Search

Four new sesquiterpenes (1-2, 6-7), a new pyranone glycoside (10) along with six known compounds, were isolated from the whole plant of Erigeron breviscapus. Their planar structures were elucidated using extensive spectroscopic analyses. Brevisterpene A (1) and brevisterpene B (2) were proved to be a pair of diastereomer followed by mixtures resolution using chiral HPLC. Their absolute configurations were determined by ECD calculation. The relative configuration of brevisnoside B (7) was elucidated by a combined analysis of NOESY spectrum and computation of 13 C NMR chemical shifts, and determination of the absolute configurations of 6 and 7 assisted by optical rotation calculations. Compounds 1 and 2 displayed moderate neuroprotective effects against H 2 O 2 -induced damage in SH-SY5Y cells., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Sarsasapogenin, an active ingredient in Rhizoma anemarrhenae, is a promising bioactive lead compound in the treatment of Alzheimer's disease. To search for more efficient anti-Alzheimer agents, a series of novel sarsasapogenin-triazolyl hybrids were designed, synthesized, and evaluated for their Aβ 1-42 aggregation inhibitory activities. Most of these new hybrids displayed potent Aβ 1-42 aggregation inhibition. In particular, the promising compounds 6j and 6o displayed a better ability to interrupt the formation of Aβ 1-42 fibrils than curcumin. Moreover, 6j and 6o exhibited moderate neuroprotective effects against H 2 O 2 -induced neurotoxicity in SH-SY5Y cells. To investigate whether 6j and 6o could improve cognitive deficits, we performed behavioral tests to examine the learning and memory impairments induced by intracerebroventricular injection of Aβ 1-42 (ICV-Aβ 1-42 ) in mice and TUNEL staining to observe neuronal apoptosis in the hippocampus. The results obtained indicated that oral treatment with 6j and 6o significantly ameliorated cognitive impairments in behavioral tests and TUNEL staining showed that 6j and 6o attenuated neuronal loss in the brain. Taken together, the results we obtained showed that the sarsasapogenin skeleton could be a promising structural template for the development of new anti-Alzheimer drug candidates, and compounds 6j and 6o have the potential to be important lead compounds for further research., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Main observation and conclusion: Nine undescribed dihydro‐β‐agarofuran sesquiterpenoid derivatives (1—9), along with a known analogue (10), were obtained from the leaves of Tripterygium wilfordii. Their gross structures were determined via extensive spectroscopic data, and the absolute configurations were elucidated by means of single‐crystal X‐ray diffraction analysis and electron circular dichroism (ECD) techniques, which include ECD exciton chirality, octant rule of saturated cyclohexanone and comparison between the experimental and calculated ECD spectra. All the isolated compounds were tested for their neuroprotective activities against H2O2‐induced cell injury in human neuroblastoma SH‐SY5Y cells. Compounds 5 and 6 improved cell viability by 16.15% and 15.12% compared with the H2O2 treated group at 25 μmol·L–1, respectively. [ABSTRACT FROM AUTHOR]