Subscribe to RSS
Arbutin production in plant in vitro cultures
Arbutin (hydroquinone β-D-glucoside), a known plant metabolite possessing important therapeutic (urodisinfectant) and cosmetic (skin whitener) values, can be obtained by biotransformation using enzymatic potential of plant cells in in vitro cultures [1–3]. This work consisted in optimization of hydroquinone biotransformation process into arbutin in in vitro cultures of Ruta graveolens L. (garden rue), R. g. ssp. divaricata (Tenore) Gams and Hypericum perforatum L. (St. John's wort). The optimization consisted in the administration of different precursor doses (96, 144, 192, 288 and 384mg/l of medium) as one portion and divided into 2 and 3 portions administered at 24-hour intervals.
Agitating cultures of the above-mentioned plants were maintained under identical conditions: on Linsmaier-Skoog medium  containing 2mg/l NAA (auxin) and 2mg/l BAP (kinin), under constant artificial light (900 lx), at 25±2oC. Arbutin contents were determined using HPLC method both in extracts from biomass and in lyophilized media collected 24h after supplementation of the last precursor dose.
In R. graveolens and R.g. ssp. divaricata, arbutin was accumulated mainly in the cultured biomass. Media contained only its trace amounts. Even a high single dose of hydroquinone did not damage the biomass under culture and facilitated product formation. Fourfold increase in precursor dose (from 96 to 386mg/l) elevated arbutin content from 1.3 to 5.5g% d.w. in R. graveolens cultures and from 1.04 to 3.44g% d.w. in R.g. ssp. divaricata cultures.
In H. perforatum cultures, hydroquinone dose division into 2 and 3 portions was conducive to arbutin formation. Max. arbutin content (5.45g% d.w.) was obtained after addition of the dose of 192mg/l (divided into 3 portions). The highest tested hydroquinone doses (288 and 384mg/l) markedly damaged the biomass and caused product accumulation in the medium (even up to 69.4%). Max. yield of biotransformation process in the cultures under study was 45, 22 and 54%, respectively.
The obtained results proved that considerable quantities of the expected product, arbutin, can be obtained by optimization of conditions of biotransformation process. These results encourage further studies in this direction.
 Suzuki T et al.: Plant Cell Rep. 1987; 6: 275–278.
 Yokoyama M et al.: Plant Cell Rep. 1990; 31; 551–555.
 Skrzypczak-Pietraszek E et al. Phytopharmaka und Phytotherapie 2004– Forschung und Praxis, Berlin 2004, Abstracts: p. 67.
 Linsmaier EM, Skoog F: Physiol Plant. 1985; 18: 100–127.