A new saponin and other constituents from Anemone rivularis Buch.-Ham

Anemhupehins A-C, Podocarpane Diterpenoids from Anemone hupehensis

Three new podocarpane diterpenoids, namely anemhupehins A-C (1-3), together with four known analogues (4-7), have been isolated from aerial parts of Anemone hupehensis. Their structures were characterized based on extensive spectroscopic data. Compounds 1 and 4 showed certain cytotoxicities against human cancer cell lines.

Anemone rivularis inhibits pyruvate dehydrogenase kinase activity and tumor growth

ETHNOPHARMACOLOGICAL RELEVANCE

Anemone rivularis Buch.-Ham. ex DC. (Ranunculaceae) have been used as a traditional remedy for treatment of inflammation and cancer. However, there is no report demonstrating experimental evidence on anti-tumor action of A. rivularis.

AIM OF STUDY

The Warburg's effect, preference of aerobic glycolysis rather than oxidative phosphorylation (OXPHOS) even in oxygen rich condition, is focused as one of major characteristics of malignant tumor. Thus, we investigated the effect of A. rivularis on the Pyruvate dehydrogenase (PDH) kinases (PDHKs), a major molecular targets for reducing aerobic glycolysis.

MATERIALS AND METHODS

The ethanol extract of whole plant of A. rivularis (ARE), fingerprinted by high performance liquid chromatography (HPLC), was applied to in vitro and cell-based PDHK activity assays. The effect of ARE on cell viabilities of several tumor cells was estimated by MTT assay. The expression of phosphor-PDH, PDH and PDHK1 were measured by Western blot analysis. The production of reactive oxygen species (ROS) and apoptosis was measured by fluorescence-activated cell sorting analysis, using 5-(and-6)-carboxy-2',7'-dichlorodihydrofluorescein diacetate (carboxy-H2DCFDA) and Annexin V/propidium iodide (PI) staining, respectively. Mitochondrial membrane potential was examined by tetramethylrhodamine methyl ester (TMRM) staining. In vivo anti-tumor efficacy of ARE was estimated by means of tumor volume and weight using allograft injection of murine Lewis lung carcinoma (LLC) cells to dorsa of C57BL/6 mice.

RESULTS

ARE inhibited the viabilities of several cancer cells, including MDA-MB321, K562, HT29, Hep3B, DLD-1, and LLC. ARE suppressed PDHK activity in in vitro kinase assay, and also inhibited aerobic glycolysis by reducing phosphorylation of PDHA in human DLD-1 colon cancer and murine LLC cells. The expression of PDHK1, a major isoform of PDHKs in cancer, was not affected by ARE treatment. Moreover, ARE increased the both ROS production and mitochondrial damage. In addition, ARE suppressed the in vitro tumor growth through mitochondria-mediated apoptosis. The growth rates of allograft LLC cells were also reduced by ARE treatment.

CONCLUSIONS

Here, we firstly report that ARE inhibits PDHK activity and growth of tumor in both in vitro and in vivo experiments. Therefore, we suggest ARE as a potential candidate for developing anti-cancer drugs.

Anti-Proliferative Effect of Triterpenoidal Glycosides from the Roots of Anemone vitifolia through a Pro-Apoptotic Way

A cytotoxicity-guided phytochemical investigation of Anemone vitifolia roots led to the isolation of six oleanane saponins (1-6), which were reported from the species for the first time. Their structures were determined by comparing its MS and NMR data with those in literature. Compounds 1-4 showed significant inhibitory effects on the proliferation of hepatocellular carcinoma HepG2 cells with IC₅₀ values ranging from 2.0 to 8.5 μM, compared to positive control methotrexate with IC₅₀ value of 15.8 μM. Flow cytometry analysis revealed that compounds 1-4 exerted anti-proliferative effects through a pro-apoptotic way of hepatocellular carcinoma cells.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids reported during 2012 including squalene derivatives, lanostanes, holostanes, cycloartanes, cucurbitanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes, isomalabaricanes and saponins; 348 references are cited.

Synthesis and biological evaluation of ( - )-13,14-dihydroxy-8,11,13-podocarpatrien-7-one and derivatives from (+)-manool

13,14-Dihydroxy-8,11,13-podocarpatrien-7-one (1) and a series of ring C aromatic diterpene derivatives were synthesised from (+)-manool (4) and evaluated for their cytotoxic, leishmanicidal and trypanocidal activities. Our results indicated that compound 1 and other podocarpane-type intermediates are cytotoxic. Cleavage of C6-C7 bond of compound 7 improved cytotoxic activity, indicating that, in particular, the 6,7-seco-podocarpane-type compound 20 might serve as a lead compound for further development.

Facile Access to Optically Active Ring C Aromatic Diterpene Derivatives from (+)-Manool. First Synthesis of 13,14-Dihydroxy-8,11,13-podocarpatrien-7-one

14,15,17-Trinorlabdan-8,13-dione 6 was efficiently synthesized via ozonolysis of (+)-manool (4) followed by treatment with aqueous NaOH in the presence of tetra- n-butylammonium bromide as catalyst. This protocol has the advantages of high yield, mild conditions and simple procedure. Utilizing this strategy, the first enantiospecific synthesis of 13,14-dihydroxy-8,11,13-podocarpatrien-7-one (1), a constituent of Taiwania cryptomerioides and Celastrus paniculatus, was achieved starting from (+)-manool (4) after a four-step sequence in 24% overall yield.