This review summarizes the current knowledge on essential vitamins B1, B2, B3, and B5. These B-complex vitamins must be taken from diet, with the exception of vitamin B3, that can also be synthetized from amino acid tryptophan. All of these vitamins are water soluble, which determines their main properties, namely: they are partly lost when food is washed or boiled since they migrate to the water; the requirement of membrane transporters for their permeation into the cells; and their safety since any excess is rapidly eliminated via the kidney. The therapeutic use of B-complex vitamins is mostly limited to hypovitaminoses or similar conditions, but, as they are generally very safe, they have also been examined in other pathological conditions. Nicotinic acid, a form of vitamin B3, is the only exception because it is a known hypolipidemic agent in gram doses. The article also sums up: (i) the current methods for detection of the vitamins of the B-complex in biological fluids; (ii) the food and other sources of these vitamins including the effect of common processing and storage methods on their content; and (iii) their physiological function.

Variations in total phenolic and flavonoid contents as well as antioxidant activity of Bellis perennis (common daisy) flowers were investigated. The flowers were collected monthly (from March to October, i.e., during the usual flowering season of the plant) at three localities in three different years. Total flavonoids were determined spectrophotometrically by two methods: by formation of a complex with aluminium chloride after acidic hydrolysis of flower extracts (method 1) and by reaction with boric and oxalic acids in extracts without their modification (method 2). Total phenolics were determined spectrophotometrically using the Folin-Ciocalteu reagent. The antioxidant activity was determined spectrophotometrically by a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. The contents of flavonoids varied from 0.31 to 0.44 mg quercetin equivalent/100 mg dry weight (method 1) and from 1.37 to 2.20 mg apigenin-7-glucoside equivalent/100 mg dry weight (method 2). Total phenolics ranged from 2.81 to 3.57 mg gallic acid equivalent/100 mg dry weight. The antioxidant activity expressed as IC 50 values varied from 66.03 to 89.27 µg/mL; it is about 50, 30, 20, and 10 times lower as compared with quercetin, ascorbic acid, Trolox ® , and butylhydroxytoluene, respectively, and about five times higher in comparison with apigenin-7-glucoside. There is a significant correlation between antioxidant activity and total phenolics. No correlation between total flavonoid contents and antioxidant activity was observed. Contents of phenolics and flavonoids as well as antioxidant activity of daisy flowers vary to a relatively small extent during the year and are not dependant on the time of collection. Thus, the flowers possess comparable quality as to these characteristics over the whole flowering

Three new alkaloids, bersavine (3), muraricine (4), and berbostrejdine (8), together with seven known isoquinoline alkaloids (1–2, 5–7, 9, and 10) were isolated from an alkaloidal extract of the root bark of Berberis vulgaris. The structures of the isolated compounds were determined by spectroscopic methods, including 1D and 2D NMR techniques, HRMS, and optical rotation, and by comparison of the obtained data with those in the literature. The NMR data of berbamine (5), aromoline (6), and obamegine (7) were completely assigned employing 2D NMR experiments. Alkaloids isolated in sufficient amounts were evaluated for their in vitro acetylcholinesterase, butyrylcholinesterase (BuChE), prolyl oligopeptidase, and glycogen synthase kinase-3β inhibitory activities. Selected compounds were studied for their ability to permeate through the blood–brain barrier. Significant human BuChE (hBuChE) inhibitory activity was demonstrated by 6 (IC50 = 0.82 ± 0.10 μM). The in vitro data were further supported by computational analysis that showed the accommodation of 6 in the active site of hBuChE.

Glycogen synthase kinase-3β (GSK-3β) is a multifunctional serine/threonine protein kinase that was originally identified as an enzyme involved in the control of glycogen metabolism. It plays a key role in diverse physiological processes including metabolism, the cell cycle, and gene expression by regulating a wide variety of well-known substances like glycogen synthase, tau-protein, and β-catenin. Recent studies have identified GSK-3β as a potential therapeutic target in Alzheimer´s disease, bipolar disorder, stroke, more than 15 types of cancer, and diabetes. GSK-3β is one of the most attractive targets for medicinal chemists in the discovery, design, and synthesis of new selective potent inhibitors. In the current study, twenty-eight Amaryllidaceae alkaloids of various structural types were studied for their potency to inhibit GSK-3β. Promising results have been demonstrated by alkaloids of the homolycorine-{9-O-demethylhomolycorine (IC50 = 30.00 ± 0.71 µM), masonine (IC50 = 27.81 ± 0.01 μM)}, and lycorine-types {caranine (IC50 = 30.75 ± 0.04 μM)}.