title: Antimalarial activity of cassane- and norcassane-type diterpenes from Caesalpinia crista and their structure-activity relationship.
abstract: Malaria is one of the most life-threatening infectious diseases worldwide and claims millions of people's lives each year. The appearance of drug-resistance Plasmodium falciparum has made the treatment of malaria increasingly problematic, and thus, it is a dire need to search the new alternatives of current drugs. In the present study, 44 cassane- and norcassane-type diterpenes isolated from Caesalpinia crista of Myanmar and Indonesia were evaluated for their antimalarial activity against the malaria parasite Plasmodium falciparum FCR-3/A2 clone in vitro. Most of the tested diterpenes displayed antimalarial activity, and norcaesalpinin E (28) showed the most potent activity with an IC50 value of 0.090 microM, more potent than the clinically used drug chloroquine (IC50, 0.29 microM). Based on the observed results, a structure-activity relationship has been established.
authors.affiliation: Institute of Natural Medicine, University of Toyama, Sugitani, Japan.
authors.forename: Surya Kant
authors.initials: SK
authors.lastname: Kalauni
authors.forename: Suresh
authors.initials: S
authors.lastname: Awale
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tezuka
authors.forename: Arjun Hari
authors.initials: AH
authors.lastname: Banskota
authors.forename: Thein Zaw
authors.initials: TZ
authors.lastname: Linn
authors.forename: Puji Budi Setia
authors.initials: PB
authors.lastname: Asih
authors.forename: Din
authors.initials: D
authors.lastname: Syafruddin
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Kadota
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D029911:Caesalpinia / Q000737:chemistry*; D002738:Chloroquine / Q000494:pharmacology; D004224:Diterpenes / Q000737:chemistry / Q000494:pharmacology*; D004912:Erythrocytes / Q000469:parasitology; D006801:Humans; D066298:In Vitro Techniques; D007214:Indonesia; D002052:Myanmar; D010963:Plasmodium falciparum / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D000962:Antimalarials; D004224:Diterpenes; D002738:Chloroquine