LY243246 ((6S)-DDATHF), the 6S diastereomer of DDATHF, is a potent competitive inhibitor of 5’-phosphoribosylglycinamide formyltransferase (GAR transformylase). 6R- and 6S-diastereomers of DDATHF are remarkably similar and equiactive antimetabolites inhibitory to de novo purine synthesis[1].
Pyrimethamine(RP4753) is a medication used for protozoal infections; interferes with tetrahydrofolic acid synthesis from folic acid by inhibiting the enzyme dihydrofolate reductase (DHFR).IC50 Value: 15.4 nM (Plasmodium falciparum) [1]Target: DHFR; antifolatein vitro: Three susceptibility levels (susceptible, intermediate, and resistant) were observed in the response of culture-adapted clones and strains to pyrimethamine (50% inhibitory concentration [IC50]) < 100, 100-2,000, and > 2,000 nM) and cycloguanil (IC50 < 50, 50-500, and > 500 nM). Based on these susceptibility levels, 73 and 68 of 96 fresh clinical isolates were susceptible to pyrimethamine (mean IC50 15.4 nM) and cycloguanil (mean IC50 11.1 nM), respectively [1]. We tested pyrimethamine(previously reported to suppress SOD1 expression), several compounds currently in trials in human and murine ALS, and a set of 1040 FDA-approved compounds. In a PC12 cell-based assay, no compounds reduced SOD1 promoter activity without concomitant cytotoxicity. Additionally,pyrimethamine failed to repress levels of SOD1 protein in HeLa cells or homogenates of liver, spinal cord and brain of wild-type mice [3].in vivo: (131)I-Pyrimethamine (specific activity: 7.08 MBq/ mol) was injected intravenously into the tail vein of the control and infected rats. Static whole body images of the rats were acquired under the gamma camera at 5 min, 45 min, 2 h, 6 h, and 24 h following the intravenous administration of the radioactivity (3.7 MBq/rat) [2]. The 10-day treatment with 10mg/kg/day of fluconazole combined with 40/1mg/kg/day sulfadiazine and pyrimethamine resulted in 93% survival of CF1 mice acutely infected with the highly virulent T. gondii RH strain, versus 36% of mice treated with just sulfadiazine and pyrimethamine [4].Toxicity: Sulfadoxine/pyrimethamine is well tolerated as treatment and when used as intermittent preventive treatment in pregnant African women. Sulfadoxine/pyrimethamine is no longer used as prophylaxis because it may cause toxic epidermal necrolysis and Stevens Johnson syndrome [5].
Methotrexate α-tert-butyl ester, capped by OtBu, significantly reduces tumor growth in HT1080 tumor bearing mice. Methotrexate is an antimetabolite and antifolate agent and is also an immunosuppressant and antineoplastic agent[1][2][3][4].
Leucovorin Calcium is a reduced folic acid.IC50 Value: 30 μM for zcSHMT and70 μM for zmSHMT [2]Target: Antifolatein vitro: Increasing concentrations of leucovorin (N5-CHO-THF) inhibit both zcSHMT and hcSHMT activities substantially, yet to a lesser extent than zmSHMT. The IC50 of leucovorin is approximately 30 μM for zcSHMT and higher than 70 μM for zmSHMT. The differential inhibition is evident with the presence of 10 μM leucovorin, the concentration estimated in serum in a high-dose leucovorin rescue regimen [2].in vivo: Following intravenous administration, peak plasma concentrations of (6R) LV, (6S) LV, and 5-CH3 THF were 148 +/- 32, 59.1 +/- 22, and 17.8 +/- 17 microM, respectively. During oral administration of LV, virtually no (6S) LV appeared in the plasma. Steady-state plasma concentrations of (6R) LV and 5-CH3 THF were approximately 1.5 +/- 0.23 and 2.8 +/- 0.41 microM, respectively [1]. 24 fasted subjects were given 4 of a series of 5 single test doses between 20 and 100 mg, at 1-week intervals, of 5-formyl-THF as an oral solution of leucovorin calcium. Six separate subjects received 200 mg iv and po in a 2-way crossover. Blood and urine samples were collected over 24 hours for differential microbiological folate assays using Lactobacillus casei and Streptococcus faecalis. Using L casei activity to measure total serum folates, the area under the concentration-time curve from 0 to infinite time (AUC[0-infinity]) was calculated. Relative bioavailabilities were 78%, 62%, 49%, and 42% for the 40-, 60-, 80-, and 100-mg doses, respectively [3].Clinical trial: Leucovorin and Fluorouracil With or Without SU-5416 in Treating Patients With Metastatic Colorectal Cancer . Phase 3
DHFR-IN-3 is a dihydrofolate reductase (DHFR) inhibitor with the IC50 values of 19 μM and 12 μM in rat liver and P. carinii DHFR, respectively[1].
