title: Antimicrobial and antiparasitic abietane diterpenoids from the roots of Clerodendrum eriophyllum.
abstract: Chromatographic separation of the roots of a Kenyan medicinal plant, Clerodendrum eriophyllum, led to the isolation of ten abietane diterpenoids (1-10), one of which (1) was isolated for the first time from a natural source. Using spectroscopic data, the structure of 1 was determined to be 12-hydroxy-8,12-abietadiene-3,11,14-trione. Circular dichroism (CD) spectra showed that the stereochemistry of compounds 1, 3, and 6-8 belongs to the normal series of abietane diterpenes, which confirmed the absolute stereochemistry of the isolated compounds. Compounds 1-10 were evaluated for their in vitro antiplasmodial, antileishmanial, antifungal and antibacterial activities. Compounds 3 and 7 exhibited potent antifungal activity (IC50/MIC 0.58/1.25 and 0.96/2.5 microg/mL, respectively) against C. neoformans, whereas 3, 6 and 7 showed strong antibacterial activity against Staphylococcus aureus and methicillin-resistant S. aureus with IC50/MIC values between 1.33-1.75/2.5-5 and 0.96-1.56/2.5 microg/mL, respectively. In addition, compounds 3 and 9 exhibited potent antileishmanial activity (IC50 0.08 and 0.20 microg/mL, respectively) against L. donovani, while 3 and 7 displayed weak antimalarial activity against Plasmodium falciparum, but 9 was inactive.
authors.affiliation: Department of Chemistry, University of Nairobi, P.O. Box 30197 (00100), Nairobi, Kenya.
authors.forename: Francis
authors.initials: F
authors.lastname: Machumi
authors.forename: Volodymyr
authors.initials: V
authors.lastname: Samoylenko
authors.forename: Abiy
authors.initials: A
authors.lastname: Yenesew
authors.forename: Solomon
authors.initials: S
authors.lastname: Derese
authors.forename: Jacob O
authors.initials: JO
authors.lastname: Midiwo
authors.forename: Frank T
authors.initials: FT
authors.lastname: Wiggers
authors.forename: Melissa R
authors.initials: MR
authors.lastname: Jacob
authors.forename: Babu L
authors.initials: BL
authors.lastname: Tekwani
authors.forename: Shabana I
authors.initials: SI
authors.lastname: Khan
authors.forename: Larry A
authors.initials: LA
authors.lastname: Walker
authors.forename: Ilias
authors.initials: I
authors.lastname: Muhammad
mesh_terms: D045784:Abietanes / Q000737:chemistry* / Q000494:pharmacology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D000977:Antiparasitic Agents / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D002522:Chlorocebus aethiops; D032409:Clerodendrum / Q000737:chemistry*; D003603:Cytotoxins / Q000737:chemistry / Q000494:pharmacology; D005658:Fungi / Q000187:drug effects; D007893:Leishmania donovani / Q000187:drug effects; D015394:Molecular Structure; D018517:Plant Roots / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000187:drug effects; D014709:Vero Cells
chemical_list: D045784:Abietanes; D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D000977:Antiparasitic Agents; D003603:Cytotoxins