ABSTRACT
Plant natural products have historically been very important to drug discovery and development, particularly in the anticancer field. This is illustrated by a discussion of the structures and activities of camptothecin and its analogues, paclitaxel (Taxol), the vinca alkaloids vinblastine and vincristine, and podophyllotoxin and its analogues. A description of the isolation of one new and three known cardenolides from the Madagascar plant Pentopetia androsaemifolia is then provided as an example of this approach to drug discovery. The paper concludes with a brief discussion of betulinic acid, an old compound which is being developed into an anticancer and anti-HIV agent, and ipomoeassin F, an interesting antiproliferative compound isolated from a plant collected in Suriname.
Subject(s)
Apocynaceae/chemistry , Cardenolides/pharmacology , Cell Proliferation/drug effects , Trees/chemistry , Cardenolides/isolation & purification , Cell Line, Tumor , Cell Survival/drug effects , Humans , Madagascar , Magnetic Resonance Spectroscopy , Molecular Structure , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plant Roots/chemistry , Plant Stems/chemistryABSTRACT
Bioassay-guided fractionation of an ethanol extract of Roupellina (Strophanthus) boivinii from the rainforest of Madagascar afforded the six new cardenolide glycosides boivinides 1-6, as well as the four known cardenolide glycosides digitoxigenin 3-O-[beta-D-glucopyrananosyl-(1-->4)-alpha-L-acofriopyranoside], corotoxigenin 3-O-beta-D-boivinoside, 17alpha-corotoxigenin 3-O-beta-D-sarmentoside, and uzarigenin 3-O-alpha-L-rhamnoside. The structures of these compounds were elucidated by various 1D and 2D NMR techniques. All new compounds showed significant antiproliferative activity against the A2780 human ovarian cancer cell line, with boivinide A being the most active at IC50 = 0.17 microM.
Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Antineoplastic Agents, Phytogenic/pharmacology , Cardenolides/isolation & purification , Cardenolides/pharmacology , Glycosides/isolation & purification , Glycosides/pharmacology , Plants, Medicinal/chemistry , Strophanthus/chemistry , Antineoplastic Agents, Phytogenic/chemistry , Cardenolides/chemistry , Drug Screening Assays, Antitumor , Female , Glycosides/chemistry , Humans , Inhibitory Concentration 50 , MadagascarABSTRACT
Bioassay-guided fractionation of the MeOH and EtOAc fractions of extracts of two lianas collected in Suriname has led to the isolation of five new diterpenoids, humirianthone 1, 1-hydroxy-humirianthone 2, 15R-humirianthol 3, patagonol 4, and patagonal 5, and the five known diterpenoids, humirianthol 7, annonalide 8, acrenol 9, icacinol 10, and the oxidized annonalide 11. All 10 diterpenoids showed cytotoxic activity against the A2780 human ovarian cancer cell line, and compounds 1, 3, 8, and 9 also showed activity against phytopathogenic fungi.
Subject(s)
Diterpenes/isolation & purification , Diterpenes/toxicity , Plants, Medicinal/chemistry , Antifungal Agents/chemistry , Antifungal Agents/isolation & purification , Antifungal Agents/pharmacology , Antifungal Agents/toxicity , Cell Line, Tumor , Cell Proliferation/drug effects , Diterpenes/chemistry , Diterpenes/pharmacology , Fungi/drug effects , Fungi/physiology , Humans , Inhibitory Concentration 50 , Magnetic Resonance Spectroscopy , Rain , Suriname , TreesABSTRACT
A beta-carboline-, a tryptamine-, and two phenylethylamine-derived alkaloids and three known aromatic compounds were isolated from the aerial parts and roots of Cyathobasis fruticulosa (Bunge) Aellen, and their structures were elucidated by spectroscopic techniques. The one new alkaloid, N-methyl-N-formyl-4-hydroxy-beta-phenylethylamine (1), showed marginal antifungal activity.