Trimethoprim is a bacteriostatic antibiotic used mainly in the prophylaxis and treatment of urinary tract infections.Target: DHFRTrimethoprim (TMP), an inhibitor of dihydrofolate reductase, decreases the level of tetrahydrofolate supplying one-carbon units for biosynthesis of nucleotides, proteins, and panthotenate. TMP caused induction of DnaK, DnaJ, GroEL, ClpB, and IbpA/B Hsps. Among these Hsps, IbpA/B were most efficiently induced by TMP and coaggregated with the insoluble proteins [1]. Trimethoprim binds to dihydrofolate reductase and inhibits the reduction of dihydrofolic acid (DHF) to tetrahydrofolic acid (THF). THF is an essential precursor in the thymidine synthesis pathway and interference with this pathway inhibits bacterial DNA synthesis. Trimethoprim's affinity for bacterial dihydrofolate reductase is several thousand times greater than its affinity for human dihydrofolate reductase. Sulfamethoxazole inhibits dihydropteroate synthetase, an enzyme involved further upstream in the same pathway. Trimethoprim and sulfamethoxazole are commonly used in combination due to their synergistic effects. This drug combination also reduces the development of resistance that is seen when either drug is used alone [2].
Pralatrexate(Folotyn) is an antifolate, and structurally a folate analog. Its IC50 is < 300 nM in some cell lines.IC50 Value: < 300 nMTarget: AntifolatePralatrexate is an antifolate (a folate analogue metabolic inhibitor) designed to accumulate preferentially in cancer cells. Based on preclinical studies, researchers believe that Pralatrexate selectively enters cells expressing reduced folate carrier type 1 (RFC-1), a protein that is overexpressed on certain cancer cells compared to normal cells.
Ketotrexate sodium is an orally active antifolate and immunosuppressant. Ketotrexate sodium has good anti-inflammatory activity and is widely used in rheumatoid arthritis (RA). Ketotrexate sodium is used in research into cancer and autoimmune diseases[1][2].
Lometrexol hydrate (DDATHF hydrate), an antipurine antifolate, can inhibit the activity of glycinamide ribonucleotide formyltransferase (GARFT) but do not induce detectable levels of DNA strand breaks. Lometrexol hydrate can further inhibit de novo purine synthesis, causing abnormal cell proliferation and apoptosis, even cell cycle arrest. Lometrexol hydrate has anticancer activity[1][2].
Methotrexate metabolite (DAMPA), the active metabolite of Methotrexate. Methotrexate is a folic acid antagonist that is widely used as an immunosuppressant and chemotherapeutic agent[1].
Folinic acid (Leucovorin) disodium is a biological folic acid and is a forms of vitamin B9. Folinic acid disodium is generally administered along with Methotrexate (MTX) as a rescue agent to decrease MTX-induced toxicity. Folinic acid disodium and Sfluorouracil adjuvant chemotherapy shows effective in colon carcinoma[1][2][3].
Trimetrexate (CI-898) isethionate is an antibiotic, also a potent and orally active dihydrofolate reductase (DHFR) inhibitor, reducing the production of DNA and RNA precursors and leading to cell death, with IC50 values of 4.74 nM and 1.35 nM for human DHFR and Toxoplasma gondii DHFR. Trimetrexate isethionate can also inhibit the growth of various cancer cells. Trimetrexate isethionate can be used for researching Pneumocystis carinii pneumonia (PCP) and cancer[1][2][3][4][5].
Proguanil-d4 is the deuterium labeled Proguanil[1]. Proguanil, an antimalarial prodrug, is metabolized to the active metabolite Cycloguanil (HY-12784). Proguanil is a dihydrofolate reductase (DHFR) inhibitor[2][3].
Trimethoprim hydrochloride is a bacteriostatic antibiotic and an orally active dihydrofolate reductase inhibitor. Trimethoprim hydrochloride is active against a wide range of Gram-positive and Gram-negative aerobic bacteria. Trimethoprim hydrochloride has the potential for the research of urinary tract infections, Shigellosis and Pneumocystis pneumonia. Trimethoprim hydrochloride can inhibit infection of Influenza A virus in chick embryo when combinated with zinc[1][2][3][4].
Trimetrexate glucuronate (NSC 352122) is a folic acid antagonist. Trimetrexate glucuronate affects DNA and RNA synthesis by inhibiting dihydrofolate reductase and preventing the synthesis of purine nucleotides and thymidylate. Trimetrexate glucuronate has potential anti-tumour activity[1].
Trimethoprim lactic is a bacteriostatic antibiotic and an orally active dihydrofolate reductase inhibitor. Trimethoprim lactic is active against a wide range of Gram-positive and Gram-negative aerobic bacteria. Trimethoprim lactic has the potential for urinary tract infections, Shigellosis and Pneumocystis pneumonia treatment[1][2][3].
