate reductase dhfr inhibition assay the effects of novel tmp analogs 118 on the activity of recombinant human dhfr were determined by dihydrofolate reductase dhfr inhibition according to the reported. Folate inhibitors antagonize the synthesis of folic acid and are used for treating bacterial, fungal and protozoal infections. Pdf dihydrofolate reductase as a therapeutic target researchgate. Synthesis was achieved from 2,4diamino5methypyrrolo2,3dpyrimidine and substituted phenylthiols under modified conditions reported by gangjee et al. Wen, in handbook of neurooncology neuroimaging, 2008. Biosynthesis of tetrahydrobiopterin in the presence of. Design, synthesis, and biological evaluation of 2,4diamino5. Although there have been attempts to develop fungalspecific inhibitors of dihydrofolate reductase dhfr, the protein itself has not been unequivocally validated as essential for fungal growth or virulence. In cellular functions, dihydrofolate reductase dhfr is an enzyme that reduces 7,8 dihydrofolate dhf to 5,6,7,8tetrahydrofolate thf using nadph as electron donor. A ineffective inhibitors, b moderately effective inhibitors, and c highly effective inhibitors.
Approaches to soft drug analogues of dihydrofolate reductase. Jun 10, 2015 the human thymidylate synthase and dihydrofolate reductase catalyze two consecutive reactions in the folate metabolism pathway, and experiments have shown that they are very likely to bind in the same multi. Inhibitors of human dihydrofolate reductase 267 gamma carbonyl group of glu30 and 4 th amino group interacting with val 115 and ile7. A novel bicyclic 2,4diaminopyrimidine inhibitor of. Correlation between calculated energy and observed affinity, abstracts of papers, 189th acs national meeting, miami beach, fl, april 28may 3, washington, dc, abstr. The purpose of this study was to establish dihydrofolate reductase as a valid antifungal target. Sulfa and trimethoprimlike drugs antimetabolites acting. Receptorbased design of dihydrofolate reductase inhibitors. Components k247100 cap code part number dhfr assay buffer 35 ml nm k2471001 dhfr substrate 450 l red k2471002 dihydrofolate reductase 1 vial green k2471003 nadph methotrexate 10 mm 1 vial. Pdf dihydrofolate reductase dhfr was discovered in the late 1950s by investigators.
Compound 1 is a potent dihydrofolate reductase dhfr inhibitor k j 12 nm with excellent in vitro cell culture growth inhibition l1210, ic 50 29 nm. Mar 23, 2015 the two potent antitubercular compounds studied in this case, belonging to the tetrahydro1,3,5triazin2amine tht family, were predicted and confirmed to be an inhibitor of dihydrofolate reductase dhfr, a known essential mtb gene, and already clinically validated as a drug target. Methotrexate is the dhfr inhibitor used most often in a clinical setting as an anti. Selective inhibitors of bacterial dihydrofolate reductase. Dihydrofolate reductase from the amethopterinresistant mutant strain a of streptococcus faecium var. Rational design of novel allosteric dihydrofolate reductase. Article synthesis, biological activity, and molecular. Most reported inhibitors for dhfrs are structural analogues of its substrate dihydrofolate and act by competitively displacing the latter.
Trimethoprim and other nonclassical antifolates an excellent. Examples of recent studies in the development of new dhfr inhibitors i. Inhibiting dihydrofolate reductase as a treatment for. These compounds are potent dihydrofolate reductase dhfr inhibitors which are useful as antibacterial, antiprotozoal and. However, the therapeutic efficacy tends to be indistinctive. The spread of plasmid borne resistance enzymes in clinical staphylococcus aureus isolates is rendering trimethoprim and iclaprim, both inhibitors of dihydrofolate reductase dhfr, ineffective.
One major reason for this is amplification of the dihydrofolate reductase dhfr gene, which causes an increase in dhfr activity and attenuation of the treatment effect. Spero therapeutics licenses dihydrofolate reductase. Dihydrofolate reductase dhfr, a key enzyme of the folate pathway, plays an important role in cell growth and proliferation4,5 and is found in many infective microorganisms including mtb. B second generation dhfr inhibitors in clinical trail. Structures of eight dhfr inhibitors tested in this study and grouped according to their inhibitory activity.
