Functional analysis of the protocatechuate branch of the ß-ketoadipate pathway in Aspergillus niger.

Bacteria and fungi catabolize plant-derived aromatic compounds by funneling into one of seven dihydroxylated aromatic intermediates, which then undergo ring fission and conversion to TCA cycle intermediates. Two of these intermediates, protocatechuic acid and catechol, converge on ß-ketoadipate which is further cleaved to succinyl-CoA and acetyl-CoA. These ß-ketoadipate pathways have been well characterized in bacteria. The corresponding knowledge of these pathways in fungi is incomplete. Characterization of these pathways in fungi would expand our knowledge and improve the valorization of lignin-derived compounds. Here, we used homology to characterize bacterial or fungal genes to predict the genes involved in the ß-ketoadipate pathway for protocatechuate utilization in the filamentous fungus Aspergillus niger. We further used the following approaches to refine the assignment of the pathway genes: whole transcriptome sequencing to reveal genes upregulated in the presence of protocatechuic acid; deletion of candidate genes to observe their ability to grow on protocatechuic acid; determination by mass spectrometry of metabolites accumulated by deletion mutants; and enzyme assays of the recombinant proteins encoded by candidate genes. Based on the aggregate experimental evidence, we assigned the genes for the five pathway enzymes as follows: NRRL3_01405 (prcA) encodes protocatechuate 3,4-dioxygenase; NRRL3_02586 (cmcA) encodes 3-carboxy-cis,cis-muconate cyclase; NRRL3_01409 (chdA) encodes 3-carboxymuconolactone hydrolase/decarboxylase; NRRL3_01886 (kstA) encodes ß-ketoadipate:succinyl-CoA transferase; and NRRL3_01526 (kctA) encodes ß-ketoadipyl-CoA thiolase. Strain carrying ΔNRRL3_00837 could not grow on protocatechuic acid, suggesting that it is essential for protocatechuate catabolism. Its function is unknown as recombinant NRRL3_00837 did not affect the in vitro conversion of protocatechuic acid to ß-ketoadipate.

Genus Suaeda: Advances in phytology, chemistry, pharmacology and clinical application (1895 - 2021).

More than 100 species of annual herb genus Suaeda widely distribute (Asia, North America, northern Africa and Europe), are rich in resources (about hundreds of millions of tons/Y) and have a long historical application. Most of them are mainly used for traditional food, feed and medicine. Recently, they have been employed to repair saline-alkali land and beautify the environment. So far, only 27 species have been reported on the bioactivity diversity, broad spectrum and effectiveness in clinical practice. Therefore, the in-depth and extensive research of Suaeda has become a research hotspot around the world. However, only one review summarized the nutritional, chemical and biological values of Suaeda. By searching the international authoritative databases (ACS Publications, ScienceDirect, PubMed, Springer, web of Science and Bing International etc.) and collecting 103 literatures closely related to Suaeda (1895-2021), herewith a comprehensive and systematic review was conducted on the phytology, chemistry, pharmacology and clinical application, enveloping the classification evolution between Amaranthaceae and Chenopodiaceae, distribution and common botanical characteristics; involving 9 chemical categories of 163 derivatives covering 14 new and 6 first-isolated ones, and appraising the content determination of 6 categories of components; mainly including the pharmacology of 13 species in vivo and vitro; estimating the clinical application of 16 species cured the related diseases of eight human physiological system except for the motor system. It is expected that this paper will provide forward-looking scientific ideas and literature support for the further modern research, development and utilization of the genus.

Production of Protocatechuic Acid from p-Hydroxyphenyl (H) Units and Related Aromatic Compounds Using an Aspergillus niger Cell Factory.

