Details

Autor(en) / Beteiligte

• Liang, Chao
• Ndi, Chi
• Semple, Susan J.
• Buirchell, Bevan
• Coriani, Sonia
• Møller, Birger Lindberg
• Staerk, Dan

Titel

Eremane, viscidane and isozizaene diterpenoids from the leaves of Eremophila rigida and their absolute configurations

Ist Teil von

• Phytochemistry (Oxford), 2024-03, Vol.219, p.113972-113972, Article 113972

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2024

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Previously undescribed eremane, viscidane, and isozizaene diterpenoids, eremorigidanes A-F, along with six known O-methylated flavonoids and three known triterpenoids were isolated and identified from the leaves of Eremophila rigida Chinnock by combined use of high-resolution PTP1B inhibition profiling, semipreparative- and analytical-scale HPLC separations, HPLC-PDA-HRMS analysis, and NMR spectroscopy. The absolute configuration of the unreported diterpenoids were determined by comparison of their experimental and calculated ECD spectra as well as by biosynthetic arguments. All isolates were evaluated for their PTP1B inhibitory activities, which revealed the flavonoid penduletin (3) to show inhibition with an IC50 value of 18.3 μM, and the triterpenoids 3,4-seco-olean-12-ene-3,28-dioic acid (15), oleanolic acid (16), and 3-oxo-oleanolic acid (17) to show inhibition with IC50 values of 55.7, 9.9, and 6.3 μM, respectively. The preliminary structure-activity relationship (SAR) of isolated flavonoids and triterpenoids is discussed. Plausible biosynthetic steps involved in eremane and isozizaene metabolism are presented and discussed. Investigation of leaf extract of Eremophila rigide (R.Br.) F.Muell. (Scrophulariaceae) revealed a series of hitherto unidentified eremane, viscidane and isozizaene diterpenoids. [Display omitted] •Eremophila rigida investigated by high-resolution PTP1B inhibition profiling.•Known O-methylated flavonoids and triterpenoids isolated and identified.•Six previously unknown eremane, viscidane, and isozizaene diterpenoids identified.•The absolute configuration of new diterpenoids determined by ECD calculation.•One flavonoid and three triterpenoids showed PTP1B inhibitory activity.