Folinic Acid is a reduced folic acid, which is used in combination with other chemotherapy drugs.Target: Folate analogApproved: 2008Folinic acid (calcium salt pentahydrate) is the calcium salt form of folinic acid, which is one of the forms of folate found naturally in foods. Folate deficiency is believed to be the most common vitamin deficiency in the world due to food processing, food selection, and intestinal disorders. Folinic acid in the body can be converted into any of the other active forms of folate.Treatment with folinic acid calcium salt pentahydrate (CF) could cause improved development in the heart and vessels in MTX-treated embryos, which proved that MTX induced the malformations by inhibiting DHFR. The transcript levels of genes such as hand2, mef2a, mef2c, and flk-1 were reduced in MTX-treated embryos. Compared with the MTX-treated group, the transcript levels of hand2, mef2a, mef2c, and flk-1 were increased in the MTX + dhfr-gfp mRNA-injected group and in the MTX + CF group [1]. Folinic acid may also be useful in the treatment of acute methotrexate overdose. Different dosing protocols are used, but folinic acid should be re-dosed until the methotrexate level is less than 5 x 10-8 M [2].
EC0488 is used to synthesize EC0531 with folate receptor (FR)-specific and anti-tumor activities[1].
Metoprine (BW 197U) is a potent histamine N-methyltransferase (HMT) inhibitor. Metoprine, a diaminopyrimidine derivative, can cross the blood-brain barrier and increase brain histamine levels by inhibiting HMT[1][2]. Metoprine is an antifolate and antitumor agent[3].
Folinic acid is an adjuvant used in cancer chemotherapy involving the drug methotrexate.Target: AntifolateFolinic acid is a 5-formyl derivative of tetrahydrofolic acid. It is readily converted to other reduced folic acid derivatives (e.g., tetrahydrofolate), and, thus, has vitamin activity that is equivalent to that of folic acid. Since it does not require the action of dihydrofolate reductase for its conversion, its function as a vitamin is unaffected by inhibition of this enzyme by drugs such as methotrexate. In 1980s, however, folinic acid was found to reactivate the dihydrofolate reductase itself even when methotrexate exists. Although the mechanism is not very clear, the polyglutamylation of methotrexate and dihydrofolate in malignant cells is considered to play an important role in the selective reactivation of dihydrofolate reductase by folinic acid in normal cells [1]. Folinic acid is generally administered along with MTX as a rescue agent to decrease MTX-induced toxicity. However, information regarding the inhibitory effect of folinic acid against cytogenetic damage caused by MTX is limited. This study was conducted to assess the cytogenetic effect of MTX and its inhibition by folinic acid (FA) using the micronucleus and chromosomal aberration assays concurrently [2].
Proguanil hydrochloride, an antimalarial prodrug, is metabolized to the active metabolite Cycloguanil (HY-12784). Proguanil hydrochloride is a dihydrofolate reductase (DHFR) inhibitor[1][2].
Pemetrexed disodium hemipenta hydrate is a novel antifolate, the Ki values of the pentaglutamate of LY231514 are 1.3, 7.2, and 65 nM for inhibits thymidylate synthase (TS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT), respectively.
Aditoprime (Aditoprim), a selective bacterial dihydrofolate reductase (DHFR) inhibitor, inhibits the transformation of dihydrofolic acid to tetrahydrofolic acid. Aditoprime inhibits E.coli and L.casei DHFR with IC50 of 47 and 520 nM, respectively. Aditoprime has a broad antimicrobial spectrum, good antibacterial activity and excellent pharmacokinetics[1][2][3].
Levoleucovorin calcium is the calcium salt of Levoleucovorin, which is the enantiomerically active form of folinic acid.IC50 value: Target: Levoleucovorin is used to treat or prevent toxic effects of methotrexate in people who have received methotrexate to treat bone cancer. Levoleucovorin is also used in combination chemotherapy with fluorouracil (5-FU) to treat colorectal cancer that has spread to other parts of the body. This medicine only treats the symptoms of colorectal cancer and does not treat the cancer itself.
Mirvetuximab (M9346A) is an anti-FOLR1 (folate receptor 1) monoclonal antibody. Mirvetuximab is the antibody moiety of novel folate receptor alpha (FRα)-targeting ADC (Mirvetuximab soravtansine). Mirvetuximab soravtansine can be used in ovarian and other FRα-positive cancer research[1].
DHFR-IN-2 (compound 4e) is a potent and uncompetitive inhibitor for MtDHFR (dihydrofolate reductase from M. tuberculosis), with an IC50 of 7 μM. DHFR-IN-2 can be used for tuberculosis (TB) research[1].
TNP-351 is an antifolate. TNP-351, a dihydrofolate reductase (DHFR) inhibitor, has potent antitumor activity against not only leukemia cells but also solid tumor cells in vitro and in vivo[1].
10-Methyl-10-deazaaminopterin is a folate analog and an antifolate. 10-Methyl-10-deazaaminopterin can be used for the research of cancer[1].
Pyrimethamine-d3 (Pirimecidan-d3) is the deuterium labeled Pyrimethamine. Pyrimethamine is a medication used for protozoal infections; interferes with tetrahydrofolic acid synthesis from folic acid by inhibiting the enzyme dihydrofolate reductase (DHFR)[1][2].
LSN 3213128 is a selective, nonclassical, orally bioavailable antifolate with potent and specific inhibitory activity for aminoimidazole-4-carboxamide ribonucleotide formyltransferase (AICARFT), with IC50 of 16 nM for AICARFT enzyme inhibiton and 19 nM in cells. Anti-tumor activity[1].