Lignans compounds analysis

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. 

Nishibe, S., H. Tsukamoto, I. Agata, S. Hisada, K. Shima, and T. Takemoto. Isolation of phenolic compounds from stems of Olea europaea. Shokugaku Zasshil981 35 251-254. Tsukamoto, H., S. Hisada, and S. Nishibe. Studies on the lignans from Oleaceae plants. Proc 26th Symposium on the Chemistry of Natural Products, Kyoto, Japan 1983 26 181—188. Paganuzzi, V. Use of silver nitrate TLC in the analysis of olive oil triterpene alcohols. I. Oils obtained from various anatomical parts of the olives. Riv Ital Sostanze Grasse 1981 58(8) 285-393. 

On the other hand, the crystal structures of 5 -demethoxy- / -peltatin A methyl ether and 2 -bromopodophyllotoxin were clarified by X-ray analyses (ref. 43) and it was established that the configuration of these lignans were 2- a -H, 3- / -H and 4- a -aryl. In view of the above experimental results and the conclusions obtained from X-ray analyses of analogous lignans, the structure of hernandin is presumed to be 5-methoxydesoxypodophyllotoxin (15). To confirm this, the absolute configuration of compound (15) was determined by X-ray analysis. 

A detailed interpretation of LC/ H-NMR in combination with LC/UV-DAD, LC/MS, and chemotax-onomical data (see the case of 3 in Figure 5) enables the identification of three known lignanes ( —)-phylligenin (3), ( —)-eudesmin (4), ( —)-epieudesmin (5) as well as polycerasoidol (6). Compound (7) could be completely identified based on online data and was finally characterized as a new polyacetylenic natural product named oropheic acid (7). This example also demonstrates the use of LC/UV LC/MS and LC/NMR in phytochemical analysis known natural products can be dereplicated by comparison... 

The stereochemistry at the chiral centres of the three new lignans, erythro-strebluslignanol, threo-T-methoxyl strebluslignanol and erythro-T-meth-oxyl strebluslignanol has been established by Li et al by analysis of vicinal proton-proton couplings as well as CD spectra and optical rotation data. The determined chemical structures of these compounds were (7 R,8 5)-5-allyl-5 -(l,2-dihydroxypropyl)[l,l -biphenyl]-2,2 -diol, (7 R,8 R)-5-allyl-5 -(2-hydroxy-l-methoxypropyl)[l,l-biphenyl]-2,2 -diol and (7 R,8 5)-5-allyl-5 -(2-hydroxy-l-methoxypropyl)[l,l-biphenyl]-2,2 -diol. 

TLC-fingerprint analysis of Saponins and Lignans Reference compounds... 

Nishibe S, Okabe K, Hisada S 1981 Isolation of phenolic compounds and spectroscopic analysis of a new lignan from Trachelospermum asiaticum van intermedium. Chem Pharm Bull 29 2078-2082... 

As the lignans have been found to be the active components in Schisanda chinensis, they are used as marker compounds in Schisandra herbs and herbal preparations. Right now HPLC is the most useful approach to analyze lignans in Schisandra and can offer good separation, shorter analysis times and easier... 

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