Optimization of extraction for Anemarrhena asphodeloides Bge. using silica gel-based vortex-homogenized matrix solid-phase dispersion and rapid identification of antioxidant substances.

A novel and simple method was established for the extraction and determination of seven compounds in Anemarrhena asphodeloides Bge. using silica gel-based vortex-homogenized matrix solid-phase dispersion and ultra-high performance liquid chromatography quadrupole-time of-flight mass spectrometer. The conditions for the extraction were optimized. Silica gel was used as the dispersant, 50% methanol-water was selected as an elution solvent and the grinding time was 3 min. Compared with the traditional ultrasonic-assisted extraction, the developed method was rapid and efficient. In order to screen potential antioxidants, extract dealing with the optimized method was applied to a polyamide chromatography column and a D-101 macroporous resin column. Fr.2.2 showed the highest antioxidant activities with the most content of flavonoid. A total of 25 peaks were identified from the active fraction. A 2,2'-diphenyl-1-picrylhydrazyl ultra-high performance liquid chromatography coupled with mass spectrometry approach was adopted for the rapid and exact screening and identification of antioxidant compounds. It indicated that flavonoids exhibited potential antioxidant activities. The antioxidant activities of nine monomeric compounds in vivo were tested. Structure-activity relationships were discussed. Five flavonoids with the concentration of 500 µg/mL would reduce the oxidative stress of PC12 cells that were induced with 2,2'-azobis[2-methylpropionamidine] dihydrochloride.

Improved bioautographic assay on TLC layers for qualitative and quantitative estimation of xanthine oxidase inhibitors and superoxide scavengers.

A new agar-free bioautographic assay for xanthine oxidase (XO) inhibitors and superoxide scavengers on TLC layers was developed and validated. Compared to the first version of TLC bioautographic agar overlay method, our bioautographic assay greatly improved the sensitivity and quantification ability. The limit of detection (LOD) of this assay was 0.017ng for allopurinol. Quantitative estimation of XO inhibitors and superoxide scavengers was achieved by densitometry scanning, expressed as allopurinol equivalents in millimoles on a per sample weight basis. This assay has acceptable accuracy (95.37-99.23%), intra-day and inter-day precisions (RSD, 2.56-6.69%), as well as intra-plate and inter-plate precisions (RSD, 2.93-9.62%). Six pure compounds and three herbal extracts were evaluated for their potential XO inhibitory and superoxide scavenging activity by this bioautographic assay on TLC layers. Four active components were separated, located and identified in Astragalus membranaceus var. mongholicus extract by the bioautographic assay after TLC separation. The developed method is rapid, simple, sensitive and stable for screening and estimation of the potential XO inhibitors and superoxide scavengers.

Isolation of a new meroterpene and inhibitors of nitric oxide production from Psoralea corylifolia fruits guided by TLC bioautography.

A new meroterpene, psoracorylifol F (1), was isolated from Psoralea corylifolia fruits, along with two known meroterpenes (2 and 3), guided by TLC bioautography against O(2)(-) radicals. The structure of 1 was elucidated by means of NMR, HRESIMS, and X-ray crystallographic analysis. All the three metroterpenes possessed potential inhibitory activity against LPS-induced NO production in RAW 264.7 cells with IC(50) values ranging from 7.71 to 27.63µM.

[Fingerprint analysis of Glehniae Radix by TLC].

OBJECTIVE: To establish TLC fingerprint of Glehniae Radix for the identification and quality control of the drug. METHODS: 10 batches of Glehniae Radix commercial drugs collected from different gathering areas and 3 batches from Laiyang, Shandong were used as qualitative identification samples. Falcarindiol, scopoletin umbelliferone and isoimperatorin were used as the chemical reference substances. Double wavelength TLCS was performed with petroleum and ethyl acetate (4:1) as developer,detection wavelength at 300 nm and reference wavelength at 260 nm. RESULTS: TLC chromatogram of 13 samples had 8 well-resolved characteristic peaks, in which 4 peaks were falcarindiol, umbelliferone, scopoletin and isoimperatorin, respectively. CONCLUSION: The method is accurate and simple, and can be used for the quality control of Glehniae Radix.

Phosphorus accumulation by bacteria isolated from a continuous-flow two-sludge system.

In this article, polyphosphate-accumulating organisms (PAOs) from a lab-scale continuous-flow two-sludge system was isolated and identified, the different phosphorus accumulation characteristics of the isolates under anoxic and aerobic conditions were investigated. Two kinds of PAOs were both found in the anoxic zones of the two-sludge system, one of them utilized only oxygen as electron acceptor, and the other one utilized either nitrate or oxygen as electron acceptor. Of the total eight isolates, five isolates were capable of utilizing both nitrate and oxygen as electron acceptors to uptake phosphorus to some extent. And three of the five isolates showed good phosphorus accumulative capacities both under anoxic or aerobic conditions, two identified as Alcaligenes and one identified as Pseudomonas. Streptococcus was observed weak anoxic phosphorus accumulation because of its weak denitrification capacity, but it showed good phosphorus accumulation capacity under aerobic conditions. One isolates identified as Enterobacteriaceae was proved to be a special species of PAOs, which could only uptake small amounts of phosphorus under anoxic conditions, although its denitrification capacity and aerobic phosphorus accumulation capacity were excellent.

Simultaneous phosphorus and nitrogen removal in a continuous-flow two-sludge system.

The ability of simultaneous biological phosphorus and nitrogen removal was investigated in a lab-scale continuous-flow two-sludge system. Alternating anaerobic and anoxic conditions were combined with contact oxidation stage for treating raw municipal wastewater. Long-term experiments showed that the contradiction of competing for the organic substrate between denitrifying bacteria and PAOs (phosphorus accumulating organisms) in traditional phosphorus and nitrogen removal system has been resolved. The system can adapt to low influent COD/TN ratio (C/N). Furthermore the SRT (sludge retention time) of nitrifying sludge and denitrifying phosphorus removal sludge can be controlled at optimal conditions respectively. The removal efficiency of COD, TP, TN, and NH4-N was 81.78%, 92.51%,75.75%, and 84.47% respectively. It was also found that the appropriate influent C/N should be controlled at the range of 3.8-6, while the optimal C/N to the system ranged between 4-5, and the BFR (bypass sludge flow rate) should be controlled at 0.35 around.