A validated spectrophotometric method for quantification of prenylated flavanones in pacific propolis from Taiwan.

INTRODUCTION: Because of its chemical diversity, the only way to standardise propolis is to specify multiple standards for different propolis types according to the corresponding chemical profile. So far, this has been done only for European propolis. OBJECTIVE: To develop a rapid low-cost spectrophotometric procedure for quantification of bioactive prenylated flavanones in Taiwanese propolis. METHODOLOGY: The proposed method quantifies the total flavanones on the basis of their absorption as coloured phenylhydrazones formed by interaction with 2,4-dinitrophenylhydrazine. The procedure was validated through model mixture of compounds representing the composition of Taiwanese propolis according to previous studies. The major flavanones of the propolis samples (propolins C, D, F and G) were quantified by HPLC. Antiradical activity against DPPH was also measured. The DNP (dinitrophenylhydrazine) spectrophotometric method is applied for the first time for quantification of prenylated flavanones. RESULTS: Spectophotometric procedure applicable to new type propolis (Macaranga type) was developed with recovery between 105 and 110% at the concentration range of 0.573-1.791 mg/mL. Six propolis samples were analysed by spectrophotometry using the procedure developed and validated, and by HPLC as the results demonstrated satisfactory agreement. Neither the spectrophotometric data nor the values measured by HPLC showed significant correlation with the antiradical activity against DPPH. CONCLUSION: The proposed spectrophotometric procedure is useful for routine analyses of Macaranga-type propolis, because of its simplicity, repeatability and acceptable accuracy. Its application to a number of commercial samples could be used as a basis for standardisation and quality control of Pacific propolis.

Impact of flood damage on pollutant removal efficiencies of a subtropical urban constructed wetland.

Typhoons and hurricanes in subtropical/tropical regions can induce significant environmental changes (e.g., mass flooding and inundations). However, the damage to the pollutant removal efficiencies of constructed wetlands brought about by these natural disturbances has been neglected in major studies conducted in temperate climates. Therefore, this study compares the pollutant removal performance of a constructed wetland in the Danshui River Basin, before and after the system was inundated with flooding from Typhoon Krosa in 2007. The pollutant removal performance of the free water surface (FWS) constructed wetland was investigated monthly from September 2006 to April 2008. Results of the study demonstrated that this FWS wetland effectively removed 64.3% BOD, 98.9% NH(4)-N, and 39.5% Total-P before Typhoon Krosa. However, the extensive flooding caused by Typhoon Krosa swept over most of the aboveground plant community and deposited the sediment onto the bottom of each compartment. Subsequently, reduced pollutant removal efficiencies were observed. Only 37.7% BOD, 35.1% NH(4)-N, and 31.8% Total-P were removed after this event, although the flow regime was immediately restored. Comparing the water quality data for the FWS wetland before and after Typhoon Krosa revealed the immediate, quantitative damage to the pollutant removal performance caused by the typhoon's inundation. Consequently, a high-flow bypass and additional preventive measures would protect any constructed wetland in areas subject to typhoons.

Marchantin A, a cyclic bis(bibenzyl ether), isolated from the liverwort Marchantia emarginata subsp. tosana induces apoptosis in human MCF-7 breast cancer cells.

Liverwort constituents have been reported to exert a broad spectrum of biological activities. In this study, we used a bioactivity-guided separation of an extract from the liverwort species Marchantia emarginata subsp. tosana to determine its anticancer activity. A high level of the active ingredient was isolated from this liverwort and its chemical structure was identified and characterized by various spectra. It was found to be identical to a well-known compound, marchantin A, a cyclic bisbibenzyl ether. However, no anticancer activities of this compound have previously been reported. We found that marchantin A efficiently induced cell growth inhibition in human MCF-7 breast cancer cells, with an IC(50) of 4.0microg/mL. Fluorescence microscopy and a Western blot analysis indicated that marchantin A actively induced apoptosis of MCF-7 cells. The levels of cleaved caspase-8, cleaved caspase-3, cleaved caspase-9, and cleaved poly (ADP ribose) polymerase (PARP) increased. However, the level of Bid markedly decreased in a dose- and time-dependent manner. We also evaluated the anticancer activities of marchantin A on the regulation of cell cycle regulators such as p21, p27, cyclin B1, and cyclin D1. The p21 and p27 gene expressions increased markedly while cyclin B1 and D1 gene expression decreased markedly by treatment with marchantin A. Many report demonstrated that liverwort was suggested to possess potent antioxidant activity. Our results indicate that marchantin A possesses free radical-scavenging activity (EC(50)=20microg/mL). Taken together, for the first time, the compound marchantin A from liverworts demonstrated to be a potent inducer of apoptosis in MCF-7 cells.