Lignans compounds extraction

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 ... 

ILs have been used for MEKC as modifiers for the quantification of the active components of lignans found in the medicinal herbs Schisandra species [52]. Preliminary inveshgations employing SDS alone as a surfactant did not lead to the necessary resolution of the studied compounds but the addition of [C4CiIm][Bp4] to the SDS micellar system resulted in the complete separation of all fhe compounds. The method was successfully applied to determine lignans in extracts of Schisandra chinensis (Turcz.) Baill. and Schisandra henryi C.B. Clarke in <13 min (5 mM borate-5 mM phosphate buffer in the presence of 20 mM SDS and 10 mM [C4CiIm][BFJ). 

Nature has been a source of medicinal agents for thousands of years. Compounds extracted from natural products have been used either as a new drug or a lead molecule to synthesize modem therapeutic agents in the treatment of variety of diseases for centuries. Pharmacologic activities have been found in different kinds of secondary metabolites such as alkaloids, terpenoids, coumarins, flavonoids, and lignans, all firstly isolated from plants. 

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... 

In certain cases, structure elucidation of aryltetralin lignans has only been established by total synthesis of the ( )-compounds. Noteworthy in this respect have been the constituents of Phyllanthus nlruri Linn. (Euphorbiaceae), extracts of which have been used medicinally (in treatment of asthma, jaundice and bronchial infections) (140). Considerable confusion resulted mainly from differing interpretations of spectroscopic data, and at least five different structures were proposed for the major constituent, hypophyllanthin. The structure of the aryltetralin constituents established by unequivocal synthesis (141) are shown in Scheme 30 they were given the names hypophyllanthin (1411. nirtetralin (1421. phyltetralin (1431 and lintetralin (1441. 

Other compounds such as resveratrol from grape skin (90), lycopene from tomato skin (91), lignans from Schisandra chinensis (92), and perillyl alcohol from Korean orange peels (93,94) have been isolated using SFE, obtaining efficiencies 30 times higher than those provided by the conventional solvent extraction methods. 

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