Catharanthus: A plant genus of the family Apocynaceae. It is the source of VINCA ALKALOIDS, used in leukemia chemotherapy.Secologanin Tryptamine Alkaloids: Compounds formed by condensation of secologanin with tryptamine resulting in a tetrahydro-beta-carboline which is processed further to a number of bioactive compounds. These are especially found in plants of the APOCYNACEAE; LOGANIACEAE; and RUBIACEAE families.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.Carbon-Nitrogen Lyases: Enzymes that catalyze the cleavage of a carbon-nitrogen bond by means other than hydrolysis or oxidation. Subclasses are the AMMONIA-LYASES, the AMIDINE-LYASES, the amine-lyases, and other carbon-nitrogen lyases. EC 4.3.Indole Alkaloids: Group of alkaloids containing a benzylpyrrole group (derived from TRYPTOPHAN)Iridoid Glucosides: A subclass of iridoid compounds that include a glucoside moiety, usually found at the C-1 position.Vinca: A plant genus of the family APOCYNACEAE. Vinca rosea has been changed to CATHARANTHUS roseus.Iridoids: A type of MONOTERPENES, derived from geraniol. They have the general form of cyclopentanopyran, but in some cases, one of the rings is broken as in the case of secoiridoid. They are different from the similarly named iridals (TRITERPENES).Plant Leaves: Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)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)Mesophyll Cells: Large and highly vacuolated cells possessing many chloroplasts occuring in the interior cross-section of leaves, juxtaposed between the epidermal layers.Plant Components, Aerial: The above-ground plant without the roots.Vinblastine: Antitumor alkaloid isolated from Vinca rosea. (Merck, 11th ed.)Aromatic-L-Amino-Acid Decarboxylases: An enzyme group with broad specificity. The enzymes decarboxylate a range of aromatic amino acids including dihydroxyphenylalanine (DOPA DECARBOXYLASE); TRYPTOPHAN; and HYDROXYTRYPTOPHAN.Phytoplasma: A genus of minute bacteria in the family ACHOLEPLASMATACEAE that inhabit phloem sieve elements of infected PLANTS and cause symptoms such as yellowing, phyllody, and witches' brooms. Organisms lack a CELL WALL and thus are similar to MYCOPLASMA in animals. They are transmitted by over 100 species of INSECTS especially leafhoppers, planthoppers, and PSYLLIDS.Plants, Medicinal: Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.Oxylipins: Eighteen-carbon cyclopentyl polyunsaturated fatty acids derived from ALPHA-LINOLENIC ACID via an oxidative pathway analogous to the EICOSANOIDS in animals. Biosynthesis is inhibited by SALICYLATES. A key member, jasmonic acid of PLANTS, plays a similar role to ARACHIDONIC ACID in animals.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Cyclopentanes: A group of alicyclic hydrocarbons with the general formula R-C5H9.Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.