title: Complement-inhibiting iridoids from Morinda morindoides.
abstract: Morinda morindoides (Baker) Milne-Redhead (syn. Gaertnera morindoides Bak.) is one of the most popular medicinal plants in the Democratic Republic of Congo. In relation to its traditional use against rheumatic pains, fractionation of both the EtOAc- and the n-BuOH-soluble fraction of the 80% MeOH extract of the leaves, guided by the anticomplementary activity on the classical activation pathway, yielded eight novel iridoids (1-8), all containing a spirolactone functionality. Their structure was elucidated using spectroscopic methods. Gaertneroside 1, acetylgaertneroside 2, and gaertneric acid 5 were found to inhibit the activation of the classical pathway of the complement system, with IC(50) values between 58 and 69 microM. In addition to the biologically active flavonoids reported before from the same plant, these complement-inhibiting iridoids may contribute at least in part to the traditional use against rheumatic pains.
authors.affiliation: Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
authors.forename: Kanyanga
authors.initials: K
authors.lastname: Cimanga
authors.forename: Nina
authors.initials: N
authors.lastname: Hermans
authors.forename: Sandra
authors.initials: S
authors.lastname: Apers
authors.forename: Sabine
authors.initials: S
authors.lastname: Van Miert
authors.forename: Hilde
authors.initials: H
authors.lastname: Van den Heuvel
authors.forename: Magda
authors.initials: M
authors.lastname: Claeys
authors.forename: Luc
authors.initials: L
authors.lastname: Pieters
authors.forename: Arnold
authors.initials: A
authors.lastname: Vlietinck
mesh_terms: D003169:Complement Inactivator Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D003170:Complement Pathway, Alternative / Q000187:drug effects; D003171:Complement Pathway, Classical / Q000187:drug effects; D015023:Democratic Republic of the Congo; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D039823:Iridoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D032066:Morinda / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D003169:Complement Inactivator Proteins; D005419:Flavonoids; D039823:Iridoids