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1.
ACS Omega ; 7(42): 37112-37121, 2022 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-36312433

RESUMEN

Novel hydroxyanthracene-based terminal alkynes 3 and 5a/b were synthesized by the acetylide addition reaction at the 9,10-position of anthraquinone 1 under mild conditions. The developed alkynes 3, 5a, and 5b on Huisgen azide-alkyne cycloaddition reaction with azido-sugars 6 in the presence of Cu(I) catalyst provided a series of triazole fasten hydroxyanthracene glycoconjugates 7, 8, and 9, respectively, in good yields. The representative compounds 9 and 7h were successfully deprotected under room-temperature conditions to liberate the corresponding free glycoconjugates 10 and 11, respectively. Further, structures of a few compounds were unmaliciously evidenced by their single-crystal X-ray.

2.
Chemosphere ; 292: 133428, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34968518

RESUMEN

On-farm extraction of commercially important essential oil from aromatic crops generates huge spent aromatic waste. This massive waste is often disposed in the unregulated landfills or burned in the open air to vacate the fields. Hence, a new method for processing of aromatic spent waste has been developed to obtain platform chemicals, such as, xylose and ethyl glucosides. The thermochemical liquefaction of acid pre-treated palmarosa (cymbopogon martini) biomass furnished a mixture of ethyl glucopyranosides in good yield (∼17 wt% relative to biomass) and selectivity (∼77%) by heating with p-cymen-2-sulphonic acid (p-CSA) in the presence of ethanol as a solvent. The detection, quantification and isolation of ethyl glucosides may provide a new application of spent aromatic biomass for use as a feed stock in the production of value added chemicals.


Asunto(s)
Cymbopogon , Biomasa , Etanol , Glucósidos
3.
Nat Prod Res ; 36(21): 5438-5448, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34905436

RESUMEN

The naturally occurring compound andrographolide 1 was used as a substrate for the synthesis of a novel terminal alkyne 3 which on copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction with azides 4a-l, 7 and 9 furnished a series of regioselective andrographolide triazolyl conjugates 5a-l, 8 and 10, respectively. A free glycoconjugate 6 was also prepared by selective deprotection of compound 5i in good yield. All the compounds were characterized by absorbance, FT-IR, NMR, and HR-MS analyses. The triazolyl conjugate 8 was further investigated as a probe for selective detection of Fe3+ ion in matrix. The mode of attachment of Fe3+ ion to the compound 8 was established by absorbance, fluorescence, infrared (IR), and nuclear magnetic resonance (NMR) spectroscopy, and high resolution mass-spectrometry (HR-MS). The logic gate circuits were constructed for the probe 8 and ethylenediaminetetraacetic acid (EDTA). The environmental perspective of probe 8 was investigated in real water samples.


Asunto(s)
Azidas , Química Clic , Espectroscopía Infrarroja por Transformada de Fourier , Azidas/química , Alquinos/química , Cobre/química , Hierro , Iones , Catálisis
4.
RSC Adv ; 10(73): 45081-45089, 2020 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-35516261

RESUMEN

Extraction of commercial essential oil from several aromatic species belonging to the genus Cymbopogon results in the accumulation of huge spent aromatic waste which does not have high value application; instead, the majority is burned or disposed of to vacate fields. Open burning of spent aromatic biomass causes deterioration of the surrounding air quality. Therefore, a new protocol has been developed for chemical processing of spent biomass to obtain 5-(chloromethyl)furfural (CMF) with high selectivity (∼80%) and yields (∼26 wt% or ∼76 mol% with respect to pre-treated biomass) via refluxing in aqueous HCl in the presence of NaCl as a cheap catalyst. No black tar formation and gasification were observed in the processing of the spent aromatic biomass. Spent aromatic waste-derived CMF was further converted to 5-(hydroxymethyl)furfural (HMF) in good yields by a novel one pot method using iodosylbenzene (PhIO) as a reagent under mild reaction conditions.

5.
Bioresour Technol ; 293: 122105, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31514116

RESUMEN

This work aimed to develop a green protocol for chemical processing of spent aromatic biomass to obtain xylose, levulinic acid, and lignin in good yields via treatment with p-cymene-2-sulphonic acid (p-CSA), a Brønsted acid synthesised from d-limonene as a renewable feedstock from citrus waste. Chemical processing of palmarosa biomass with p-CSA under heating in an autoclave resulted in hydrolysate containing xylose (~16% yield). Further processing of pre-treated biomass with p-CSA in presence of aq. HCl under refluxing caused a selective degradation of cellulose to levulinic acid (~22% yield with respect to biomass). The residual biomass was used to afford lignin in good yields.