Protocatechuic acid (3,4-dihydroxybenzoic acid) is a chemical building block for polymers and plastics. In addition, protocatechuic acid has many properties of great pharmaceutical interest. Much research has been performed in creating bacterial protocatechuic acid production strains, but no protocatechuic acid-producing fungal cell factories have been described. The filamentous fungus Aspergillus niger can produce protocatechuic acid as an intermediate of the benzoic acid metabolic pathway. Recently, the p-hydroxybenzoate-m-hydroxylase (phhA) and protocatechuate 3,4-dioxygenase (prcA) of A. niger have been identified. It has been shown that the prcA deletion mutant is still able to grow on protocatechuic acid. This led to the identification of an alternative pathway that converts protocatechuic acid to hydroxyquinol (1,3,4-trihydroxybenzene). However, the gene involved in the hydroxylation of protocatechuic acid to hydroxyquinol remained unidentified. Here, we describe the identification of protocatechuate hydroxylase (decarboxylating) (PhyA) by using whole-genome transcriptome data. The identification of phyA enabled the creation of a fungal cell factory that is able to accumulate protocatechuic acid from benzyl alcohol, benzaldehyde, benzoic acid, caffeic acid, cinnamic acid, cinnamyl alcohol, m-hydroxybenzoic acid, p-hydroxybenzyl alcohol, p-hydroxybenzaldehyde, p-hydroxybenzoic acid, p-anisyl alcohol, p-anisaldehyde, p-anisic acid, p-coumaric acid, and protocatechuic aldehyde. IMPORTANCE Aromatic compounds have broad applications and are used in many industries, such as the cosmetic, food, fragrance, paint, plastic, pharmaceutical, and polymer industries. The majority of aromatic compounds are synthesized from fossil sources, which are becoming limited. Plant biomass is the most abundant renewable resource on Earth and can be utilized to produce chemical building blocks, fuels, and bioplastics through fermentations with genetically modified microorganisms. Therefore, knowledge about the metabolic pathways and the genes and enzymes involved is essential to create efficient strategies for producing valuable aromatic compounds such as protocatechuic acid. Protocatechuic acid has many pharmaceutical properties but also can be used as a chemical building block to produce polymers and plastics. Here, we show that the fungus Aspergillus niger can be engineered to produce protocatechuic acid from plant-derived aromatic compounds and contributes to creating alternative methods for the production of platform chemicals. .

Co-Administration of Propionate or Protocatechuic Acid Does Not Affect DHA-Specific Transcriptional Effects on Lipid Metabolism in Cultured Hepatic Cells.

Long-chain n-3 polyunsaturated fatty acids (n-3 LC-PUFAs) are collectively recognized triglyceride-lowering agents, and their preventive action is likely mediated by changes in gene expression. However, as most studies employ fish oil, which contains a mixture of n-3 LC-PUFAs, the docosahexaenoic acid (DHA)-specific transcriptional effects on lipid metabolism are still unclear. The aim of the present study was to further elucidate the DHA-induced transcriptional effects on lipid metabolism in the liver, and to investigate the effects of co-administration with other bioactive compounds having effects on lipid metabolism. To this purpose, HepG2 cells were treated for 6 or 24 h with DHA, the short-chain fatty acid propionate (PRO), and protocatechuic acid (PCA), the main human metabolite of cyanidin-glucosides. Following supplementation, we mapped the global transcriptional changes. PRO and PCA alone had a very slight effect on the transcriptome; on the contrary, supplementation of DHA highly repressed the steroid and fatty acid biosynthesis pathways, this transcriptional modulation being not affected by co-supplementation. Our results confirm that DHA effect on lipid metabolism are mediated at least in part by modulation of the expression of specific genes. PRO and PCA could contribute to counteracting dyslipidemia through other mechanisms.

Synthesis of 4-Hydroxybenzoic Acid Derivatives in Escherichia coli.

Hydroxybenzoic acids (HBAs) such as 4-hydroxybenzoic acid (4-HBA) and 3,4-dihydroxybenzoic acid (DHB; protocatechuic acid) and its ester with methanol (methylparaben [MP]) are known to have various functional biological properties, including antibacterial, anticancer, antidiabetic, antiaging, antiviral, and anti-inflammatory activities. Since these compounds are widely used in cosmetic, food, and pharmaceutical industries, the use of renewable feedstocks for the production of HBAs is an area of growing interest. In this study, we used Escherichia coli to synthesize these three hydroxybenzoic acid derivatives (4-HBA, DHB, and MP). We overexpressed ubiC in E. coli to synthesize 4-HBA from chorismate, a substrate that is produced by the shikimate pathway in E. coli. For the synthesis of DHB, an additional gene (pobA) was introduced, while hbad and EHT1 were co-expressed to synthesize MP. To supply more chorismate, we introduced the shikimate gene module construct and selected the best construct for increased yields. Using this approach, 723.5 mg/L 4-HBA, 942.0 mg/L DHB, and 347.7 mg/L MP were synthesized. Our study showed that the shikimate gene module constructs can be applicable to increase the yields of HBA derivatives in HBA-tolerant microorganisms.

