P-16 アスヒカズラLycopodium complanatum由来の新規アルカロイドの構造と生物活性(ポスター発表の部)

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Club moss (Lycopodiaceae) is known to be a rich source of Lycopodium alkaloids posessing unique heterocyclic ring systems such as C_<16>N, C_<16>N_2, and C_<27>N_3, which have attracted great interest from biogenetic, synthetic, and biological points of view. In our continuing efforts to find new Lycopodium alkaloids, lycopladines A-D (1-4), lyconadin B (5), and complanadines C (6), D (7) were isolated from the club moss Lycopodium complanatum. The structures for 1-7 were elucidated on the basis of spectral data. Lycopladine A (1) obtained as colorless amourphous solid, showed the pseudomolecular ion peak at m/z 260 (M+H)^+ in the ESIMS, and the molecular formula, C_<16>H_<21>NO_2, was established by HRESIMS [m/z 260.1653, (M+H)^+, △+0.2mmu]. The gross structure of 1 was elucidated on the basis of 2D NMR data. The relative stereochemistry of 1 was elucidated from NOESY data. Lycopladine A (1) possesses an unprecedented skeleton different from known C_<16>N-type Lycopodium alkaloids. The stuructures of lycopladines B-D (2-4) were elucidated on the basis of spectroscopic data and modified Mosher's method. Lycopladine B (2) was 5-hydroxyl, △_<8,15>, △_<13,14>, and 17-methyl ester form of fawcettidane skeleton. Lycopladine C (3) was assigned as 5-O-acetyl form of 2. Lycopladine D (4) had fawcettidane skeleton with hydroxyl group at C-5 and lactone ring (C-13〜C-16). The absolute stereochemistry of 2 and 4 were elucidated by modified Mosher's method. The absolute configuration at C-5 of 2 and 4 were assigned to be S and R, respectively. Lyconadin B (5) was assigned as dihydro form of lyconadin A. Complanadines C (6) and D (7) were obtained as colorless amorphous solids. The structures and relative stereochmistry of 6 and 7 were elucidated on the basis of spectroscopic data. Complanadine C (6) was assigned as the dimer of 9-keto, △_<10,11> form of lycopodine and △_<9,10> form of lycopodine. The dimer of lycopodane skeleton has not been reported previously. Complanadine D (7) was tetrahydro form of complanadine A. A plausible biogenetic path of lyconadin A (8) was proposed on the basis of structure of lycopladine A (1). Biogenetically, lyconadines A (8) and B (5) might be derived from L-lysine via pelletierine, phlegmarane skeleton, and an intermediate X from which lycopladine A (1) might be provided. Effects of lycopladines A-D (1-4), and lyconadins A (8) and B (5) on neurotrophic factor biosynthesis in 1321N1 human astrocytoma cells were examined. The mRNA expressions of NGF in 1321N1 cells were examined by a semiquantitative RT-PCR method. The mRNA expressions for NGF were enhanced by lyconadins A (8) and B (5).
天然有機化合物討論会の論文
2006-09-15

P-16 アスヒカズラLycopodium complanatum由来の新規アルカロイドの構造と生物活性(ポスター発表の部)

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