Proton and Carbon-13 NMR Studies of Steroids and Triterpenes

  • Geoffrey A. Cordell
  • Long-Ze Lin
  • Roberto R. Gil
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 405)


Steroids and triterpenes are common constituents of higher and lower plants, as well as marine flora and fauna. Derived from mevalonic acid with squalene as an intermediate, their skeletal diversity is essentially unmatched. Some of these compounds are important as mammalian hormones (testosterone, estrone), while others are potent toxic agents either as molluscicides, insecticides or as cytotoxic agents. Thus, as well as chemical diversity, these compounds also represent biological diversity in their mode of action. Some of the compounds, for example beta-sitosterol, are probably almost ubiquitous in the plant kingdom, indicating that while there may be many selective biosynthetic pathways depending on a particular taxonomic and ecologic niche, there is also a pathway which may be primordial in nature remaining unchanged and common to all plants.


Oleanolic Acid Nuclear Magnetic Resonance Spectroscopy Triterpenoid Saponin Nuclear Magnetic Resonance Technique Methyl Resonance 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Agrawal, P.K.; Jain, D.C. I3C NMR spectroscopy of oleanane triterpenoids. Progr. NMR Spectr. 1992, 24, 1–90.CrossRefGoogle Scholar
  2. Agrawal, P.K.; Jain, D.C.; Gupta, R.K.; Thakur, R.S. Carbon-13 nmr spectroscopy of steroidal sapogenin and steroidal saponins. Phytochemistry 1985, 24, 2479–2496.CrossRefGoogle Scholar
  3. Arisawa, M.; Cordell, G.A.; Kinghom, A.D.; Farnsworth. N.R. Plant anticancer agents XXIII. 6α-Senecioyl—oxychaparrin, a new antileukemic quassinoid of Simaba multiflora. J. Nat. Prod. 1983, 46, 218–221.PubMedCrossRefGoogle Scholar
  4. Arisawa, M.; Fujita, A.; Morita, N; Cox, P.J.; Howie, R.A.; Cordell, G.A.; Farnsworth, N.R. Triterpenes from Simaba multiflora. Phytochemistiy, 1987, 26, 3301–3303.CrossRefGoogle Scholar
  5. Arisawa, M.; Fujita, A.; Morita, N; Kinghorn, A.D.; Cordell, G.A.; Farnsworth, N.R. Plant anticancer agents XXXV. Further constituents of Simaba multiflora (Simaroubaceae). Planta Med. 1985, 50, 348–349.CrossRefGoogle Scholar
  6. Atta-ur-Rahman.One and Two Dimensional Nuclear Magnetic Resonance Techniques. Elsevier, Amsterdam, Holland, 1989; p. 578.Google Scholar
  7. Aue, W.P.; Bartholdi, E.; Ernst, R.R. Two—dimensional spectroscopy. Application to nuclear magnetic resonance. J. Chem. Phys. 1976, 64, 2229–2246.CrossRefGoogle Scholar
  8. Bavovada, R; Blaskó, G.; Shieh, H.-L.; Pezzuto, J.M.; Cordell, G.A. Spectral Assignment and Cytotoxicity of 22- Hydroxytingenone from Glyptopetalum sclerocarpum. Planta Med. 1990, 56, 380–382.PubMedCrossRefGoogle Scholar
  9. Bax., A. Broadband homonuclear decoupling in heteronuclear shift correlation nmr spectroscopy. J. Magn. Reson. 1983,55,517–520.Google Scholar