A Growth-Based, High-Throughput Selection Platform Enables Remodeling of 4-Hydroxybenzoate Hydroxylase Active Site.

We report an aerobic, growth-based selection platform founded on NADP(H) redox balance restoration in Escherichia coli, and we demonstrate its application in the high-throughput evolution of an oxygenase. A single round of selection followed by a facile growth assay enabled Pseudomonas aeruginosa 4-hydroxybenzoate hydroxylase (PobA) to efficiently hydroxylate both 4-hydroxybenzoic acid (4-HBA) and 3,4-dihydroxybenzoic acid (3,4-DHBA), two consecutive steps in gallic acid biosynthesis. Structural modeling suggests precise reorganization of active site hydrogen bond network, which is difficult to obtain without deep navigation of combinatorial sequence space. We envision universal application of this selection platform in engineering NADPH-dependent oxidoreductases.

Chemical constituents from Syneilesis aconitifolia (II) / 中草药

Objective: To study the chemical constituents from Syneilesis aconitifolia. Methods: The chemical constituents were isolated by silica gel column chromatography and HPLC, and its structure were identified by their spectral data and physicochemical properties analysis. Results: Eighteen compounds were isolated from methanol extract ethyl acetate extracts of S.aconitifolia with the structures identified as 3β-angeloyoxy-eremophil-6-en-8-oxo-12,15β-diacid (1), quercetin-3-O-α-L-rhamnoside (2), triacontanol (3), 8β-methoxyeremophil-3,7(11)-diene-8α,12(6α,15)-dilactone (4), 3,4-dihydroxybenzoic acid (5), 8-oxo-eremophil-6,9-dien-12-oic acid (6), 8βH-eremophil-3,7(11)-dien-12,8α(14,6α)-diolide (7), 8αH-6α,10β-dihydroxyeremophilenolide (8), pinoresinol (9), 6β,8β,10β-trihydroxyeremophil-7(11)-en-12,8-olide (10), 10α,15-dihydroxy-oplopan-4-one (11), 6α,15α-epoxy-1β,4β-dihydroxyeudesmane (12), caryolane-1,9β-diol (13), (-)-clovane-2,9-diol (14), cis-3-hexenyl-β-D-glucopyranoside (15), kaempferol-3-O-α-L-rhamnoside (16), quercetin-3-O-β-D-glucopyranoside(17) and (-)-oplopan-4-one-10-α-O-β-D-glucoside (18). Conclusion: Compound 1 is a new compound, named as syneilesis acid. Compounds 4-16 and 18are isolated from this plant for the first time.

Use of coffee flower as a novel resource for the production of bioactive compounds, melanoidins, and bio-sugars.

Although coffee beans have been widely studied, application of coffee flower (CF) has not been previously investigated. Here, we evaluated the use of CF for the production of bioactive compounds, melanoidins, and bio-sugars through the green process. Pressurized hot water extraction was found to be the most appropriate method for extracting bioactive compounds from CF, which contain high values of total phenolic content and have antioxidant properties. Caffeine and trigonelline were the main compounds in CF with yields of 1070.8 mg and 1092.8 mg/100 g dry weight (DW), respectively. Melanoidins were also identified and quantified in the CF extracts that is approximately 30.2% were efficiently recovered in the initial extracts of CF. Bio-sugar was also obtained from cellulase and pectinase at a 92.8% conversion rate. The aim of this study is to promote a novel approach using high amounts of CFs in the production of functional healthy foods and beverages.

Contribution of phenolic compounds, ascorbic acid and vitamin E to antioxidant activity of currant (Ribes L.) and gooseberry (Ribes uva-crispa L.) fruits.