Efficacy of various dihydrofolate reductase dhfr inhibitors of streptococcus suis dhfr ssdhfr and s. Publications on dihydrofolate reductase dhfr inhibitors. Durans was reacted with idocacetate according to three procedures. Keywords antibacterial, carbonic anhydrase, dihydrofolate reductase, dihydropteroate synthase, sulfa drug, trimethoprim history received 21 february 20 revised 15 march 20. Cloning, expression, and characterization of mycobacterium.
The production of tetrahydrofolate thf allows for the synthesis of dna that is needed for bacterial cell tb growth. A safer treatment for toxoplasmosis would be achieved by improving the selectivity and potency of dihydrofolate reductase dhfr inhibitors, such as pyrimethamine 1, for toxoplasma gondii dhfr tgdhfr relative to human dhfr hdhfr. Request pdf dihydrofolate reductase inhibitors as antibacterial agents although only a few dhfr inhibitors have progressed as antibiotics to the market there is much renewed interest in the. Mar 11, 2009 the extended aromatic system was designed to better interact with a phenylalanine residue phe69 of dihydrofolate reductase from the opportunistic pathogen pneumocystis carinii to afford potent and selective inhibitors of pneumocystis carinii dihydrofolate reductase. Three crystal structures of ternary complexes of m. Interactions between inhibitors of dihydrofolate reductase. The identity of this compoundwasnot suspected initially because of its anomalous behavior on sephadex g15. While the functional dihydrofolate reductase gene has been mapped to chromosome 5, multiple intronless processed pseudogenes or dihydrofolate reductase like genes have. Inhibitors of dhfr are successful agents for the treatment of various infectious diseases as well as for cance r methotrexate mtx.
Selective inhibitors of dihydrofolate reductase figure 11. Structureactivity relationships of dihydrofolated reductase inhibitors. Dihydrofolate reductase dhfr inhibitors are an important class of thera. It is potentiated by sulfonamides and the trimethoprimsulfamethoxazole combination is the form most often used for tuberculosis patients. Thus far, all of the clinically useful drugs of this class have been inhibitors of dihydrofolate reductase dhfr, a key enzyme in the synthesis of. Approaches to soft drug analogues of dihydrofolate. A group of arylzalkoxy5benzylpyrimidines wherein z is oxy, thio, imino, carbonyl, carbamoyl, sulfonyl, sulfinyl or sulfamoyl has been prepared from 2,4diamino5benzylpyrimidine via alkylation with either an arylzalkyl halide or a substituted glycidyl ether. The natural process shown to the right, models the normal activity of dhfr in a bacterial cell. Here, we report the crystal structure of dihydrofolate reductase from mycobacterium tuberculosis, a human pathogen responsible for the death of millions of human beings per year. Pdf dihydrofolate reductase dhfr was discovered in the late 1950s by investigators searching for folatedependent enzymes involved in. Rational drug design, synthesis and biological evaluation.
Therefore, it is desirable to find new targets and inhibitors to overcome the problems of antibiotic resistance. Dihydrofolate reductase dhfr is an important enzyme required to maintain bacterial growth, and hence inhibitors of dhfr have been proven as effective agents for treating bacterial infections. Dihydrofolate reductase dhfr, tetrahydrofolate dehydrogenase. Design, synthesis, and biological evaluation of 2,4. Methotrexate is a dihydrofolate reductase inhibitor used in the treatment of leukemia, lymphomas including central nervous system lymphoma, choriocarcinoma, breast cancer and leptomeningeal metastases. The blocking of the enzymatic activity of dhfr is a key element in the treatment of many diseases, including cancer, bacterial and protozoal infections, and also. The basis of the antiinfective selectivity of these compounds is clear. Since there is no nutritional requirement for the biopterin cofactor, we attempted to create a druginduced deficiency in rats in order to study the role of tetrahydrobiopterin in regulating the biosynthesis of dopamine and serotonin.
