Four New Nonaoxygenated C18 Dibenzocylcooctadiene Lignans from Kadsura philippinensis

Abstract

Plants belonging to genus Kadsura (Schizandraceae) have been used for long time in traditional Chinese medicine to treat several diseases and have been well known as a rich source of C 18 dibenzocyclooctadiene lignans. [1][2][3][4][5] This type of lignans have been shown significant anti-HIV, 5) antioxidant, 6) antihepatotoxic, 7,8) antihepatitis, 9) cytotoxic, 10) antitumor-promotion, 11) and anti-lipid peroxidative activities. 12)Our previous investigation on the chemical constituents of Kadsura philippinensis ELMER, growing in the Southern islet of Taiwan, led to the isolation of twelve dibenzocyclooctadiene lignans including new kadsuphilins A and B, 6-epigomisin and 1-demethylkadsuphilin A from the EtOAc soluble portion of the alcoholic extact. 13) Further chromatographic separation and purification of the more polar fractions afforded additional four new polyoxygenated dibenzocylcooctadiene lignans, kadsuphilins C-F (1-4) and schizanrin G (5).14) Their structures were elucidated on the bases of spectroscopic analyses, including 2D NMR experiments, comparison of the spectral data with those of the related metabolites. Their stereochemistries were assigned by CD and NOESY spectra. The in vitro antiplatelet aggregation activity of metabolites 1-5 also have been evaluated. Results and DiscussionThe EtOAc-soluble portion from the alcoholic extract of Kadsura philippinensis was subjected to flash column chromatography over silica gel. Eluted polar fractions were further isolated or purified using normal or reversed phase HPLC to afford the new kadsuphilins C-F (1-4) and schizanrin G (5).Kadsuraphilin C (1) had a molecular formula C 31 H 32 O 11 , as deduced from its HR-ESI-MS (m/z 581.2020, [MϩH] ϩ ) and NMR spectral data (Tables 1, 2). The IR spectrum suggested the presence of hydroxyl (n max 3564, 3450 cm Ϫ1 ) and ester (1744, 1721 cm Ϫ1 ) functionalities in the molecule. The UV spectrum showed l max (MeOH) at 219, 257, and 280 nm while its CD spectrum exhibit strong negative cotton effect at l max 251 nm, designating 1 as a dibenzocyclooctadiene lignan [1][2][3][4][5] with an S-biphenyl configuration. Four new nona-oxygenated C 18 dibenzocyclooctadiene lignans, kadsuphilins C-F (1-4), were isolated from the EtOAc soluble portion of the alcoholic extract of the aerial parts of Kadsura philippinensis. The structures of 1-4 were elucidated on the basis of extensive spectroscopic analyses, including 2D NMR (HMQC, HMBC, and NOESY) experiments, comparison of the spectral data with those of the related metabolites. The stereochemistries of the biphenyl and octadiene moieties were deduced from circular dichorism (CD) and the NOESY spectra, respectively. The in vitro antiplatelet aggregation activity of metabolites 1-4 also have been evaluated.

In silico Analysis and Experimental Validation of Lignan Extracts from Kadsura longipedunculata for Potential 5-HT1AR Agonists

“…Kadsura longipedunculata Finet et Gagnep (Nanwuweizi), which is a type of traditional Chinese medicine, is widely distributed in the southern part of China [3,4]. Kadsura longipedunculata (KL) has been used for the treatment of a variety of diseases, including tumors, hepatitis [5,6], inflammation [7], immunosuppression [8], and insomnia [9,10], for thousands of years.…”

An Efficient and Versatile Approach for Optical Resolution of C2-Symmetric Axially Chiral Biaryl Dials. Synthesis of Enantiopure Biaryl-Derived Cyclic trans-1,2-Diols

“…Axially chiral biaryl frameworks are found in a large number of natural products as well as pharmaceutical molecules .…”

Intermedins A and B; New metabolites from Schisandra propinqua var. intermedia

“…The lack of NOE response between H-4 and Me-18 further supported the β-orientation of Me-18. Further, the ROESY correlations between H-4 and H-6, Me-17 and H-9, as well as between H-9 and H-11 indicated a twist-boat-chair (TBC) conformation of the cyclooctadiene ring (Chen et al, 2004;Shen et al, 2007). Besides, 1 showed two negative Cotton effects around 235-255 nm and two positive ones around 215-225 nm, indicating that 1 possess an Sbephenyl configuration (Ikeya et al, 1979a).…”

“…The 1 H-NMR spectrum of 1 showed signals of two aromatic protons (δ H 6.87 and 6.82 (each 1H, s)) of a biphenyl moiety. The signals at δ H 3.14, 3.33, 3.45, 3.83, 3.95 (each 3H, s), and 5.68 (1H, br s) indicated the presence of five methoxyls, and a phenolic hydroxyl, as substituents on the biphenyl rings (Shen et al, 2007).…”