Berries of four gooseberry (Ribes uva-crispa L.) cultivars of Invicta, Rixanta, Karat and Black Negus and five currant (Ribes L.) cultivars of NS 11, Focus, Ben Gairn, Otelo and Viola were evaluated as potential sources of bioactive compounds with extraordinary antioxidant activity. Their total phenolic, flavonoid and anthocyanin contents were determined in the range of 3.52-30.77 g GA.kg-1, 2.83-17.35 g RE.kg-1 and 0.03-186.12 mg COG.100 g-1, respectively. Furthermore, quantification of phenolic compounds and vitamins was established by high-performance liquid chromatography-diode array detection. Flavonoids were the most abundant phenolic substances in the range of 345.0-3726.5 mg.kg-1. Ascorbic acid and vitamin E were established in the amounts of 6.2-14.04 g.kg-1 and 0.43-12.85 mg.kg-1, respectively. Considering all analyzed factors and antioxidant activities determined by various methods (DPPH, ACW and ACL), red gooseberry Black Negus and black currant Otelo were the most significant cultivars.

A new rhamnoside from Aspidopterys obcordate / 中草药

Objective To study the chemical constituents of Aspidopterys obcordate. Methods The chemical constituents from 95% EtOH extract of the stem of A. obcordate were isolated by repeated chromatograph with silica gel, Sephadex LH-20, and ODS. The structures were elucidated by spectroscopic analysis. Results Eight compounds were isolated and identified as 3,4-dihydroxybenzoic acid-3-O-α-L-rhamnoside (1), 3,4-dihydroxyphenyl acetate (2), 3,4-dihydroxybenzoic acid (3), catechin (4), β-sitosterol (5), daucosterol (6), cinnacasolide C (7), and alantan (8). Conclusion Compound 1 is a new compound, named as apobcoroside. All compounds are isolated from the plant of A. obcordate for the first time.

Study on HPLC Fingerprints of Nauclea officinalis Extract Syrup and Content Determination of 9 Components / 中国药房

OBJECTIVE： To establish HPLC fingerprints of Nauclea officinalis extract syrup， and to determine the contents of 9 components. METHODS： HPLC method was adopted. The determination was performed on Diamonsil C18（2）column with mobile phase consisted of acetonitrile-0.1％ phosphoric acid solution （gradient elution） at the flow rate of 1.0 mL/min. The detection wavelength was set at 240 nm， and column temperature was 30 ℃. The sample size was 10 μL. Using strictosamide as reference， HPLC chromatograms of 20 batches of N. officinalis extract syrup were drawn. The similarity of HPLC chromatograms were evaluated by using TCM Fingerprint Similarity Evaluation System （2004A edition） to confirm common peaks. The contents of 9 components were determined by standard curves. RESULTS： There were 26 common peaks in 20 batches of HPLC chromatograms， and the similarity was higher than 0.98. Compared with mixed control， 9 chemical components were identified， such as 3，4-dihydroxybenzoic acid， neochlorogenic acid， loganic acid， chlorogenic acid， cryptochlorogenic acid， swertioside， pumiloside， strictosamide and vincosamide. The linear range of 9 components were 17.24-275.84， 7.56-120.96， 15.40-246.40， 7.84-125.44， 8.64-138.24， 7.96-127.36， 8.40-134.40， 48.56-776.96， 4.16-66.56 μg/mL（all r≥0. 999）， respectively. The limits of detection were 0.043 1， 0.126 0， 0.038 5， 0.130 7， 0.144 0， 0.066 3， 0.070 0， 0.012 1， 0.052 0 μg/mL， respectively. The limits of quantitation were 0.215 5， 0.189 0， 0.077 0， 0.196 0， 0.288 0， 0.132 7， 0.105 0， 0.097 6， 0.138 7 μg/mL， respectively. RSDs of precision， stability and reproducibility tests were all lower than 2.0％ （n＝6）. Average recoveries were 99.6％、106.3％、100.1％、102.0％、98.4％、100.0％、99.3％、100.6％ and 101.2％， and RSDs were 1.20％、0.24％、0.59％、1.00％、0.73％、1.30％、1.10％、1.80％、1.90％（n＝6）. CONCLUSIONS： Established HPLC fingerprints and quantitative determination method of N. officinalis extract syrup are accurate， specific and sensitive. It can provides reference for quality control of N. officinalis extract syrup.

