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1.
Int J Biol Macromol ; 254(Pt 1): 127803, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37913879

RESUMEN

The physicochemical properties of Lipu taro starch (LTS), cassava starch (CS) and wheat starch (WS) were analyzed. These starches exhibited a comparable starch content (86 %). However, LTS had a significantly lower amylose content (15.93 %) compared to CS (26.62 %) and WS (33.53 %). Moreover, LTS demonstrated an irregular polygonal cubic morphology with a smaller particle size of 2.55 µm while possessed an A-type crystal structure with high crystallinity at 25.07 %. In contrast, CS and WS had larger particle sizes of 13.33 µm and 16.68 µm, respectively, with lower crystallinities of 22.52 % and 20.33 %. Due to these physicochemical properties, LTS exhibited superior emulsification properties with a higher emulsifying activity index of 8.63 m2/g and an emulsion stability index of 69.18 min, whereas CS and WS had values of 2.35 m2/g and 25.15 min, and 0.37 m2/g and 11.48 min, respectively. LTS also demonstrated enhanced thermal stability, characterized by higher gelatinization temperature (indicated by To, Tp, Tc, and ΔT) and reduced paste viscosity (indicated by PV, TV, FV, SBV, and BDV) compared to CS. However, the mechanical strength of the gel made from LTS (indicated by hardness, adhesiveness, springiness, gumminess, and chewiness) was comparatively inferior to those from CS and WS.


Asunto(s)
Colocasia , Almidón , Almidón/química , Colocasia/química , Amilosa/química , Tamaño de la Partícula , Viscosidad
2.
Angew Chem Int Ed Engl ; 62(16): e202300654, 2023 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-36811228

RESUMEN

A series of vanadyl complexes bearing 3-t-butyl-5-bromo, 3-aryl-5-bromo, 3,5-dihalo-, and benzo-fused N-salicylidene-tert-leucinates was examined as catalysts for 1,2-alkoxy-phosphinoylation of 4-, 3-, 3,4-, and 3,5-substituted styrene derivatives (including Me/t-Bu, Ph, OR, Cl/Br, OAc, NO2 , C(O)Me, CO2 Me, CN, and benzo-fused) with HP(O)Ph2 in the presence of t-BuOOH (TBHP) in a given alcohol or cosolvent with MeOH. The best scenario involved the use of 5 mol % 3-(2,5-dimethylphenyl)-5-Br (i.e., 3-DMP-5-Br) catalyst at 0 °C in MeOH. The desired catalytic cross coupling reactions proceeded smoothly with enantioselectivities of up to 95 % ee of (R)-configuration as confirmed by X-ray crystallographic analysis of several recrystallized products. The origin of enantiocontrol and homolytic substitution of the benzylic intermediates by vanadyl-bound methoxide and radical type catalytic mechanism were proposed.

3.
Bioorg Chem ; 109: 104715, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33647741

RESUMEN

This paper presents the design and synthesis of 4-(3-hydroxyanilino)-6-(1H-1,2,3-triazol-4-yl)quinazolines of scaffold 9 as selective B-Raf/B-RafV600E and potent EGFR/VEGFR2 kinase inhibitors. Total 14 compounds of scaffold 9 having different side chains at the triazolyl group with/without fluoro substituents at the anilino group were synthesized and investigated. Among them, 9m with a 2-carbamoylethyl side chain and C-4'/C-6' difluoro substituents was the most potent, which selectively inhibited B-Raf (IC50: 57 nM) and B-RafV600E (IC50: 51 nM) over C-Raf (IC50: 1.0 µM). Compound 9m also actively inhibited EGFR (IC50: 73 nM) and VEGFR2 (IC50: 7.0 nM) but not EGFRT790M and PDGFR-ß (IC50: >10 µM). Despite having good potency for B-Raf and B-RafV600E in the enzymatic assays, 9m was less active to inhibit melanoma A375 cells which proliferate due to constitutively activated B-Raf600E. The inferior activity of 9m for A375 was similar to that of sorafenib (6), suggesting that 9m might bind to the inactive conformations of B-Raf and B-RafV600E. Docking simulations could thus be performed to reveal the binding poses of 9m in B-Raf, B-RafV600E, and VEGFR2 kinases.


Asunto(s)
Receptores ErbB/antagonistas & inhibidores , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Quinazolinas/farmacología , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Quinasas raf/antagonistas & inhibidores , Línea Celular Tumoral , Receptores ErbB/genética , Receptores ErbB/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Simulación del Acoplamiento Molecular , Quinazolinas/química , Receptor 2 de Factores de Crecimiento Endotelial Vascular/genética , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo
4.
J Med Chem ; 64(3): 1435-1453, 2021 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-33492141

RESUMEN

In this paper, we present a copper(I)-catalyzed nitrile-addition/N-arylation ring-closure cascade for the synthesis of 5,11-dihydro-6H-indolo[3,2-c]quinolin-6-ones from 2-(2-bromophenyl)-N-(2-cyanophenyl)acetamides. Using CuBr and t-BuONa in dimethylformamide (DMF) as the optimal reaction conditions, the cascade reaction gave the target products, in high yields, with a good substrate scope. Application of the cascade reaction was demonstrated on the concise total syntheses of alkaloid isocryptolepine. Further optimization of the products from the cascade reaction led to 3-chloro-5,12-bis[2-(dimethylamino)ethyl]-5,12-dihydro-6H-[1,3]dioxolo[4',5':5,6]indolo[3,2-c]quinolin-6-one (2k), which exhibited the characteristic DNA topoisomerase-I inhibitory mechanism of action with potent in vitro anticancer activity. Compound 2k actively inhibited ARC-111- and SN-38-resistant HCT-116 cells and showed in vivo activity in mice bearing human HCT-116 and SJCRH30 xenografts. The interaction of 2k with the Top-DNA cleavable complex was revealed by docking simulations to guide the future optimization of 5,11-dihydro-6H-indolo[3,2-c]quinolin-6-ones as topoisomerase-I inhibitors.


Asunto(s)
Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Cobre/química , Nitrilos/química , Quinolonas/síntesis química , Quinolonas/farmacología , Inhibidores de Topoisomerasa I/síntesis química , Inhibidores de Topoisomerasa I/farmacología , Animales , Catálisis , ADN-Topoisomerasas de Tipo I/química , Diseño de Fármacos , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Humanos , Masculino , Ratones , Ratones Desnudos , Modelos Moleculares , Simulación del Acoplamiento Molecular , Quinolonas/farmacocinética , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , Inhibidores de Topoisomerasa I/farmacocinética , Ensayos Antitumor por Modelo de Xenoinjerto
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