Vincamine: A major alkaloid of Vinca minor L., Apocynaceae. It has been used therapeutically as a vasodilator and antihypertensive agent, particularly in cerebrovascular disorders.Harringtonines: Tetracyclic spiro-BENZAZEPINES isolated from the seeds of CEPHALOTAXUS. They are esters of the alkaloid cephalotaxine and may be effective as antineoplastic agents.Alkaloids: Organic nitrogenous bases. Many alkaloids of medical importance occur in the animal and vegetable kingdoms, and some have been synthesized. (Grant & Hackh's Chemical Dictionary, 5th ed)Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Bromine: A halogen with the atomic symbol Br, atomic number 36, and atomic weight 79.904. It is a volatile reddish-brown liquid that gives off suffocating vapors, is corrosive to the skin, and may cause severe gastroenteritis if ingested.Ergot Alkaloids: Alkaloids originally isolated from the ergot fungus Claviceps purpurea (Hypocreaceae). They include compounds that are structurally related to ergoline (ERGOLINES) and ergotamine (ERGOTAMINES). Many of the ergot alkaloids act as alpha-adrenergic antagonists.Vinca Alkaloids: A group of indole-indoline dimers which are ALKALOIDS obtained from the VINCA genus of plants. They inhibit polymerization of TUBULIN into MICROTUBULES thus blocking spindle formation and arresting cells in METAPHASE. They are some of the most useful ANTINEOPLASTIC AGENTS.Cinchona Alkaloids: Alkaloids extracted from various species of Cinchona.Benzylisoquinolines: ISOQUINOLINES with a benzyl substituent.Pyrrolizidine Alkaloids: A group of ALKALOIDS, characterized by a nitrogen-containing necine, occurring mainly in plants of the BORAGINACEAE; COMPOSITAE; and LEGUMINOSAE plant families. They can be activated in the liver by hydrolysis of the ester and desaturation of the necine base to reactive electrophilic pyrrolic CYTOTOXINS.Berberine Alkaloids: A group of related plant alkaloids that contain the BERBERINE heterocyclic ring structure.Berberine: An alkaloid from Hydrastis canadensis L., Berberidaceae. It is also found in many other plants. It is relatively toxic parenterally, but has been used orally for various parasitic and fungal infections and as antidiarrheal.Cinchona: A genus of rubiaceous South American trees that yields the toxic CINCHONA ALKALOIDS from their bark; QUININE; QUINIDINE; chinconine, cinchonidine and others are used to treat MALARIA and CARDIAC ARRHYTHMIAS.Stereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Chloroacetates: ACETIC ACID or acetic acid esters substituted with one or more CHLORINE atoms.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Quinidine: An optical isomer of quinine, extracted from the bark of the CHINCHONA tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular ACTION POTENTIALS, and decreases automaticity. Quinidine also blocks muscarinic and alpha-adrenergic neurotransmission.Veratrum Alkaloids: Alkaloids with powerful hypotensive effects isolated from American or European Hellebore (Veratrum viride Ait. Liliaceae and Veratrum album L. Liliaceae). They increase cholinergic and decrease adrenergic tone with appropriate side effects and at higher doses depress respiration and produce cardiac arrhythmias; only the ester alkaloids have been used as hypotensive agents in specific instances. They have been generally replaced by drugs with fewer adverse effects.Copyright: It is a form of protection provided by law. In the United States this protection is granted to authors of original works of authorship, including literary, dramatic, musical, artistic, and certain other intellectual works. This protection is available to both published and unpublished works. (from Circular of the United States Copyright Office, 6/30/2008)Veratrum: A plant genus of the family LILIACEAE with roots that contain VERATRUM ALKALOIDS used as emetics, parasiticides, antihypertensives. It is the main ingredient of Boicil.Equipment Reuse: Further or repeated use of equipment, instruments, devices, or materials. It includes additional use regardless of the original intent of the producer as to disposability or durability. It does not include the repeated use of fluids or solutions.Gentiana: A plant genus of the family Gentianaceae whose members contain SECOIRIDOIDS and have been used in TRADITIONAL MEDICINE for suppressing INFLAMMATION.Cevanes: Structurally-related alkaloids that contain the cevane carbon backbone.Dictionaries, MedicalDictionaries as Topic: Lists of words, usually in alphabetical order, giving information about form, pronunciation, etymology, grammar, and meaning.Dictionaries, ChemicalLanguage: A verbal or nonverbal means of communicating ideas or feelings.DictionaryCodeine: An opioid