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A concise method was established to determine the relative and absolute configurations of aryl-glycerols that depend on the chemical shift differences (Δδ) of the diastereotopic methylene protons (H-3) by 1H NMR spectroscopy. When using DMSO-d6 as the preferred solvent, the threo configuration corresponded to a larger ΔδH3a–H3b value (>0.15 ppm), whereas the erythro configuration ( 0.20 ppm. In the erythro enantiomers, the Δδ value of 1R,2S was >0.09 ppm, and that of 1S,2R was

New phloroglucinol glycosides, aglycones, and oxidative dearomatized products of aglycones were discovered from Agrimonia pilosa, and the mechanism of the auto oxidative dearomatization was disclosed as a free radical chain reaction with 3O2.

One new tanshinone derivative, which possesses an unusual 6/6/5/6 fused-ring skeleton system (1), together with four new five-membered lactone benzohexa-membered ring compounds (2, 3, 4A and 4B), and three new carboxyl substituted 5,5-spiroketal compounds (5–7), were isolated from the dried rhizomes of Salvia miltiorrhiza. The structures of these compounds were determined by multiple spectral analyses (UV, IR, NMR, and HR-ESI-MS). In addition, the absolute configurations were established by X-ray diffraction experiments, calculated and experimental circular dichroism spectra. Evaluation of antitumor activity showed that 1 had strong cytotoxicity to tumor-repopulating cells (TRCs) with an IC50 value of 2.83 μM. In the evaluation of neuroprotective activity, 4A and 6 showed a strong improvement in the survival rates of SK-N-SH cell injury induced by oxygen glucose deprivation (OGD).

Six methyl-substituted phloroglucinol glycosides (1-6) were isolated from

A concise method was established to determine the relative and absolute configurations of aryl-glycerols that depend on the chemical shift differences (Δ

One new tanshinone derivative, which possesses an unusual 6/6/5/6 fused-ring skeleton system (1), together with four new five-membered lactone benzohexa-membered ring compounds (2, 3, 4A and 4B), and three new carboxyl substituted 5,5-spiroketal compounds (5-7), were isolated from the dried rhizomes of

Lycium chinense Mill. is a deciduous shrub in the Solanaceae family that is known for its fruits (Lycii fructus) and root bark (Lycii cortex). In our ongoing search for α-glucosidase inhibitors from the root bark of L. chinense, lyciumflavane A, one new flavane with an unusual benzofuran unit, one new amide possessing a naphthalene skeleton, one new sesquiterpene, three new lignan glucosides, and three new phenolic glucosides were isolated along with eight known compounds. Their structures were elucidated using NMR, HRESIMS, UV, ECD, and IR spectroscopic data. Their α-glucosidase inhibitory activity was screened using acarbose as a positive control (IC50 = 385 μM). Compound 1 showed strong inhibitory activity against α-glucosidase (IC50 = 20.89 μM).

Eleven new phthalide derivatives (1–11) have been isolated from the rhizome of Ligusticum chuanxiong. In particular, 1 and 2 contain a mercaptopropionic acid moiety in the phthalide derivatives. All the structures, including their absolute configurations, were determined by UV, IR, HRESIMS, 1D and 2D NMR spectroscopic measurements, and by a comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Results of a bioassay showed that compound 4 has a moderate neuroprotective activity on human neuroblastoma SH-SY5Y cell injury induced by H2O2 and oxygen glucose deprivation (OGD).

During our continuing study on the fruits of Forsythia suspensa, one new heterodimer (forsythoneoside E) containing a flavonoid and a phenethanoid glycoside formed through a pyran ring, one new phenylethanoid glycoside dimer (forsythoneoside F) with a C–O bond, along with a pair of flavonoid glycoside dimers (forsythobiflavone A and B) possessing different axial chirality, were obtained. Their chemical structures, including absolute configurations, were established by NMR, HRESIMS, UV, IR, and ECD spectroscopic data and comparison of experimental and calculated electronic circular dichroism (ECD) spectra. All of the compounds were evaluated for their neuroprotective effects against rotenone-induced neurotoxicity in PC12 cells at 1 μM.

Polyflavanostilbene B (1), an unusual adduct of epicatechin-3-O-gallate fused to piceid through a carbon–carbon bond, four new dimeric stilbene glycosides (2–5), three new stilbene glucosides (6–8), one new flavan glucoside (9), and six known compounds were isolated from the rhizome of Polygonum cuspidatum. The structures of these compounds were elucidated using spectroscopic data, including electronic circular dichroism (ECD) and Rh2(OCOCF3)4-induced CD spectra. All of the compounds were screened for their inhibitory activity against α-glucosidase using acarbose as a positive control (IC50 = 385 μM), and strong inhibitory activity against α-glucosidase was observed for compound 8 (IC50 = 3.04 μM).