Alkaloids of Scopolia tangutica

A L K A L O I D S OF S c o p o l i a t a n g u t i c a S. Ao M i n i n a , T. V. A s t a k h o v a , and D. A. F e s e n k o UDC 547.944/945 From the epigeal part of Scopolia tangutica Maxim., grown in the Leningrad oblast under crop conditions, by adsorption column chromatography and selective elution we have isolated two more alkaloids, in addition to hyoscyarnine and scopolamine: base I with Rf 0.45 [TLC, A1203, chloroform-methanol (20 : 1) system] and 0.41 [PC, Filtrak F N - I I paper, butan-l-ol-acetic acid-water (4 : 1 : 5) system] and base (II) with Rf 0.34 and 0.55, re spe ctively. The molecular weight of base I with the composition CI?H21OsN (M+ 319) differed by 16 m/e from the molecular weight of scopolamine. We have given some constants of the alkaloid previously [i]. The NMR spectrum of I (CFsCOOH, internal standard TMS) showed the following signals: 7.48 (SH, multiplet, rnonosubstituted benzene ring), 4.39 (IH, doublet, J= 12 Hz), and 4.84 (1H, doublet, J= 12 IIz) (CH2 group), and the IR spectrum contained absorption bands corresponding to an ester carbonyl group (1740 cm-I), a benzene nucleus (860 crn-l), and active hydrogen (3510, 3600 cm-l). The hydrolysis of I by Reimers' method [2] yielded an amino alcohol which was identified as scopoline and an acid C9HI004, the constants of which have been published [1]. The NMR spectrum of the acid (CFsCOOH, internal standard TMS) has the signals of the protons of a rnonosubstituted benzene ring at 7.3-7.7 pprn (5H, rnultiplet) and also two doublets at 4.21 pprn (IH, J= 12 Hz) and 4.70 ppm (IH, J= 12 Hz) corresponding to a CH2 group having no protons in the ~ positions. It follows from this that the acid is ~-phenyl-~,fl-dihydroxypropionic acid, i.e., it differs from tropic acid by an additional tertiary alcoholic group. This is confirmed by the presence in the IR spectrum of the acid of an additional band at 3620 crn-I in addition to the usual absorption band for tropic acid at 3530 crn-l. Base I has the structure of an ester of scopine (scopoline) with this acid and is identical in structure with anisodine isolated from S_: tangutica, growing in China [3]. Base II consisted of white acicular crystals with rnp 62-63°C (frornbenzene), PKbase 5.2° IR spectrum crn-l: 700, 742, 760 (benzene nucleus), 3400-3490 (active hydrogen), 1725 (ester carbonyl group). NMR spectrum (CDCI3, internal standard, HMDS pprn): 7.12-7.30 (5H, rnultiplet, rnonosubstituted benzene nucleus), 4.95 (1H, triplet, J= 5 H_z, H3 of a tropane nucleus), 4.30 (IH, quartet, J~8 Hz, J N 2Hz, H6 of a tropane nucleus), 4.11 (1H, triplet, J=11 Hz, H at the ~-C of tropic acid), 2.36 (3H, singlet, N-CH3), The IR and NMR spectra were similar to the spectra of hyoseyarnine. The molecular weight of (If) (M+ 305) differed from that of hyoscyarnine by 16 rn/e. The presence in the mass spectrum of (If) of peaks of ions with rn/e 261, 140, 96, 95, and 94 shows the s-cleavage of the pyrolidine ring with the subsequent elimination of oxyethylene (peaks of an ion with m/e 261). Such a fragment is characteristic for 6-hydroxyhyoscyarnine [4]. The melting point of (If) also agrees with this alkaloid [4]. The acid isolated from II on hydrolysis by Reirner's method [2] was identified as tropic acid from the absence of a depression of the melting point of a mixture; the amino alcohol had Rf 0.12 [PC, Filtrak FN-11 paper, butan-l-ol-aeetic acid-water (4: 1: 5) system]; melting point of its picrate (from 40% ethanol) 248249°C. Consequently, II has the structure of 6-hydroxyhyoscyarnine, which has been isolated previously from Physochlaina dubia [4] and has been detected chromatographically in S_ tangutica growing in China [5]. LITERATURE 1. 2. 3. 4. 5. CITED S. A. Minina, T. V. Astakhova, and N. V. Nazarova , R a s t . Res., II, 493 (1975). F. R e i r n e r s , Quart. J. Pharrn. P h a r m a c o l . , 21, 470 (1948). Hsieh, Ching-Hsu, Wang Lin, Liu Yung-Lung, Shang Tian-ming, Hsieh Feng-Chik, and Ke Ta-Lun, K'o Hsueh T'ung Pao, 20, 52 (1975); Ref. Zh. Khim., 2_22,E64 (1976). R. T. M i r z a m a t o v , V. M. Malikov, K. L. Lutfullin, and S. Yu. Yunusov, Khirn. P r i r o d n . Soedin, 493 (1972). Hsiao P e i - K e n , Hsia Kuang-Cheng, and Ho Li-Vi, Acta Botanica Sinica, 15, 187 (1973). Leningrad Institute of P h a r m a c e u t i c a l Chemistry. T r a n s l a t e d from Khirniya P r i r o d n y k h Soedinenii, No. 5, pp. 712-713, S e p t e m b e r - O c t o b e r , 1977. Original article submitted March 3, 1977. 598 0009-3130/77/1305- 0598 $07.50 © 1978 Plenum Publishing Corporation  (...truncated)