Selective extraction of 3,4-dihydroxybenzoic acid in Ilex chinensis Sims by meticulous mini-solid-phase microextraction using ternary deep eutectic solvent-based molecularly imprinted polymers.

A ternary deep eutectic solvent (TDES) was used as both template and functional monomer in the synthesis of TDES-based molecularly imprinted polymers (TDES-MIPs). A meticulous miniaturized solid-phase microextraction (mini-SPME) method followed by high-performance liquid chromatography (HPLC) were used for the optimal speciation of 3,4-dihydroxybenzoic acid (3,4-DHBA) in the needle of a syringe system with response surface methodology (RSM). Under the optimal conditions for the determination of 3,4-DHBA (amount of adsorbent (2 mg), sample volume (1 mL), cycles for adsorption and desorption (6)), the actual extraction amount was 8.46 µg g-1. The limits of detection (LODs, S/N = 3) for 3,4-DHBA in Ilex chinensis Sims were 0.26-0.31 µg mL-1, and the intra-day and inter-day precision (relative standard deviations, n = 4) after spiking with 5 µg mL-1, 100 µg mL-1, and 200 µg mL-1 were both less than 4.21%. The meticulous method (TDES-MIP-mini-SPME) combined with RSM offers a significant advance over existing methods, because of the meticulous operation and excellent selectivity of 3,4-DHBA from complex samples. Graphical abstract ᅟ.

Binary polymorphic cocrystals: an update on the available literature in the Cambridge Structural Database, including a new polymorph of the pharmaceutical 1:1 cocrystal theophylline-3,4-dihydroxybenzoic acid.

An analysis and classification of the 2925 neutral binary organic cocrystals in the Cambridge Structural Database is reported, focusing specifically on those both showing polymorphism and containing an active pharmaceutical ingredient (API). The search was confined to molecules having only C, H, N, O, S and halogens atoms. It was found that 400 out of 2925 cocrystals can be classified as pharmaceutical cocrystals, containing at least one API, and that of those, 56 can be classified as being polymorphic cocrystals. In general, the total number of polymorphic cocrystal systems of any type stands at 125. In addition, a new polymorph of the pharmaceutical cocrystal theophylline-3,4-dihydroxybenzoic acid (1/1), C7H8N4O2·C7H6O4, is reported.

Chemical constituents from rhizomes of Cimicifuga dahurica / 中草药

Objective To study the chemical constituents from the rhizomes of Cimicifuga dahurica. Methods The chemical constituents from the rhizomes of C. dahurica in ethyl acetate extraction phase and H2O fraction were isolated and purified by chromatographic methods, such as silica gel, opening ODS column, Sephadex LH-20, ODS and semi-preparative HPLC. Which stucture were identified by NMR and physicochemical analysis. Results Fifteen compounds were isolated and identified as 20(R),23 (R),24(R),25(S),26(S)-16β:23; 23:26; 24:25-triepoxy-12β-acetoxy-3β,26-dihydroxy-9,19-cyclolanost-7-ene-3-O-β- D-xylopyranoside (1), cimiaceroside B (2), 23-O-acetylshengmanol-3-O-β-D-xylopyranoside (3), 7,8-didehydro-24-O-acetylhydroshengmanol-3-O-β-D- xylopyranoside (4), 24-epi-cimigenol-3-O-β-D-xylopyranoside (5), 24-O-acetyldahurinol-3-O-β-D-xylopyranoside (6), 24-epi-24-O- acetylhydroshengmanol-3-O-β-D-xylopyranoside (7), 12β-O-acetylcimigenol-3-O-β-D-xylopyranoside (8), 23-O-acetyl-7,8- didehydroshengmanol-3-O-β-D-xylopyranoside (9), 7,8-didehydro-25-dehydrocimigenol-3-O-β-D-xylopyranoside (10), 25-O- ethylcimigenol-3-O-β-D-xylopyranoside (11), 3,4-dihydroxybenzoic acid (12), 24-O-acetylisodahurinol-3-O-α-L-arabinopyranoside (13), 2,3-dihydroxy-2-[(4-hydroxyphenyl) methyl]-1-ethyl ester (14), and 2,3-dihydroxy-2-[(4-hudroxyphenyl) methyl]-4-ethyl ester (15). Conclusion Compounds 6, 11-12, and 14-15 are isolated from Cimicifuga genus for the first time. Compounds 1, 4-5, 8-10, and 13 are isolated from C. dahurica for the first time.

Studies on chemical constituents and bioactivities of leaves of Torreya grandis / 中草药

Objective To study the chemical constituents and bioactivities of leaves of Torreya grandis. Methods The chemical constituents were isolated by MCI-Gel CHP-20, Diaion HP-20, Toyopearl HW-40, Sephadex LH-20, RP-18 and silica gel column chromatographic methods. Their structures were identified on the basis of physicochemical and spectroscopic analysis. The cytotoxic activity and antitumor activity of compounds 1-4 were investigated by lethal-to-prawn larva bioactivity determining method and MTT assay. Results Ten compounds were isolated from EtOAc extract and n-BuOH of leaves of T. grandis. Their structures were identified as torreyagrandate (1), hinokiol (2), 4-epiagathadial (3), 3,4-dihydroxybenzoic acid 3-O-β-D-glucoside (4), dehydroabietic acid (5), trans-communic acid (6), cis-communic acid (7), (2-methoxy-1,4-phenylene) dimethanol (8), pinoresinol (9), and β-sitosterol (10). The bioactivity experiment indicated that compounds 1-4 possessed certain cytotoxic activity towards brine shrimp, and LC50 value were 7.7, 8.0, 8.8, and 4.2 μg/mL, respectively. In addition, it was found that compound 4 presented remarkable inhibitory effect on two kinds of cells of human liver cancer cells of Huh7 (67%) and HepG2 (69%) at a dose of 10 μg/mL. Conclusion All compounds are isolated from leaves of T. grandis for the first time expect compound 10. Compounds 1-4 exhibite certain cytotoxic activity, and compound 4 displays stronger antitumor activity towards Huh7 and HepG2 liver cancer cells.

Effects of acid diffusibility and affinity to cellulose on strength loss of polycarboxylic acid crosslinked fabrics.

1,2,3,4-Butanetetracarboxylic acid (BTCA) imparts good anti-wrinkle property to cotton fabrics and results in significant strength loss due to cross-linking and acid degradation of cellulose simultaneously. However, benzophenone-3,3',4,4'- tetracarboxylic acid (BPTCA), an aromatic acid, crosslinks cellulose effectively but causes less strength loss to the products under similar conditions. The difference in damages to cellulose fibers was analyzed by using diffusibility and corresponding affinity of the acids to cellulose fibers, which were estimated by their molecular sizes and Hansen solubility parameters (HSP). Both experimental results and theoretical speculations revealed consistent agreement, indicating that smaller acid molecules could diffuse into cellulose fiber more rapidly and deeply, resulting in more acid degradation. Besides, the aliphatic acid such as BTCA has higher molecular affinity than BPTCA to cellulose, causing additional more degradation of cellulose. Both factors are potential reasons of the observed more severe tensile strength loss of the BTCA treated cotton fabrics.

Monoamine oxidase-induced hydroxyl radical production and cardiomyocyte injury during myocardial ischemia-reperfusion in rats.