  10. Bax, A. Structure determination and spectral assignment by pulsed polarization transfer via long-range 1H–13C couplings. J. Magn. Reson. 1984, 57, 314–318.Google Scholar
  11. Bax, A.; Aszalos, A.; Dinya, Z.; Sudo, K. Structure elucidation of the antibiotic desertomycin through the use of new two—dimensional NMR techniques. J. Am. Chem. Soc. 1986,108, 8056–8063.CrossRefGoogle Scholar
  12. Bax, A.; Davis, D.G. MLEV-17-Based two—dimensional homonuclear magnetization transfer spectroscopy. J. Magn. Reson. 1985, 65, 355–360.Google Scholar
  13. Bax, A.; Freeman, R. Investigation of complex networks of spin—spin coupling by two—dimensional nmr. J. Magn. Reson. 1981, 44, 542–561.Google Scholar
  14. Bax, A.; Freeman, R.; Frenkeil, T.A. An NMR technique for tracing out the carbon skeleton of an organic molecule. J. Am. Chem. Soc. 1981,103, 2102–2104.CrossRefGoogle Scholar
  15. Bax, A.; Morris, G.A. An improved method for heteronuclear chemical shift correlation by two—dimensional nmr. J. Magn. Reson. 1981, 42, 501–505.Google Scholar
  16. Bax, A.; Subramanian, S. Sensitivity—enhanced two—dimensional heteronuclear shift correlation nmr spectroscopy. J. Magn. Reson. 1986, 67, 565–569.Google Scholar
  17. Bax, A; Summers, M.F. 1H and 13C Assignments from sensitivity—enhanced detection of heteronuclear multiple—bond connectivity by 2D multiple quantum NMR. J. Am. Chem. Soc. 1986, 108, 2093–2094.CrossRefGoogle Scholar
  18. Bhacca, N.S; Williams, D.H. Application of NMR spectroscopy in organic chemistry, illustration for the steroid field. Holden—Day, San Francisco, CA 1964; pp 198.Google Scholar
  19. Blunt, J.W.; Stothers, J.D. 13C N.m.r. spectra of steroids — a survey and commentary. Org. Magn. Reson. 1977, 9, 439–464.CrossRefGoogle Scholar
  20. Bodenhausen, G.; Freeman, R. Correlation of chemical shifts of potons and carbon-13. J. Am. Chem. Soc. 1978, 100, 320–321.CrossRefGoogle Scholar
  21. Bothner-By, A.A.; Stephens, R.L.; Lee, J.; Warren, C.D.; Jeanloz, R.W. Structure determination of a tetrasaccharide: transient nuclear Overhauser effects in the rotating frame. J. Am. Chem. Soc. 1984,106, 811–813.CrossRefGoogle Scholar
  22. Braunschweiler, L.; Ernst, R.R. Coherence transfer by isotopic mixing: application to proton correlation spectroscopy. J. Magn. Reson. 1983,53,521–528.Google Scholar
  23. Byrne, L.T. Nuclear magnetic resnance spectroscopy strategies for structural determination. In Bioactive Natural Products. Detection, Isolation and Structure Determination; Colegate, S.M.; Molyneux, R.J., Eds.; CRC Press, Boca Raton, FL, 1993; pp 75–104.Google Scholar
  24. Carpenter, K.A.; Reynolds, W.F.; Yang, J.-P.; Enriquez, R.G. Further improvements in the FLOCK sequence. Magn. Reson. Chem. 1992, 30, S35–S41.CrossRefGoogle Scholar
  25. Chang, P.T.O.; Cordell, G.A.; Fong, H.H.S.; Farnsworth, N.R. Velutinic acid, a new freidelane derivative from Xylosma velutina. Phytochemistry, 1977,16, 1443–1445.CrossRefGoogle Scholar
