J . Nat. Prod. 1996,59, 55-58
55
Chemical Constituents from Dehaasia triandra. 1. Three New Alkaloids, Isocorydione, Norisocorydione, and Dehatriphine, from the Leaves Shoei-Sheng Lee," Chien-Kuang Chen, Ih-Sheng Chen,' and Chung-Hsiung Chen School of Pharmacy, College of Medicine, National Taiwan University, Taipei 100, Taiwan, Republic of China, and School of Pharmacy, Kaohsiung College of Medicine, Kaohsiung, Taiwan, Republic of China Received February 22, 1995@
The reinvestigation of Dehaasia triandra Merr. resulted in the isolation of three novel alkaloids, besides the most abundant aporphine isocorydine (1)from the leaves. They are isocorydione (2), norisocorydione (3),and dehatriphine (4). Isocorydione has been prepared semisynthetically. Dehatriphine, the first ether-linked bisaporphine, was elucidated a s 9-O-(8'-isocorydinyl)-Nmethyllaurotetanine. Structural elucidation of these compounds was based on spectral analysis and chemical correlation. Past studies on the constituents of Dehaasia trzandra Merr. (Lauraceae) have resulted in the isolation of five aporphines from the leaves-isocorydine (11, corytuberine, atheroline, nantenine, and xanthoplanine-and three bisbenzylisoquinolines-dehatridine from the leaf and obaberine and dehatrine from the stem.Q Being interested in the biological activities of the dimeric compounds, we reinvestigated this plant and report herein on the chemical constituents of the leaves. The EtOH extract of the leaves was triturated with 0.1 N HC1 to give an aqueous fraction containing base salts, and exhaustive partitioning against CHCb yielded the CHCl3-soluble alkaloidal salts. This fraction was further fractionated by centrifugal partition chromatograph, Sephadex LH-20, and Si gel columns to give four bases. Among them, (+I-isocorydine (1)was identified by comparison with an authentic sample isolated from the same plant previous1y.l
6.89). Compound 2 is a new natural product and is named isocorydione. Based on the NOESY, HMQC, and HMBC data, the lH- and 13C-NMR assignments for 2 are listed (Table
1).
Compound 3,another violet amorphous solid, has a molecular formula of C19H17N05 from HREIMS, which is 14 mass units fewer than 2. The IH- and I3C-NMR spectra showed an absence of the N-Me signals (6 H 3.13 and 6 C 40.1 in 2). These differences aside, compounds 2 and 3 had similar spectra. Hence, 3 is norisocorydione and is also novel. Its lH- and 13C-NMRdata (Table 1) were assigned by comparison with those of 2. Compound 4 showed a [MI+, at mlz 680.3058 (HREIMS) for a formula of C40H44N208 (calcd 680.3098). Its lH-NMR spectrum displayed two NMe signals at 6 2.26 and 2.45; six Me0 singlets at 6 3.95, 3.89, 3.87, 3.85, 3.73, and 3.68; five aromatic proton singlets at 6 8.16, 6.74, 6.68, 6.58, and 6.42; and a D2O exchangeable singlet at 6 8.70. The DzO exchangeable signal is characteristic for 1-OH or 11-OH in a 1,2,10,11- or a 1,2,3,10,11-oxygenated aporphine such as 11-OH in 1, and the downfield aromatic singlet (6 8.16) for H-11 in aporphines.5 The IR spectrum of 4 showed absorption at 3436 cm-', but its UV spectrum under alkaline R conditions failed to give the anticipated bathochromic 1. R'=H, R"=OH 2. R=Me 6 5. R=OH, R"=H 3. R=H shift of a free phenolic OH, thus indicating a hindered phenolic OH. The presence of two NMe signals, six Compound 2, a violet amorphous