To elucidate the involvement of monoamine oxidase (MAO) in hydroxyl radical production and cardiomyocyte injury during ischemia as well as after reperfusion, we applied microdialysis technique to the heart of anesthetized rats. Dialysate samples were collected during 30 min of induced ischemia followed by 60 min of reperfusion. We monitored dialysate 3,4-dihydrobenzoic acid (3,4-DHBA) concentration as an index of hydroxyl radical production using a trapping agent (4-hydroxybenzoic acid), and dialysate myoglobin concentration as an index of cardiomyocyte injury in the ischemic region. The effect of local administration of a MAO inhibitor, pargyline, was investigated. Dialysate 3,4-DHBA concentration increased from 1.9 ± 0.5 nM at baseline to 3.5 ± 0.7 nM at 20-30 min of occlusion. After reperfusion, dialysate 3,4-DHBA concentration further increased reaching a maximum (4.5 ± 0.3 nM) at 20-30 min after reperfusion, and stabilized thereafter. Pargyline suppressed the averaged increase in dialysate 3,4-DHBA concentration by ∼72% during occlusion and by ∼67% during reperfusion. Dialysate myoglobin concentration increased from 235 ± 60 ng/ml at baseline to 1309 ± 298 ng/ml at 20-30 min after occlusion. After reperfusion, dialysate myoglobin concentration further increased reaching a peak (5833 ± 1017 ng/ml) at 10-20 min after reperfusion, and then declined. Pargyline reduced the averaged dialysate myoglobin concentration by ∼56% during occlusion and by ∼41% during reperfusion. MAO plays a significant role in hydroxyl radical production and cardiomyocyte injury during ischemia as well as after reperfusion.

Simultaneous determination of phenolic compounds in sesame oil using LC-MS/MS combined with magnetic carboxylated multi-walled carbon nanotubes.

A novel magnetic carboxylated multi-walled carbon nanotubes (c-MWCNT-MNPs) was proposed for magnetic solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry to determine phenolic compounds in sesame oil. In this study, c-MWCNT-MNPs were acquired by simply dispersing Fe3O4 magnetic nanoparticles into carboxylated multi-walled carbon nanotubes. The major parameters affecting extraction efficiency were optimized, including the type and volume of desorption solvents, extraction and desorption time, washing solution, and sorbent amount. The limit of quantifications and limit of detections were from 0.03µg/kg to 43.00µg/kg and from 0.01µg/kg to 13.60µg/kg, respectively. The recoveries of phenolic compounds in vegetable oils were in the range of 83.8-125.9% with inter-day and intra-day precisions of less than 13.2%. It was confirmed that this method was simple, rapid and reliable with an excellent potential for routine analysis of phenolic compounds in oil samples.

Propensity of salicylamide and ethenzamide cocrystallization with aromatic carboxylic acids.

The cocrystallization of salicylamide (2-hydroxybenzamide, SMD) and ethenzamide (2-ethoxybenzamide, EMD) with aromatic carboxylic acids was examined both experimentally and theoretically. The supramolecular synthesis taking advantage of the droplet evaporative crystallization (DEC) technique was combined with powder diffraction and vibrational spectroscopy as the analytical tools. This led to identification of eleven new cocrystals including pharmaceutically relevant coformers such as mono- and dihydroxybenzoic acids. The cocrystallization abilities of SMD and EMD with aromatic carboxylic acids were found to be unexpectedly divers despite high formal similarities of these two benzamides and ability of the R2,2(8) heterosynthon formation. The source of diversities of the cocrystallization landscapes is the difference in the stabilization of possible conformers by adopting alternative intramolecular hydrogen boding patterns. The stronger intramolecular hydrogen bonding the weaker affinity toward intermolecular complexation potential. The substituent effects on R2,2(8) heterosynthon properties are also discussed.

Phenolic compounds of Brazilian beers from different types and styles and application of chemometrics for modeling antioxidant capacity.

In the present study we aimed at investigating, for the first time, phenolic compounds in Brazilian beers of different types and styles. We also aimed at applying chemometrics for modeling beer's antioxidant capacity as a function of their physicochemical attributes (density, refractive index, bitterness and ethanol content). Samples (n=29) were analyzed by PCA originating five groups, especially according to ethanol contents and bitterness. In general, Group V (alcoholic beers with very high bitterness) presented higher refractive index, bitterness, ethanol and phenolics contents than Groups I (non-alcoholic beers) and II (alcoholic beers with low bitterness). Brazilian beers phenolics profile was distinct from that of European beers, with high contents of gallic acid (0.5-14.7 mg/L) and low contents of ferulic acid (0.2-1.8 mg/L). Using PLS, beer's antioxidant capacity measured by FRAP assay could be predicted with acceptable precision by data of ethanol content and density, bitterness and refractive index values.