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The present study aimed to investigate the protective effects of kamebakaurin (KA) and 1O, 20O-diacetyl kamebakaurin (Ac

Three new dammarane-type triterpene ginsenosides, together with six known ginsenosides, were isolated from the leaves of Panax ginseng C.A. Meyer. The new saponins were named as ginsenoside Rh₁₁, ginsenoside Rh₁₂, and ginsenoside Rh₁₃. Their structures were elucidated as (20S)-3β,6α,12β,20-tetrahydroxydammara-25-ene-24-one 20-O-β-d-glucopyranoside (1), (20S)-3β,12β,20,24,25-pentahydroxydammarane 20-O-β-d-glucopyranoside (2), and (20S,23E)-3β,12β,20,25-tetrahydroxydammara-23-ene 20-O-β-d-glucopyranoside (3) on the basis of 1D and 2D NMR experiments and mass spectra. The known ginsenosides were identified as ginsenoside M(₇cd), ginsenoside Rg₆, ginsenoside Rb₃, gypenoside XVII, gypenoside IX, and 20-(E)-ginsenoside F₄.

A novel 14,20-epoxy-ent-kaurene diterpenoid, excisanin H (1), and three new ent-kaurene diterpenoids, 2-4, were isolated from aerial parts of Rabdosia excisa along with eight known ent-kaurene diterpenoids, 5-12. The structural elucidations were made using spectral (HREIMS, IR, (1)H, (13)C, and 2D NMR) methods. The absolute configuration of 1 was determined by demonstrating that oxidation of kamebakaurin (8) produced excisanin H (1). These ent-kaurene diterpenoids all showed significant cytotoxic activity against P388 murine leukemia cells.

To determine actinoside C in the leaves of Actinidia kolomikta with different growth periods.The separation was performed at 25 degrees C on ZORBAX Extend C18 column (4.6 mm x 250 mm, 5 microm), using amixture of methanol and water (51:49) as a mobile phase. The flow rate was 1.2 mL x min(-1), and the wavelength for measurement was 267 nm.The results showed that the contents of actinoside C in the leaves of A. kolomikta were variety in different growth periods. Actinoside C could reach its highest content in the middle ten days of June, then the content would decrease in the middle ten days of July slightly, it could reach their lowest content in the middle ten days of August.The optimal collective date for A. kolomikta are in the middle ten days of June.

1-O-Monoacyl, 12-O-monoacyl, 1-,12-O-diacyl, and 11,12-dehydrated excisanin A 7,14-acetonides were synthesized from excisanin A isolated from Rabdosia excisa. The structure and cytotoxic activity relationships (SAR) of the natural parent ent-kaurene diterpenes and these semisynthetic analogues were studied by using P388 murine leukemia cells.