Diketopiperazine
Mostrando 1-12 de 13 artigos, teses e dissertações.
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1. PHYTOTOXIC CONSTITUENTS FROM ENDOPHYTIC FUNGUS Xylaria cubensis ASSOCIATED WITH Eugenia brasiliensis
The upscaling of Xylaria cubensis, an endophyte of Eugenia brasiliensis (Myrtaceae), in PDB medium led to the isolation of known compounds including cytochalasin D (7) and cytochalasin C (8), which exhibited relatively higher phytotoxic activity in all the concentrations tested compared to the commercial herbicide GOAL®. Besides the aforementioned metabolit
Quím. Nova. Publicado em: 18/07/2019
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2. Cyclo-(trp-phe) diketopiperazines from the endophytic fungus Aspergillus versicolor isolated from Piper aduncum
Six known compounds, three peptide derivatives: cyclo-(tryptophyl-phenylalanyl) (2), diketopiperazine dimer WIN 64821 (3) and 3-hydroxy-15H-tryptophenaline (4), one adenine derivative: 2-hydroxy-6-N-isopentenyl-adenine (5), one phtalide derivative: 4-methoxyphtalide (1) and one benzoic acid derivative: 3-hydroxy-4-(1-hydroxy-1,5-dimethyl-hexyl) benzoic acid
Quím. Nova. Publicado em: 2017-02
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3. Síntese e avaliação biológica de glicodicetopiperazinas relacionadas a mucinas de células tumorais e parasitárias / Synthesis and biological evaluation of glycodiketopiperazines related to mucins from tumoral and parasite cells
Mucinas são glicoproteínas altamente O-glicosiladas cuja principal característica estrutural é a presença de -GalNAc ligado aos resíduos hidroxilados de serina e treonina. Em alterações celulares malignas, esse núcleo é exposto como um antígeno carboidrato associado a tumor (Tn) e sua alta expressão em células cancerosas faz dele um alvo para o
Publicado em: 2010
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4. Estudo da estabilidade e do perfil de liberação de comprimidos de maleato de enalapril e determinação da concentração plasmática em pacientes
The stability of a pharmaceutical formulation can be a major factor in assuring the quality of a drug product and, as a consequence, the efficacy of the treatment. Enalapril is an anti-hypertensive pro-drug that, after being absorbed, is hydrolised into enalaprilat, an agent responsible for blocking the conversion of angiotensin I into angiotensin II. Stabil
Publicado em: 2008
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5. In Vivo Production of Artificial Nonribosomal Peptide Products in the Heterologous Host Escherichia coli
Nonribosomal peptide synthetases represent the enzymatic assembly lines for the biosynthesis of pharmacologically relevant natural peptides, e.g., cyclosporine, vancomycin, and penicillin. Due to their modular organization, in which every module accounts for the incorporation of a single amino acid, artificial assembly lines for the production of novel pepti
American Society for Microbiology.
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6. Histidyl-proline diketopiperazine (His-Pro DKP) immunoreactivity is present in the glucagon-containing cells of the human fetal pancreas.
Histidyl-proline diketopiperazine (His-Pro DKP) cells in the pancreas of human fetuses aged between 12 and 19 wk were localized by the indirect antibody-enzyme method on semithin sections. To study their fine structure, two techniques were used: a superimposition technique consisting of comparison of the same cells in semithin and electron microscopic prepar
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7. Maculosin, a host-specific phytotoxin for spotted knapweed from Alternaria alternata
Several diketopiperazines have been isolated from liquid cultures of Alternaria alternata, the causal agent of black leaf blight of spotted knapweed, Centaurea maculosa Lam. One of these compounds, maculosin [the diketopiperazine cyclo(-L-Pro-L-Tyr-)], was active in the nicked-leaf bioassay at 10-5 M; synthetic maculosin possessed chemical and biological act
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8. Isolation of cairomycins A and C.
Cairomycin B in the fermentation broths of Streptomyces sp. strain AS-C-19 accompanied cairomycin A and cairomycin C. The cairomycins are peptides with potent activity against gram-positive bacteria. On acid hydrolysis, cairomycin A yielded valine and aspartic acid, whereas cairomycin C yielded lysine, glycine, valine, leucine, and aspartic acid, as identifi
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9. On how a myosin tryptophan may be perturbed.
A well-known indication that a nucleotide has bound to myosin is the enhancement of the fluorescence of a specific tryptophan in the "subfragment 1" segment of the protein. Empirically the effect has been enormously useful in myosin enzymology. But beyond an early suggestion that it arises from a purine-tryptophan charge-transfer complex, the mechanism of th
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10. A novel antiviral agent which inhibits the endonuclease of influenza viruses.
A novel anti-influenza virus compound, flutimide, was identified in extracts of a recently identified fungal species, Delitschia confertaspora (F. Pelaez, J.D. Polishook, M. Valldosera, and J.Guarro, Mycotaxon 50:115-122, 1994). The compound, a substituted 2,6-diketopiperazine, selectively inhibited the cap-dependent transcriptase of influenza A and B viruse
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11. Neurohypophyseal hormones, analogs, and fragments: their effect on puromycin-induced amnesia.
Neurohypophyseal hormones and several of their analogs, as well as N-terminal and C-terminal fragments, have been studied for their ability to attenuate puromycin-induced amnesia in mice. [8-Lysine]vasopressin, [8-arginine]vasopressin, and the analogs des-9-glycinamide-[8-lysine]vasopressin, [1-beta-mercaptopropionic acid, 8-lysine]vasopressin, [1,6-aminosub
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12. Racemization of aspartic acid and phenylalanine in the sweetener aspartame at 100 degrees C.
The racemization half-lives (i.e., the time required to reach a D/L = 0.33) at pH 6.8 for aspartic acid and phenylalanine in the sweetener aspartame (L-aspartyl-L-phenylalanine methyl ester) were determined to be 13 and 23 hours, respectively, at 100 degrees C. Racemization at this pH does not occur in aspartame but rather in its diketopiperazine decompositi