Lignans compounds

The inhibition of proliferation of several cancer cells was investigated with the compounds shown in Fig. 8. One of these lignans, compound 143, was active, having an IC50 of ca. 35 fxmol/1 against HT 29 colon cancer cells [75] and others [76]. This result was in agreement with previously observed cytotoxicities of a-unfunctionalized lactone lignans [77]. 

Mimura, M., Y. Takahara, A. Ichikawa, and T. Osawa. Lignan compounds and their manufacture with S1063 Sesamum indicum. Patent-Japan Kokai Tokkyo Koho-63,207,389 1997 5 pp. 

Chiu, J. T., and 1. B. Haydik. Sesame seed oil anaphylaxis. J Allergy Clin Immunol 1991 88(3) 414-415. Mimura, M., Y. Takahara, A. Ichikawa, and T. Osawa. Lignan compounds and their manufacture with Sesamum indicum. Patent-Japan Kokai Tokkyo Koho-36,207,389 1988 5 pp. Murui, T., and A. Ide. Anticarcino-genic glycosides with aglycones extracted from sesame seeds. Patent-Japan Kokai Tokkyo Koho-62,238,287 1987 ... 

Lignans, compounds formed by the condensation of two lignin monomer units, oeeur frequently in softwoods, an example of these is pinoresinol which occurs in spruce and other species (Fengel and Wegener, 1984). 

Y Ohtani, M nomura, T Hida, K Miyamoto, M Kanitani, T Aizawa, M Aburada. Inhibition by gomisin A, a lignan compound, of hepatocarcinogenesis by 3 -methyl-4-dimethylaminoazobenzene in rat. Biol Pharm Bull 17 808-814,1994. 

S Takeda, Y Kase, I Arai, Y Ohkura, M Hasegawa, Y Sekiguchi, A Tatsugi, S Funo, M Aburada, E Hosoya. Effect of TJN-101, a lignan compound isolated from Schizandra fruits, on liver fibrosis and on liver regeneration after partial hepatectomy in rats with chronic liver injury induced by CC14. Folia Pharmacol Japan 90 51-65, 1987. 

M Nose, T Eujimoto, T Takeda, S Nishibe, Y Ogihara. Structural transformation of lignan compounds in rat gastrointestinal tract. Planta Medica 58 520-523, 1992. 

Isoflavonoid and lignan compounds exhibit a range of mammalian health-promoting activities that are currently the focus of intense study (Table 1.1). Dietary genistein reduces susceptibility to mammary cancer in rats (Fritz et al., 1998) and... 

TABLE 1.1 Selected Animal Health-Promoting Effects of Isoflavonoid and Lignan Compounds ... 

Schisandra chinensis is a rich source of lignan compounds and their lignans have been analyzed by various methods including HPLC, GC, GC-MS, TLC, LC-MS and CE. Comparing with other methods, HPLC is widely used and more reliable method for Schisandra lignans analysis and LC/MS is vety useful for identification of lignans in Schisandra fruits. 

An inverse correlation between thyroid cancer risk and phytoestrogens was recently proposed as a result of a multi-ethnic population-based case control study conducted in the San Francisco Bay Area (Hom-Ross et al., 2002). In this study, dietary habits and phytoestrogen consumption were assessed by a food-frequency questionnaire and by a nutrient database. The outcome of the study was that soy-based foods and alfalfa sprouts were associated with a reduction of thyroid cancer risk, whereas a Western diet did not influence cancer risk. No difference was observed between American and Asian women or between pre- and postmenopausal women. Furthermore, among the few compounds examined, the isoflavones genistein and daidzein and the lignan secoisolariciresinol were the phytoestrogens most frequently associated with risk reduction (Horn-Ross et al., 2002). 

Various extraction methods for phenolic compounds in plant material have been published (Ayres and Loike, 1990 Arts and Hollman, 1998 Andreasen et ah, 2000 Fernandez et al., 2000). In this case phenolic compounds were an important part of the plant material and all the published methods were optimised to remove those analytes from the matrix. Our interest was to find the solvents to modily the taste, but not to extract the phenolic compounds of interest. In each test the technical treatment of the sample was similar. Extraction was carried out at room temperature (approximately 23 °C) for 30 minutes in a horizontal shaker with 200 rpm. Samples were weighed into extraction vials and solvent was added. The vials were closed with caps to minimise the evaporation of the extraction solvent. After 30 minutes the samples were filtered to separate the solvent from the solid. Filter papers were placed on aluminium foil and, after the solvent evaporahon, were removed. Extracted samples were dried at 100°C for 30 minutes to evaporate all the solvent traces. The solvents tested were chloroform, ethanol, diethylether, butanol, ethylacetate, heptane, n-hexane and cyclohexane and they were tested with different solvent/solid ratios. Methanol (MeOH) and acetonitrile (ACN) were not considered because of the high solubility of catechins and lignans to MeOH and ACN. The extracted phloem samples were tasted in the same way as the heated ones. Detailed results from each extraction experiment are presented in Table 14.2. 

EtOH extraction was the most efficient way to improve the flavour of the phloem. A solvent/solid ratio of at least 10 1/kg was needed to achieve a significant change in the taste. The loss of catechins was approximately 27% and that of lignans was 35%. All the catechins and lignans were found from the EtOH extract. Losses of lignans and catechins were smaller with other sovents, but either the taste was not modified or the cost of solvent treatment would be too high. Phenolic compounds like lignans and catechins also have a bitter taste and some improvement in flavour may have occurred because of the lower concentration of these. The disappearance of the characteristic... 

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