Triterpenes from Archidendron clypearia (Jack) I.C.N. with anti-ß-amyloid aggregation activity.

A new triterpene as well as five known compounds were isolated from the twigs and leaves of Archidendron clypearia (Jack) I.C.N. Their structures were established by comprehensive spectroscopic analyses including 1D, 2D NMR and HRESIMS data. The ability of all isolated compounds to inhibit ß-amyloid aggregation was investigated by a ThT-based fluorometric assay. Among them, compounds 3 (67.8%) and 6 (77.7%) exhibited higher inhibitory activity than the positive (48.0%). In addition, molecular dynamics and molecular docking have been utilized to predict the detailed binding interaction between ligands and Aß1-42.

The identification of phenylpropanoids isolated from the root bark of Ailanthus altissima (Mill.) Swingle.

Chemical investigation of 75% EtOH exact of the root bark of Ailanthus altissima (Mill.) Swingle led to the isolation and identification of two new phenylpropanoids (1-2), along with six known compounds (3-8). Their chemical structures were elucidated by extensive spectroscopic data analyses including NMR experiments and HRESIMS analyses, as well as computer-assisted structure elucidation software (ACD/Spectrus Processor). All compounds were evaluated for cytotoxic activities against Hep 3B and Hep G2 cells. Compound 1 and 7 displayed weak cytotoxic activities against the Hep 3B cell line.

Benzoic acid derivatives from the root barks of Ailanthus altissima.

Two new benzoic acid derivatives (1-2), together with four known compounds (3-6) have been isolated from the n-BuOH soluble fraction of ethanolic extract from Ailanthus altissima. The gross structures of the new compounds were deduced by detailed spectroscopic analysis including HRESIMS and 1D/2D NMR spectroscopy. The stereochemistry of 1 was determined by modified Mosher's method. All compounds were evaluated for their neuroprotective effects against H2O2-induced oxidative stress in human neuroblastoma SH-SY5Y cells and none of them displayed obvious neuroprotective activities. [Formula: see text].

Structure elucidation of a new terpenylated coumarin with the combination of CASE algorithms and DFT/NMR approach.

One new terpenylated coumarin ailanthuscoumarin was isolated from the root barks of Ailanthus altissima (Mill.) Swingle. The high oxidation of the compound led to the difficulty of structure elucidation by 2D-NMR spectra. Its structure was determined with the aid of computer-assisted structure elucidation (CASE) expert systems and Gauge-independent atomic orbital (GIAO) NMR calculations. The absolute configuration of ailanthuscoumarin was determined by the comparison between the experimental and calculated electronic circular dichroism (ECD) spectra. The anti-hepatoma activity of ailanthuscoumarin against two human hepatoma cells (Hep3B, HepG2) was also reported.

Terpenylated coumarins from the root bark of Ailanthus altissima (Mill.) Swingle.

Seven undescribed terpenylated coumarins, named altissimacoumarin I-O, together with seven known compounds, altissimacoumarin C, altissimacoumarin E, altissimacoumarin G, altissimacoumarin H, puberulin, 7-(3-Methyl-2-butenyloxy)-6-methoxycoumarin and artelin were isolated from the root bark of Ailanthus altissima (Mill.) Swingle. Their structures were elucidated by comprehensive spectra data analysis, NMR calculation, DP4+ analysis and ACD/Structure Elucidator software simulation. The absolute configurations of altissimacoumarins K, L, M and N were determined by modified Mosher's method. All isolates were tested for their cytotoxic effect against two hepatoma carcinoma cell lines (HepG2, Hep3B). Altissimacoumarin C exhibited moderate cytotoxic effect against Hep3B cells, with IC50 of 45.21 µM.

Anti-ß-amyloid aggregation activity of enantiomeric furolactone-type lignans from Archidendron clypearia (Jack) I.C.N.

The phytochemical investigation on the twigs and leaves of Archidendron clypearia (Jack) I.C.N. led to the isolation of three pairs of furolactone-type lignans enantiomers, including a pair of new compounds (1R,5S,6S)-Kachiranol (1a) and (1S,5R,6R)-Kachiranol (1b) and four known compounds (2a/2b and 3a/3b). Separation of the furolactone-type lignans enantiomeric mixtures was achieved using chiral HPLC for the first time. Their structures were determined by spectroscopic analysis and comparison between the experimental and calculated electronic circular dichroism (ECD) spectra. All optical pure compounds were evaluated for their inhibitory effects on ß-amyloid aggregation by ThT assay. Among them, the inhibitory activity of the compound 1b (71.1%) was higher than the positive control (61.0%) and other compounds. In addition, molecular dynamics and molecular docking were employed to explore the binding relationship between the ligand and the receptor.

Chiral resolution and bioactivity of enantiomeric furofuran lignans from Juglans mandshurica Maxim.

