lignans and tracheloside

In this paper, as novelties to the field, it is confirmed at first, that the fruits of Cirsium species, regarded as injurious weeds, do contain lignans, two, different butyrolactone-type glycoside/aglycone pairs: the well known arctiin/arctigenin and the particularly rare tracheloside/trachelogenin species. These experiences were supported by gas chromatography-mass spectrometry (GC-MS), by liquid chromatography tandem mass spectrometry (LC-MS/(MS)) and by nuclear magnetic resonance (NMR) spectroscopy. The study reflects the powerful impact of the complementary chromatographic mass fragmentation evidences resulting in the identification and quantification, the extremely rare, with on line technique not yet identified and described, tracheloside/trachelogenin pair lignans, without authentic standard compounds. Fragmentation pattern analysis of the trimethylsilyl (TMS) derivative of trachelogenin, based on GC-MS, via two different fragmentation pathways confirmed the detailed structure of the trachelogenin molecule. The complementary chromatographic evidences have been unambiguously confirmed, by (1)H and (13)C NMR analysis of trachelogenin, isolated by preparative chromatography. Identification and quantification of the fruit extracts of four Cirsium (C.) species (C. arvense, C. canum, C. oleraceum, and C. palustre), revealed that (i) all four species do accumulate the tracheloside/trachelogenin or the arctiin/arctigenin butyrolactone-type glycoside/aglycone pairs, (ii) the overwhelming part of lignans are present as glycosides (tracheloside 9.1-14.5 mg/g, arctiin 28.6-39.3 mg/g, expressed on dry fruit basis), (iii) their acidic and enzymatic hydrolyses to the corresponding aglycones, to trachelogenin and arctigenin are fast and quantitative and (iv) the many-sided beneficial trachelogenin and arctigenin can be prepared separately, without impurities, excellent for medicinal purposes.

Topics: 4-Butyrolactone; Chromatography, Liquid; Cirsium; Fruit; Gas Chromatography-Mass Spectrometry; Glucosides; Lignans; Nuclear Magnetic Resonance, Biomolecular; Oximes; Plant Extracts; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Trimethylsilyl Compounds

The lignan glycoside, tracheloside, was isolated from seeds of Carthamus tinctorius (Compositae) as an anti-estrogenic principle against cultured Ishikawa cells by employing a bioassay-linked HPLC-ELSD method. Tracheloside significantly decreased the activity of alkaline phosphatase (AP), an estrogen-inducible marker enzyme, with an IC(50) value of 0.31 microg/ml, a level of inhibition comparable to that of tamoxifen (IC(50) = 0.43 microg/ml).

Topics: 4-Butyrolactone; Carthamus tinctorius; Cell Line; Enzyme Activation; Estrogens; Glucosides; Glycosides; Lignans; Molecular Structure; Plant Extracts; Seeds; Solubility

Tracheloside, one of the plant lignans which can be extracted from the debris after safflower oil is produced from the seeds of Carthamus tinctorious, is an analogue of another plant lignan, arctiin, the side-chain C-2 of the five-membered ring being changed from a hydrogen to a hydroxyl group. We have already demonstrated that arctiin has chemopreventive effect on mammary carcinogenesis. Therefore, chemopreventive effects of tracheloside on the initiation or post-initiation period of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced mammary carcinogenesis in female rats were examined. For initiation, female Sprague-Dawley (SD) rats at the 6 weeks of age were given intragastric administrations of 100 mg/kg body weight of PhIP once a week for 8 weeks. The animals were treated with 0.2 or 0.02% tracheloside during or after this carcinogen exposure. Control rats were fed basal diet with PhIP initiation or 0.2% tracheloside or basal diet alone without initiation throughout the experimental period. All surviving animals were necropsied at the week 52 of administration. There were no clear treatment-related changes with statistical significance in all parameters for mammary carcinomas measured in this experiment. These results indicate that tracheloside may not exert significant effects on PhIP-induced mammary carcinogenesis at least under the present experiment condition.

Topics: 4-Butyrolactone; Animals; Anticarcinogenic Agents; Carcinogens; Female; Glucosides; Imidazoles; Lignans; Mammary Neoplasms, Experimental; Rats; Rats, Sprague-Dawley

Serum concentrations of arctiin, tracheloside, and their metabolites formed in the gastrointestinal tract were investigated in the rat. Arctiin or tracheloside was not detected in the serum after oral administration (200 mg/kg). In regard to their metabolites, each metabolite 1 (AM1, TM1), their genuine genins, appeared in the serum, and the serum concentration of arctiin metabolite 1 (AM1) reached its peak at 4 h and that of tracheloside metabolite 1 (TM1) reached its peak at 8 h. On the other hand, both metabolites 2 (AM2, TM2), which each possess a catechol moiety as reported previously, were not found in the serum. Now, we have studied the detection of their metabolites in the rat large intestinal contents after oral administration. It was revealed that all metabolites reported previously were certainly formed in rat gastrointestinal tract in vivo. Thus, we presumed a possibility that metabolite 2 was converted into metabolite 1 through C-3" methylation by catechol-O-methyltransferase (COMT) in rat liver. Each metabolite 2 was incubated with rat liver cytosol in the presence of S-adenosyl-L-methionine. It was proved that metabolite 2 was rapidly converted into metabolite 1 within 3 min. We suggest that arctiin or tracheloside was transformed to at least two metabolites in the gastrointestinal tract, and after absorption from the intestine, metabolite 2 was converted into metabolite 1 through methylation by COMT in the liver, and arctiin and tracheloside existed as metabolite 1, the genuine genin, in the blood stream.

Topics: 4-Butyrolactone; Animals; Digestive System; Drugs, Chinese Herbal; Furans; Glucosides; Lignans; Lignin; Male; Molecular Structure; Rats; Rats, Wistar

Structural transformation of arctiin and tracheloside, major components of seeds of Arctium lappa and Carthamus tinctorius, were investigated using rat gastric juice (pH 1.2-1.5) and rat large intestinal flora in vitro. Quantitative analysis of lignans and their metabolites was carried out by high performance liquid chromatography. Both lignans were stable in rat gastric juice and arctiin was rapidly transformed to arctigenin in rat large intestinal flora, followed by conversion to the major metabolite, 2-(3",4"-dihydroxybenzyl)-3-(3',4'-dimethoxybenzyl)-butyrolactone. On the other hand, tracheloside also decreased dependently with time and was converted to trachelogenin and its major metabolite, 2-(3",4"-dihydroxybenzyl)-3-(3',4'-dimethoxybenzyl)-2-hydroxybutyrola ctone. These experiments suggest that in the course of metabolism of lignans, firstly a cleavage of the glycosidic bond occurred and then demethylation of the phenolic methoxy group in the alimentary tract followed.

Topics: 4-Butyrolactone; Animals; Biotransformation; Furans; Glucosides; Lignans; Lignin; Male; Plants, Medicinal; Rats; Rats, Wistar