  26. Chen, J.-J.; Qiu, S.-X.; Zhang, Z.-X.: Zhou, J. The chemical constituents of Gymnema yunnanense. Acta Bot. Yunnan. 1989,11, 203–208.Google Scholar
  27. Chen, S.-X.; Snyder, J.K. General strategy for the structure determination of saponins: molluscicidal saponins from Allium vineale. In Bioactive Natural Pmducts. Detection, Isolation and Structure Determination; Colegate, S.M.; Molyneux, R.J., Eds.; CRC Press, Boca Raton, FL, 1993; pp 349–403.Google Scholar
  28. Cohen, A.I.; Rock, S.; Anisotropy of substituents on the proton resonance of C-18 and C-19 methyl groups. Evaluation by computer regression. Steroids 1964,3, 243–257.CrossRefGoogle Scholar
  29. Cordell, G.A. Selective INEPT spectroscopy — a powerful tool for the spectral assignment and structure elucidation of natural products. Phytochem. Anal. 1991, 2, 49–59.CrossRefGoogle Scholar
  30. Cordell, G.A.; Kinghorn, A.D. One—dimensional proton—carbon correlations for the structure determination of natural products. Tetrahedron 1991, 47, 3521–3534.CrossRefGoogle Scholar
  31. Cordell, G.A.; Lyons, R.L.; Fong, H.H.S.; Benoit, P.S.; Farnsworth, N.R. Biological and phytochemical investigations of Dianthus barbatus cv. “China Doll” (Caryophyllaceae). Lloydia 1977, 40, 361–363.PubMedGoogle Scholar
  32. Davis, O.G.; Bax, A. Assignment of complex 1H nmr spectra via two—dimensional homonuclear Hartmann—Hahn Spectroscopy. J. Am. Chem. Soc. 1985,107, 2820–2821.CrossRefGoogle Scholar
  33. Derome, A.E. Modern NMR Techniques for Chemistry Research. Pergamon Press, Oxford, England, 1987; pp 280.Google Scholar
  34. Derome, A.E. The use of N.M.R. spectroscopy in the structure determination of natural products: two—dimensional methods. Nat. Prod. Repts. 1989,6, 111–141.CrossRefGoogle Scholar
  35. Edwards, M.W.; Bax, A. Complete proton and carbon-13 nmr assignment of the alkaloid gephyrotoxin through the use of homonuclear Hartmann—Hahn and two—dimensional nmr spectrosscopy. J. Am. Chem. Soc. 1986,108, 918–923.CrossRefGoogle Scholar
  36. Ekong, D.E.U. Chemistry of the meliacins (limonoids). The structure of nimbolide, a new meliacin from Azadirachta indica. Chem. Commun. 1967, 808.Google Scholar
  37. Gil, R.R.; Lin, L.-Z.; Chai, H.-B.; Pezzuto, J.M.; Cordell, G.A. Cardenolides from Nierembergia stricta (Solanaceae). J. Nat. Prod. In press.Google Scholar
  38. Gottlieb, H.; Kirson, I. 13C NMR spectroscopy of the withanolides and other highly oxygenated C28 steroids. Org. Magn. Reson. 1981,16, 20–25.CrossRefGoogle Scholar
  39. Griesinger, C.; Ernst, R.R. Frequency offset effects and their elimination in nmr rotating frame cross—relaxation spectroscopy. J. Magn. Reson. 1987, 75, 261–271.Google Scholar
  40. Gunasekera, S.P.; Cordell, G.A.; Farnsworth, N.R. Plant anticancer agents XX. constituents of Nicandra physaloides (Solanaceae). Planta Med. 1981, 43, 389–391.PubMedCrossRefGoogle Scholar