analgesic related to MORPHINE but with less potent analgesic properties and mild sedative effects. It also acts centrally to suppress cough.Shellfish: Aquatic invertebrates belonging to the phylum MOLLUSCA or the subphylum CRUSTACEA, and used as food.Shellfish Poisoning: Poisoning from toxins present in bivalve mollusks that have been ingested. Four distinct types of shellfish poisoning are recognized based on the toxin involved.Indole Alkaloids: Group of alkaloids containing a benzylpyrrole group (derived from TRYPTOPHAN)EncyclopediasHemidesmus: A plant genus of the family ASCLEPIADACEAE. It is a source of PREGNANES. It is sometimes an adulterant of commercial sarsaparilla.Opium: The air-dried exudate from the unripe seed capsule of the opium poppy, Papaver somniferum, or its variant, P. album. It contains a number of alkaloids, but only a few - MORPHINE; CODEINE; and PAPAVERINE - have clinical significance. Opium has been used as an analgesic, antitussive, antidiarrheal, and antispasmodic.Nicotine: Nicotine is highly toxic alkaloid. It is the prototypical agonist at nicotinic cholinergic receptors where it dramatically stimulates neurons and ultimately blocks synaptic transmission. Nicotine is also important medically because of its presence in tobacco smoke.Forecasting: The prediction or projection of the nature of future problems or existing conditions based upon the extrapolation or interpretation of existing scientific data or by the application of scientific methodology.ArchivesBiological Science Disciplines: All of the divisions of the natural sciences dealing with the various aspects of the phenomena of life and vital processes. The concept includes anatomy and physiology, biochemistry and biophysics, and the biology of animals, plants, and microorganisms. It should be differentiated from BIOLOGY, one of its subdivisions, concerned specifically with the origin and life processes of living organisms.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.PubMed: A bibliographic database that includes MEDLINE as its primary subset. It is produced by the National Center for Biotechnology Information (NCBI), part of the NATIONAL LIBRARY OF MEDICINE. PubMed, which is searchable through NLM's Web site, also includes access to additional citations to selected life sciences journals not in MEDLINE, and links to other resources such as the full-text of articles at participating publishers' Web sites, NCBI's molecular biology databases, and PubMed Central.Directories as Topic: Lists of persons or organizations, systematically arranged, usually in alphabetic or classed order, giving address, affiliations, etc., for individuals, and giving address, officers, functions, and similar data for organizations. (ALA Glossary of Library and Information Science, 1983)Invertebrates: Animals that have no spinal column.Senecio: A species of toxic plants of the Compositae. The poisonous compounds are alkaloids which cause cattle diseases, neoplasms, and liver damage and are used to produce cancers in experimental animals.Plant Poisoning: Poisoning by the ingestion of plants or its leaves, berries, roots or stalks. The manifestations in both humans and animals vary in severity from mild to life threatening. In animals, especially domestic animals, it is usually the result of ingesting moldy or fermented forage.Boraginaceae: The Borage plant family is in the class Magnoliopsida, subclass Asteridae, order Lamiales. It is characterized by hairy foliage, usually alternate and simple; flowers are funnel-shaped or tubular. Some of the species contain PYRROLIZIDINE ALKALOIDS.Crotalaria: A plant genus of the family FABACEAE that contains crotalarin.Monocrotaline: A pyrrolizidine alkaloid and a toxic plant constituent that poisons livestock and humans through the ingestion of contaminated grains and other foods. The alkaloid causes pulmonary artery hypertension, right ventricular hypertrophy, and pathological changes in the pulmonary vasculature. Significant attenuation of the cardiopulmonary changes are noted after oral magnesium treatment.Comfrey: Perennial herb Symphytum officinale, in the family Boraginaceae, used topically for wound healing. It contains ALLANTOIN, carotene, essential oils (OILS, VOLATILE); GLYCOSIDES; mucilage, resin, SAPONINS; TANNINS; triterpenoids, VITAMIN B12, and ZINC. Comfrey also contains PYRROLIZIDINE ALKALOIDS and is hepatotoxic if ingested.Mutagenicity Tests: Tests of chemical substances and physical agents for mutagenic potential. They include microbial, insect, mammalian cell, and whole animal tests.Mutagens: Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.Microsomes, Liver: Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.