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.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)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.Indole Alkaloids: Group of alkaloids containing a benzylpyrrole group (derived from TRYPTOPHAN)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.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.Coptis: A plant genus of the family RANUNCULACEAE. Members contain BERBERINE and other isoquinoline ALKALOIDS.Cinchona Alkaloids: Alkaloids extracted from various species of Cinchona.Amaryllidaceae Alkaloids: Alkaloids derived from TYRAMINE combined with 3,4-dihydroxybenzaldehyde via a norbelladine pathway, including GALANTAMINE, lycorine and crinine. They are found in the Amaryllidaceae (LILIACEAE) plant family.Benzylisoquinolines: ISOQUINOLINES with a benzyl substituent.Hydrastis: A plant genus of the family RANUNCULACEAE. Members contain BERBERINE.Aconitum: A plant genus of the family RANUNCULACEAE. Members contain a number of diterpenoid alkaloids including: aconitans, hypaconitine, ACONITINE, jesaconitine, ignavine, napelline, and mesaconitine. The common name of Wolfbane is similar to the common name for ARNICA.Aporphines: Dibenzoquinolines derived in plants from (S)-reticuline (BENZYLISOQUINOLINES).Claviceps: A genus of ascomycetous fungi, family Clavicipitaceae, order Hypocreales, parasitic on various grasses (POACEAE). The sclerotia contain several toxic alkaloids. Claviceps purpurea on rye causes ergotism.Plant Extracts: Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.Catharanthus: A plant genus of the family Apocynaceae. It is the source of VINCA ALKALOIDS, used in leukemia chemotherapy.