title: Semisynthesis of Derivatives of Oleanolic Acid from Syzygium aromaticum and Their Antinociceptive and Anti-Inflammatory Properties.
abstract: Oleanolic acid is a pentacyclic triterpenoid compound widely found in plants and well known for its medicinal properties. Oleanolic acid (OA) was isolated from the ethyl acetate extract of Syzygium aromaticum flower buds. Semisynthesis afforded both acetate and ester derivatives. The derived compounds were monitored with thin layer chromatography and confirmed with nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), Fourier infrared (FT-IR) spectroscopy, and melting point (Mp). All these compounds were evaluated for their analgesic and anti-inflammatory properties at a dose of 40 mg/kg. Significant analgesic and anti-inflammatory effects were noted for all OA-derived compounds. In the formalin-induced pain test, the derivatives showed better analgesic effects compared to their precursor, whereas, in the tale flick test, oleanolic acid proved to be superior in analgesic effects compared to all its derivatives with the exception of the acetyl derivative. Acute inflammatory tests showed that acetyl derivatives possessed better anti-inflammatory activity compared to the other compounds. In conclusion, semisynthesis of oleanolic acid yielded several derivatives with improved solubility and enhanced analgesic and anti-inflammatory properties.
authors.affiliation: Department of Chemistry, Faculty of Science and Agriculture, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa.
authors.forename: Sibusiso
authors.initials: S
authors.lastname: Rali
authors.affiliation: Department of Chemistry, Faculty of Science and Agriculture, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa.
authors.forename: Opeoluwa O
authors.identifier: 0000-0002-1240-3718
authors.initials: OO
authors.lastname: Oyedeji
authors.affiliation: Department of Human Biology, Faculty of Health Sciences, Walter Sisulu University, Private Bag X1, Mthatha 5117, South Africa.
authors.forename: Olukayode O
authors.initials: OO
authors.lastname: Aremu
authors.affiliation: Department of Chemical and Physical Sciences, Faculty of Natural Sciences, Walter Sisulu University, Private Bag X1, Mthatha 5117, South Africa.
authors.forename: Adebola O
authors.initials: AO
authors.lastname: Oyedeji
authors.affiliation: Department of Biological and Environmental Science, Faculty of Natural Sciences, Walter Sisulu University, Private Bag X1, Mthatha 5117, South Africa.
authors.forename: Benedicta N
authors.initials: BN
authors.lastname: Nkeh-Chungag
mesh_terms: D000700:Analgesics / Q000737:chemistry*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry*; D001681:Biological Assay; D005260:Female; D035264:Flowers / Q000737:chemistry; D007249:Inflammation; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D009828:Oleanolic Acid / Q000138:chemical synthesis / Q000737:chemistry*; D010936:Plant Extracts / Q000138:chemical synthesis / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D027842:Syzygium / Q000737:chemistry*; D013696:Temperature
chemical_list: D000700:Analgesics; D000893:Anti-Inflammatory Agents; D010936:Plant Extracts; D009828:Oleanolic Acid