  41. Gunasekera, S.P.; Cordell, G.A.; Farnsworth, N.R. 3β-Hydroxy-28-p-coumaroyloxy—lup-20(29)-en-27-oic acid from Caraipa densifolia. J. Nat. Prod. 1983, 46, 118–122.PubMedCrossRefGoogle Scholar
  42. Hamburger, M.O.; Cordell, G.A. 1H- and,13C-NMR Studies of Selected Quassinoids. Planta Med. 1988,52, 352–355.CrossRefGoogle Scholar
  43. Handa, S.S.; Kinghorn, A.D.; Cordell, G.A.; Farnsworth, N.R. Plant anticancer agents XXV. Constituents of Soulamea soulameoides (Simaroubaceae). J. Nat. Prod. 1983, 46, 359–364.PubMedCrossRefGoogle Scholar
  44. Hikino, H.; Kiso, Y. Natural products for liver diseases. Economic and Medicinal Plant Research; Hikino, H.; Wagner, H.; Farnsworth, N.R., Eds; Vol: 2, Academic Press, London, 1988; pp 39–72.Google Scholar
  45. Jacquesy, J.C.; Levisalles, J. Stéréochemie de l’halogenation des céto-3(5a) stéroïdes. Bull. Soc. Chim. Fr. 1962, 1866–1874.Google Scholar
  46. Jeener, J.; Meier, B.H.; Bachman, P.; Ernst, R.R. Investigation of exchange processes by two—dimensional nmr spectroscopy. J. Chem. Phys. 1979, 71, 4546–4553.CrossRefGoogle Scholar
  47. Jia, Q.; Zhang, R.-Y. Progress in the research on the chemistry of the saponins from the genus Bupleurum. Acta Pharm. Sinica 1989, 24, 961–971.Google Scholar
  48. Kawaguchi, K.; Asaka, I.; Hirotani, M.; Furuya, T.; Katsuki, S. Cardenoildes in the regenerated plants obtained from Strophantus divaricatus calli. Phytochemistry 1993, 34, 1317–1321.CrossRefGoogle Scholar
  49. Kessler, H.; Griesinger, C.; Zarbock, J.; Loosli, H.R. Assignment of carbonyl carbons and sequence analysis in peptides by heteronuclear shift correlation via small coupling constants with broadband decoupling in t1 (COLOC). J. Magn. Reson. 1984, 57, 331–336.Google Scholar
  50. Kigodi, P.G.K.; Blaskó, G.; Thebtaranonth, Y.; Cordell, G.A. Spectroscopic and biological investigation of nimbolide and 28-deoxynimboIide from Azadirachta indica. J. Nat. Prod. 1989, 52, 1246–1251.PubMedCrossRefGoogle Scholar
  51. Koike, K.; Bevelle, C.; Talapatra, S.K.; Cordell; G.A.; Farnsworth, N.R. Plant anticancer agents V. Cardiac glycosides of Asclepias albicans. Chem. Phann. Bull. Japan. 1980, 28, 401–405.Google Scholar
  52. Konno, C.; Xue, H.-Z.; Lu, Z.-Z.; Soejarto, D.D.; Cordell, G.A.; Fong, H.H.S.; Hodgson, W. 3β-(3,4-Dihydroxy—cinnamoyl)-erythrodiol and3β-(4-hydroxy—cinnamoyl) erythrodiol from Larrea tridentata. Phytochemistry 1988, 27, 233–235.CrossRefGoogle Scholar
  53. Kriwacki, R.W.; Pitnér, T.P. Current aspects of practical two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy: applications to structure elucidation. Pharmaceut. Res. 1989, 6, 531–553.CrossRefGoogle Scholar
  54. Lehn, J.M. Résonance magnétique nucléaire de produits naturels - II. Triterpènes de la série du dammarane: les groupes méthyles. Bull. Soc. Chim. Fr. 1962, 1832–1837.Google Scholar
