title: Three new cholinesterase-inhibiting cis-clerodane diterpenoids from Otostegia limbata.
abstract: Three new tricyclic cis-clerodane type diterpenoids trivially named as limbatolide A (1), limbatolide B (2) and limbatolide C (3) have been isolated from the roots of Otostegia limbata along with two known compounds; oleanic acid and beta-sitosterol. The structure elucidation of the new compounds was based primarily on two-dimensional (2D) NMR techniques. Compounds 1-3 displayed inhibitory potential in a concentration-dependent manner against acetylcholinesterase (AChE; EC 3.1.1.7) and butyrylcholinesterase (BChE; EC 3.1.1.8) enzymes, respectively.
authors.affiliation: International Center for Chemical Sciences, H.E.J. Research Institute of Chemistry, University of Karachi, Pakistan. vuahmad@cybernet.pk
authors.forename: Viqar Uddin
authors.initials: VU
authors.lastname: Ahmad
authors.forename: Afsar
authors.initials: A
authors.lastname: Khan
authors.forename: Umar
authors.initials: U
authors.lastname: Farooq
authors.forename: Farzana
authors.initials: F
authors.lastname: Kousar
authors.forename: Saleha Suleman
authors.initials: SS
authors.lastname: Khan
authors.forename: Sarfraz Ahmad
authors.initials: SA
authors.lastname: Nawaz
authors.forename: Muhammad Athar
authors.initials: MA
authors.lastname: Abbasi
authors.forename: Muhammad Iqbal
authors.initials: MI
authors.lastname: Choudhary
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry / Q000378:metabolism; D002091:Butyrylcholinesterase / Q000737:chemistry / Q000378:metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002725:Chloroform; D002800:Cholinesterase Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D004224:Diterpenes / Q000302:isolation & purification / Q000494:pharmacology*; D045785:Diterpenes, Clerodane / Q000302:isolation & purification / Q000494:pharmacology*; D007700:Kinetics; D019686:Lamiaceae / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010936:Plant Extracts / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D012997:Solvents; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002800:Cholinesterase Inhibitors; D004224:Diterpenes; D045785:Diterpenes, Clerodane; D010936:Plant Extracts; D012997:Solvents; D002725:Chloroform; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase