ALKALOIDS FROM OXYTROPIS MYRIOPHYLLA (PALL) DC

Summary Five alkaloids were isolated from the epigeal part of Oxytropis myriophylla. Three alkaloids were identified as N-be~lzoyl-P-phenylethylamine, N-trans-cinnamoyl-P-phenylethylamine, N-cis-cinnamoyl-P-phenylethylamine and the structures of two new alkaloids were elucidated to be N-benzoyl-P-hydroxyphenylethylarnine (2), N-trans-cinnamoyl-P-hydroxy-phenylethylamine (5). The absolu.te structures were established by modified Mosher method. on Lober ODs with a 50% to give 1 3 mg) and 4 2 with a solvent mixture of and pinitol (5


Introduction
The Oxytropis genus is one of the most wide spread genus of the family Fabaceae and 81 Oxytropis species are growing in Mongolia (11. Oxytropis species are widely used in Mongolian and Tibetan traditional medicines as diuretic, anti-septic, antifever, preventing from some infectious diseases [ 2 ] . 0. myriophylla is the most popular component of many traditional prescriptions and named as "stag-sha" in Mongolian traditional medicine. O.myriophylla is perennial herbaceous plants reaching 15-40 cm in height and distributed in forested high mountainous part of Mongolia. 0. myriophylla has been reported to contain flavonoids (kaempferol and quercetin derivatives [3]) and alkaloids.
Compound 4, which has cis-cinnamoyl group is very rare in nature, compounds 2 and 5 are the new alkaloids. The structure of alkaloids 1-5 have been elucidated as outlined below.

Results and Discussion
Compound 2 showed a [M+H]' peak at m/' 242 corresponding to a molecular formula of CI5HISO2N. The IR spectrum of 2 showed absorption bands for aromatic bond (1640 cm-I).
The 'H and '.'c NMR spectra of 2 revealed the presence of one benzoyl group which bound to p-hydroxyphenylethylamine, confirmed by the two mono-substituted benzen ring and an amidic CO (6, 170.6) and a h y d r o x y m e h (6H 4.90, 6, 73.6) coupled with methylene (aH 3.54, 3.64, 6, 48.3). The confirmation of the structure was possible by application of the HMBC. Therefore, the structure of 2 was elucidated to be N-benzoyl-Phydroxyphenylethylamine.
Compound 1 was also confirmed as N-benzoyl-P-phenylethylarnine by NMR. 1 and 2 have been isolated fiom 0.trichophysa [4]. But, absolute structure of 2 have not been elucidated.
In order to determine the absolute configuration of 2 at the C-7 position, we applied the modified Mosher method to t h s compound [6]. Two diastereomers were prepared fiom 2 by the treatment with (+) and (-)-MTPA chloride in the presence of DMAP. The & values, which were calculated by the measurement of 'H NMR, are shown Fig. 1. Thus, it was determined that 2 was ( 7 3 . Compound 3 and 4 gave rise to 'H and "C NMR spectra that were similar to those of 1, except for the presence of trans olefm at aH 6.57, 7.52 (J=16Hz) as trans-cinnamoyl group at 3, and cis olefin at ?jH 5.98, 6.73 (J=l3Hz) as cis-cinnamoyl group at 4. On the basis of NMR including HMBC, 3 and 4 were assigned N-trans-cinnamoyl-P-phenylethylamine and N-cis-cinnamoyl-P-phenylethylamine respectively.

K. K o j i m a et al.:
Compound 5 showed a [M+H]' peak at m/z 269 corresponding to a molecular formula of C17H1702N. The 'H and "C NMR spectra of 5 also revealed the presence of one transcinnamoyl group which bound P-hydroxyphenylethylamine. Thus, it was elucidated to be Ntranscinnamoyl-phydroxyphenylethylamine. The absolute configuration was assumed to be (75' ) by optical rotation compared with 2.

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EtOH and concentrated to give an concentrated EtOH extract. The EtOH extract was dissolved in water, which was extracted with hexane, chloroform, ethyl acetate, and nbutanol successively. The chloroform extract was subjected to Silica gel column chromatography with a solvent mixture of hexane and ethyl acetate (9: 1-1:9). Four fractions (I-IV) were collected according to TLC analysis. Fraction I was rechromatographed on Silica gel with a solvent mixture of hexane and ethyl acetate in stepwise manner to give 2 (17 mg), 5 (5 mg). Fraction I1 was rechromatographed on Silica gel with a solvent mixture of hexane and ethyl acetate in stepwise manner to give benzoic acid (10 mg). Fraction 111 was rechromatographed on Lober ODs with a 50% CH3CN to give 1 (20 mg), 3 (6 mg) and 4 ( 2 mg). Fraction IV was rechromatographed on Silica gel with a solvent mixture of chloroform and MeOH in stepwise manner to give pinitol (5 mg). (