  55. Levitt, M.H.; Ernst, R.R. Improvement of pulse performance in nmr coherence transfer experiments. A compensated INADEQUATE experiment. Mol. Phys. 1981, 50, 1109–1124.CrossRefGoogle Scholar
  56. Likhitwitayawuid, K.; Bavovada, R.; Lin, L.-Z.; Cordell, G.A. Revised structure of 20-hydroxytingenone and 13C nmr assignments of 22β-hydroxytingenone. Phytochemistry 1993, 34, 759–763.CrossRefGoogle Scholar
  57. Lin, L.-J.; Lin, L.-Z.; Gil, R.R; Cordell, G.A.; Ramesh, M.; Srilatha, B.; Reddy, B.; Appa Rao, A.V.N. New pregnane glycosides from Caralluma umbellata. Phytochemistry 1994, 35, 1549–1553.CrossRefGoogle Scholar
  58. Lin, L.-Z.; Cordell, G.A.; Ni, C.-Z.; Clardy, J. A quassinoid from Brucea javanica. Phytochemistry 1990, 29, 2720–2722.CrossRefGoogle Scholar
  59. Lin, L.-Z.; Lin, L.-J.; Cordell, G.A.; Luo, S.-Q.; Jiang, H.-F. Spectral assignment of 2-O-β-D- glucopyranosylsaikosaponin B2 by two—dimensional nmr techniques. Magn. Reson. Chem. 1992,30,1097–1103.CrossRefGoogle Scholar
  60. Luo, S.-Q.; Lin, L.-Z.; Cordell, G.A. Saikosaponins from Bupleurum wenchuanense. Phytochemistry 1993, 33, 1197–1205.PubMedCrossRefGoogle Scholar
  61. Luo, S.-Q.; Lin, L.-Z.; Cordell, G.A.; Xue, L.; Johnson, M.E. Assignment of the 1H- and 13C nmr spectra of the C21 steroids 12β-O-acetyltenacigenin A and tenacigenin A by two—dimensional nmr techniques and computer modeling. Magn. Reson. Chem. 1993a, 34, 215–221.CrossRefGoogle Scholar
  62. Luo, S.-Q.; Lin, L.-Z.; Cordell, G.A.; Xue, L.; Johnson, M.E. Polyoxypregnanes from Marsdenia tenacissima. Phytochemistry 1993b, 34, 1615–1620.CrossRefGoogle Scholar
  63. Luo, S.-Q.; Qiu, S.-X.; Lin, L.-Z.; Cordell, G.A. Minor polyoxypregnanes from Marsdenia tenacissima. Phytochemistry, In press.Google Scholar
  64. Mahato, S.B.; Kindu, A.P. 13C NMR spectra of pentacyclic triterpenoids — a compilation and some salient features. Phytochemistry 1994,37, 1517–1575.CrossRefGoogle Scholar
  65. Martin, G.E. and Zektzer, A.S. (1988) Two—Dimensional NMR Methods for Establishing Molecular Connectivity. VCH Publishers, Inc., New York, NY, pp. 508.Google Scholar
  66. Meksuriyen, D.; Nanayakkara, N.P.D.; Phoebe, Jr., C.H.; Cordell, G.A.; Farnsworth, N.R. Two triterpenoids from Davidsonia pruriens. Phytochemistry 1986, 25, 1685–1689.CrossRefGoogle Scholar
  67. Ogura, M.; Cordell, G.A.; Farnsworth, N.R. Jacoumaric acid, a new triterpene acid from Jacaranda caucana (Bignoniaceae). Phytochemistry 1977a, 16, 286–288.CrossRefGoogle Scholar
  68. Ogura, M.; Cordell, G.A.; Farnsworth, N.R. Plant anticancer agents IV. Constituents of Jacaranda caucana. Lloydia 1977b, 40, 157–168.PubMedGoogle Scholar
  69. Ogura, M.; G.A. Cordell, A.D. Kinghorn and N.R. Farnsworth. Plant anticancer agents VI. Constituents of Ailanthus excelsa. Lloydia 1977, 40, 579–584.PubMedGoogle Scholar
