Li-Li Lou

Antioxidant and anti-inflammatory neolignans from the seeds of hawthorn.

Seven new neolignans (1-2, 7-11) and five known compounds (3-6, 12) were isolated from the 70% EtOH extract of hawthorn seeds. Their structures were determined by spectroscopic analyses. The antioxidant and anti-inflammatory activities of all the isolates were investigated. Most of the isolates showed moderate radical scavenging activity in the DPPH assay and significant activities in the ABTS and FRAP assays. Furthermore, compounds 7-12 exhibited marked nitric oxide (NO) inhibition and compounds 1-4 had a potent necrosis factor-α (TNF-α) inhibitory effect. The results we obtained showed that hawthorn seeds can be regarded as a potential new and cheap source of antioxidants and inflammation inhibitors.

3, 3′-Neolignans from Pithecellobium clypearia Benth and their anti-inflammatory activity

Abstract The twigs and leaves of Pithecellobium clypearia Benth have been used as a folk medicine for the treatment of diseases related to inflammation in southern China for many years. To search for novel bioactive constituents as lead structures for anti-inflammatory drug development, seven new 3, 3′-neolignans ( 1 – 7 ), together with four known ones ( 8 – 11 ) were isolated from the 70% EtOH extract of the twigs and leaves of P. clypearia . Their structures were determined by spectroscopic analyses, especially the 1D, 2D NMR and CD spectra. The antioxidant and anti-inflammatory activities of all the isolated compounds were investigated. Among them, compound 11 showed promising activity against nitric oxide (NO) and considerable antioxidant activity. These findings will help in the effective use of P. clypearia as a valuable source of novel compounds for the prevention and treatment of inflammation-related disorders.

Enantiomeric neolignans from Picrasma quassioides exhibit distinctive cytotoxicity on hepatic carcinoma cells through ROS generation and apoptosis induction

Three pairs of enantiomeric neolignans 1a/1b-3a/3b were isolated from the stems of Picrasma quassioides, and separated successfully by chiral-phase HPLC. Their structures were established by comprehensive spectroscopic analyses as well as ECD spectroscopy. The in vitro cytotoxicity of the isolates was evaluated against human hepatocellular carcinoma HepG2 and Hep3B cells. Among them, 1 and its enantiomers 1a/1b, 3 and 3a/3b displayed similar cytotoxicity in pair-wise comparison against HepG2 and Hep3B cells, and the similar effects of 2 and 2a/2b were found in Hep3B cells. Interestingly, 2a and 2b had different cytotoxic activities on HepG2 cells with IC50 values of 35.6 μM and 104.4 μM, respectively. In addition, 2 exerted middle cytotoxicity against HepG2 cells with an IC50 value of 78.6 μM. The different cytotoxicity between enantiomers 2a and 2b attracted our interest. To investigate the underlying mechanisms responsible for the distinct cytotoxicity, we further assessed the effects of 2a and 2b on cell cycle distribution, cell apoptosis and reactive oxygen species (ROS) generation. The results indicated that 2a had more significant effect than 2b on apoptosis induction and ROS generation, but both had no obvious effect on cell cycle of HepG2 cells. It is concluded that the different configurations of 2a/2b determined the enantioselective cytotoxicity on HepG2 cells through apoptosis induction and ROS generation.

A new coumarin from Juglans mandshurica Maxim induce apoptosis in hepatocarcinoma cells

Abstract In this study, a new coumarin, juglansoside C (1) was isolated from the bark of Juglans mandshurica. Its chemical structure was identified by comprehensive spectroscopic analyses. The in vitro cytotoxicity assay showed that 1 exhibited moderate cytotoxicity against human hepatocellular carcinoma Hep3B cells with an IC50 value of 70.9 μM. Furthermore, Annexin V-FITC/PI staining assay indicated that 1 markedly induced apoptosis in Hep3B cells.

Chemical constituents from the roots of Tripterygium wilfordii and their cytotoxic activity.

Abstract In our ongoing search for bioactive constituents, a new sesquiterpene polyol ester, named triptersinine U (1), together with five known triterpenes (2–6) and seven sesquiterpene pyridine alkaloids (7–13), were isolated from the roots of Tripterygium wilfordii Hook. f. Their chemical structures were elucidated using extensive spectroscopic analyses, including 1D and 2D NMR, and HRESIMS, as well as comparison with previously reported data. Cytotoxic activities of all compounds 1–13 were evaluated against six human tumor cell lines (HepG2, Hep3B, Bcap37, U251, MCF-7 and A549) using the MTT in vitro assay. The results showed that triterpenes exhibited moderate cytotoxic activities toward the tested cell lines.