Antioxidant and anti-proliferative activity of free, conjugates and bound phenolic compounds from tomato and industrial tomato by-product.

The aim of this study was to evaluate the antioxidant and anti-proliferative activity of different fractions of phenolic compounds from tomato and tomato by-product. Soluble free phenolics and bound phenolics (BP) fractions from saladette tomato and industrial tomato by-product as well as, conjugated acid-hydrolysable phenolics (AHP) and alkaline-hydrolysable phenolics (AKHP) from saladette tomato, grape tomato and industrial tomato by-product, were tested. The scavenging effects of phenolic fractions on superoxide anion were determined using the PMS-NADH-NBT system. The myoglobin protection ratios of samples against hydroxyl radical were evaluated and the anti-proliferative effects in the MCF-7 breast cancer cell line were determined. AHP fraction from tomato by-product and AKHP fraction from grape and saladette tomato showed the highest inhibitory capacity of the superoxide anion (p ≤ 0.05). All samples had a myoglobin protection ratio from 30 to 50%. Regarding to cytotoxicity assays, all phenolic fractions from tomato by-product, as well as, BP, AHP, AKHP from saladette tomato and AHP from grape tomato showed important anti-proliferative activity against MCF-7 breast cancer cell line (IC50 < 20 µg/mL). From the results, we can conclude that tomato and tomato by-product are a good source of natural compound with important antioxidant and anti-proliferative activity.

Pesticides in water and sediments of Chacahua-Pastoria Lagoon System, Oaxaca, Mexico.

This is the first report about the presence of pesticide residues in water and sediments from Chacahua-Pastoria Lagoon System in the Oaxaca Coast, Mexico. Organochlorine and organophosphate pesticides were analyzed in water and sediment samples collected during rainy and dry seasons in 2018. The pesticides extraction was carried out by 525.2 EPA and QuEChERS methods for water and sediments samples, respectively. The quantification was done by gas chromatography coupled to electron microcapture (µECD) and flame photometric (FPD) detectors. Univariate and multivariate analysis were carried out to evaluate the distribution patterns, comparing between lagoons, seasons and matrices. The spatial distribution of malathion and organochlorines in water showed the highest values near to adjacent land with some patterns differences. DDT was the most frequent in water and sediments samples, showed the highest concentrations in the Pastoria Lagoon. These results indicate the need to establish a permanent monitoring programs to implement mitigation measures.

Phenolic composition of tomato varieties and an industrial tomato by-product: free, conjugated and bound phenolics and antioxidant activity.

The aim of this study was to isolate, identify and quantify soluble free phenolics, conjugated acid-hydrolysable phenolics (AHP) and alkaline-hydrolysable phenolics, and bound phenolics (BP) fractions from two tomato varieties (saladette and grape) and an industrial tomato by-product, as well as, to determine their antioxidant capacity. Phenolic composition was determined using Folin-Ciocalteu's method and HPLC-DAD. AHP were predominant in grape and saladette tomato extracts (91.47 ± 17.28 mg gallic acid equivalents (GAE) per g dry extract (DE) and 57.41 ± 8.80 mg GAE per g DE, respectively), while BP form was predominant in tomato by-product (51.30 ± 10.91 GAE per g DE). AHP extract of grape tomato presented the highest antioxidant capacity by DPPH assay (252.35 ± 42.55 µmol trolox equiv (TE) per g DE). In the case of ORAC assay, AHP fractions from both grape (1005.19 ± 138.52 µmol TE per g DE) and saladette tomatoes (804.16 ± 131.45 µmol TE per g DE), and BP fraction from by-product (852.40 ± 71.46 µmol TE per g DE) showed the highest ORAC values. Caffeic acid was the most abundant phenolic acid and it was found mainly in its conjugated forms. Naringenin was the most abundant flavonoid and it was mainly detected in bound form. Our analysis allowed a better characterization of phenolic compounds in whole tomato and by-product, remarking the importance of the fractionation. The valorization of the industrial tomato by-product, through the use of its different fractions of phenolic antioxidant compounds, could generate additional income to the tomato industry and reduce the waste disposal problem.

Phenolic profile and antioxidant activity from non-toxic Mexican Jatropha curcas L. shell methanolic extracts.

Jatropha curcas seed shells are the by-product obtained during oil extraction process. Recently, its chemical composition has gained attention since its potential applications. The aim of this study was to identify phenolic compounds profile from a non-toxic J. curcas shell from Mexico, besides, evaluate J. curcas shell methanolic extract (JcSME) antioxidant activity. Free, conjugate and bound phenolics were fractionated and quantified (606.7, 193.32 and 909.59 µg/g shell, respectively) and 13 individual phenolic compounds were detected by HPLC. The radical-scavenging activity of JcSME was similar to Trolox and ascorbic acid by DPPH assay while by ABTS assay it was similar to BHT. Effective antioxidant capacity by ORAC was found (426.44 ± 53.39 µmol Trolox equivalents/g shell). The Mexican non-toxic J. curcas shell is rich in phenolic compounds with high antioxidant activity; hence, it could be considerate as a good source of natural antioxidants.