Discovery of eudesmane-type sesquiterpenoids with neuroprotective effects from the roots of Chloranthus serratus.

Seven eudesmane-type sesquiterpenoids, including three pairs of racemic compounds (1a-3a and 1b-3b) and a sesquiterpenoid lactone (4), were obtained from the roots of Chloranthus serratus. The structures of these sesquiterpenoids were characterized based on spectroscopic analyses, ECD calculations, and X-ray diffraction experiment. Neuroprotection assays of the isolated eudesmane-type sesquiterpenoids were conducted on H2O2 damaged PC12 cells. At the concentration of 10 µM, compounds 1b and 4 increased cell viability from 54.8 ± 3.3% to 76.8 ± 2.3 and 72.7 ± 8.2%, respectively.

Sesquiterpenoids with neuroprotective activities from the Chloranthaceae plant Chloranthus henryi.

A rare sesquiterpenoid possessing a 6/6 bicyclic system fused with two clustered furan units and a pair of guaiane-type sesquiterpenoids were acquired from the roots of Chloranthus henryi. Their structures with absolute configurations were characterized with spectroscopic data, ECD, and X-ray diffraction analysis. All three sesquiterpenoids showed moderate neuroprotective activities on PC12 cells damaged with hydrogen peroxide.

Neuroprotective triterpene saponins from the leaves of Panax notoginseng.

Two new triterpene saponins, namely notoginsenoside Ng5 (1) and notoginsenoside Ng6 (2) were isolated from the leaves of Panax notoginseng, along with five known ones. Their structures were determined by chemical methods, NMR and X-ray experiments. The absolute configuration of compound 3 with four sugar units was confirmed by single crystal X-ray analysis. Compounds 2-4 and 6 inhibited PC12 cell damage induced by serum deprivation, and increased cell viability from 58.7 ± 6.7% to 66.7 ± 4.5%, 76.1 ± 6.1%, 64.7 ± 5.2% and 67.2 ± 5.0% at 10 µM, respectively.

Novel oligomeric neolignans with PTP1B inhibitory activity from the bark of Magnolia officinalis var. biloba.

The barks of Magnolia officinalis var. biloba, Magnoliae cortex, have been used as traditional Chinese medicines for several centuries. In this study, phytochemical investigation of M. officinalis var. biloba bark extract afforded five pairs of novel enantiomeric oligomeric neolignans, (±)-mooligomers A-E (1-5). (±)-1 and (±)-2 were two diastereomeric pairs of enantiomers with six C6-C3 subunits, and (±)-4 was a pair of previously unreported tetrameric neolignans bearing eight C6-C3 subunits. (±)-5 is the first example of a naturally occurring trilignan featuring an eight-membered ring with a magnolol moiety. The absolute configurations of (±)-1-(±)-5 were elucidated on the basis of HRESIMS, 1D and 2D NMR spectroscopy and electronic circular dichroism (ECD) calculations. Among the compounds tested for their PTP1B inhibitory activities, (±)-2, (±)-4 and (±)-5 displayed significant PTP1B inhibitory activities with IC50 values of 0.14-2.10 µM. Furthermore, a Molecular docking simulation of PTP1B and active compounds [(±)-2, (±)-4 and (±)-5] exhibited that these active compounds possess low binding affinities ranging from - 5.9 to - 7.7 kcal/mol.

Neuroprotective racemic germacranolides from the roots of Chloranthus henryi.

Three pairs of new germacranolides, (+)/(-)-chlogermacrones A-C, along with two known analogues were obtained from the roots of Chloranthus henryi. Spectroscopic techniques and single-crystal X-ray crystallographic analyses were used for the structure elucidation of the compounds. All of the isolated compounds were tested for their neuroprotective effects on H2O2 damaged PC12 cells, compounds 3 and 5 increased cell viability from 43.4 ± 1.3% to 99.6 ± 8.7 and 68.1 ± 4.8% at 10 µM, respectively.

Cytotoxic 9,19-cycloartane Triterpenoids from the Roots of Actaea dahurica.

Eight undescribed 9,19-cycloartane type triterpenoid glycosides (cimdalglnoside A-H) and ten known analogues were obtained from the phytochemical research on the roots of Actaea dahurica (syn. Cimicifuga dahurica). All compounds were characterised by spectroscopic experiments, and chemical method. All the compounds isolated were assayed for cytotoxicity to five human cancer cell lines. Cimdalglnoside G showed promising cytotoxicities against Hela, and MCF-7 cell lines with IC50 values at 7.7 and 12.2 µM.

Dihydroagarofuran sesquiterpenoids esterified with organic acids from the leaves of Tripterygium wilfordii.

Six new and one known dihydroagarofuran sesquiterpenoids esterified with organic acids were obtained from the leaves of Tripterygium wilfordii. Spectroscopic techniques (UV, IR, MS, NMR, ORD and CD) were used for the structure elucidation of the compounds. The structures of compounds 1 and 2 were confirmed by X-ray single crystallographic analyses. The inhibitory effects on NO production in LPS-induced macrophages of 1-7 were conducted. At 10 µmol/L, compounds 1, 2 and 7 showed moderate inhibitory effects on NO production in LPS-induced macrophages with inhibitory rate at 31.2 ±â€¯3.6, 40.9 ±â€¯4.3, and 66.79 ±â€¯3.1%, respectively.

Magmenthanes A-H: Eight new meroterpenoids from the bark of Magnolia officinalis var. Biloba.

Eight new meroterpenoids with different types of monoterpene units, namely, magmenthanes A-H (1-8), were identified from the bark of Magnolia officinalis var. biloba. Magmenthane A (1) possesses a 1,3-dioxabicyclo [4.3.01,5] nonane skeleton, 1-5 possess five pairs of enantiomers and 6 possesses a 1,1'-diallyl-biphenyl fragment. The structures of 1-8 were elucidated on the basis of 1D and 2D NMR, HRESIMS and electronic circular dichroism (ECD) calculations. Compounds 5 and 8 displayed significant PTP1B inhibitory activities with IC50 values of 4.38 and 3.88 µM, respectively.

Hepatoprotective glycosides from the rhizomes of Imperata cylindrical.

Three new C-methylated phenylpropanoid glycosides (1, 2), a new 8-4'-oxyneolignan (3), together with two known analogs (4, 5), were isolated from the rhizomes of Imperata cylindrical Beauv. var. major (Nees) C. E. Hubb. Their structures were determined by spectroscopic and chemical methods. Compounds 1, 2, and 5 (10 µM) exhibited pronounced hepatoprotective activity against N-acetyl-p-aminophenol (APAP)-induced HepG2 cell damage in vitro assays. Furthermore, their antioxidant activities against Fe2+-cysteine-induced rat liver microsomal lipid peroxidation and the effects on the secretion of TNF-α in murine peritoneal macrophages (RAW264.7) induced by lipopolysaccharides were evaluated.

Two new saponins from the leaves of Panax notoginseng.

Two new saponins, notoginsenosides Ng1 (1) and Ng2 (2), together with seven known compounds (3-9), were isolated from the leaves of Panax notoginseng. Their structures were elucidated by UV, IR, HRESIMS, and NMR experiments. Compounds 6 and 7 showed moderate cytotoxic activities against HCT-116, with IC50 values of 4.98 and 0.64 µmol/L, respectively.