Rapid LC-MS/MS Determination of Hesperidin in Fermented Tea Prepared from Unripe Satsuma Mandarin (Citrus unshiu) Fruits and Third-crop Green Tea (Camellia sinensis) Leaves

Antioxidant and anti-inflammatory activity through inhibition of NF-κB and sEH of some citrus peel and phytoconstituent characteristics

In Indonesia, there are many types of citrus where parts of the fruit, leaves, and peel can be utilized as food, drinks, spices, and medicine. This research aims to determine the phytochemical characteristics, antioxidant activities, and anti-inflammatory activity through inhibition of NF-κB and sEH, and the main phytoconstituents of three types of citrus fruits that are commonly used as herbs in Indonesia. The flesh and peel of Citrus amblycarpa/CAm, C. aurantiifolia/CAu, and C. hystrix/CH were extracted by Ultrasound-Assisted Extraction (UAE) with 70 % ethanol and then concentrated. All extracts were tested for total flavonoid content (TFC), total polyphenolic content (TPC), chemical constituents using LCMS, and DPPH radical scavenging activity. Molecular docking tests of 33 compounds containing CAm, CAu, and CH fruit peels from the literature study against NF-κB (Nuclear Factor Kappa Beta) and sEH (Soluble Epoxide Hydrolase) were also conducted. The TFC in fruit peels was 13.47-17.34 mg QE/g extract, and in flesh was 1.35-2.51 mg QE/g extract. The TPC in fruit peels was 4.28-6.3 mg GAE/g extract, and in flesh was 0.85-2.09 mg GAE/g extract. The IC50 values of antioxidant activity on fruit peel were 74.01-168.54 µg/mL; and flesh 185.62-2669 µg/mL. CAu peels provided the highest antioxidant activity and polyphenol content. The LC-MS/MS test on citrus peels shows the main chemical compounds: naringin (C27H32O14), naringenin (C15H12O5), hesperidin (C28H34O15), and hesperitin (C16H14O6). Molecular docking shows that naringin and neohesperidin predicted inhibit NF-κB, and hesperidin, neohesperidin, narirutin, naringin, apigenin, kaempferol, quercetin, rutin, eriocitrin, sinensetin, and vitamin A predicted can inhibit sEH enzyme. All citrus peel has stronger antioxidant activity and more flavonoids and phenolics than the flesh. Naringin and neohesperidin can inhibit NF-κB and sEH enzymes. The main flavonoid contents of the citrus peels and presumed to have activity are hesperidin and naringin. These flavonoids and their glycosides can be used as marker phytoconstituents in the quality assurance of pharmaceutical products.

Portable Microelectrochemical Sensors for Rapid and Sensitive Determination of Hesperidin in Citrus reticulate 'Chachi' Peel

Portable and low-cost analytical devices are essential for rapid detection of bioactive substrates in agricultural products. This study presents the first highly integrated microelectrochemical sensor based on pencil graphite for rapid and sensitive detection of hesperidin in Citrus reticulate 'Chachi' peel. The surface morphology and characterization as well as the electrochemical property of pencil graphite was investigated and discussed. A high electrocatalytic efficiency of hesperidin has been found at used pencil graphite-based microelectrodes. Kinetic analysis was carried out to further understand the electrochemical process of hesperidin at a pencil graphite microelectrode. Consequently, a portable and highly-integrated microelectrochemical sensor exhibits a sensitivity of 0.7251 μA cm^-2 μM^-1 and a detection limit as low as 25 nM (S/N = 3), and high selectivity was fabricated. Proposed microelectrochemical sensors were applied to electrochemically determinate the hesperidin content in the extract of Citrus reticulata "chachi" peel. As a result, the concentration of hesperidin in the actual real sample detected electrochemically with the proposed portable and low-cost microelectrochemical sensors is highly consistent to that obtained with a common chromatographic method, thus indicating the good reliability and that it can be used in practical applications.

Microbial biotransformation of Pericarpium Citri Reticulatae (PCR) by Aspergillus niger and effects on antioxidant activity

Pericarpium Citri Reticulatae (PCR), the mature fruit peel of Citrus reticulata Blanco and its different cultivars, is an important citrus by-product with beneficial health and nutritive properties. However, due to the lack of value-added methods for its development and utilization, a large amount of PCR is discarded or wasted. To explore a possibly more effective method to utilize PCR, we compared the chemical and biological differences before (CK) and after (CP) microbial transformation of PCR by Aspergillus niger. UPLC-ESI-MS/MS, HPLC, and LC-MS methods were used to compare the chemical profiles of CK and CP. The results demonstrated that microbial biotransformation by A. niger could transform flavonoid compounds by utilizing the carbohydrate and amino acid nutrients in PCR. This could also promote the accumulation of polyhydroxyflavones compounds in CP. The antioxidant assay demonstrated that CP had significantly greater free radical-scavenging activity than CK. The higher antioxidant activity of CP may result from the high level of flavonoids with associated phenolic hydroxyl groups. Microbial biotransformation is an effective method for improving the antioxidant capacity of PCR and may be effective and useful in other natural product situations.

Screening Method for the Quality Evaluation of Cannabidiols in Water-based Products Using Liquid Chromatography Tandem Mass Spectrometry

A sensitive, useful and preliminary screening method was proposed to quantitate the containable cannabinoids most commonly included in mineral water and gummi candy products, specifically cannabidiol (CBD), cannabinol (CBN), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCA), cannabigerol (CBG), and cannabidiolic acid (CBDA), using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for quality evaluations. Based on the electrospray positive ion mode, the limit of detection and the limit of quantification values were 0.2 to 0.5 ng/mL and 0.8 and 2.0 ng/mL. Samples (0.5 g) were diluted by water/methanol (50/50), to which stable isotope internal standards were added; the recovery results appeared in range from 91.3 to 101.2%. This method was applied to evaluate CBD products (6 kinds) from the Japanese market. Our survey found obvious discrepancies between the labeling and the results were overserved in products. In addition, CBN, THCA, CBG, and CBDA were not detected in full-spectrum products that contained various cannabinoids that naturally occur in the cannabis plant. Thus, it is necessary to be able to verify the accurate concentration and impurity in various CBD products from the Japanese market as quickly as possible.