Trimethoprim is a successful pyrimidine antifolate due to its selective mode of action. Kinetics, tissue distribution, and extent of metabolism of pyrimethamine, metoprine, and etoprine in the rat, dog, and man. Super in vitro synergy between inhibitors of dihydrofolate. K247dihydrofolate reductase inhibitor screening kit. Rational drug design, synthesis and biological evaluation of. Provides the direction for carrying out the in silico analysis for this manuscript. We previously reported on the identification of metabiphenyl. The folate antagonists are an important class of therapeutic compounds, as evidenced by their use as antiinfective, antineoplastic, and antiinflammatory drugs. Inhibitor binding analysis of dihydrofolate reductases from.
Super in vitro synergy between inhibitors of dihydrofolate reductase and inhibitors of other folaterequiring enzymes. Amplification of the human dihydrofolate reductase gene via. Dihydrofolate reductase inhibitors for use as antimicrobial agents. Inhibitors of thymidylate synthase and dihydrofolate reductase potentiate the antiviral effect of acyclovir mark n. Molecular aspects and mechanism of action of dihydrofolate. Substrate channeling between the human dihydrofolate. Progress in understanding the biochemical basis of mechanisms responsible for enzyme selectivity and antiproliferative effects has renewed the interest in antifolates for cancer chemotherapy and prompted the medicinal chemistry. The structurebased design and synthesis of selective inhibitors of trypanosoma cruzi dihydrofolate reductase. Dihydrofolate reductase is a valid target for antifungal. Insights into the slowa onset tighta binding inhibition of. While reports on the protozoa thymidylate synthase. Dihydrofolate reductase as a therapeutic target schweitzer.
Malarial plasmodium falciparum dihydrofolate reductase. Here, we revue the state of the art in the field of antibacterials based on inhibitors of these three enzyme families. Aminoacid changeslinkedto the dihydrofolate reductase. Cox, 2 george papadatos, 1 gerard van westen, 1 joel lelievre, 3 szymon t. Mycobacterial dihydrofolate reductase inhibitors identified using chemogenomic methods and in vitro validation grace mugumbate, 1 katherine a. Jun 11, 2015 insight into inhibitory activity of mycobacterial dihydrofolate reductase inhibitors by in silico molecular modeling approaches. The main objective of the research described in this thesis has been the design and synthesis of inhibitors of the enzyme dihydrofolate reductase dhfr. This antimicrobial drug class includes sulfonamides, dihydrofolate reductase inhibitors and combinations of these two subclasses. Xray radiotherapy has been widely used in the treatment of cervical cancer, a common gynecologic malignant tumor.
Dihydrofolate reductases have been purified approximately 100fold from escherichia coil, staphylococcus aureus, and proteus vulgaris and to a lesser degree from rat, rabbitr guinea pig, and human liver. Discovery of selective toxoplasma gondii dihydrofolate. The fact that so few antibacterial dhfr inhibitors have reached the public does not mean that the chemist and biologist have been idle in this area for the past. Pdf insight into inhibitory activity of mycobacterial. Its therapeutic utility depends mainly on differences in uptake, glutamylation, cellular excretion, cellular metabolic balance, and other factors.
The inhibitors were designed to avoid steric clash of the pcl group of the inhibitors with. Baccanari dp, joyner ss 1981 dihydrofolate reductase hysteresis and its effect on inhibitor binding analyses. Major indications for the use of folate inhibitor combinations are urinary tract infections, enteric infections caused by susceptible. Continued exploitation of these targets will require compounds that can broadly inhibit these resistanceconferring isoforms. Inhibitors of this enzyme are used in the treatment of several human diseases, namely, bacterial, protozoal, and fungal infections, psoriasis, autoimmune diseases such as rheumatoid arthritis, and neoplastic diseases table 1. Within a few years of the introduction of the dihydrofolate reductase inhibitors pyrimethamine and proguanil as antimalarial treatments in the late 1940s and early 1950s, highlevel resistance was noted in both p. The antifolates are also important in the treatment of malaria, although little. Inhibitors of thymidylate synthase and dihydrofolate.
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