Symbols and Abbreviations 1 Short Introduction to Basic Principles and Methods 1.1 Chemical shift 1.2 Spin-spin coupling 1.3 Coupling constants 1.4 Signal multiplicity (multiplets) 1.5 Spectra of first and higher order 1.6 Chemical and magnetic equivalence 1.7 Continuous wave (CW) and Fourier transform (FT) NMR spectra 1.8 Spin decoupling 1.9 Nuclear Overhauser effect 1.10 Relaxation, relaxation times 2 Recognition of Structural Fragments by NMR

6] S. Pasynkiewicz, Po/i./idron 1990. 9. 429. 171 Crystal data of [3(thf),] 6 T H F M = 1986.46, rhomhohedral, space group R k . [I = h = 2353.6(3). c = 3133.0(6) pm. Y = 15.030(4) nm'. Z = 6. pL,,,Cd = 1.317 Mgm-3. F(000) = 6264. ; . =71.073 pm, T = -120 C . p(MoK,) = 1.651 mni-'. crystal dimensions: 0.7 x0.5 xO.5 mm, 6 5 2 0 < 40 ; of the 6127 collected reflections, 2440 are independent, and these were used for the refinement of 164 parameters with the help of 198 restraints: maximal residual electron density: 899 enin-'. R I ( F > 4 o ( F ) ) = 0.069 and wR2 = 0.199 (all data) with R1 = X l l F , l ~ ~k :~~, I~F o \ and PIRZ = (Zii,F~:-Ff)*:Zii.(F3)l)il '.The data here collected on a Stoe-Huher diffractometer. Intensities of 3 rapidlq cooled crgstiil in a n oil drop [XI Mere collected by 2 0 :~ method. Semiempirical absorption corrections were carried out on all data. The structure was solved hg direct methods (SHELXS-90) [9] and refined by least squares on F' [lo]. The disorders of the T H F solvent molecules were refined with dictance restraints. The refinement of the inversion twinning paramter 11 I ] ( \ = 0.00 (4) for .r = 0 for the correct absolute structure and i = + 1 for the inverted structure) confirmed the absolute structure of3. The solution of the structure and the refinement in the space group R5c were unsuccessful. The structure could he solved in the space group C<,, but a refinement was also here unsuccessful. Further details of the crystal structure investigation may he obtained from the Director of the Cambridge Crystallographic Data Centre. 12 Union Road, GB-Cambridge CB2 IEZ. on quoting the full journal citation. 1i5. 4971. An,qew. Chon. Inr. E d Engl. 1994, 33. No. 12 VCH Yerluxsgrsellschufr mhH, 0-69451 Weinherni, 1994 0570-0833,'94!1212-1?47 J 10.00 + .2SW

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Dos frutos deIlex paraguariensis foram isolados um novo glicosídeo triterpenóide, o ácido rotúndico 3β-O-α-L-arabinopiranosídeo, denominado matesídeo (4), os triterpenos ácido ursólico (1), ácido acetilursólico (2), ácido 23-hidroxi-ursólico (3) e as saponinas ziyu-glicosídeo I (5) e ilexosídeo II (6). As estruturas foram estabelecidas com base em métodos espectroscópicos, principalmente RMN mono-e bidimensional. Os valores de amargor foram determinados para matesídeo e ilexosídeo II e comparados com os valores obtidos para as saponinas de I. paraguariensis e outras espécies de Ilex. O elevado amargor encontrado para o ilexosídeo II, uma das saponinas majoritárias presentes nos frutos e não encontrada nas folhas de I. paraguariensis, sugere que o uso dos frutos alteraria de maneira significativa o sabor do produto erva-mate e também poderia produzir efeitos fisiológicos ainda não conhecidos.A new triterpenoid glycoside, 3β-O-α-L-arabinopyranosyl rotundic acid, named here mateside (4), and the known triterpenes ursolic acid (1), acetylursolic acid (2), 23-hydroxyursolic acid (3), the saponins ziyu-glycoside I (5) and ilexoside II (6), were isolated from fruits of Ilex paraguariensis. Their structures were established on the basis of 1D and 2D NMR spectroscopic methods. The threshold bitterness values for mateside and ilexoside II were also determined and compared with saponins obtained from leaves of I. paraguariensis and other Ilex species. The high bitterness of Ilexoside II, one of the main saponins found the fruits, but not in the leaves of I. paraguariensis, suggests that the utilization of the fruits in the Maté production can produce a strong taste variation and unknown physiological effects.

Carbon-13 chemical shifts of 8 chromones and 35 isoflavones variously substituted by hydroxy-, acetoxy-, and methoxy-groups are assigned. The applicability of chemical shift increments reflecting inductive and resonance effects is discussed. Some general relations between substitution patterns and carbon shielding useful for the identification of naturally occurring isoflavones are outlined. Typical C—H couplings of chromone and phenyl carbons are analyzed for a 4′,6,7-trisubstituted derivative.