• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.151-157
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• 2000

This study was carried out to isolate and identify the maysin and related flavonoid analogues in corn silks. Silks were covered with silk bag to prevent pollination and were sampled at 3-5 days after silking. The silks were filled with 100% MeOH and stored at $0^{\circ}C$ until analysis. The MeOH extracts of corn silks were filtered and concentrated at 35-4$0^{\circ}C$. The ${CH}_2$${Cl}_2$ was added on the concentrated aqueous solution to remove the chlorophyll and lipids. The Cis open column (25mm$\times$54 cm) was washed and activated with serial treatment of 500$m\ell$ of 100% MeOH(twice)longrightarrow75% MeOH longrightarrow50% MeOHlongrightarrow30% MeOHlongrightarrow100% $H_2$O(2 times). The concentrated aqueous solution was applied to the $C_{18}$ column and washed with $H_2O$ several times to remove the sugars and water soluble pigments. Neochlorogenic acid, chlorogenic acid and 4-caffeoylquinic acid were eluted with 10% MeOH, and rhamosyl isoorientin was eluted with 30% MeOH, but maysin was eluted with 50% MeOH from the $C_18$ open column. Collected fractions were analyzed with HPLC by using revers-phase Ultras-phere $C_{18}$ column (4.6$\times$250mm, 5$\mu\textrm{m}$) and $H_2$O (10% MeOH containing 0.1% $H_3$${PO}_4$)/MeOH (100% MeOH containing 0.1% H$_3$PO$_4$) linear gradient from 20% to 90% MeOH for 35 minutes, a flow rate of 1 $m\ell$/min and detection at 340nm. The selected fractions were concentrated and applied to the silicic acid column. Maysin was eluted with 500$m\ell$ of 100% ethyl acetate from the silicic acid column for the first purification, and the purity of collected fractions was about 75%, but the purity from the second purification with the Cis column (1/2 $\times$ 43") was greater than 95%. FAB-MS spectral data was obtained with VG7O-VSEQ VG analytical fast atom bombardment mass (UK). $^1$H-NMR and $^{13}$ C-NMR data were obtained with Bruker DPX 400 MHz NMR spectrometers (German) in DMSO-d$_{6}$ at 400 and 100 MHz, respectively.vely.