Fischdiabietane A, an Antitumoral Diterpenoid Dimer Featuring an Unprecedented Carbon Skeleton from Euphorbia fischeriana.

Fischdiabietane A (1), a novel asymmetric diterpenoid dimer with a unique nonacyclic 6/6/6/5/7/6/6/6/6 ring system possessing unprecedented 2-oxaspiro[4.5]decane-1-one and 2-oxabicyclo[3.2.2]nonane frameworks in D/E/F rings, was isolated from the roots of Euphorbia fischeriana. Its structure was determined by spectroscopic techniques, electronic circular dichroism calculations, and X-ray diffraction experiments. Notably, 1 is the first abietane-type [4 + 2] Diels-Alder dimer identified from nature. The IC50 of 1 against T47D cells was about sixfold higher than that of cisplatin (the positive control). Furthermore, 1 induced apoptosis in T47D cells through the activation of caspase-3 and the degradation of poly(ADP-ribose) polymerase.

Diverse gallotannins with α-glucosidase and α-amylase inhibitory activity from the roots of Euphorbia fischeriana steud.

A phytochemical investigation of the roots of Euphorbia fischeriana Steud. led to the isolation of eleven undescribed gallotannins, fishertannins A-K, together with four known analogues. Their structures were elucidated by the comprehensive spectroscopic data including UV, IR, HR-ESI-MS, and NMR, while the absolute configurations of the sugar moiety were determined by the acid hydrolysis and HPLC analyses. Fishertannin A possessed an unusual skeleton comprised of acetophenone, galloyl group, arabinofuranosyl and glucopyranosyl moieties. Fishertannin B, fishertannin H, fishertannin K, 1,2,3-tri-O-galloyl-ß-D-glucopyranose, 3,4,6-tri-O-galloyl-D-glucopyranose, and 1,6-di-O-galloyl-ß-D-glucopyranose displayed the potent α-glucosidase inhibitory activities with the IC50 values of 15.48-177.13 µM. Examination of the structure-activity relationships (SAR) demonstrated that the galloyl and glucopyranosyl moieties played a key role in the inhibitory activity for both α-glucosidase and α-amylase inhibitory activity. Among all isolates, 1,2,3-tri-O-galloyl-ß-D-glucopyranose showed the most potent and highly specific inhibitory activity against α-glucosidase with an IC50 value of 15.48 ± 0.60 µM. The kinetic analysis of 1,2,3-tri-O-galloyl-ß-D-glucopyranose disclosed the mixed inhibition type on α-glucosidase, and the molecular docking visualized the stable binding with the catalytic pocket of α-glucosidase (pdb 3A4A). These findings indicated the excellent antidiabetic potential of the gallotannins from E. fischeriana, while 1,2,3-tri-O-galloyl-ß-D-glucopyranose could be developed as a promising candidate for the treatment of T2DM with fewer side effects.

Existing knowledge on Euphorbia fischeriana Steud. (Euphorbiaceae): Traditional uses, clinical applications, phytochemistry, pharmacology and toxicology.

ETHNOPHARMACOLOGICAL RELEVANCE: Euphorbia fischeriana Steud. (Euphorbiaceae) is a perennial herb distributed in grassland, hill slopes or gravel hillside, with average altitude of 100-600 m. The whole grass of E. fischeriana is toxic with roots used as folk medicine to treat Zhushui, dyspepsia, abdominal distension, abdominal pain, cough, as well as external applications such as cure of scabies and tuberculosis of lymph nodes. AIM OF THE REVIEW: This systematic review aims to provide a detailed and in-depth summary about the reported advances in traditional uses, clinical applications, phytochemistry, pharmacology and toxicity of E. fischeriana, so as to offer fresh ideas and broader vision and insights for subsequent studies. MATERIALS AND METHODS: Various scientific data bases such as CNKI, Elsevier, Google Scholar, Pubmed, Science Direct, SciFinder Scholar and Web of Science were searched to collect information about E. fischeriana. Other relevant literatures were searched in 'Flora of China Editorial Committee', ancient books, Ph.D and Masters' Dissertation to get more data of E. fischeriana. RESULTS: A total of 241 chemical constituents have been identified from the roots of E. fischeriana, including diterpenoids, triterpenoids, meroterpenoids, acetophenones, flavonoids, coumarins, steroids, phenolic acids, tannins, etc. Various pharmacological activities have been demonstrated, especially anti-tumor, antibacterial, anti-inflammatory, antiviral and anti-leukemia activities. Moreover, different investigations about clinical uses and toxicology of E. fischeriana indicated that attention should be paid to its usage and dosage. CONCLUSION: The researches of E. fischeriana are excellent, but gap still remains. As a poisonous traditional Chinese medicine, there are not enough studies on the toxicity of E. fischeriana. In addition, scholars' research on the pharmacological mechanism of E. fischeriana focuses more on the anti-tumor activity, which can be broadened in the future. Presumably, chemical constituents and biological activities of diterpenoids and trace meroterpenoids in E. fischeriana deserve further research in-depth in the future, in order to provide low toxicity and high efficiency lead compounds. Meanwhile, further studies on other medicinal aspects may lay a foundation for the comprehensive development and utilization of E. fischeriana.

Triterpene saponins from the seeds of Erythrophleum fordii and their cytotoxic activities.

Erythrosides A-G, seven undescribed oleanane-type triterpenoid saponins, were isolated from the seeds of Erythrophleum fordii. Their structures with absolute configurations were determined by extensive spectroscopic analysis including one-dimensional [1D] and two-dimensional [2D] nuclear magnetic resonance [NMR], high-resolution electrospray ionization mass spectroscopy [HR-ESI-MS] analysis, and chemical methods. Erythrosides A-G featured a diverse oligosaccharide chain containing 4-6 pentoses or hexoses at C-3 and a monoterpenic acid or a (E)-cinnamic acid unit at the C-21 position. Of particular interest, erythrosides A-C, E and F contained a rare alpha xylose in their sugar chains. The bioassay results indicated that erythrosides A-C showed moderate cytotoxic activities against human lung cancer cell line PC9 with IC50 values of 13.14, 16.67 and 17.59 µM, respectively (the positive control, Taxol, IC50 = 0.60 nM).