Structure Elucidation of Two New Diterpenoids from Isodon phyllostachys: Phyllostacins A and B |
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Authors: | Xian Li Wei‐Lie Xiao Sheng‐Xiong Huang Zhi‐Ying Weng Yun‐Heng Shen Quan‐Bin Han Han‐Dong Sun |
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Affiliation: | 1. State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, Yunnan, P.?R. China (phone: +?86‐871‐5223251;2. fax: +?86‐871‐5216343);3. College of Pharmacy, Kunming Medical College, Kunming 650031, Yunnan, P.?R. China |
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Abstract: | Two new ent‐kaurane‐derived diterpene derivatives, phyllostacins A ( 1 ) and B ( 2 ), were isolated from the aerial parts of Isodon phyllostachys, together with two known compounds, irroratin A ( 3 ) and serrin B ( 4 ). Both 1 and 2 were found to be present as diastereoisomers. In the case of 1 , the corresponding diastereoisomeric diacetates 5 and 6 were prepared and separated. The structures of the new compounds were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic methods, in combination with MS experiments. In (D5)pyridine solution, the two epimers of 1 are present in equal amounts, but in CDCl3 or CD3OD, the (S)‐epimer predominates in the mixture of hemiacetals. |
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Keywords: | Isodon phyllostachys Diterpenoids ent‐Kauranoid NMR Spectroscopy Phyllostacin A and B |
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