Do organocobalt porphyrins have agostic alkyl groups? An investigation of the structure of ethyl cobalt(III) octaethylporphyrin and the nuclear magnetic resonance spectra of 13C-labeled alkyl cobalt(III) porphyrin complexes
作者:Yang Cao、Jeffrey L. Petersen、Alan M. Stolzenberg
DOI:10.1016/s0020-1693(97)82284-0
日期:1997.10
A , α = 79.539(8), β = 86.386(7), γ = 79.298(8)° , and V = 1568.2(2) A 3 at 173(2) K. The structural features of the ordered axial ethyl group were inconsistent with an agostic interaction in the solid state. Synthesis and use of 13C-labeled compounds were necessary to observe the 13C NMR spectra of the axial alkyl groups and to measure informative coupling constants. The 13C resonances of carbons
Pyrrolizidine alkaloid biosynthesis. Incorporation of 2-aminobutanoic acid labelled with 13C or 2H into the senecic acid portion of rosmarinine and senecionine
作者:Iain R. Stirling、Isabel K. A. Freer、David J. Robins
DOI:10.1039/a605623g
日期:——
(±)-[3,4-13C2]-2-Aminobutanoic acid
10 and (±)-[3,4-2H5]-2-aminobutanoic acid
11 are synthesized by alkylating diethyl acetamidomalonate with labelled
ethyl iodide followed by acid hydrolysis. These compounds are used to
obtain complete labelling patterns for the first time in a necic acid by
studying the pyrrolizidine alkaloids rosmarinine 3 and senecionine 1
using NMR spectroscopy. The senecic acid portion 12 of both alkaloids
shows equal incorporation of
[3,4-13C2]-2-aminobutanoic acid 10 into the two
C5 halves of the C10 acid consistent with
formation of senecic acid via two molecules of isoleucine.
After feeding [3,4-2H5]-2-aminobutanoic acid 11,
retention of 2H at C-13 and C-20 of both alkaloids 13
confirms that the biosynthesis does not involve keto intermediates at
these carbon atoms.
Provided herein are pharmaceutical agents useful for therapy and/or prophylaxis in a mammal, pharmaceutical composition comprising such compounds, and their use as menin/MLL protein/protein interaction inhibitors, useful for treating diseases such as cancer, including but not limited to leukemia, myelodysplastic syndrome (MDS), and myeloproliferative neoplasms (MPN); and diabetes.