ABSTRACT
In a two-microelectrode voltage clamp assay using Xenopus laevis oocytes, a petroleum ether extract prepared from a commercial sample of the traditional Chinese herbal drug labelled as " Chaihu" (Bupleurum chinense DC. roots) enhanced the I(GABA) by 156â% ± 22â% when tested at 100 µg/mL. By means of HPLC-based activity profiling combined with high-resolution LC-MS and microprobe NMR, the germacranolide aristolactone was identified as one of the main active compounds (EC50 56.02 µM ± 5.09 µM). However, aristolactone has been previously reported only from the genus Aristolochia (Aristolochiaceae), suggesting a possible adulteration. With the aid of a validated HPTLC protocol for detection of aristolochic acids and with reference samples, the commercial sample was confirmed to be a mixture of Aristolochia manshuriensis root and Bupleurum chinense root. This finding was corroborated by macroscopic inspection of the drug. This case of adulteration with a highly nephrotoxic drug raises concerns about adequate quality control of TCM drugs commercialized in Europe.
Subject(s)
Aristolochia/chemistry , Aristolochia/toxicity , Aristolochic Acids/chemistry , Aristolochic Acids/toxicity , Bupleurum/chemistry , Kidney Diseases/chemically induced , Plant Extracts/chemistry , Animals , Drug Contamination , Drugs, Chinese Herbal/chemistry , Humans , Oocytes/drug effects , Plant Roots/chemistry , Plants, Medicinal/chemistry , Receptors, GABA-A/metabolism , Toxicity Tests , XenopusABSTRACT
In a screen of 1800 plant and fungal extracts for antiplasmodial, antitrypanosomal, and leishmanicidal activity, the n-hexane extract of Chrysanthemum cinerariifolium (Trevir.) Vis. flowers showed strong activity against Plasmodium falciparum. We isolated the five pyrethrins [i.e., pyrethrin II (1), jasmolin II (2), cinerin II (3), pyrethrin I (4), and jasmolin I (5)] from this extract. These were tested together with 15 synthetic pyrethroids for their activity against P. falciparum and Trypanosoma brucei rhodesiense and for cytotoxicity in rat myoblast L6 cells. The natural pyrethrins showed antiplasmodial activity with IC(50)s between 4 and 12 µM, and antitrypanosomal activity with IC(50)s from 7 to 31 µM. The pyrethroids exhibited weaker antiplasmodial and antitrypanosomal activity than the pyrethrins. Both pyrethrins and pyrethroids showed moderate cytotoxicity against L6 cells. Pyrethrin II (1) was the most selective antiplasmodial compound, with a selectivity index of 24.
Subject(s)
Antimalarials/pharmacology , Antiprotozoal Agents/pharmacology , Chrysanthemum cinerariifolium/chemistry , Flowers/chemistry , Pyrethrins/pharmacology , Animals , Cell Line , Cell Survival/drug effects , Myoblasts, Skeletal/drug effects , Plant Extracts/chemistry , Plasmodium falciparum/drug effects , Pyrethrins/chemistry , Rats , Trypanosoma brucei rhodesiense/drug effectsABSTRACT
Lipophilic and polar extracts of iris rhizomes (Iris germanica) were submitted to a phytochemical profiling by a combination of HPLC-PDA-MS and semi-preparative HPLC/off-line microprobe NMR measurements. A total of 20 compounds were purified in sub-milligram to milligram amounts via two successive chromatographic steps. They were identified as isoflavones, isoflavone glycosides and acetovanillone by analysis of on-line MS and PDA, and off-line NMR data. A new isoflavone glycoside, iriflogenin-4'-O-gentiobioside, was subsequently isolated at preparative scale for full chemical characterization. This study demonstrates the applicability of the HPLC/off-line microprobe NMR approach as a robust means for rapid phytochemical profiling of plant extracts.
Subject(s)
Acetophenones/isolation & purification , Glycosides/isolation & purification , Iris Plant/chemistry , Isoflavones/isolation & purification , Plant Extracts/chemistry , Acetophenones/chemistry , Chromatography, High Pressure Liquid/methods , Glycosides/chemistry , Isoflavones/chemistry , Magnetic Resonance Spectroscopy/methods , RhizomeABSTRACT
Phyteumosides A (1) and B (2), two saponins with unprecedented triterpenoid aglycons, were isolated from the aerial parts of Phyteuma orbiculare (Campanulaceae). Their structures were elucidated by spectroscopic and chemical methods and corroborated by X-ray diffraction analyses of the aglycons obtained through enzymatic hydrolysis. The aglycon of 1 can be considered as an incompletely cyclized onoceroid or gammaceroid triterpene with two additional tetrahydropyran rings arising from oxygen bridges. Compound 2 possesses a new 17-polypodene aglycon.
