title: In vitro biological activities of alkaloids from Cryptolepis sanguinolenta.
abstract: In our biological screening of higher plants, an aqueous and an 80% EtOH extract from the root bark of Cryptolepis sanguinolenta showed potent antibacterial, anticomplementary, and moderate antiviral activities, but no antifungal effect could be detected. Bioassay-guided fractionation of the 80% EtOH extract led to the isolation of three alkaloids: quindoline (1), hydroxycryptolepine (2), cryptolepine.HCl (3), and the corresponding base cryptolepine (4). All compounds strongly inhibited the growth of Gram-positive bacteria (MIC < or = 100 micrograms/ml) and showed a moderate (MIC = 125 or 250 micrograms/ml), a weak (MIC = 500 micrograms/ml), or no activity (MIC > 500 micrograms/ml) against selected Gram-negative bacteria. They also possessed a bactericidal effect depending on the bacterial strain. Compounds 1, 2 and 3 displayed a dose-dependent inhibitory effect on the classical pathway of the complement system while compounds 2 and 3 activated the alternative pathway, except for compound 1. Compound 3 was found to possess an antiherpetic activity. Compounds 1 and 4 showed no antiviral effect, but were quite cytotoxic in the antiviral test system down to a concentration of 1 microgram/ml.
authors.affiliation: Department of Pharmaceutical Sciences, University of Antwerp, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Cimanga
authors.forename: T
authors.initials: T
authors.lastname: De Bruyne
authors.forename: A
authors.initials: A
authors.lastname: Lasure
authors.forename: B
authors.initials: B
authors.lastname: Van Poel
authors.forename: L
authors.initials: L
authors.lastname: Pieters
authors.forename: M
authors.initials: M
authors.lastname: Claeys
authors.forename: D V
authors.initials: DV
authors.lastname: Berghe
authors.forename: K
authors.initials: K
authors.lastname: Kambu
authors.forename: L
authors.initials: L
authors.lastname: Tona
authors.forename: A J
authors.initials: AJ
authors.lastname: Vlietinck
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D003169:Complement Inactivator Proteins / Q000737:chemistry / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D018517:Plant Roots / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D000470:Alkaloids; D000900:Anti-Bacterial Agents; D003169:Complement Inactivator Proteins