|
Camptothecin
Camptothecin (CPT) is a topoisomerase inhibitor. It was discovered in 1966 by M. E. Wall and M. C. Wani in systematic screening of natural products for anticancer drugs. It was isolated from the Bark (botany), bark of ''Camptotheca acuminata'' (喜树 "Happy tree"), a tree native to China used in traditional Chinese medicine. It has been used clinically in China for the treatment of gastrointestinal tumors. CPT showed anticancer activity in preliminary clinical trials, especially against breast, ovarian, colon, lung, and stomach cancers. However, it has low solubility and adverse effects have been reported when used therapeutically, so synthetic and medicinal chemists have developed numerous syntheses of camptothecin and various derivatives to increase the benefits of the chemical, with good results. Four CPT Analog (chemistry), analogues have been approved and are used in cancer chemotherapy today: topotecan, irinotecan, belotecan, and trastuzumab deruxtecan. Camptothecin has als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topoisomerase Inhibitor
Topoisomerase inhibitors are chemical compounds that block the action of topoisomerases, which are broken into two broad subtypes: type I topoisomerases (TopI) and type II topoisomerases (TopII). Topoisomerase plays important roles in cellular reproduction and DNA organization, as they mediate the cleavage of single and double stranded DNA to relax supercoils, untangle catenanes, and condense chromosomes in eukaryotic cells. Topoisomerase inhibitors influence these essential cellular processes. Some topoisomerase inhibitors prevent topoisomerases from performing DNA strand breaks while others, deemed topoisomerase poisons, associate with topoisomerase-DNA complexes and prevent the re-ligation step of the topoisomerase mechanism. These topoisomerase-DNA-inhibitor complexes are cytotoxic agents, as the un-repaired single- and double stranded DNA breaks they cause can lead to apoptosis and cell death. Because of this ability to induce apoptosis, topoisomerase inhibitors have gained i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topotecan
Topotecan, sold under the brand name Hycamtin among others, is a chemotherapeutic agent medication that is a topoisomerase inhibitor. It is a synthetic, water-soluble analog of the natural chemical compound camptothecin. It is used in the form of its hydrochloride salt to treat ovarian cancer, lung cancer and other cancer types. After GlaxoSmithKline received final FDA approval for topotecan on 15 October 2007, it became the first topoisomerase I inhibitor for oral use. Uses * Ovarian cancer (FDA May 1996). * Cervical cancer (FDA June 2006). * Small cell lung carcinoma (SCLC) (FDA Oct 2007). Experimental uses As of 2016, experiments were under way for neuroblastoma, brainstem glioma, Ewing's sarcoma and Angelman's syndrome. In addition, topotecan is experimentally treating non-small cell lung cancer, colorectal cancer-, breast cancer, non-Hodgkin lymphoma, endometrial cancer, and oligodendroglioma. Angelman's syndrome Angelman's syndrome is a neuro-genetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irinotecan
Irinotecan, sold under the brand name Camptosar among others, is an anti-cancer medication used to treat colon cancer and small cell lung cancer. For colon cancer it is used either alone or with fluorouracil. For small cell lung cancer it is used with cisplatin. It is given intravenously. Common side effects include diarrhea, vomiting, bone marrow suppression, hair loss, shortness of breath, and fever. Other severe side effects include blood clots, colon inflammation, and allergic reactions. Those with two copies of the UGT1A1*28 gene variant are at higher risk for side effects. Use during pregnancy can result in harm to the baby. Irinotecan is a topoisomerase inhibitor—it blocks the topoisomerase I enzyme, resulting in DNA damage and cell death. Irinotecan was approved for medical use in the United States in 1996. It is on the World Health Organization's List of Essential Medicines. It is made from the natural compound camptothecin which is found in the Chinese orn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chonemorpha Fragrans
''Chonemorpha fragrans'', the frangipani vine or climbing frangipani, is a plant species in the genus ''Chonemorpha''. It is a vigorous, generally evergreen, climbing shrub producing stems or more long that can climb to the tops of the tallest trees in the forests of Southeast Asia. It has scented, white flowers and large shiny leaves. It is native to China, India (the Himalayas), Indonesia, Malaysia, Myanmar, Sri Lanka and Thailand. It is very commonly used in Ayurveda (an Indian traditional medicine) and it is also cultivated mostly worldwide in frost-free places. Description ''Chonemorpha fragrans'' is a vigorous climber, reaching up to .T. Pullaiah, P.B. Raghavendra, S. Karuppusamy, V. Raveendran and M. Anuradha It can also grow or spread to about wide, depending on the support. It has a rusty brown,P.K. Warrier, V.P.K. Nambiar and C. Ramankutty or grey barked stem which is numerously Lenticel, lenticelled.K. Vanangamudi, V. Anbukkarasi and M. Prabhu The bark can produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camptotheca Acuminata
