Black cumin (Nigella sativa L. [N.sativa]) seed extracts demonstrated numerous beneficial biological effects including, among others, antidiabetic, anticancer, immunomodulatory, antimicrobial, anti-inflammatory, antihypertensive, and antioxidant activity. To better understand the phytochemical composition of N. sativa seeds, methanol seed extracts were analyzed for phenolic acid and flavonoid content. Furthermore, we tested N. sativa methanol, n-hexane, and aqueous seed extracts for their inhibitory activity against butyrylcholinesterase (BChE) and catalase (CAT) as well as for antimicrobial activity against several bacterial and a yeast strains. The phenolic content of N. sativa was analyzed using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The inhibition of BChE was assessed by modified Ellman’s method, and the inhibition of CAT was determined by monitoring hydrogen peroxide consumption. The extracts were tested against Bacillus subtilis, Staphylococcus aureus, Salmonella enterica, and Escherichia coli using the agar diffusion method. The UHPLC-MS/MS method allowed the identification and quantification of 23 phenolic compounds within 15 minutes. The major components found in N. sativa seed extract were sinapinic acid (7.22 ± 0.73 µg/mg) as a phenolic acid and kaempferol (11.74 ± 0.92 µg/mg) as a flavonoid. All extracts showed inhibitory activity against BChE, with methanol seed extract demonstrating the highest inhibitory activity (inhibitory concentration 50% [IC50] 79.11 ± 6.06 µg/ml). The methanol seed extract also showed strong inhibitory activity against CAT with an IC50 value of 6.61 ± 0.27 µg/ml. Finally, the methanol extract exhibited considerable inhibitory activity against the tested microbial strains. Overall, this is the first study to investigate the ability of black cumin seed extracts to inhibit CAT. Our results indicate that N. sativa seed can be considered as an effective inhibitor of CAT activity.

Quantification of fatty acids, phenolic acids, and flavonoids, antioxidant and enzyme inhibition activity of anise (Pimpinella anisum L.) seeds was the subject of this study. In fixed oil were found two saturated and four unsaturated fatty acids and linoleic acid were majors. Successive extraction of seed with 80% methanol was used to prepare four different fractions of phenolic compounds that is, free phenolics (PA-M1), esters (PA-M2), phenolic glycosides (PA-M3), and bounded phenolics (PA-M4). Six phenolic acids (5-hydroxyferulic, 3-hydroxybenzoic, ferulic, sinapinic, salicylic, and trans-cinnamic acid) were found in four different fractions. Apigenin was the only identified flavonoid. The antioxidant capacity of anise seed extracts was evaluated by four methods. Total phenolic content showed a correlation with antioxidant activity. Determination of butyrylcholinesterase inhibition was performed by modified Ellman's assay, while monitoring of hydrogen peroxide consumption was used for catalase inhibition assessment. Seed extracts showed potent inhibition of both enzymes. Novelty impact statement This study was evaluated chemical profile and biological activities of imported Pimpinella anisum L. seed, where linoleic acid was found as a major fatty acids, and ferulic acid and sinapinic acid as major phenolic compounds. Also, were demonstrated butyrylcholinesterase and catalase inhibition activities, as well as antioxidant activities. Furthermore, this is the first study describing the catalase inhibitory activity of anise seed extracts.

Ascorbic acid (AA) is one of the most important vitamin for human nutrition that is supplied by fruits and vegetables. In this study, a simple and sensitive fluorimetric method determination of ascorbic acid was used in 25 different samples of fruits and vegetables. This method is based on the condensation reaction of AA with o-phenylenediamine (OPDA) in the absence of the oxidant. The fluorescence intensity is measured at excitation and emission wavelengths of 330nm and 430nm, respectively. The effect of pH and OPDA concentration on fluorescence intensity of the system was examined. Optimum pH was between 9.4 and 9.5, and optimal concentration of OPDA was 0.05% (w/v). Under optimal conditions, a linear relationship is obtained between the fluorescence intensity and the concentration of AA in the range 1–10 micro g/mL. The regression coefficient was 0.9999. The content of AA were found between 3 and 60mg/100g of fresh fruits and between 17 and 50mg/100g of fresh vegetables. The detection limit (3σ) was found to be 0.20 micro g/mL of AA (σ from 4 determination of 5 micro g/mL). A relative standard deviation of 1.0% was recorded for 4 measurements of 5 micro g/mL standard AA solution. Limit of quantification AA was 0.68 micro g/mL. The results obtained with this method are comparable with the results obtained by other methods [1]. Presented method seems to be useful in the nutritional analytical practice. References: 1. Eitenmiller RR, Ye L, Landen WO (2008) Vitamin analysis for the health and food sciences, CRC press

Phenolic aldehydes and their derivatives found in nature are well-known for their potential biological activity. In this study, four 1-substituted 1,2,3,4-tetrahydroisoquinolines (THIQs) derived from phenolic aldehydes were synthesized by phosphate buffer mediated Pictet-Spengler reaction. All derivatives were chemically and structurally characterized by elemental CHN analysis and spectroscopic methods (IR, HR-ESI-MS, 1H- and 13C-NMR). 1-Substituted THIQs derived from 3,4-dihydroxybenzaldehyde and 4-hydroxy-3-methoxybenzaldehyde were described for the first time. In order to cover the diversity of the mechanistic approach, but also to establish the relationship between structure and activity, antioxidant activity was examined by five different in vitro methods, namely: neutralization and reduction of stable free radicals 2,2-diphenyl-1-picrylhydrazyl and radical cation derived from [(2,2´-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)], ferric reducing antioxidant power, oxygen radical absorbance capacity, and ability to chelate Fe(II) ions. In vitro inhibition of acetylcholinesterase (AChE) was examined by the Ellman's colorimetric method, while computer-simulated docking was used to reveal the preferred binding site and major interaction between AChE and THIQs. Antibacterial testing was examined using the agar well method and results were presented in the form of zones of inhibition (mm).