title: New pregnane-type steroidal alkaloids from Sarcocca saligna and their cholinesterase inhibitory activity.
abstract: Five new steroidal alkaloids, 5,14-dehydro-N(a)-demethylsaracodine [3beta-N(a)-methyl-20S-N(b)-acetyl-N(b)-methylamino-pregn-5,14-diene] (1), 14-dehydro-N(a)-demethylsaracodine [3beta-N(a)-methyl-20S-N(b)-acetyl-N(b)-methylamino-5alpha-pregn-14-ene] (2), 16-dehydrosarcorine [(20S)-20-(N,N-dimethylamino)-3beta-(N(a)-acetylamido)-5alpha-pregn-16-ene] (3), 2,3-dehydrosarsalignone [(20S)-20-(N,N-dimethylamino)-3beta-(tigloylamino)-pregn-2,5-diene-4-one] (4), and 14,15-dehydrosarcovagine-D [(20S)-20-(N,N-dimethylamino)-3beta-(tigloylamino)-5alpha-pregn-2,14-diene-4-one] (5), were isolated from the ethanolic extract of Sarcococca saligna, along with two known bases, sarcovagenine-C (6) and salignarine-C (7). Their structures were elucidated on the basis of spectroscopic methods. All seven compounds were found to possess cholinesterase inhibitory potential in a concentration-dependent manner with the IC50 values ranging from 12.5 to 200 microM against acetylcholinesterase and from 1.25 to 32.2 microM against butyrylcholinesterase.
authors.affiliation: H.E.J. Research Institute of Chemistry, International Center for Chemical Sciences, University of Karachi, Karachi 75270, Pakistan.
authors.lastname: Atta-ur-Rahman
authors.forename: Fareeda
authors.initials: F
authors.lastname: Feroz
authors.forename: Ismat
authors.initials: I
authors.lastname: Naeem
authors.lastname: Zaheer-ul-Haq
authors.forename: Sarfraz Ahmad
authors.initials: SA
authors.lastname: Nawaz
authors.forename: Naeema
authors.initials: N
authors.lastname: Khan
authors.forename: M Riaz
authors.initials: MR
authors.lastname: Khan
authors.forename: M Iqbal
authors.initials: MI
authors.lastname: Choudhary
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000494:pharmacology; D002800:Cholinesterase Inhibitors / Q000737:chemistry; D002802:Cholinesterases / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000431:Ethanol / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D010936:Plant Extracts; D010944:Plants / Q000378:metabolism*; D011278:Pregnanes / Q000737:chemistry*; D013053:Spectrophotometry; D013256:Steroids / Q000737:chemistry / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D000470:Alkaloids; D002800:Cholinesterase Inhibitors; D004791:Enzyme Inhibitors; D010936:Plant Extracts; D011278:Pregnanes; D013256:Steroids; C442166:sarcovagine A; D000431:Ethanol; D002802:Cholinesterases