Screening 5-lipoxygenase inhibitors from selected traditional Chinese medicines and isolation of the active compounds from Polygoni Cuspidati Rhizoma by an on-line bioactivity evaluation system.

To identify natural products as new prototypes for 5-lipoxygenase (5-LOX), 12 traditional Chinese medicines (TCMs) were selected for screening their 5-LOX inhibition activities. The results showed that the methanol extracts of all selected TCMs (n = 12) possessed inhibitory activities against 5-LOX at 200 µg/mL, of which six extracts of the TCMs showed significant inhibitory effects with IC50 values in the range from 33.2 ± 1.4 µg/mL to 153.5 ± 1.7 µg/mL, and the extract of Polygoni Cuspidati Rhizoma (RPC) was the most active sample. An on-line ultra-performance liquid chromatography-photodiode array-MSn -5-LOX-fluorescence detector (UPLC-PDA-MSn -5-LOX-FLD) method was applied to further identify the potential 5-LOX inhibitory constituents in RPC extracts, which resulted in the identification of seven components with 5-LOX-binding activities. Finally, four compounds (polydatin, resveratrol, emodin-8-O-glucoside, and emodin) were successfully purified from RPC extracts. The 5-LOX inhibition action was assayed in vitro, and the results showed that these compounds possessed potent inhibitory effects against 5-LOX with IC50 values of 15.3 ± 2.1, 4.5 ± 1.2, 23.8 ± 0.4, and 11.8 ± 1.5 µg/mL, respectively. This was the first study to reveal the 5-LOX inhibitory constituents of RPC, and the present investigation might provide a valuable approach for the rapid discovery of natural inhibitors from TCMs.

[Preparation and quality standard of standard decoction of Scrophulariae Radix pieces].

The standard decoction of Chinese herbal decoction pieces is a standard reference substance to measure whether different dosage forms of Chinese medicine are basically consistent with those of clinical decoction,and provides new ideas and methods for effectively solving the problems of uneven quality in Chinese medicine dispensing granules. In this study,a systematic method for evaluating the quality of Scrophulariae Radix decoction was established from the perspective of " standard decoction",providing reference for the quality control of the Scrophulariae Radix dispensing granules. 15 batches of Scrophulariae Radix decoction pieces from different origins were collected,and 15 batches of standard decoctions were prepared according to the standardized process with water as solvent.Harpagide and harpagoside were used as quantitative detection indicators to determine the content,calculate the transfer rates and determine the extraction rate. The high performance liquid chromatography( HPLC) was used to establish a standard decoction fingerprint analysis method. The results showed that the transfer rates of harpagide and harpagoside in 15 batches of Scrophulariae Radix pieces standard decoction were( 70. 84±13. 39) % and( 48. 56±6. 40) % respectively; the extraction rate was( 57. 47±5. 89) %. Nine peaks were identified in the HPLC fingerprint,and the similarity was higher than 0. 97 between the fingerprints of 15 batches of standard decoction and the control fingerprint. In this study,the preparation process of standard decoction of Scrophulariae Radix pieces conformed to the traditional decoction preparation method. The sources of the samples were representative,and the established fingerprint method was stable and feasible,which can provide reference for the preparation and quality control of Scrophulariae Radix dispensing granules.

LC-MS guided isolation of gracilistones A and B, a pair of diastereomeric sesquiterpenoids with an unusual tetrahydrofuran-fused tricyclic skeleton from Acanthopanax gracilistylus and their potential anti-inflammatory activities.

Gracilistones A (1) and B (2), two new eudesmane-type sesquiterpenoids with an unusual tetrahydrofuran-fused 6/6/5 tricyclic ring system, were obtained from Acanthopanax gracilistylus under the guidance of LC-MS investigation. Their structures and absolute configurations were assigned by extensive spectroscopic analyses and quantum calculation methods. Compounds 1 and 2 showed potent inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages, compared with the positive control L-NMMA. In addition, compounds 1 and 2 were also evaluated for their antioxidant (DPPH• and ABTS•+) and xanthine oxidase (XO) inhibitory activities, and they exhibited weak inhibitory effects at 100 µM.