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The medicinal plant Rabdosia excisa in the Lamiaceae family is found in Northeastern China and is used to treat a fever due to a cold, mastitis, arthralgia, and bruises[1]. A previous study reported that an aqueous extract from that plant yielded ent -kaurene diterpenes with antitumor action. In addition, diterpenes have been used to synthesize analogs in relatively large quantities, and their structureactivity relationship in terms of cytotoxic activity[2] and inhibition of the activation of the intracellular transcription factor NF-κB[3] has been examined. Various studies have also examined ent -kaurene diterpenes[4] ― [7]. Three diterpenes―kamebakaurin (1), kamebanin (2), and excisanin A (3)―can be obtained in relatively large quantities from R. excisa . The current study examined the effects of those diterpenes on cardiac function in guinea pigs. Some of those findings are reported here.

The present study aimed to investigate the protective effects of kamebakaurin (KA) and 1O, 20O-diacetyl kamebakaurin (Ac2KA) on acetaminophen (APAP)-induced hepatotoxicity and compare the hepatoprotective mechanisms of the two chemicals. Seven-week-old male C57BL/6J mice were orally administered KA, Ac2KA, or an ethanol/olive oil emulsion once per day for 7-days. Twenty-four hours after the final administration, the mice were fasted and then intraperitoneally injected with 450 mg/kg APAP or saline. At 16 h after injection, the mice were euthanized and blood samples were collected for plasma analysis. Pretreatment with KA and Ac2KA significantly attenuated APAP-induced hepatic injury. The protective effect of Ac2KA was stronger than that of KA. These two chemicals attenuated oxidative stress, inflammatory cytokine production, c-jun N-terminal kinase activation, and receptor-interacting protein (RIP)-3 activation. Ac2KA also decreased APAP-induced RIP-1 activation and nuclear factor kappa B (NF-κB) p65 translocation. Moreover, Ac2KA repressed mRNA expression of Cyp1a2/2e1 in the liver. Our results showed that KA and Ac2KA exerted protective effects against APAP-induced hepatotoxicity. The responsible mechanisms may be related to the chemicals' antioxidant activity and the inhibition of c-jun N-terminal kinase activation and RIP-3 activation. The effects of Ac2KA included those of KA, as well as RIP-1 inactivation, NF-κB inhibition, and Cyp inhibition.

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

Transformation of plant-origin 7,14-dihydroxy-ent-kaurenes to ent-abietanes having a cis-fused α-methylene γ-lactones was accomplished efficiently under the Mitsunobu reaction conditions. The yields of the desired products were apparently influenced by the steric hindrance at C-1. The cytotoxic activity on P388 murine leukemia cells of the ent-abietanes having cis-fused α-methylene γ-lactones produced were assayed.

Background Kamebakaurin (KA) is an ent -kaurane diterpenoid known to have anti-inflammatory potential. In the current study, we investigated whether pretreatment with KA could ameliorate acetaminophen (APAP)-induced hepatotoxicity by inhibiting the anti-inflammatory response in mice. Methods Seven-week-old C57BL/6J mice were orally administered KA or olive oil emulsion for seven days. Twenty-four hours after the last KA or olive oil administration, the mice were intraperitoneally injected with 400 mg/kg APAP or saline under feed deprived condition. The mice from each group were euthanized and bled for plasma analysis 24 h after the injection. Result APAP increased plasma levels of hepatic injury markers ( i.e. , alanine aminotransferase and aspartate aminotransferase), lipid peroxidation, and pro-inflammatory cytokines. Pretreatment with KA reduced the magnitude of APAP-induced increases in plasma levels of hepatic injury markers, lipid peroxidation, and inflammatory response. In addition, KA exhibited antioxidant capacity in a dose-dependent manner, with slight reactive oxygen species scavenging activity. Conclusion Our results indicate that KA has the ability to protect the liver from APAP-induced hepatotoxicity, presumably by both inhibiting the inflammatory response and oxidative stress.

A series of rabdokunmin C analogues were prepared and their inhibitory effect on NF-κB activation was assayed. One of them, 18-acetyl-12-deoxy-11,12-dehydrorabdokunmin C (16) was found to be a promising candidate for an anti-inflammatory agent.

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.

One new acetylated flavonoid, kaempferide-7-O-(4″-O-acetyl)-α-L-rhamnoside, and six known flavonoids were isolated from the EtOAc fraction of the leaves of Actinidia kolomikta (Rupr. et Maxim.) Planch. The chemical structures of the isolated compounds were established by application of chemical and spectroscopic analysis. The new acetylated flavonoid was screened for its protective effect on human erythrocytes against AAPH-induced hemolysis, and it can slow the hemolysis induced by AAPH.

The interaction between three kinds of flavonoids and bovine serum albumin (BSA) was investigated by fluorescence and UV–vis absorption spectrometry. The results indicated that flavonoids have strong ability to quench the intrinsic fluorescence of BSA by forming complexes. The binding constants, number of binding sites, thermodynamic parameters and energy transfer mechanisms were also investigated. Conformation change of BSA was observed from synchronous, three-dimensional fluorescence and circular dichroism spectrum.

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.

Facile transformation of 7,14-dihydroxy-ent-kaurenes such as excisanin A (8), kamebanin (9), and kamebakaurin (10), which are abundant in plants of the genus Rabdosia species (Labiatae), to ent-abietanes was accomplished under the Mitsunobu reaction conditions. The δ, e-unsaturated cis-fused α-methylene γ-lactones (17, 18, and 25) thus prepared showed a moderate cytotoxic activity on 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.

To determine 20(S)-ginsengnoside Rh2 in the hydrolysis product of saponins from leaves of Panax qinquefolium.The separation was performed on ZORBAX EXEND C18 column (4.6 mm x 250 mm, 5 microm), eluted with methanol and water (85:15) as mobile phase with the rate of 1.2 mL x min(-1) at 25 degrees C, the wavelength for measurement was 203 nm.The calibration curve was linear in the range of 0.5-25 microg for 20(S)-ginsengnoside Rh2(r = 0.9999, n = 7). The average recovery was 99.7% (RSD= 1.0%).This method is simple, accurate, reliable and reproducible. The result shows that the transform ratio of 20(S)-ginsengnoside Rh2 is high by this hydrolysis method.

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.