Biotransformation of hydroquinone and 4-hydroxybenzoic acid in Schisandra chinensis (Chinese magnolia vine) in vitro cultures

Optimization of the process of biotransformation of hydroquinone into its β-D-glucoside – arbutin, was performed in agitated shoot cultures of Schisandra chinensis. The optimisation involved testing various concentrations of the precursor and different ways of administering it. Arbutin was accumulated mainly in the in vitro cultured biomass (85.2–98.6%). By optimizing the process, a 2.26-fold increase in the overall product content was obtained. The highest amount (17.8 mg·g–1 DW) was found after administering 384 mg·l–1 hydroquinone in a dose divided into two portions. An experiment with the biotransformation of 4-hydro- xybenzoic acid did not produce arbutin but a mixture of two products of glucosylation of the precursor – hydroxybenzoic acid 4-O-β-glucopyranoside and 4-hydroxybenzoic acid β-glucopyranosyl ester. The identity of all biotransformation products was confirmed by 1H-NMR analysis. The results for the production of arbutin by the biotransformation of hydroquinone are of potential practical importance. On the other hand, the fact of confirming the presence of two glucosylation products has a great cognitive value

Arbutin production via biotransformation of hydroquinone in in vitro cultures of Aronia melanocarpa (Michx.) Elliott

Arbutin (hydroquinone β-D-glucoside) is a compound of plant origin possessing valuable therapeutic (urinary tract disinfection) and cosmetic (skin whitening) properties, which can be obtained from in vitro cultures of plants belonging to different taxa via biotransformation of exogenously supplemented hydroquinone. Agitating cultures of Aronia melanocarpa were maintained on the Murashige and Skoog medium containing growth regulators: the cytokinin - BAP (6-benzylaminopurine), 2 mg/l and the auxin NAA (α-naphthaleneacetic acid), 2 mg/l. The biomass was cultured for 2 weeks and then hydroquinone was supplemented at the following doses: 96, 144, 192, 288 and 384 mg/l either undivided or divided into two or three portions added at 24-hour intervals. The content of the reaction product - arbutin, was determined using an HPLC method in methanolic extracts from biomass and lyophilized medium samples collected 24 hours after the addition of the last precursor dose. The total amounts of arbutin were very diverse, from 2.71 to 8.27 g/100g d.w. The production of arbutin rose with increasing hydroquinone concentration. The maximum content of the product was observed after hydroquinone addition at 384 mg/l divided into two portions. Biotransformation efficiency also varied widely, ranging from 37.04% do 73.80%. The identity of the product - arbutin, after its isolation and purification was confirmed by spectral analysis (1H-NMR spectrum). The maximum amount of arbutin obtained was higher than that required by the latest 9th Edition of the Polish Pharmacopoeia and by the newest 8th Edithion of European Pharmacopoeia for Uvae ursi folium (7.0 g/100g d.w.), and is interesting from practical point of view

In Vivo Anti-inflammatory Activity of Lipoic Acid Derivatives in Mice

Background: In mammals lipoic acid (LA) and its reduced form dihydrolipoic acid (DHLA) function as cofactors for multienzymatic complexes catalyzing the decarboxylation of α-ketoacids. Moreover, LA is used as a drug in a variety of diseases including inflammatory diseases. The aim of the study was to examine anti-inflammatory properties of LA metabolites.Material/methods:The present paper reports the chemical synthesis of 2,4-bismethylthio-butanoic acid (BMTBA) and tetranor-dihydrolipoic acid (tetranor-DHLA). BMTBA is one of the biotransformation products of LA, while tetranor-DHLA is an analogue of DHLA. Structural identity of these compounds was confirmed by 1H NMR. These compounds were assessed for their anti-inflammatory activity in mice. For this purpose, the zymosan-induced peritonitis and the carrageenan-induced hind paw edema animal models were applied.Results/conclusions: The obtained results indicated that the early vascular permeability measured at 30 min of zymosan-induced peritonitis was significantly inhibited in groups receiving BMTBA (10, 30, 50 mg/kg). The early infiltration of neutrophils measured at 4 hours of zymosan-induced peritonitis was inhibited in the group receiving BMTBA (50 mg/kg) and tetranor-DHLA (50 mg/kg). The results indicated that the increase in paw edema was significantly inhibited in the groups receiving BMTBA (50, 100 mg/kg) and tetranor-DHLA (30, 50 mg/kg). In summary, the present studies clearly demonstrated that both BMTBA and tetranor-DHLA were able to act as anti-inflammatory agents. This is the first study examining in vivo the anti-inflammatory properties of LA metabolites

In vitro Cultures of some medicinal plant species (Cistus x incanus, Verbena officinalis, Scutellaria lateriflora, and Scutellaria baicalensis) as a rich potential source of antioxidants-evaluation by CUPRAC and QUENCHER-CUPRAC assays

Comparative estimations of the antioxidant activity of methanolic extracts from biomasses of different types of in vitro cultures of Cistus × incanus, Verbena officinalis, Scutellaria lateriflora, and S. baicalensis and also from plant raw materials were performed. The antioxidant measurements were based on the modern assays—cupric ion reducing antioxidant capacity (CUPRAC) and quick, easy, new, cheap, and reproducible CUPRAC (QUENCHER-CUPRAC). The total extractable antioxidants (CUPRAC assay) ranged from 10.4 to 49.7 mmol (100 g)−1 of dry weight (DW) expressed as Trolox equivalent antioxidant capacity (TEAC), and the global antioxidant response (QUENCHER-CUPRAC assay) ranged from 16.0 to 79.1 mmol (100 g)−1 DW for in vitro cultures, whereas for plant raw materials the total extractable antioxidants ranged from 20.9 to 69.5 mmol (100 g)−1 DW, and the global antioxidant response ranged from 67.2 to 97.8 mmol (100 g)−1 DW. Finally, the in vitro cultures could be regarded as an antioxidant-rich alternative resource for the pharmaceutical, health food and cosmetics industries