Cytotoxic lignan esters from Cinnamomum osmophloeum.

The bark and roots of Cinnamomum osmophloeum are widely used in Taiwan as spice substitutes for C. CASSIA. We have isolated three novel lignan esters, one dibenzylbutane-type ligan ester [9,9'-di-O-feruloyl-(+)-5,5'-dimethoxy secoisolariciresinol (3)] and two cyclolignan esters [(7' S,8' R,8 R) -lyoniresinol-9-O-(E)-feruloyl ester ( 5) and (7' S,8' R,8 R)-lyoniresinol-9,9'-di-O-(E)-feruloyl ester (6)], and several known lignans from the heartwood and roots of C. osmophloeum. We identified these compounds using 1D and 2D NMR spectroscopy and mass spectrometry. Cytotoxicity assays of these novel lignan esters revealed that compound 6 has strong activities against human liver cancer (HepG2 and Hep3B) and oral cancer (Ca9-22) cells, with IC(50) values of 7.87, 4.31, and 2.51 microg/mL, respectively.

Isolation and cytotoxicity of the lignanoids from Chamaecyparis formosensis.

In this study, we assessed the antitumor activity of the methanol extract from wood chips of the heartwood of the Taiwan red cypress, Chamaecyparis formosensis Matsumura, which is a precious tree species endemic to Taiwan. A brine shrimp lethality test (BST) indicated that the ethyl acetate (EtOAc)-soluble extract from the MeOH extract was a suitable candidate (LC (50) = 15.36 microg/mL) for further studies of the antitumor activity of its components. From this EtOAc fraction, we isolated six lignans and two norlignans and tested their cytotoxic activities IN VITRO against promyelocytic leukemia (HL-60) and hepatoma (Hepa-G2) cell lines. Among these compounds, 7,7'-( S)-dihydrotaiwanin C, isolated for the first time from nature, with its single crystal structure depicted in this study, exhibited significant cytotoxic activity against HL-60 cell lines IN VITRO (IC (50) = 4.03 microg/mL) after 24 hours. BST:brine shrimp lethality test Hepa-G2:human hepatoma HL-60:human leukemia IC (50):half-maximal inhibitory concentration SARs:structure-activity relationships AS:adenine sulfate.

Determination of aconitine-type alkaloids as markers in fuzi (Aconitum carmichaeli) by LC/(+)ESI/MS(3).

LC/(+)ESI/MS(3) was used to determine aconitine, mesaconitine, and hypaconitine as target markers in crude methanol extracts of (i) the raw lateral roots of Aconitum carmichaeli, (ii) roots treated by three different refining processes, and (iii) eight generally available traditional Chinese medicine (TCM) preparations containing fuzi (treated lateral roots of A. carmichaeli). The optimal ionization behavior resulted when using electrospray ionization (ESI) in positive-ion mode with 0.005% TFA as an additive in the mobile phase. The consecutive reaction monitoring (CRM) mode provided additional improvements in selectivity, which was exploited to minimize the noise and interference problems. Employing this approach, aconitine and mesaconitine were found to decompose readily during the refining processes, but hypaconitine remains present at the same content, presumably because of its characteristic chemical structure. Thus, treated and untreated fuzi samples can be distinguished by monitoring the ratio of aconitine and mesaconitine to hypaconitine. The limits of detection (LODs) for these three markers were 0.05, 0.08, and 0.03 ng/ml. The linearity range for the three marker compounds was 0.1-1,000 ng/ml. The analysis time was 12 min per sample.

Supercritical fluid extraction and quantification of aflatoxins in Zizyphi Fructus by liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry.

An integrated method combining supercritical fluid extraction (SFE) with liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry (LC/APCI-MS/MS) was developed and successfully applied to quantify aflatoxins (AFs) in Zizyphi Fructus (fruits of Zizyphus jujube), a traditional Chinese medicine. To minimize the potential interferences caused by the complex matrix in Zizyphi Fructus, a SFE pretreatment was performed. In addition, electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) spectra were also compared. The results showed that the calibration curves of AFB(1), AFB(2), AFG(1), and AFG(2) were all linear over the range of concentration from 1 to 50 ng/g, the squared correlation coefficients (r(2)) were over 0.995, and the detection limits of the method were between 0.17 and 0.32 ng/g. It showed high recovery and good precision in quantitating AFs in Zizyphi Fructus without further clean-up. Further, fragmentation pathways of protonated AFs in APCI-MS/MS were clearly proposed which could predict the existence of AFB or AFG series. To test the empirical validity of the proposed methodology in this paper, eight random samples of Zizyphi Fructus collected from supermarkets and traditional Chinese medicine stores in different geographical areas of Taiwan were analyzed. The results indicated that low levels of AFs were detected in only one of them.

LC-APCI-MS method for detection and analysis of tryptanthrin, indigo, and indirubin in daqingye and banlangen.

A rapid, selective, and sensitive LC-APCI-MS method is developed in this study for detecting and analyzing tryptanthrin, indigo, and indirubin in daqingye and banlangen, which are, respectively, the leaves and roots of Isatis indigotica and Strobilanthes cusia in traditional Chinese medicine. The detection of the three active components is linear in concentrations ranging from 100 to 1500 ng/mL, the squared correlation coefficient is higher than 0.996, the precision as measured by the relative standard deviation is no larger than 9.5%, and the recovery is greater than 86.6%. The analysis of the 21 banlangen samples led to considerably different conclusions on the contents of tryptanthrin, indigo, and indirubin in fresh leaves versus those in dried leaves. These results should shed some light on future plant selection and breeding. Compared with the traditional TLC and HPLC-UV methods, the new LC-APCI-MS approach has proven to be an optimal tool for detecting and analyzing the three marker compounds in the Chinese herbal medicines of daqingye and banlangen.

Quality control of Chinese medicinal preparations LC/ESI(+)/MS/MS analyses of saikosaponins-a and -c as markers of Bupleuri radix samples.

We have used LC/ion trap tandem MS analysis to determine saikosaponin-a and -c as target markers in crude 70% methanol extracts from three different species of Bupleuri radix and the 10 most-popular Chinese medicinal preparations containing "Chaihu" (B. radix) without any clean-up. The optimal ionization characteristics were obtained when using positive-ion electrospray ionization (ESI) with 50 microM sodium acetate as an additive in the mobile phase. We observed good linearity over the range from 0.02 to 2 microg/ml for saikosaponin-a and from 0.02 to 1 microg/ml for saikosaponin-c. The intra-day precisions varied between 3.3 and 8.8% for saikosaponin-a and 0.3 and 11.1% for saikosaponin-c. The limits of detection were 0.01 microg/ml for both markers. The recoveries of saikosaponin-a and -c from the extract of a medicinal preparation sample (Chai-Hu-Ching-Gan-Tang, No. 13 in the table of section Analysis on actual samples) were 97 and 100%, respectively, at a 1 microg/ml spiking concentration of each marker. The highest concentrations of saikosaponin-a and -c among the three B. radixes were found in B. kaoi Liu Chao & Chuang (10.1 mg/g) and in B. falcatum (3.4 mg/g), respectively. The amounts of these saikosaponins in the 10 Chinese medicinal preparations ranged between 0.11 and 1.22 mg/g for saikosaponin-a and between 0.01 and 0.33 mg/g for saikosaponin-c.