  70. Oksüz, S.; Shieh, H.-L.; Pezzuto, J.M.; Ozhatay, N.; Cordell, G.A. Biologically active compounds from the Euphorbiaceae. Part 1. Triterpenoids of Euphorbia nicaeensis subsp. glabra. Planta Med. 1993, 59, 472–473.CrossRefGoogle Scholar
  71. Oksüz, S.; Gil, R.R.; Chai, H.-B.; Pezzuto, J.M.; Cordell, G.A.; Ulubelen, A. Biologically active compounds from the Euphorbiaceae. Part 2. Triterpenoids of Euphorbia cyparissias. Planta Med. 1994, 60, 594–596.PubMedCrossRefGoogle Scholar
  72. Pauli, G.F.; Junior, P.; Berger, S.; Matthiesen, U. Alepposides, cardenolide oligoglycosides from Adonis aleppica. J; Nat. Prod. 1993, 56, 67–75.PubMedCrossRefGoogle Scholar
  73. Piantini, U; Sorenson, O.W.;Ernst, R.R. Multiple quantum filters for elucidating nmr coupling networks. J. Am. Chem. Soc. 1982,104, 6800–6801.CrossRefGoogle Scholar
  74. Qiu, S.-X.; Lin, L.-Z.; Nan, Y.; Lin, P.; Chen, J.-J.; Zhang, Z.-X.; Zhou, J.; Cordell, G.A. Internal acyl migration of gymnemarsgenin. Phytochemistry, In press.Google Scholar
  75. Qiu, S.-X.; Zhang, Z.-X.; Zhou, J. Studies on the constituents of Marsdenia globifera. Acta Bot. Sinica 1990, 32, 936–942.Google Scholar
  76. Rance, M.; Sorenson, O.W.; Bodenhausen, G.; Wagner, G.; Ernst, R.R.; Wuthrich, K. Improved spectral resolution in COSY 1H nmr spectra of proteins by double quantum filtering. Biochem. Biophys. Res. Commun. 1983,117, 479–485.PubMedCrossRefGoogle Scholar
  77. Reddy, B.M.; Rao, N.K.; Ramesh, M.; Appa Rao, A. V.N.; Lin, L.-J.; Cordell, G.A. Chemical investigation of the fruits of Terminalia chebula. Int. J. Pharmacog. 1994, 32, 352–356.CrossRefGoogle Scholar
  78. Reich, H.J.; Jautelat, M.; Messe, M.T.; Weigert, F.J.; Roberts, J.D. Nuclear magnetic resonance spectroscopy. Carbon-13 spectra of steroids. J. Am. Chem. Soc. 1969, 91, 7445–7454.CrossRefGoogle Scholar
  79. Reynolds, W.F.; McLean, S.; Perpick-Dumont, M.; Enriguez, R.G. Improved 13C–1H shift correlation spectra for indirectly bonded carbons and hydrogens: the FLOCK sequence. Magn. Reson. Chem. 1989, 27, 162–169.CrossRefGoogle Scholar
  80. Robien, W.; Kopp, B.; Schabl, D.; Schwarz, H. Carbon-13 nmr spectroscopy of cardenolides and bufadienolides. Progr. NMR Spectr. 1987,19, 131–181.CrossRefGoogle Scholar
  81. Schneider, H.-J.; Buchheit, U.; Becker, N.; Schmidt, G.; Siehl, U. 1H NMR analyses, shielding mechanisms, coupling constants, and conformations in steroids bearing halogen, hydroxy, oxo groups, and double bonds. J. Am. Chem. Soc. 1985,107, 7027–7039.CrossRefGoogle Scholar
  82. Schun, Y.; Cordell, G. A. Cytotoxic steroids of Gelsemium sempervirens (Loganiaceae). J. Nat. Prod. 1987, 50, 195–198.PubMedCrossRefGoogle Scholar
  83. Schun, Y.; Cordell, G.A.; Cox, P.J.; Howie, R.A. Wallenone, a new C-32 triterpenoid from the leaves of Gyrinops walla. Phytochemistry 1986, 25, 753–755.CrossRefGoogle Scholar
