20 research outputs found
The determination of impact of malt grist moisture on porosity and permeability using measurement of differential air pressure
ArticleThis article is focused on determination of malt grist and spent grains porosity and
permeability using measurement of differential pressure of the air passing through the layer
of malt grist and spent grains. For preparation of malt grist were used different disintegration
equipment (two roller mill and disc mill). The method of differential pressure measuring is used
for the determination of porosity of malt grist layer, defined as fraction of the volume of voids
over the total volume. Measurement confirmed the logical assumption; the higher-pressure
difference is above and below the spent grain layer, the lower value of porosity
A study of dynamics of bitter acids and xanthohumol in hop pellets during storage
ArticleEight varieties of hop pellets were analyzed for the contents of α
-
acids, Ăź
-
acids and
xanthohumol according to the EBC 7.7 analytical method. The pellets were extracted with
acidified mixture methanol
-
diethylether
and analyzed using HPLC with a diode
-
array detector
and a Nova
-
Pak column C
18
. Four series of analyses were performed: immediately after the
unpacking of the pellets and
then
after five, seven and nine months of storage at 4
°C. According
to the first ser
i
es of analyses, the contents were assayed as following (α
-
acids, Ăź
-
acids,
xanthohumol resp., all in weight % in pellets): Galaxy (13.4, 8.0, 0.74), Citra (11.1, 3.0, 0.48),
Tradition (8.2, 8.0, 0.58), Cascade (4.5, 5.2, 0.25), Northern Brewer (4.0, 2.9, 0.
37), Sládek (3.5,
4.0, 0.48), Saaz (2.0, 3.4, 0.24), and Triskel (1.7, 3.6, 0.18). According to these results, variety
Galaxy was found as the richest in all three parameters. After nine months of storage at 4
°C, the
weight
loss of α
-
acids ranged from 4.1
% (Citra and Triskel) to 66.4% (Galaxy). The losses of β
-
acids and xanthohumol were less distinctive (from zero to 31.3% and 25.7%, resp.) and indicated
good long storage possibilities of these compounds at convenient conditions (darkness, low
temperature,
elimination of direct influence of oxygen)
In Vitro and In Silico Analyses of the Inhibition of Human Aldehyde Oxidase by Bazedoxifene, Lasofoxifene, and Structural Analogues
Aldehyde oxidase (AOX1) is a molybdo-flavoprotein and has emerged as a drug-metabolizing enzyme of potential therapeutic importance because drugs have been identified as AOX1 substrates. Selective oestrogen receptor modulators (SERM), which are drugs used to treat and prevent various conditions, differentially inhibit AOX1 catalytic activity. Tamoxifen, raloxifene, and nafoxidine are selective oestrogen receptor modulators (SERMs) reported to inhibit the catalytic activity of human aldehyde oxidase 1 (AOX1). How these drugs interact with AOX1 and whether other SERMs inhibit this drug-metabolizing enzyme are not known. Therefore, a detailed in vitro and in silico study involving parent drugs and their analogues was conducted to investigate the effect of specific SERMs, particularly acolbifene, bazedoxifene, and lasofoxifene on AOX1 catalytic activity, as assessed by carbazeran 4-oxidation, an AOX1-selective catalytic marker. The rank-order in the potency (based on IC50 values) of AOX1 inhibition by SERMs was raloxifene > bazedoxifene ~ lasofoxifene > tamoxifen > acolbifene. Inhibition of liver cytosolic AOX1 by bazedoxifene, lasofoxifene, and tamoxifen was competitive, whereas that by raloxifene was noncompetitive. Loss of 1-azepanylethyl group increased the inhibitory potency of bazedoxifene, whereas the N-oxide group decreased it. The 7-hydroxy group and the substituted pyrrolidine ring attached to the tetrahydronaphthalene structure contributed to AOX1 inhibition by lasofoxifene. These results are supported by molecular docking simulations in terms of predicted binding modes, encompassing binding orientation and efficiency, and analysis of key interactions, particularly hydrogen bonds. The extent of AOX1 inhibition by bazedoxifene was increased by estrone sulfate and estrone. In summary, SERMs differentially inhibited human AOX1 catalytic activity. Structural features of bazedoxifene and lasofoxifene contributed to AOX1 inhibition, whereas those of acolbifene rendered it considerably less susceptible to AOX1 inhibition. Overall, our novel biochemical findings and molecular docking analyses provide new insights into the interaction between SERMs and AOX1. Structural features of bazedoxifene and lasofoxifene contribute to AOX1 inhibition, whereas those of acolbifene render it considerably less susceptible to AOX1 inhibition. Our novel biochemical findings, together with molecular docking analyses, provide new insights into the differential inhibitory effect of SERMs on the catalytic activity of human AOX1, how SERMs bind to AOX1, and increase our understanding of the AOX1 pharmacophore in the inhibition of AOX1 by drugs and other chemicals