Gallic acid (3,4,5-trihydroxybenzoic acid) is a naturally occurring plant phenol obtained by the hydrolysis of tannins and is know to show some pharmacological activities. In screening anti-cancer agents in traditional Chinese medicines, gallic acid was found to show cytotoxicity against all cancer cells that we examined in this study (IC50s: 4.8-13.2 micrograms/ml). Gallic acid was found to show cytotoxicity against primary cultured rat hepatocytes and macrophages, and lesser cytotoxicity against fibroblasts and endothelial cells. Cell death in dRLh-84 cells occurred within 6h after gallic acid treatment at a concentration of more than 20 micrograms/ml. A study of structurally related compounds suggested that the cytotoxicity shown by gallic acid was not a common feature in phenolic compounds, but was a fairly specific characteristic of gallic acid. That is, three adjacent phenolic hydroxyl groups of gallic acid were responsible for the cytotoxicity, and the carboxyl group was not responsible, but seemed to be implicated in distinguishing between normal cells and cancer cells.

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Chiral bis(guanidino)iminophosphoranes were designed and synthesized as chiral uncharged organosuperbase catalysts that facilitate activation of less-acidic pro-nucleophiles. The newly developed bis(guanidino)iminophosphoranes, which possess the highest basicity among chiral organocatalysts reported to date, were proven to be a superb class of chiral organosuperbases by reaction of azodicarboxylates with 2-alkyltetralones and their analogues as the less acidic pro-nucleophiles.

Panax ginseng, an ancient and famous herbal drug in traditional chinese medicines, has been used in Chinese folklore for more than 4000 years. In the course of our studies to find bioactive saponins from natural medicines, a number of dammarane-type triterpene oligoglycosides having anti-cancer, anti-arrhythmia and inhibitory effects on reducing sideeffects of steroid hormones were found.1,2) In a continuing study, further systematic research on chemical constituents from the leaves of P. ginseng, we now report the isolation and structural elucidation of six new saponins, together with 14 known ones among which, majoroside-F 2 was the first isolated from P. ginseng.The 70% EtOH extract from the dried leaves of P. ginseng were separated by a macro-reticular resin column to give the 50% EtOH eluates which upon drying afforded the total saponins. The total saponins were chromatographed on silica gel, a reversed-phase column and finally on HPLC to afford ginsenoside-Rh 5 (1, 8 mg), -Rh 6 (2, 9 mg), -Rh 7 (3, 10 mg), -Rh 8 (4, 5 mg), -Rh 9 (5, 9 mg), -Rg 7 (6, 10 mg), majoroside-F 2 (7, 9 mg), ginsenoside-Rh 1 (8, 100 mg), chikusetsusaponin-L 8 3) (9, 15 mg), notoginsenoside-Fe 4) (10, 10 mg), majoroside- H COSY and HMBC experiments of 1. In the HMBC spectrum, a methyl proton signal at d 1.83 showed long-range correlations between d 51.0 (C-17), d 142.4, and 122.2. So this methyl signal can be assigned to the proton of C-21, and the two olefinic carbon signals can be assigned for C-20 and C-22, respectively. Similarly, the HMBC spectrum also revealed long-range correlations between the following protons and carbons: H-23 and C-20, 22, 24; H-27 and C-24, 25, 26 (Fig. 1). In addition, in the 1 H-1 H COSY spectrum, the signals at d 2.41, 2.55 (H-23) showed a correlation with each other, and the correlations between H-23 with d 5.69 (t like, Jϭ7.5 Hz, H-22) and d 4.37 (dd, Jϭ3.5, 8.5 Hz,. The stereochemistry of the double bond at C-20 (22) was proposed to be (E) since the signal for C-21 was observed at d 13.2 in the 13 C-NMR spectrum of 1, while the methyl carbon of a (Z)-type structure is usually observed at about d 20-30. 7,8) From the above results, the structure of 1 was determined as 3b,6a,12b,24x-tetrahydroxy-dammar-20 (22)

Methanolic extracts of trunk exudates of Dalbergia sissoo yielded two new open-chain neoflavonoids (1, 2), a new flavonoid (3), a new flavanone (4), and 26 known compounds. Their structures were elucidated by detailed spectroscopic analyses. The ability of the isolated compounds to prevent nitric oxide (NO) production by LPS-stimulated J774.1 cells was also studied. All of the isolated compounds except 4, formononetin, and zenognosin B exhibited significant activity in a concentration-dependent manner. Compounds 2 and 3 were among the most potent NO production inhibitors, with IC50 values of 3.19 and 6.22 microM, respectively, and compound 1 had an IC50 of 31.6 microM.