Asunto(s)
Citrus , Lignina , Biomasa , Ácidos Levulínicos , Limoneno , Xilosa
6.
J Microencapsul ; 36(3): 215-235, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31092084

RESUMEN

Bio-availability is a major concern in delivery of dietary phytochemicals for better bio-efficacy. The reduced bio-availability of food bioactive compounds is evident due to degradation during human digestion process which involves liberation, absorption, distribution, metabolism and elimination. The bio-efficacy of any nutrient can be increased by increasing bio-availability. Different technologies are available for engineered efficient delivery systems; still many challenges remain with advancement of delivery systems. The ease of preparedness and adaptability of liposomes has resulted in wide-range of applicability and acceptability in scientific field, especially as delivery vehicles. In view, of properties like biocompatibility and biodegradability, liposomes have been modified with different usable methodologies for delivery of phytochemicals. The aim of this review is to abridge liposomes, methods of preparation, their application as delivery cargo in dietary phytochemicals, result of using different preparation techniques on properties.


Asunto(s)
Liposomas/metabolismo , Fitoquímicos/administración & dosificación , Animales , Disponibilidad Biológica , Sistemas de Liberación de Medicamentos/métodos , Humanos , Liposomas/química , Fitoquímicos/farmacocinética
7.
Bioresour Technol ; 250: 621-624, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29220805

RESUMEN

In citrus processing industries, where up to 60% of the whole fruit is discarded, generates citrus waste (peel, seeds, membrane, and pulp) on a massive scale. The waste does not currently have high-value applications, instead the majority is disposed of or pelletized for animal feed. Therefore, a concise and efficacious protocol for processing of Kinnow mandarin (Citrus reticulata) fruit waste to numerous novel Brønsted acidic ionic liquids (3a-k) have been developed. BAILs were characterized using spectroscopic techniques (FT-IR and NMR). Water immiscibility of ILs 3a, 3g and 3h, a property never observed with sulfonic acid ILs, allowed the catalytic application of BAIL 3a in hydrolysis of sucrose/table sugar, giving a mixture of d-glucose and d-fructose in excellent yields. The ionic liquid could be recycled for >3 times without significant loss of activity.


Asunto(s)
Citrus , Sacarosa , Animales , Frutas , Hidrólisis , Líquidos Iónicos , Espectroscopía Infrarroja por Transformada de Fourier
8.
Injury ; 39(10): 1141-6, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18582886

RESUMEN

AIM: Comparison of renal function in patients who died within 30 days of surgery for hip fractures with surviving patients matched for age, type of surgery, type of anaesthesia and clinical assessment of fitness for surgery. MATERIALS & METHODS: A retrospective case-control study of 80 patients was performed. Pre- and post-operative urea, creatinine, estimated glomerular filtration rate (eGFR), sodium and potassium of 40 patients who died within 30 days post-surgery (cases) were compared with 40 patients who survived matched for age, sex, surgical procedure and pre-operative ASA grade (controls). Statistical analysis involved univariable analysis by paired t-test and logistic conditional regression analysis. RESULTS: Pre- and post-operative mean serum creatinine were significantly higher in patients who died compared with surviving controls (pre-op 108.2 vs. 90.2 micromol/l [p=0.002], post-op 103.9 vs. 87.1 micromol/l [p=0.003]). However, mean creatinine values for both groups were still within normal laboratory reference ranges. Mean serum urea was also higher in patients who died (pre-op 8.81 vs. 6.75 mmol/l [p=0.010] and post-op 9.30 vs. 6.63 mmol/l [p=0.004], respectively). Pre- and post-operative eGFR was significantly lower in those patients who died within 30 days of hip fracture surgery (pre-op 61.75 vs. 68.78 ml/min per 1.73 m(2) [p=0.011], post-op 63.03 vs. 76.03 ml/min per 1.73 m(2) [p=0.009]). The mean eGFR values for survivors and non-survivors fell in the chronic kidney disease mild renal impairment category. There were no significant differences in mean serum sodium or potassium concentration between groups. Stepwise conditional logistic regression analysis, showed that after allowing for creatinine, urea was no longer significantly related to mortality. CONCLUSION: These results suggest that when allowance is made for demography, fitness for surgery and surgical procedure, subtle reductions in eGFR are still associated with mortality risk. However, these are of questionable clinical use.


Asunto(s)
Fracturas del Cuello Femoral/fisiopatología , Fracturas del Cuello Femoral/cirugía , Riñón/fisiopatología , Anciano de 80 o más Años , Artroplastia de Reemplazo de Cadera , Biomarcadores/sangre , Creatinina/sangre , Métodos Epidemiológicos , Femenino , Fijación Interna de Fracturas , Tasa de Filtración Glomerular , Humanos , Masculino , Pronóstico , Urea/sangre
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