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Cycloguanil Synthesis
Cycloguanil is a dihydrofolate reductase inhibitor, and is a metabolite of the antimalarial drug proguanil; its formation in vivo has been thought to be primarily responsible for the antimalarial activity of proguanil. However, more recent work has indicated that, while proguanil is synergistic with the drug atovaquone Atovaquone, sold under the brand name Mepron, is an antimicrobial medication for the prevention and treatment of ''Pneumocystis jirovecii'' pneumonia (PCP). Atovaquone is a chemical compound that belongs to the class of naphthoquinones. Atova ... (as in the combination Malarone), cycloguanil is in fact antagonistic to the effects of atovaquone, suggesting that, unlike cycloguanil, proguanil may have an alternative mechanism of antimalarial action besides dihydrofolate reductase inhibition. Although cycloguanil is not currently in general use as an antimalarial, the continuing development of resistance to current antimalarial drugs has led to renewed interes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydrofolate Reductase Inhibitor
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. For example, methotrexate is used as cancer chemotherapy because it can prevent neoplastic cells from dividing. Bacteria also need DHFR to grow and multiply and hence inhibitors selective for bacterial vs. host DHFR have found application as antibacterial agents. Classes of small-molecules employed as inhibitors of dihydrofolate reductase include diaminoquinazoline and diaminopyrroloquinazoline, Most of the above specified inhibitors are structural analogues of the substrate dihydrofolate and bind to the active site of the enzyme. Further, it has been recently shown that, in ''E. coli'' DHFR, allosteric site binders can inhibit the enzyme either uncompetitively or non-competitively. The examples provided below are sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimalarial Drug
Antimalarial medications or simply antimalarials are a type of antiparasitic chemical agent, often naturally derived, that can be used to treat or to prevent malaria, in the latter case, most often aiming at two susceptible target groups, young children and pregnant women. As of 2018, modern treatments, including for severe malaria, continued to depend on therapies deriving historically from quinine and artesunate, both parenteral (injectable) drugs, expanding from there into the many classes of available modern drugs. Incidence and distribution of the disease ("malaria burden") is expected to remain high, globally, for many years to come; moreover, known antimalarial drugs have repeatedly been observed to elicit resistance in the malaria parasite—including for combination therapies featuring artemisinin, a drug of last resort, where resistance has now been observed in Southeast Asia. As such, the needs for new antimalarial agents and new strategies of treatment (e.g., new com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proguanil
Proguanil, also known as chlorguanide and chloroguanide, is a medication used to treat and prevent malaria. It is often used together with chloroquine or atovaquone. When used with chloroquine the combination will treat mild chloroquine resistant malaria. It is taken by mouth. Side effects include diarrhea, constipation, skin rashes, hair loss, and itchiness. Because malaria tends to be more severe in pregnancy, the benefit typically outweighs the risk. If used during pregnancy it should be taken with folate. It is likely safe for use during breastfeeding. Proguanil is converted by the liver to its active metabolite, cycloguanil. It is on the World Health Organization's List of Essential Medicines. In the United States and Canada it is only available in combination as atovaquone/proguanil. History When the Japanese attack on Pearl Harbor started World War II in the Pacific, the US became very interested in antimalarial medications and funded a large joint US-UK program t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atovaquone
Atovaquone, sold under the brand name Mepron, is an antimicrobial medication for the prevention and treatment of ''Pneumocystis jirovecii'' pneumonia (PCP). Atovaquone is a chemical compound that belongs to the class of naphthoquinones. Atovaquone is a hydroxy-1,4-naphthoquinone, an analog of both ubiquinone and lawsone. Medical uses Atovaquone is a medication used to treat or prevent: * For pneumocystis pneumonia (PCP), it is used in mild cases, although it is not approved for treatment of severe cases. * For toxoplasmosis, the medication has antiparasitic and therapeutic effects. * For malaria, it is one of the two components (along with proguanil) in the drug Malarone. Malarone has fewer side effects and is more expensive than mefloquine. Resistance has been observed. * For babesia, it is often used in conjunction with oral azithromycin. Trimethoprim/sulfamethoxazole (TMP-SMX, Bactrim) is generally considered first-line therapy for PCP (not to be confused with sulfadi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malarone
