Spirosteroids and α-glucosidase inhibitory norlignans from Asparagus racemosus Willd. roots

Cholpisut Tantapakul; Boonyanoot Chaiyosang; Trinop Promgool; Apisara Somteds; Virayu Suthiphasilp; Kwanjai Kanokmedhakul; Surat Laphookhieo; Raymond J Andersen; Brian O Patrick; Somdej Kanokmedhakul

doi:10.1016/j.phytochem.2020.112439

Spirosteroids and α-glucosidase inhibitory norlignans from Asparagus racemosus Willd. roots

Phytochemistry. 2020 Sep:177:112439. doi: 10.1016/j.phytochem.2020.112439. Epub 2020 Jun 18.

Affiliations

¹ Natural Products Research Unit, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand; The Research Unit of Natural Product Utilization, School of Science, Walailak University, Thasala, Nakhon Si Thammarat, 80161, Thailand.
² Natural Products Research Unit, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
³ Center of Chemical Innovation for Sustainability (CIS) and School of Science, Mae Fah Luang University, Tasud, Muang, Chiang Rai, 57100, Thailand.
⁴ Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada; Department of Earth, Ocean & Atmospheric Sciences, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
⁵ Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.
⁶ Natural Products Research Unit, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand. Electronic address: somdej@kku.ac.th.

PMID: 32562917
DOI: 10.1016/j.phytochem.2020.112439

Abstract

Three undescribed spirosteroids, asparacemosones A-C, an undescribed spiro-21-norsteroid, asparacemosone D, along with seven known compounds were isolated from Thai herbal plant Asparagus racemosus Willd. roots. Their structures were elucidated by spectroscopic analysis including NMR, UV, IR and mass spectrometry. The absolute configurations of asparacemosones A, B, and D were determined by single crystal X-ray diffraction using CuKα radiation. Among the isolated compounds, the norlignan nyasol and three acetylenic norlignans demonstrated potent α-glucosidase inhibition, with IC₅₀ values ranging from 0.003 to 0.004 μM which is 5 × 10⁴ fold more potent than the standard acarbose.

Keywords: Asparacemosone; Asparagaceae; Asparagus racemosus; Norlignan; Shatavari; Spioro-21-norsteroid; Spirosteroid; α-Glucosidase inhibition.

MeSH terms

Asparagus Plant*
Plant Extracts
Plant Roots
alpha-Glucosidases*

Substances

Plant Extracts
alpha-Glucosidases