Enantiomers have generally been reported mostly for racemic mixtures with a 1:1 ratio, as in that case there were weak Cotton effects in the ECD spectrum and negligible optical rotations. A furofuran lignan (sesamin), with a remarkable rotation and significant Cotton effects, was isolated from Juglans mandshurica Maxim. Subsequently, sesamin was resolved by chiral HPLC to afford a pair of enantiomers, (+)-sesamin (a) and (-)-sesamin (b), in a ratio of approximately 1:3. Their absolute configurations were determined by computational analysis of their electronic circular dichroism (ECD) spectrum. In addition, the pair of enantiomers were evaluated for the inhibition of self-induced Aß aggregation. Interestingly, (+)-sesamin (a) (67.7%) and (-)-sesamin (b) (80.6%) exhibited different degrees of anti-Aß aggregation activity. The different inhibition profiles were further explained by molecular dynamics and docking simulation study.

Enantiomeric 8,4'-type oxyneolignans from the root barks of Ailanthus altissima (Mill.) Swingle and their neuroprotective effects against H2O2-induced SH-SY5Y cells injury.

Ailanthus altissima Swingle is a deciduous tree, belonging to the Simaroubaceae family. Phytochemical investigation of the root barks of A. altissima showed the presence of eight pairs of enantiomeric 8,4'-type oxyneolignans (1a/1b-8a/8b) including nine undescribed compounds (1b, 2a, 3a/3b, 4a/4b, 5b, 7b, 8a). Their structures were elucidated by comprehensive spectroscopic analyses, and their absolute configurations were determined by comparison of the experimental and quantum chemical calculations of electronic circular dichroism (ECD) curves. In addition, their neuroprotective effects against H2O2-induced oxidative stress in human neuroblastoma SH-SY5Y cells were investigated. Among them, 4a, 4b, and 8b exhibited moderate neuroprotective activity.

Network pharmacology-based screening of the active ingredients and potential targets of the genus of Pithecellobium marthae (Britton & Killip) Niezgoda & Nevl for application to Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder associated with synaptic dysfunction, pathological accumulation of ß-amyloid (Aß), and neuronal loss. Given the prevalence of AD and the lack of effective long-term therapies, there is a pressing need to discover viable leads that can be developed into clinically approved drugs with disease-modifying effects. The analysis of current reported literatures confirms the importance of the plants of Pithecellobium genus as candidate against AD. Hence, it is necessary to identify selective anti-dementia agents from this genus. To explore potential compounds with marked effect on AD in Pithecellobium genus, a compound database based on the methods of network pharmacology prediction was established in this paper by constructing the compound-disease target network. The result showed that the most effective compound in the plants of this genus might be (7'R,8'R)-7'-methoxyl strebluslignanol, and the most potential target might be Macrophage colony-stimulating factor 1 receptor.

Investigation of chemical constituents of safflower and their tyrosinase inhibitory activity.

Investigation on bioactive chemical constituents of safflower led to the isolation of 10 compounds from the aqueous extract, including a new alkaloid (1), a new glucopyranoside (2), and 8 known compounds (3-10). The structures of two new compounds were elucidated on the basis of extensive spectral analyses, including 1D, 2D-NMR and HRESIMS. Biological research on the isolates indicated that compounds 3, 4 and 9 remarkably inhibited tyrosinase with IC50 at 0.11, 0.20 and 0.11 mM, respectively, compared with the positive control arbutin (0.26 mM). To investigate the interaction between enzyme and isolated compounds, an in silico docking study was carried out. The research provided valuable experience for phytochemistry and biological investigation on safflower.

Racemic phenylpropanoids from the root barks of Ailanthus altissima (Mill.) Swingle with cytotoxicity against hepatoma cells.

Four pairs of racemic phenylpropanoids (1a/1b-4a/4b), including five new compounds (1a/1b, 2a, 3a, and 4a) were obtained from the root barks of Ailanthus altissima (Mill.) Swingle. Their structures were determined by comprehensive spectroscopic analyses. The absolute configurations of the enantiomers were determined by comparison of the experimental ECD and OR with the calculated data. The antitumor activity of all isolates was evaluated against two human hepatoma carcinoma cells (HepG2 and Hep3B) in vitro. It was demonstrated that 1a/1b showed potent selective cytotoxicity against HepG2 cells. Additionally, 1a/1b could also induce apoptosis enantioselectively as demonstrated by Hoechst staining experiment.

Flavonoids and their derivatives with ß-amyloid aggregation inhibitory activity from the leaves and twigs of Pithecellobium clypearia Benth.

To explore potential compounds with marked effect on Alzheimer's disease (AD) in Pithecellobium clypearia Benth., nineteen compounds (1-19) were obtained, including two new flavonoid derivatives, named pithecellobiumol A (1) and pithecellobiumol B (2) and 17 flavonoids (3-19). Their structures were elucidated based on 1D and 2D-NMR spectra as well as HR-ESI-MS data. The absolute configurations of new compounds were assigned by comparing their experimental specific rotation or ECD curves with the calculated data. The inhibitory activity on Aß aggregation was screened by ThT assay, and compounds 7 (70.7%), 9 (86.5%), 10 (88.4%), 15 (86.1%) and 16 (87.7%) showed outstanding inhibition rate at 20µM compared to the positive control, curcumin (65.64%). In addition, docking study was performed to initially examine possible molecular mechanisms. Considering the important role of oxidative stress in AD, all the isolated compounds were tested for their H2O2-induced damage in human neuronblastoma SH-SY5Y cells. Among them, compound 16 (91.0%) was the most potent candidate in the treatment of AD.