  84. Seida, A. A.; Kinghorn, A.D.; Cordell, G.A.; Farnsworth, N.R. Potential anticancer agents IX. The isolation of a new simaroubolide 6α-tigloyloxy—chaparrinone from Ailanthus integrifolia subsp. calycina. Lloydia 1978, 41, 584–587.Google Scholar
  85. Shao, Y.; Zhou, B.-N.; Lin, L.-Z.; Cordell, G.A. Two new triterpenoid saponins, asterbatanoside F and G, from Aster batangensis. Nat. Prod. Letts. 1994a, 5, 233–240.CrossRefGoogle Scholar
  86. Shao, Y.; Zhou, B.-N.; Lin, L.-Z.; Cordell, G.A. Asteryunnanoside E, A new triterpenoid saponin from Aster yunnanensis. Chin. Chem. Letts. 1994b, 5, 761–764.Google Scholar
  87. Shao, Y.; Zhou, B.-N.; Lin, L.-Z.; Cordell, G.A. Two oleanolic acid saponins from Aster yunnanensis. Chin. Chem. Letts. 1994c, 5, 843–846.Google Scholar
  88. Shao, Y.; Zhou, B.-N.; Lin, L.-Z.; Cordell, G.A. Triterpenoid saponins from Aster batangensis. Phytochemistry 1995a, 38,927–933.PubMedCrossRefGoogle Scholar
  89. Shao, Y.; Zhou, B.-N.; Lin, L.-Z.; Cordell, G.A. The structure of asterbatanoside J from Aster batangensis. Chin. Chem. Letts. 1995b, 6, 221–224.Google Scholar
  90. Shao, Y.; Zhou, B.-N.; Lin, L.-Z.; Cordell, G.A. Triterpene saponins from Aster yunnanensis. Phytochemistry 1995c, 38,1487–1492.PubMedCrossRefGoogle Scholar
  91. Sherman, M.; Borris, R.P.; Cordell, G.A.; Ogura, M.; Famsworth, N.R. 3S,24S,25-Tri—hydroxytirucall-7-ene from Ailanthus excelsa. Phytochemistry 1980,19, 1499–1501.Google Scholar
  92. Shoolery, J.N.; Rogers, M.J. Nuclear magnetic resonance spectra of steroids. J. Am. Chem. Soc. 1958,80, 5121–5135.CrossRefGoogle Scholar
  93. Smith, L.L. Recognition of structure in hydroxy steroids. II. Nuclear magnetic resonance spectra. Steroids 1964 4, 395–414.CrossRefGoogle Scholar
  94. Summers, M.F.; Marzilli, L.G.; Bax, A. Complete 1H and 13C assignments of coenzyme B12 through the use of new two-dimensional nmr experiments. J. Am. Chem. Soc. 1986,108, 4285–4294.CrossRefGoogle Scholar
  95. Yuan, J.-L.; Ding, W.-P.; Shi, J.-P.; Lu, Z.-Z.; Zhou, B.-N; Erdelmeier, C.A.J.; Cordell, G.A.; Fong, H.H.S.; Famsworth, N.R. Studies on the antifertility components of Marsdenia koi. J. Tongji Med. Univ. 1991, 11, 165–168.PubMedCrossRefGoogle Scholar
  96. Yuan, J.-L.; Lu, Z.-Z.; Chen, G.-X.; Ding, W.-P.; Zhou, B.-N.; Erdelmeier, C.A.J.; Hamburger, M.O.; Fong, H.H.S.; Cordell, G.A. The pregnane glycoside marsdekoiside A from Marsdenia koi. Phytochemistry 1992, 31, 1058–1060.PubMedCrossRefGoogle Scholar
  97. Zurcher, R.F. Protonresonanzspektroskopie und steroidsstruktur I. Das C-19-methylsignal in funktion der substituion. Helv. Chim. Acta 1961, 44, 1380–1395.CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1996

Authors and Affiliations

  • Geoffrey A. Cordell
    • 1
  • Long-Ze Lin
    • 1
  • Roberto R. Gil
    • 1
  1. 1.Program for Collaborative Research in the Pharmaceutical Sciences Department of Medicinal Chemistry and Pharmacognosy College of PharmacyUniversity of Illinois at ChicagoChicagoUSA

Personalised recommendations