ent-Clerodane diterpenoids from the stems of Croton krabas

Oue-Artorn Rajachan; Waranya Lakornwong; Siripit Pitchuanchom; Natcha P Suchaichit; Jaursup Boonmak; Sujittra Youngme; Kwanjai Kanokmedhakul; Somdej Kanokmedhakul

doi:10.1016/j.fitote.2021.104912

ent-Clerodane diterpenoids from the stems of Croton krabas

Fitoterapia. 2021 Jul:152:104912. doi: 10.1016/j.fitote.2021.104912. Epub 2021 Apr 29.

Authors

Oue-Artorn Rajachan¹, Waranya Lakornwong², Siripit Pitchuanchom³, Natcha P Suchaichit⁴, Jaursup Boonmak⁵, Sujittra Youngme⁵, Kwanjai Kanokmedhakul², Somdej Kanokmedhakul²

Affiliations

¹ Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand. Electronic address: oueartorn.r@msu.ac.th.
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 Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand.
⁴ Department of Applied Chemistry, Faculty of Sciences and Liberal Arts, Rajamangala University of Technology Isan, Nakhon Ratchasima 30000, Thailand.
⁵ Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.

PMID: 33933538
DOI: 10.1016/j.fitote.2021.104912

Abstract

The first phytochemical investigation from the stems of Croton krabas resulted in the isolation of three new ent-clerodane diterpenoids, crotonkrabases A-C (1-3), along with two known compounds, 12-oxohardwickiic acid (4) and crotonpyrone B (5). Their structures were elucidated using extensive spectroscopic methods. The structure of 3 was unambiguously proven by X-ray crystallography. Furthermore, the absolute configurations of compounds 1-3 were identified by NOESY and the comparison of their experimental ECD spectra with those of calculated ECD spectra reported in the literature. Compounds 1, 2, and 5 showed antibacterial activities against two Gram-positive bacteria (Bacillus cereus and Bacillus subtilis); whereas compound 4 exhibited weak antibacterial against B. cereus. In addition, compound 4 showed potent α-glucosidase inhibitory activity, which was lower than the reference standard acarbose.

Keywords: Antibacterial; Clerodane diterpenoids; Croton krabas; Euphorbiaceae; α-Glucosidase inhibition.

MeSH terms

Anti-Bacterial Agents / isolation & purification
Anti-Bacterial Agents / pharmacology*
Bacillus / drug effects
Croton / chemistry*
Diterpenes, Clerodane / isolation & purification
Diterpenes, Clerodane / pharmacology*
Glycoside Hydrolase Inhibitors / isolation & purification
Glycoside Hydrolase Inhibitors / pharmacology*
Phytochemicals / isolation & purification
Phytochemicals / pharmacology
Plant Stems / chemistry
Thailand

Substances

Anti-Bacterial Agents
Diterpenes, Clerodane
Glycoside Hydrolase Inhibitors
Phytochemicals