Structure of leurocristine methiodide dihydrate by anomalous scattering methods: relation to leurocristine (vincristine) and vincaleukoblastine (vinblastine)

Moncrief, J. William; Lipscomb, W.N.

doi:10.1107/s0365110x66002883

Cited by 48 publications

(9 citation statements)

References 4 publications

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“…(25, ion y m/e 121 26). If one looks at the hydroxyl group in I, whose stereochemistry was determined by X-ray analysis (8,9), one can reasonably assume that if the hydroxyl of velbanamine was involved in this epoxy linkage, the methine hydrogen of the epoxy would be cis to the bridge proton, and the J,i, coupling constant and chemical shifts would agree with the proposed structure. This evidence also would eliminate the other possible attachments of oxygen to any place in the epoxyvelbanamine structure since either the chemical shifts, multiplicities, and/or coupling constants would be different.…”

Section: Ion Qmentioning

confidence: 98%

Structure Elucidation and Chemistry of Catharanthus Alkaloids III: Structure of Leurosine, an Active Anticancer Alkaloid

Abraham

Farnsworth

1969

Journal of Pharmaceutical Sciences

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Section: Ion Qmentioning

confidence: 98%

Structure Elucidation and Chemistry of Catharanthus Alkaloids III: Structure of Leurosine, an Active Anticancer Alkaloid

Abraham

Farnsworth

1969

Journal of Pharmaceutical Sciences

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“…In addition to development of methods, there has been a progression to larger structures. In the intermediate stage I note Roussin's black salt [47] which has an Fe& core, and vincristine [48] for which the stereochemistry was established in our study. This latter compound is one of the effective drugs for treatment of childhood leukemia.…”

mentioning

confidence: 59%

Molecular structure and function

Lipscomb

1991

Int. J. Quantum Chem.

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In my high school class in 1936, in which the planetary analogy was used for the hydrogen atom, the question "Why doesn't the electron eventually fall into the nucleus"? was asked, but no one there (including me) could give an answer. At the University of Kentucky a fewyears later, I achieved an understanding of this question from Dushman's book on quantum mechanics, which I read on my own because this area was not yet interesting to the Chemistry Faculty there. These studies, and the interest of one teacher in particular (Otto Koppius), led me to accept an offer of a teaching assistantship in Physics at Caltech for $20 a month, where I was to assist in the demonstration lectures to the general public. I had gone to Caltech to study quantum mechanics with William V. Houston, but the war intervened, and after one semester I switched to Chemistry under the influence of Linus Pauling.Because of my interests in molecular structure, Pauling suggested studies in electron diffraction, X-ray diffraction, and magnetic susceptibility, and so I began with Verner Schomaker a series of studies of structures of gas molecules by electron diffraction on chloroethylenes (resonance effects), vanadium tetrachloride (Jahn-Teller distortion), and diketene (a problem I had been interested in as an undergraduate). Again the war intervened, and I was transferred to war-related projects at Caltech. I survived handling beakers of pure nitroglycerin, and, in my spare time began an X-ray diffraction study of methylamine hydrochloride, so that Pauling would have a reliable C-N single-bond distance. Another war-related project led me to do some electron microscopy. After the war was over, Pauling suggested that I try to obtain electron micrographs of an antibody hapten complex, an example of his insight and enormous breadth of interests.The limitations of electron diffraction of gas molecules, and the relative certainty of X-ray diffraction results on crystals led me to decide on a series of studies of molecular structures in crystals grown at low temperatures. The techniques were worked out on structures of diketene and on several structures (NO dimer, N2H4, CH30H, CH3NH2, C0Cl2) in which residual entropy problems existed or were thought to occur. However, the longer range aspect was to determine the structures of the boron hydrides, particularly B4HI0, B5Hg, an6 BsHl I . Although structures were proposed, later shown to be incorrect, from early electron diffraction studies and discussed by Pauling in the Second Edition of the Nature of the Chemical *

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“…By using the same procedure as outlined above for tubocurarine ( 2 ), six “ artificial ” RDC data sets based on the solid‐state structure of vincristine ( 3 ) were generated by using all methine (

D_{normalC normalH}

) and methylene (sum

D_{C H} + D_{C H^{'}}

) protons; methyl group RDCs were omitted. In addition, NOE restraints from pairs of protons separated by less than 2.7 Å in the X‐ray structure were used.…”

Section: Resultsmentioning

confidence: 99%

Configurational Analysis by Residual Dipolar Coupling Driven Floating Chirality Distance Geometry Calculations

Immel

Köck

Reggelin

2018

Chemistry A European J

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A new method implemented into a computer program (ConArch ) has been developed and applied to demonstrate the successful implementation of residual dipolar couplings (RDCs) in distance geometry (DG) calculations for the configurational assignment of chiral compounds. Unlike established protocols, the new approach combines floating chirality (fc) in 4D- and 3D-distance bounds driven dynamics (DDD) calculations with structural information from RDCs. Thus, relative configurations of chiral compounds were generated only by observables (e.g., NOEs, RDCs) rendering tedious evaluations of calculated structures against RDCs obsolete. We demonstrate the potential of this novel procedure by the simultaneous determination of the configuration and the conformation of three natural products, (-)-isopinocampheol (1), tubocurarine (2), and vincristine (3), as well as for diisopropylidene-β-d-fructopyranose (4).

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Structure of leurocristine methiodide dihydrate by anomalous scattering methods: relation to leurocristine (vincristine) and vincaleukoblastine (vinblastine)

Cited by 48 publications

References 4 publications

Structure Elucidation and Chemistry of Catharanthus Alkaloids III: Structure of Leurosine, an Active Anticancer Alkaloid

Structure Elucidation and Chemistry of Catharanthus Alkaloids III: Structure of Leurosine, an Active Anticancer Alkaloid

Molecular structure and function

Configurational Analysis by Residual Dipolar Coupling Driven Floating Chirality Distance Geometry Calculations

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