Lacinilene C 7-methyl ether, lacinilene and their cadalene precursors were extracted from dried green and senescent cotton bracts with methanol-acetone (8:2, v/v). Preliminary separation of the concentrated extract was effected with silica and reverse phase SEP-PAK cartridges. The final eluate, containing the four compounds, was separated on a Supelcosil LC-C18HPLC column using a mobile phase consisting of acetonitrile-methanol-isopropanol-water (45:13:2:40, v/v). The observed amounts of the methyl ether never exceeded 60 ppm, which was sustantially lower than previously reported by others. These determinations were unaffected by the method of tissue preparation and diethyl ether was not as effective as an extraction solvent as methanol-acetone (8:2, v/v). The reported procedure may be applicable to the simultaneous quantification of the two lacinilenes and their cadalene precursors.
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