Baytopine (2), a new alkaloid, was isolated from leaves and flowers of Merendera kurdica Bornm. and its structure was determined by spectroscopic means.All eight presently known natural homoaporphine alkaloids were found in plants 1 of the Liliaceae family . This communication describes the structure of baytopine, a new homoaporphine alkaloid lsolated during our recent phytochemical study 2of several Merendera species .Baytopine, an optically active compound ( [dlD +74' (c 0.28, CHCl>)), amorphous 3solid, was isolated from leaves and flowers of M. kurdica Bornm. . It gave a positive FeC13 test for phenols. Its uv spectrum, which is characteristic of 4 a homoaporphine type alkaloid , is pH-dependent and similar to that of bechuanine (75-(+)-floramultine) (1) (Table 1). The ir spectrum of baytopine showed the 1 presence of hydroxyl functionality (bands at 3400-3500 cm- ). Mass measurements (M+ m/z 371) established the molecular formula C21H25N0y The base peak (m/z 354) in the mass spectrum (70 eV) of baytopine corresponds to ~+-17 which indicates, by analogy with other homoaporphines, that position C-1 or C-13 carries'~edicated to Professor Derek Barton on the occasion of his 70th birthday.a phenolic hydroxy group697. According to its '~-nmr spectrum, baytopine contains the same building blocks as bechuanine (1): 3 methoxyls, one N-methyl, 2 isolated aromatic protons; one ArCH2CH2N system, and one NCHCH2CH2 system. The presence of two phenolic hydroxyls is inferred from the difference between the total number of hydrogen atoms in the molecule (ms) and the number of protons attached to carbons (13c-nmr). However, the nonidentical 'H and 13c-nmr spectra (Table 2) indicate that the two compounds are positional isomers. Only one methoxyl (3.92 ppm) exhibits a NOE (1251, to the 6.68 ppm singlet. Since the latter signal is assigned to H-3 on the basis of its long-range coupling to the proton at 3.15 ppm which forms part of the AA'BB'system of the CH2CHZ group, one methoxyl is located at C-2. Because of the single NOE between the methoxyl and aromatic proton, the second methoxyl cannot be placed at C-11. With both bechuanine and baytopine, one methoxyl resonates in higher field - an effect typical for methoxyl at C-1 or C-13 (ref. 8). That requires a reversed substitution pattern (OH at C-13, OCH, at C-1) in baytopine, leading to the formula 2. Both alkaloids exhibit a negative Cotton effect at l~a transition (Table 1). Thus the 7(5) absolute configuration for baytopine (2) is directly assignable from CD 9 spectrum .