Bioactive steroidal alkaloids from Buxus macowanii Oliv

Cheuk W Lam; Andrew Wakeman; Abin James; Athar Ata; Robert M Gengan; Samir A Ross

doi:10.1016/j.steroids.2014.12.002

Bioactive steroidal alkaloids from Buxus macowanii Oliv

Steroids. 2015 Mar:95:73-9. doi: 10.1016/j.steroids.2014.12.002. Epub 2014 Dec 18.

Authors

Cheuk W Lam¹, Andrew Wakeman², Abin James², Athar Ata³, Robert M Gengan⁴, Samir A Ross⁵

Affiliations

¹ Department of Chemistry, Richardson College for the Environmental and Science Complex, The University of Winnipeg, 599 Portage Avenue, Winnipeg, MB R3B 2G3, Canada; Department of Chemistry, The University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
² Department of Chemistry, Richardson College for the Environmental and Science Complex, The University of Winnipeg, 599 Portage Avenue, Winnipeg, MB R3B 2G3, Canada.
³ Department of Chemistry, Richardson College for the Environmental and Science Complex, The University of Winnipeg, 599 Portage Avenue, Winnipeg, MB R3B 2G3, Canada. Electronic address: a.ata@uwinnipeg.ca.
⁴ Department of Chemistry, Durban University of Technology, Durban, South Africa.
⁵ National Center for Natural Products Research, Department of Pharmacognosy, School of Pharmacy, University of Mississippi, MS 38677, USA.

PMID: 25528196
DOI: 10.1016/j.steroids.2014.12.002

Abstract

Chemical investigation of the crude methanolic extract of Buxus macowanii resulted in the isolation of five new steroidal alkaloids, 31-hydroxybuxatrienone (1), macowanioxazine (2), 16α-hydroxymacowanitriene (3), macowanitriene (4), macowamine (5), along with five known steroidal bases, Nb-demethylpapillotrienine (6), moenjodaramine (7), irehine (8), buxbodine B (9) and buxmicrophylline C (10). Structures of compounds 1-10 were elucidated with the aid of spectroscopic methods including 1D and 2D NMR techniques and mass spectrometry. Compounds 1, 3, and 4 belong to a rare class of Buxus alkaloids having Δ(1,2) 9(10→19) abeo triene system. All isolates were evaluated for in vitro acetylcholinesterase (AChE) inhibitory activity and found to exhibit moderate to weak anti-AChE activity with IC50 values in the range of 10.8-98μM. Compounds 1 and 6 were also moderately active in BACE1 inhibitory assay.

Keywords: 16α-Hydroxymacowanitriene; 31-Hydroxybuxatrienone; Acetylcholinesterase inhibitory activity; Buxus macowanii; Macowamine; Macowanioxazine.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acetylcholinesterase / metabolism
Alkaloids / chemistry*
Alkaloids / isolation & purification
Alkaloids / pharmacology*
Amyloid Precursor Protein Secretases / antagonists & inhibitors
Buxus / chemistry*
Cholinesterase Inhibitors / chemistry*
Cholinesterase Inhibitors / isolation & purification
Cholinesterase Inhibitors / pharmacology*
Inhibitory Concentration 50
Steroids / chemistry*

Substances

Alkaloids
Cholinesterase Inhibitors
Steroids
Acetylcholinesterase
Amyloid Precursor Protein Secretases