solid, C20H19N05 methylene carbons, and two methine carbon signals was (HREIMS), exhibited a conjugated IR carbonyl absorpconfirmed by the 13C-NMRspectrum. In addition, the tion (1654 cm-l), and the 13C-NMRspectrum displayed molecular formula requires 12 double bonds and an two carbonyl signals at 6 178.3 and 186.5, similar to additional 8 ring-forming carbons and leads to the 1,4-dicarbonyl signals in 2-methoxy-8-methyl-l,4-naph- conclusion that 4 is a bisaporphine-type of dimeric t h ~ q u i n o n e . The ~ lH-NMR spectrum showed singlet isoquinolines. Subtracting the seven oxygens (6 x OMe signals for three aryl protons (6 6.91, 6.89, and 5.871, and 1 x OH) from the formula leaves one oxygen to link three Me0 (6 3.94, 3.90, and 3.851, one NMe (6 3.131, the monomeric aporphines. This ether links two aroand two triplets for two vicinal coupled methylenes (6 matic rings, as deduced from substitution pattern (total: 3.43 and 3.08, J = 6.6 Hz). These data were consistent 14, including 6 x OMe, 1 x OH, 5 x Ar-H), and the with those reported for a p-quinone4 prepared from 1 location of these substituents and the diphenyl ether by oxidation with Fremy's salt. This structure was linkage was determined as follows. supported by NOESY and HMBC techniques. The The lH-NMR spectrum of 4 displayed a relatively NOESY spectrum spatially interconnects the 2-OMe to upfield-shifted H-7'P at 6 1.99 (t,J = 13.8 Hz), (62.44 H-3, and H-9 to 10-OMe. The presence of 1-OMe was in 1) and a relatively downfield-shifted H-7'a at 6 3.33 confirmed from the HMBC data, which indicated that (dd, J = 3.3, 13.8 Hz) (6 3.04 in 1). The 13C-NMR C-1 is coupled to a methoxy singlet (63.94) and H-3 (6 spectrum showed an upfield-shifted C-7' at 6 28.07 (t) (6 35.6 in 11, identified by the correlation in a HMQC Kaohsiung College of Medicine. spectrum, This evidence suggested that C-8' is oxygenAbstract published in Advance ACS Abstracts, December 1, 1995. @
0163-3864/96/3259-0055$12,00/0
0 1996 American Chemical Society and American Society of Pharmacognosy
Notes
56 Journal of Natural Products, 1996, Vol. 59, NO. 1
Table 1. 1H- and I3C-NMR Data (d/ppm) for Compounds 2 and 3 and HMBC data for Compound 2 in CDC13 HMBC of 2 ( J = 8 Hz) 1H (mult) (Hz) 13C (mult) position
2
3
1
2 3 3a 3b 4 5 6-Me 6a 7 7a 8 9 10 11 lla llb 1-OMe 2-OMe 10-OMe
6.89 s
6.94 s
3.08 t (6.6) 3.43 t (6.6) 3.13 s
3.12 t (6.2) 3.53 m
6.91 s
6.97 s
5.87 s
5.89 s
3.94 s 3.90 s 3.85 s
3.98 s 3.95 s 3.88 s
2
3
143.9 s 152.2 s 112.8 d 128.4 s 119.3 s 29.2 t 50.2 t 40.1 q 150.3 s 98.2 d 136.4 s 186.5 s 105.2 d 163.9 s 178.3 s 118.0 s 126.9 s 60.7 g 56.5 g 56.4 q
144.0 s 152.6 s 113.4 d 128.8 s 118.7 s 29.2 t 40.8 t 149.6 s 100.8 d 136.5 s 186.1 s 105.2 d 164.0 s 178.4 s 118.5 s 127.3 s 60.7 g 56.6 q 56.4 q
H-4a: 2.64 in H-4!3: 3.12 in H-5a: 2.47 in H-5!3: 3.00 m H-6a: 2.91 br d, J=13.8 Hz H-7a: 2.80 dd, J=4.0, 13.8 Hz H-7!3: 2.41 t, J43.8 HZ H-4h: 2.66 m H-473: 3.12 m H-Sa: 2.38 dt, J=3.2, 1 1.6 Hz H-S'P: 2.94 m H-6a: 2.75 br d, J=13.8Hz H-7'a: 3.33 dd, J=3.3, 13.8 Hz H-7'0: 1.99 t, Jz13.8 HZ
_.
NOEs (%. italics) and 'H-NMR data of 4 (6/ppm, CDC13) 11139
($=
2929
3 R9
171
2n 07
x 7(!
M'O
1 85
(628
10591
'I
9 147 10 9a;; 147 57
1126R
126 (17 6255
J l h 12671
43Y6
12718 128 R9
51 29
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60 28
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