Strophiofimbrins A and B: Two Rearranged Norditerpenoids with Novel Tricyclic Carbon Skeletons from Strophioblachia fimbricalyx.

Two rearranged norditerpenoids with novel tricyclic carbon skeletons, strophiofimbrin A (1) and strophiofimbrin B (2), were isolated from Strophioblachia fimbricalyx. Their structures were established by 1D/2D NMR spectroscopy, HRESIMS, quantum chemistry calculations, and X-ray diffraction analyses. 1 and 2 represented the first examples of diterpenoids with unprecedented 5/6/7-fused ring systems. In the proposed biosynthetic pathway, they were suspected to derive from cleistanthane norditerpenoids via ring opening, expansion, cyclization, and rearrangement based on the existence of phenanthrenone and cleistanthane diterpenoids from Strophioblachia and Trigonostemon, two closely related genera of the Euphorbiaceae family. Furthermore, compounds 1 and 2 exhibited significant proliferation inhibition and obvious neuroprotective effects.

RRLC-DAD-ESI-MS based and bioactivity guided phytochemical analysis and separation of coumarins from raw extracts of Trigonostemon lutescens.

As extensively active compounds, coumarins are rarely reported on the phytochemistry of the genus Trigonostemon. We herein proposed a fast strategy for analysis and separation of antitumoral active coumarins from the twigs of T. lutescens. Rapid Resolution liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry (RRLC-DAD-ESI-MS) analysis indicated the existence of coumarins in the twig extracts. Bioactivity guided phytochemical analysis assays revealed that the twig extract contained some active components that significantly inhibited cancer cell viability. Accordingly, a series of coumarins including a new furanocoumarin have been isolated from the twigs of T. lutescens by semi-preparative chromatographic separation. All compounds, especially furan-type coumarins, were reported for the first time from the genus Trigonostemon. The proposed strategy, by combining RRLC-DAD-ESI-MS based and bioactivity guided phytochemical analysis, exemplify a fast method for screening and identifying active components from raw extracts of herbs.

Lutescins A and B, two new ellagitannins from the twigs of Trigonostemon lutescens and their antiproliferative activity.

Two new ellagitannins, lutescins A and B (1-2), along with eight known compounds (3-10), were isolated from the twigs of Trigonostemon lutescens. Their structures were elucidated by extensive spectroscopic analyses as well as by comparison with literature data. Compounds 1 and 2 are the first examples of ellagitannins reported in Trigonostemon Genus, and their structures featured a hexahydroxydiphenoyl (HHDP) moiety less often as R configurations in natural products. In addition, all isolated compounds were tested for their inhibitory effects against HeLa, HCT116 and HepG2 cancer cell lines. Compounds 1, 2, 5 showed potent antiproliferative activity, compared with the positive control Cisplatin.

Experimental and theoretical calculation studies on the structure elucidation and absolute configuration of calyxins from Alpinia katsumadai.

Six novel calyxins, named calyxin T-W, ent-calyxin T and ent-calyxin U were isolated from the seeds of Alpinia katsumadai Hayata. Their relative configurations were elucidated by means of detailed UV, IR, NMR and MS spectroscopic data. Their absolute configurations were assigned by collaborative studies on single crystal X-ray diffraction analysis, Mosher's method, electronic circular dichroism (ECD), optical rotation and theoretical calculations. These compounds are Friedel-Cranft alkylation adducts composed of coexisted diarylheptanoids and flavanone from the seeds of Alpinia katsumadai. The antiproliferative activity of the six compounds against NCI-H460, HeLa, SMMC-7721 and HCT-116 cell lines was also reported, and most of them showed moderate to strong activities.

Calyxin Y induces hydrogen peroxide-dependent autophagy and apoptosis via JNK activation in human non-small cell lung cancer NCI-H460 cells.

Calyxin Y has been recently isolated from Alpinia katsumadai which has a folk use as an anti-tumor medicine. Calyxin Y induced caspase-dependent cell death in NCI-H460 cells, and concomitantly, provoked cytoprotective autophagy with the upregulation of critical Atg proteins. The cleavage of Atg proteins by caspases acted as a switch between autophagy and apoptosis induced by calyxin Y. Intracellular hydrogen peroxide (H2O2) production was triggered upon exposure to calyxin Y via the induction of autophagy and apoptosis. We provided evidence that activated JNK was upstream effectors controlling both autophagy and apoptosis in response to elevated H2O2. Therefore, our findings demonstrate that calyxin Y serves multiple roles as a promising chemotherapeutic agent that induces H2O2-dependent autophagy and apoptosis via JNK activation.

A [2 + 2] cycloaddition dimer and a Diels-Alder adduct from Alpinia katsumadai.

An unusual katsumadain dimer via a [2 + 2] cycloaddition, katsumadain C (1), and a unique chalcone-diarylheptanoid adduct via a Diels-Alder reaction, calyxin Y (2) with novel carbon frameworks, were isolated from the seeds of Alpinia katsumadai. Their structures and relative configurations were determined by spectroscopic evidence.