TY - JOUR

T1 - Serrulatane diterpenoids with unusual side chain modifications from root bark of Eremophila longifolia

AU - Rasmussen, Line Fentz

AU - Anton, Jennifer

AU - Kjaerulff, Louise

AU - Zhao, Yong

AU - Semple, Susan J.

AU - Ndi, Chi

AU - Buirchell, Bevan

AU - Møller, Birger Lindberg

AU - Stærk, Dan

PY - 2022

Y1 - 2022

N2 - The plant genus Eremophila is endemic to Australia and widespread in arid regions. Root bark extract of Eremophila longifolia (R.Br.) F.Muell. (Scrophulariaceae) was investigated by LC-PDA-HRMS, and dereplication suggested the presence of a series of diterpenoids. Using a combination of preparative- and analytical-scale HPLC separation as well as extensive 1D and 2D NMR analysis, the structures of 12 hitherto unreported serrulatane diterpenoids, eremolongine A-L, were established. These structures included serrulatanes with unusual side chain modifications to form hitherto unseen skeletons with, e.g., cyclopentane, oxepane, and bicyclic hexahydro-1H-cyclopenta[c]furan moieties. Serrulatane diterpenoids in Eremophila have recently been shown to originate from a common biosynthetic precursor with conserved stereochemical configuration, and this was used for tentative assignment of the relative and absolute configuration of the isolated compounds. Triple high-resolution α-glucosidase/α-amylase/PTP1B inhibition profiling demonstrated that several of the eremolongines had weak inhibitory activity towards targets important for management of type 2 diabetes.

AB - The plant genus Eremophila is endemic to Australia and widespread in arid regions. Root bark extract of Eremophila longifolia (R.Br.) F.Muell. (Scrophulariaceae) was investigated by LC-PDA-HRMS, and dereplication suggested the presence of a series of diterpenoids. Using a combination of preparative- and analytical-scale HPLC separation as well as extensive 1D and 2D NMR analysis, the structures of 12 hitherto unreported serrulatane diterpenoids, eremolongine A-L, were established. These structures included serrulatanes with unusual side chain modifications to form hitherto unseen skeletons with, e.g., cyclopentane, oxepane, and bicyclic hexahydro-1H-cyclopenta[c]furan moieties. Serrulatane diterpenoids in Eremophila have recently been shown to originate from a common biosynthetic precursor with conserved stereochemical configuration, and this was used for tentative assignment of the relative and absolute configuration of the isolated compounds. Triple high-resolution α-glucosidase/α-amylase/PTP1B inhibition profiling demonstrated that several of the eremolongines had weak inhibitory activity towards targets important for management of type 2 diabetes.

U2 - 10.1016/j.phytochem.2022.113408

DO - 10.1016/j.phytochem.2022.113408

M3 - Journal article

C2 - 36063865

VL - 203

JO - Phytochemistry

JF - Phytochemistry

SN - 0031-9422

M1 - 113408

ER -