Atovaquone/proguanil, sold under the brand name Malarone among others, is a fixed-dose combination medication used to treat and prevent malaria, including chloroquine-resistant malaria. It contains atovaquone and proguanil. It is not recommended for severe or complicated malaria. It is taken by mouth. Common side effects include abdominal pain, vomiting, diarrhea, cough, and itchiness. Serious side effects may include anaphylaxis, Stevens–Johnson syndrome, hallucinations, and liver problems. Side effects are generally mild. It is unclear if use during pregnancy or breastfeeding is safe for the baby. It is not recommended to prevent malaria in those with poor kidney function. Atovaquone works by interfering with the function of mitochondria in malaria while proguanil blocks dihydrofolate reductase. Atovaquone/proguanil was approved for medical use in the United States in 2000. It has been available as a generic medication since 2011. Medical uses Malaria treatment Atovaquo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycloguanil Synthesis
Cycloguanil is a dihydrofolate reductase inhibitor, and is a metabolite of the antimalarial drug proguanil; its formation in vivo has been thought to be primarily responsible for the antimalarial activity of proguanil. However, more recent work has indicated that, while proguanil is synergistic with the drug atovaquone Atovaquone, sold under the brand name Mepron, is an antimicrobial medication for the prevention and treatment of ''Pneumocystis jirovecii'' pneumonia (PCP). Atovaquone is a chemical compound that belongs to the class of naphthoquinones. Atova ... (as in the combination Malarone), cycloguanil is in fact antagonistic to the effects of atovaquone, suggesting that, unlike cycloguanil, proguanil may have an alternative mechanism of antimalarial action besides dihydrofolate reductase inhibition. Although cycloguanil is not currently in general use as an antimalarial, the continuing development of resistance to current antimalarial drugs has led to renewed interes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimalarial Agents
Antimalarial medications or simply antimalarials are a type of antiparasitic chemical agent, often natural product, naturally derived, that can be used to treat or to prevent malaria, in the latter case, most often aiming at two susceptible target groups, young children and pregnant women. As of 2018, modern treatments, including for severe malaria, continued to depend on therapies deriving historically from quinine and artesunate, both parenteral (injectable) drugs, expanding from there into the many classes of available modern drugs. Incidence and distribution of the disease ("malaria burden") is expected to remain high, globally, for many years to come; moreover, known antimalarial drugs have repeatedly been observed to elicit resistance in the malaria parasite—including for combination therapies featuring artemisinin, a drug of last resort, where resistance has now been observed in Southeast Asia. As such, the needs for new antimalarial agents and new strategies of treatment ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triazines
Triazines are a class of nitrogen-containing heterocycles. The parent molecules' molecular formula is . They exist in three isomeric forms, 1,3,5-triazines being common. Structure The triazines have planar six-membered benzene-like ring but with three carbons replaced by nitrogens. The three isomers of triazine are distinguished by the positions of their nitrogen atoms, and are referred to as 1,2,3-triazine, 1,2,4-triazine, and 1,3,5-triazine. Other aromatic nitrogen heterocycles are pyridines with one ring nitrogen atom, diazines with 2 nitrogen atoms in the ring, triazoles with 3 nitrogens in a 5-membered ring, and tetrazines with 4 ring nitrogen atoms. Uses Melamine A well known triazine is melamine (2,4,6-triamino-1,3,5-triazine). With three amino substituents, melamine is a precursor to commercial resins. Guanamines are closely related to melamine, except with one amino substituent replaced by an organic group. This difference is exploited in the use of guanamine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guanidines
Guanidine is the compound with the formula HNC(NH2)2. It is a colourless solid that dissolves in polar solvents. It is a strong base that is used in the production of plastics and explosives. It is found in urine predominantly in patients experiencing renal failure. A guanidine moiety also appears in larger organic molecules, including on the side chain of arginine. Structure Guanidine can be thought of as a nitrogenous analogue of carbonic acid. That is, the C=O group in carbonic acid is replaced by a C=NH group, and each OH is replaced by a group. A detailed crystallographic analysis of guanidine was elucidated 148 years after its first synthesis, despite the simplicity of the molecule. In 2013, the positions of the hydrogen atoms and their displacement parameters were accurately determined using single-crystal neutron diffraction. Production Guanidine can be obtained from natural sources, being first isolated in 1861 by Adolph Strecker via the oxidative degradation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
