Pseudolarenone, an unusual nortriterpenoid lactone with a fused 5/11/5/6/5 ring system featuring an unprecedented bicyclo[8.2.1]tridecane core from Pseudolarix amabilis

Pseudoamaolide P, a 1,2:3,4:9,10:9,19-tetraseco-cycloartane triterpene spiroketal lactone from seeds of Pseudolarix amabilis

A 1,2:3,4:9,10:9,19-tetraseco-cycloartane triterpene spiroketal lactone, pseudoamaolide P (1), two new labdane-type diterpenoids, pseudoamains A and B (2-3), and four known cembrane-type diterpenoids (4-7) were isolated from the seeds of Pseudolarix amabilis. The structures of these compounds were elucidated by spectroscopic analyses, including HRESIMS, 1D-, and 2D-NMR. The anti-inflammatory activities of the compounds were evaluated by suppressing the transcription of the NF-κB-dependent reporter gene in LPS-induced 293 T/NF-κB-luc cells. All compounds do not show potent activity.

Electrochemical Decarboxylative Alkoxy-alkoxycarbonylation of Alkenes

A method is presented for decarboxylative alkoxy-alkoxycarbonylation of various alkenes with alcohols by electrochemical anodic oxidation of monopotassium ethyloxalate salts with good functional group compatibility. The reaction involves anodic oxidation to form an acyl radical, followed by addition to an olefin to yield a new alkyl radical, which is anodically oxidized to a carbon cation and captured by alcohols to afford β-alkoxyalkanoates. Adding catalytic amounts of ammonium iodide enhanced the efficiency of the reactions.

3,4-Secocycloartane Triterpenoids from the Cones of Pseudolarix amabilis

Four new 3,4-secocycloartane triterpenoids, pseudolactones A-D (1-4), were isolated from the ethanol extract of the cones of Pseudol arixamabilis. Their structures were established by extensive 1D- and 2D-NMR experiments. The cones of P. arixamabilis are enriched in the ring-expanded or cleaved cycloartane triterpenoids. This work provides new insight into cycloartane triterpenoids from the cones of P. arixamabilis.

Cycloartane triterpenoids from Pseudolarix amabilis and their antiviral activity

Seven undescribed cycloartane triterpenoids, pseudolarnoids A-G, together with ten known ones, were isolated from the seeds of Pseudolarix amabilis (J. Nelson) Rehder. Their structures were elucidated on the basis of spectroscopic analysis, X-ray crystallography, and ECD data. Pseudolarnoids A-C are cycloartane triterpenoids with a unique 16S, 23R-spirolactone moiety. Pseudolarnoids F, G, and pseudolarolide C demonstrated potent antiviral effects on HSV-1 in vitro.

Triterpenoids

Covering: 2013. Previous review: Nat. Prod. Rep., 2015, 29, 1028-1065This review covers the isolation and structure determination of triterpenoids reported during 2013 including squalene derivatives, lanostanes, holostanes, cycloartanes, cucurbitanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes, isomalabaricanes and saponins; 350 references are cited.

Inhibition of HL-60 cell growth via cell cycle arrest and apoptosis induction by a cycloartane-labdane heterodimer from Pseudolarix amabilis

Pseudolaridimer C (), a rarely encountered cycloartane-labdane Diels-Alder adduct was isolated from the cones of Pseudolarix amabilis. The structure and absolute configuration of were established by comprehensive NMR and CD spectral analysis. The WST-8 assay indicated that time and dose dependently inhibited the proliferation of human leukemia cells HL-60 at 1-10 μM. DAPI and Annexin V-FITC/PI double staining method, and DNA ladder experiments all proved that had significant dose-dependent effects on HL-60 cell apoptosis. A further mechanism study indicated that the apoptosis was associated with the cell cycle arrest during the G2/M phase, and the activation of caspase-9, -3, -7, and poly-(ADP-ribose)-polymerase (PARP).