''Camptotheca acuminata'' is a species of tree in the '' Camptotheca'' genus that is native to north Vietnam and southern China. It is also cultivated in the southern United States. A eudicot, it is a flowering deciduous tree with light gray bark. It can grow to a height of . Its large, papery leaves are somewhat oval in shape, usually long and wide. The flowers, which bloom from May through July, produce a gray-brown fruit with one seed in September. Uses ''Camptotheca acuminata'' is a source of camptothecin chemicals, which have been tested for potential use as treatments for cancer and HIV. The modern chemotherapy drugs topotecan and irinotecan are derived from it, though now the molecules are produced in a lab environment rather than extracted from the leaves and bark of the tree. Because of this, it is sometimes called the "cancer tree". In traditional Chinese medicine, the tree is called ("tree of joy" or "happy tree") and was considered a relatively unimportan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemotherapy
Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy regimen, regimen. Chemotherapy may be given with a cure, curative intent (which almost always involves combinations of drugs), or it may aim only to prolong life or to Palliative care, reduce symptoms (Palliative care, palliative chemotherapy). Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called ''oncology#Specialties, medical oncology''. The term ''chemotherapy'' now means the non-specific use of intracellular poisons to inhibit mitosis (cell division) or to induce DNA damage (naturally occurring), DNA damage (so that DNA repair can augment chemotherapy). This meaning excludes the more-selective agents that block extracellular signals (signal transduction) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belotecan
Belotecan is a drug used in chemotherapy. It is a semi-synthetic camptothecin analogue indicated for small-cell lung cancer and ovarian cancer Ovarian cancer is a cancerous tumor of an ovary. It may originate from the ovary itself or more commonly from communicating nearby structures such as fallopian tubes or the inner lining of the abdomen. The ovary is made up of three different ..., approved in South Korea under the trade name Camtobell, presented in 2 mg vials for injection. The drug has been marketed by Chong Kun Dang Pharmaceuticals since 2003. Mechanism of action Belotecan blocks topoisomerase I with a pIC50 of 6.56, stabilizing the cleavable complex of topoisomerase I-DNA, which inhibits the religation of single-stranded DNA breaks generated by topoisomerase I; lethal double-stranded DNA breaks occur when the topoisomerase I-DNA complex is encountered by the DNA replication machinery, DNA replication is disrupted, and the tumor cell undergoes apoptosis. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptosis
Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biology), morphology) and death. These changes include Bleb (cell biology), blebbing, Plasmolysis, cell shrinkage, Karyorrhexis, nuclear fragmentation, Pyknosis, chromatin condensation, Apoptotic DNA fragmentation, DNA fragmentation, and mRNA decay. The average adult human loses 50 to 70 1,000,000,000, billion cells each day due to apoptosis. For the average human child between 8 and 14 years old, each day the approximate loss is 20 to 30 billion cells. In contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organism's life cycle. For example, the separation of fingers and toes in a developing human embryo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drugs
A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via inhalation, injection, smoking, ingestion, absorption via a patch on the skin, suppository, or dissolution under the tongue. In pharmacology, a drug is a chemical substance, typically of known structure, which, when administered to a living organism, produces a biological effect. A pharmaceutical drug, also called a medication or medicine, is a chemical substance used to treat, cure, prevent, or diagnose a disease or to promote well-being. Traditionally drugs were obtained through extraction from medicinal plants, but more recently also by organic synthesis. Pharmaceutical drugs may be used for a limited duration, or on a regular basis for chronic disorders. Classification Pharmaceutical drugs are often classified into drug classes—groups of related drugs that hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactone
Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated. Lactones are formed by lactonization, the intramolecular esterification of the corresponding hydroxycarboxylic acids. Nomenclature Greek alphabet#Letters, Greek prefixes in alphabetical order indicate ring size. Lactones are usually named according to the precursor acid molecule (''aceto'' = 2 carbon atoms, ''propio'' = 3, ''butyro'' = 4, ''valero'' = 5, ''capro'' = 6, etc.), with a ''-lactone'' suffix and a Greek letter prefix that specifies the number of carbon atoms in the heterocycle — that is, the distance between the relevant -OH and the -COOH groups along said backbone. The first carbon atom after the carbon in the -COOH group on the parent compound is labelled α, the second will be labeled β, and so forth. Therefore, the prefixes also indicate the size of the lactone ring: α-lactone = 3-membered ring, β-lac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy groups. Both the negatively charged anion , called hydroxide, and the neutral radical , known as the hydroxyl radical, consist of an unbonded hydroxy group. According to IUPAC definitions, the term ''hydroxyl'' refers to the hydroxyl radical () only, while the functional group is called a ''hydroxy group''. Properties Water, alcohols, carboxylic acids, and many other hydroxy-containing compounds can be readily deprotonated due to a large difference between the electronegativity of oxygen (3.5) and that of hydrogen (2.1). Hydroxy-containing compounds engage in intermolecular hydrogen bonding increasing the electrostatic attraction between molecules and thus to higher boiling and melting points than found for compounds that lack thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
