- SYNTHESIS OF OMEGA-AMINO CARBOXYLIC ACIDS AND THEIR ESTERS FROM UNSATURATED FATTY ACID DERIVATIVES
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The invention relates to a process for preparing omega-amino acids or their esters, which is characterized by the following steps: c) ozonolysis of unsaturated fatty acids or fatty acid derivatives,d) reductive amination of the reaction mixture obtained from the reaction with ozone, to give the omega-amino acid or ester thereof, the reaction being carried out with a C1-C5 alcohol in a mixture with at least 0.5% by weight of water as solvent, based on the total amount of solvent.
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Paragraph 0034; 0035
(2013/07/05)
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- METHOD FOR SYNTHESISING 9-AMINONONANOIC ACID OR THE ESTERS THEREOF FROM NATURAL UNSATURATED FATTY ACIDS
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The invention relates to a method for synthesizing 9-aminononanoic acid or the esters thereof from natural unsaturated fatty acids, comprising at least one step of metathesis of the natural fatty acid and an oxidation step by oxidative cleaving. Said synthetic method uses widely available renewable starting materials and hence economical.
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- Oncinotine-type spermidine alkaloids from Oncinotis tenuiloba. Transformation of N-acetyloncinotin-12-one to N,N-diacetylinandenin-12-one
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From extracts of Oncinotis tenuiloba STAPF, two novel polyamine alkaloids, oncinotin-11-one (5) and oncinotin-12-one (6), were isolated. Peracetylation of 6 provided the N-acetyl derivative 11 as well as N,N'-diacetylinandenin-10-en-12-one (12) due to a β-elimination-type side reaction resulting in ring enlargement of 11. Deuteration of 12 yielded 13, showing the same retention time as N,N'-diacetylinandenin-12-one (14), when co-HPLC was performed together with different keto-isomeric N,N'-diacetylinandeninones. Structure elucidation was extended by Schmidt degradation of 6 and N,N'-diacetyl(10,11-2H2)inandenin-12-one (13); the degradation products were identified by GC and ESI-MS. The structure of 5 was proposed on the basis of spectroscopic means. Comparison of the spectroscopic data of 5 with those obtained from synthetic material as well as co-HPLC of the N-acetyl derivative 20 together with the corresponding synthetic compound revealed the identity of the substances and confirmed the structure of 5. Additionally, oncinotine (2) and neooncinotine (3) were isolated, separated, and identified with authentic samples by co-HPLC of their N-acetyl derivatives 8 and 9, respectively.
- Doll,Guggisberg,Hesse
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p. 973 - 981
(2007/10/03)
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- Design, synthesis, and biochemical evaluation of N-substituted maleimides as inhibitors of prostaglandin endoperoxide synthases
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N-(Carboxyalkyl)maleimides are rapid as well as time-dependent inhibitors of prostaglandin endoperoxide synthase (PGHS). The corresponding N- alkylmaleimides were only time-dependent inactivators of PGHS, suggesting that the carboxylate is critical for rapid inhibition. Several N-substituted maleimide analogs containing structural features similar to those of the nonsteroidal anti-inflammatory drug aspirin were synthesized and evaluated as inhibitors of PGHS. Most of the aspirin-like maleimides inactivated the cyclooxygenase activity of purified ovine PGHS-1 in a time- and concentration-dependent manner similar to that of aspirin. The peroxidase activity of PGHS was also inactivated by the maleimide analogs. The cyclooxygenase activity of the inducible isozyme, i.e., PGHS-2, was also inhibited by these compounds. The corresponding succinimide analog of N-5- maleimido-2-acetoxy-1-benzoic acid did not inhibit either enzyme activity, suggesting that inactivation was due to covalent modification of the protein. The mechanism of inhibition of PGHS-1 by N-(carboxyheptyl)maleimide was investigated. Incubation of apoPGHS-1 with 2 equiv of N-(carboxyheptyl)[3,4- 14C]maleimide led to the incorporation of radioactivity in the protein, but no adduct was detected by reversed-phase HPLC, suggesting that it was unstable to the chromatographic conditions. Furthermore, hematin- reconstituted PGHS-1, which was rapidly inhibited by N- (carboxyheptyl)maleimide, displayed spontaneous regeneration of about 50% of the cyclooxygenase and peroxidase activities, suggesting that the adduct responsible for the inhibition breaks down to regenerate active enzyme. ApoPGHS-1, inhibited by N-(carboxyheptyl)maleimide, did not display regeneration of enzyme activity, but addition of hematin to the inhibited apoenzyme led to spontaneous recovery of about 50% of cyclooxygenase activity. These results suggest that addition of heme leads to a conformational change in the protein which increases the susceptibility of the adduct toward hydrolytic cleavage. ApoPGHS-1, pretreated with N(carboxyheptyl)maleimide, was resistant to trypsin cleavage, suggesting that the carboxylate functionality of the maleimide binds in the cyclooxygenase channel. A model for the interaction of N-(carboxyheptyl)maleimide in the cyclooxygenase active site is proposed.
- Kalgutkar, Amit S.,Crews, Brenda C.,Marnett, Lawrence J.
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p. 1692 - 1703
(2007/10/03)
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