Isolation and Structural Characterization of Echinocystic Acid Triterpenoid Saponins from the Australian Medicinal and Food Plant Acacia ligulata

Diana Jæger; Chi P Ndi; Christoph Crocoll; Bradley S Simpson; Bekzod Khakimov; Ruth Marian Guzman-Genuino; John D Hayball; Xiaohui Xing; Vincent Bulone; Philip Weinstein; Birger L Møller; Susan J Semple

doi:10.1021/acs.jnatprod.7b00437

Isolation and Structural Characterization of Echinocystic Acid Triterpenoid Saponins from the Australian Medicinal and Food Plant Acacia ligulata

J Nat Prod. 2017 Oct 27;80(10):2692-2698. doi: 10.1021/acs.jnatprod.7b00437. Epub 2017 Oct 4.

Authors

Diana Jæger^{1

2}, Chi P Ndi¹, Christoph Crocoll³, Bradley S Simpson⁴, Bekzod Khakimov⁵, Ruth Marian Guzman-Genuino^{1

6

7}, John D Hayball^{1

6

7}, Xiaohui Xing^{8

9}, Vincent Bulone^{8

9}, Philip Weinstein¹⁰, Birger L Møller², Susan J Semple¹

Affiliations

¹ Sansom Institute for Health Research, School of Pharmacy and Medical Sciences, University of South Australia , Adelaide, South Australia 5000, Australia.
² Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen , Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
³ DynaMo Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen , Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
⁴ Flinders Centre for Innovation in Cancer, Flinders University , Bedford Park, South Australia 5042, Australia.
⁵ Department of Food Science, Faculty of Science, University of Copenhagen , Rolighedsvej 26, DK-1958 Frederiksberg C, Denmark.
⁶ Experimental Therapeutics Laboratory, Hanson Institute and Sansom Institute , Adelaide, South Australia 5000, Australia.
⁷ Robinson Research Institute and Adelaide Medical School, University of Adelaide , Adelaide, South Australia 5005, Australia.
⁸ ARC Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, The University of Adelaide , Waite Campus, Urrbrae, 5064, Australia.
⁹ Division of Glycoscience, Royal Institute of Technology (KTH), School of Biotechnology, AlbaNova University Centre , Stockholm, SE-10691, Sweden.
¹⁰ Department of Ecology and Environmental Sciences, School of Biological Sciences, The University of Adelaide , Adelaide, South Australia 5005, Australia.

PMID: 28976773
DOI: 10.1021/acs.jnatprod.7b00437

Abstract

The Australian plant Acacia ligulata has a number of traditional food and medicinal uses by Australian Aboriginal people, although no bioactive compounds have previously been isolated from this species. Bioassay-guided fractionation of an ethanolic extract of the mature pods of A. ligulata led to the isolation of the two new echinocystic acid triterpenoid saponins, ligulatasides A (1) and B (2), which differ in the fine structure of their glycan substituents. Their structures were elucidated on the basis of 1D and 2D NMR, GC-MS, LC-MS/MS, and saccharide linkage analysis. These are the first isolated compounds from A. ligulata and the first fully elucidated structures of triterpenoid saponins from Acacia sensu stricto having echinocystic acid reported as the aglycone. Compounds 1 and 2 were evaluated for cytotoxic activity against a human melanoma cancer cell line (SK-MEL28) and a diploid fibroblast cell line (HFF), but showed only weak activity.

Publication types

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

MeSH terms

Acacia
Antineoplastic Agents, Phytogenic / chemistry
Australia
Drug Screening Assays, Antitumor
Fibroblasts / drug effects
Gas Chromatography-Mass Spectrometry
Humans
Molecular Structure
Nuclear Magnetic Resonance, Biomolecular
Oleanolic Acid / analogs & derivatives*
Oleanolic Acid / chemistry
Oleanolic Acid / isolation & purification
Oleanolic Acid / pharmacology
Saponins / chemistry
Saponins / isolation & purification*
Saponins / pharmacology*
Triterpenes / chemistry
Triterpenes / isolation & purification*
Triterpenes / pharmacology*

Substances

Antineoplastic Agents, Phytogenic
Saponins
Triterpenes
ligulataside A
ligulataside B
Oleanolic Acid
echinocystic acid