Bioactive chemical constituents of Duboscia macrocarpa Bocq., and X-ray diffraction study of 11β, 12β-epoxyfriedours-14-en-3α-ol

Ramsay S T Kamdem; Pascal Wafo; Amadou Dawe; Dieu Ne Dort Nganteng; Umeokoli Blessing Ogechukwu; Saima Rasheed; Omeje E Ogechukwu; Gamall Makhloufi; Zulfiqar Ali; Ikhlas A Khan; Muhammad Iqbal Choudhary; Christoph Janiak; Peter Proksch

doi:10.1016/j.fitote.2017.12.015

Bioactive chemical constituents of Duboscia macrocarpa Bocq., and X-ray diffraction study of 11β, 12β-epoxyfriedours-14-en-3α-ol

Fitoterapia. 2018 Mar:125:65-71. doi: 10.1016/j.fitote.2017.12.015. Epub 2017 Dec 19.

Affiliations

¹ Institute of Pharmaceutical Biology and Biotechnology, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany; Department of Organic Chemistry, Higher Teachers Training College, the University of Yaounde I, P.O. Box 47, Yaounde, Cameroon. Electronic address: Ramsay.Kamdem@uni-duesseldorf.de.
² Department of Organic Chemistry, Higher Teachers Training College, the University of Yaounde I, P.O. Box 47, Yaounde, Cameroon.
³ Department of Chemistry, Higher Teachers Training College, the University of Maroua I, P.O. Box 47, Maroua, Cameroon.
⁴ Institute of Pharmaceutical Biology and Biotechnology, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany; Department of Pharmaceutical and Medicinal Chemistry, Nnamdi Azikiwe University, Awka, Nigeria.
⁵ H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
⁶ Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Nigeria, 410001 Nsukka, Enugu State, Nigeria.
⁷ Institute of Inorganic and Structural Chemistry, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
⁸ National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Oxford, MS 38655, USA.
⁹ Institute of Pharmaceutical Biology and Biotechnology, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany.

PMID: 29273414
DOI: 10.1016/j.fitote.2017.12.015

Abstract

A new γ-lactone triterpenoid, Evodoulolide (1) and a new triterpenoid Duboscic acid B (2), along with five known compounds, maslinic acid (3), arboreic acid (4), (E)-3-(4-hydroxyphenyl)-N-[2-(4-hydroxyphenyl) ethyl] prop-2-enamide (5), (E)-heptacos-19-enoic acid (6) and 11β,12β-epoxyfriedours-14-en-3α-ol (7) were isolated from the trunk wood of Duboscia macrocarpa. Their structures were elucidated from extensive ¹D- and ²D-NMR and MS and by comparison of their spectra with published data. Compounds 1, 3, 5 and 6 exhibited significant α-glucosidase inhibitory activity. Compound 5 was found to be a potent inhibitor (IC₅₀=5.1±0.1μM) of α-glucosidase as compared to acarbose (IC₅₀=625.0±1μM) used as standard drug. These compounds did not show anti-glycation activity using the BSA-MG glycation model or inhibition against the α-chymotrypsin enzyme. The chemotaxonomic connotation of the isolated secondary metabolites is also herein described. The single-crystal X-ray and absolute configuration diffraction analysis of 11α, 12α-epoxyfriedours-14-en-3-ol (7) is also described here for the first time.

Keywords: Duboscia macrocarpa Bocq.; Duboscic acid B; Evodoulolide; Molecular structure; Triterpenes.

MeSH terms

Glycoside Hydrolase Inhibitors / chemistry*
Glycoside Hydrolase Inhibitors / isolation & purification
Malvaceae / chemistry*
Molecular Structure
Triterpenes / isolation & purification*
Wood / chemistry*
X-Ray Diffraction
alpha-Glucosidases

Substances

Glycoside Hydrolase Inhibitors
Triterpenes
duboscic acid
maslinic acid
alpha-Glucosidases