Abietane type diterpene compound, preparation method and application thereof

A preparation method of the abietane type diterpene compound of formula (I):

• comprising:
• S1, taking air-dried Leucosceptrum canum as raw materials, crushing, leaching with organic solvent, and concentrating under a reduced pressure at a low temperature to obtain an extract;
• S2, mixing the extract with water to obtain a suspension, adding ethyl acetate for extraction, and concentrating under the reduced pressure at the low temperature to obtain an ethyl acetate extracting phase;
• S3, separating the ethyl acetate extracting phase by silica gel column chromatography, and performing gradient elution with petroleum ether-ethyl acetate as an eluent, where the petroleum ether and the ethyl acetate are in a volume ratio of (9.8-10.2):1, (4.8-5.2):1, and (2.8-3.2):1;
• collecting the eluent corresponding to the volume ratio of petroleum ether to ethyl acetate of (2.8-3.2):1, followed by thin-layer chromatographic analysis and combining similar fractions to obtain initial components;
• and
• S4, separating the initial components by preparative liquid chromatography, and performing isocratic elution by using acetonitrile and water as an eluant to obtain the abietane type diterpene compound.