Production of aglycone protopanaxatriol from ginseng root extract using Dictyoglomus turgidum ß-glycosidase that specifically hydrolyzes the xylose at the C-6 position and the glucose in protopanaxatriol-type ginsenosides.

The hydrolytic activity of a recombinant ß-glycosidase from Dictyoglomus turgidum that specifically hydrolyzed the xylose at the C-6 position and the glucose in protopanaxatriol (PPT)-type ginsenosides followed the order Rf > Rg1 > Re > R1 > Rh1 > R2. The production of aglycone protopanaxatriol (APPT) from ginsenoside Rf was optimal at pH 6.0, 80 °C, 1 mg ml⁻¹ Rf, and 10.6 U ml⁻¹ enzyme. Under these conditions, D. turgidum ß-glycosidase converted ginsenoside R1 to APPT with a molar conversion yield of 75.6 % and a productivity of 15 mg l⁻¹ h⁻¹ after 24 h by the transformation pathway of R1 → R2 → Rh1 → APPT, whereas the complete conversion of ginsenosides Rf and Rg1 to APPT was achieved with a productivity of 1,515 mg l⁻¹ h⁻¹ after 6.6 h by the pathways of Rf → Rh1 → APPT and Rg1 → Rh1 → APPT, respectively. In addition, D. turgidum ß-glycosidase produced 0.54 mg ml⁻¹ APPT from 2.29 mg ml⁻¹ PPT-type ginsenosides of Panax ginseng root extract after 24 h, with a molar conversion yield of 43.2 % and a productivity of 23 mg l⁻¹ h⁻¹, and 0.62 mg ml⁻¹ APPT from 1.35 mg ml⁻¹ PPT-type ginsenosides of Panax notoginseng root extract after 20 h, with a molar conversion yield of 81.2 % and a productivity of 31 mg l⁻¹ h⁻¹. This is the first report on the APPT production from ginseng root extract. Moreover, the concentrations, yields, and productivities of APPT achieved in the present study are the highest reported to date.

ß-glucosidase from Penicillium aculeatum hydrolyzes exo-, 3-O-, and 6-O-ß-glucosides but not 20-O-ß-glucoside and other glycosides of ginsenosides.

A novel ß-glucosidase from Penicillium aculeatum was purified as a single 110.5-kDa band on SDS-PAGE with a specific activity of 75.4 U mg⁻¹ by salt precipitation and Hi-Trap Q HP and Resource Q ion exchange chromatographies. The purified enzyme was identified as a member of the glycoside hydrolase 3 family based on its amino acid sequence. The hydrolysis activity for p-nitrophenyl-ß-D-glucopyranoside was optimal at pH 4.5 and 70 °C with a half-life of 55 h. The enzyme hydrolyzed exo-, 3-O-, and 6-O-ß-glucosides but not 20-O-ß-glucoside and other glycosides of ginsenosides. Because of the novel specificity, this enzyme had the transformation pathways for ginsenosides: Rb1 → Rd → F2 → compound K, Rb2 → compound O → compound Y, Rc → compound Mc1 → compound Mc, Rg3 → Rh2 → aglycone protopanaxadiol (APPD), Rg1 → F1, and Rf → Rh1 → aglycone protopanaxatriol (APPT). Under the optimum conditions, the enzyme converted 0.5 mM Rb2, Rc, Rd, Rg3, Rg1, and Rf to 0.49 mM compound Y, 0.49 mM compound Mc, 0.47 mM compound K, 0.23 mM APPD, 0.49 mM F1, and 0.44 mM APPT after 6 h, respectively.

Production of rare ginsenosides (compound Mc, compound Y and aglycon protopanaxadiol) by ß-glucosidase from Dictyoglomus turgidum that hydrolyzes ß-linked, but not α-linked, sugars in ginsenosides.

Optimal hydrolytic activity of ß-glucosidase from Dictyoglomus turgidum for the ginsenoside Rd was at pH 5.5 and 80 °C, with a half-life of ~11 h. The enzyme hydrolysed ß-linked, but not α-linked, sugar moieties of ginsenosides. It produced the rare ginsenosides, aglycon protopanaxadiol (APPD), compounds Y, and Mc, via three unique transformation pathways: Rb(1) → Rd → F(2) → compound K → APPD, Rb(2) → compound Y, and Rc → compound Mc. The enzyme converted 0.5 mM Rb(2) and 0.5 mM Rc to 0.5 mM compound Y and 0.5 mM compound Mc after 3 h, respectively, with molar conversion yields of 100 %.

Ginsenoside F1 production from ginsenoside Rg1 by a purified ß-glucosidase from Fusarium moniliforme var. subglutinans.

Fusarium moniliforme var. subglutinans was selected from among 100 strains of fungi for producing ginsenoside F(1) from ginsenoside Rg(1). The enzyme responsible was purified as a single 85 kDa band with a specific activity of 136 U mg(-1). It hydrolysed glucose-linked ginsenosides Rb(1), Rd and Rg(1) but not for other monosaccharide-linked ginsenosides, Rb(2), Rc, R(1), and Re. Under the optimum conditions of pH 6.0, 50 °C, 30 U l(-1) of enzyme, and 5 mg Rg(1) ml(-1), 4 mg F(1) ml(-1) was produced after 4 h, with a molar yield of 100% and a productivity of 1 g l(-1) h(-1). This represents the highest productivity and conversion yield of F(1) yet reported.

Dosimetric comparison of three different treatment modalities for total scalp irradiation: the conventional lateral photon-electron technique, helical tomotherapy, and volumetric-modulated arc therapy.

The aim of this study was to compare lateral photon-electron (LPE), helical tomotherapy (HT), and volumetric-modulated arc therapy (VMAT) plans for total scalp irradiation. We selected a single adult model case and compared the dosimetric results for the three plans. All plans mainly used 6-MV photon beams, and the prescription dose was 60 Gy in 30 fractions. First, we compared the LPE, HT and VMAT plans, with all plans including a 1-cm bolus. We also compared HT plans with and without the bolus. The conformity indices for LPE, HT and VMAT were 1.73, 1.35 and 1.49, respectively. The HT plan showed the best conformity and the LPE plan showed the worst. However, the plans had similar homogeneity indexes. The dose to the hippocampus was the highest in the VMAT plan, with a mean of 6.7 Gy, compared with 3.5 Gy in the LPE plan and 4.8 Gy in the HT plan. The doses to the optical structures were all within the clinically acceptable range. The beam-on time and monitor units were highest in the HT plan. The HT plans with and without a bolus showed similar target coverage and organ-at-risk (OAR) sparing. The HT plan showed the best target coverage and conformity, with low doses to the brain and hippocampus. This plan also had the advantage of not necessarily requiring a bolus. Although the VMAT plan showed better conformity than the LPE plan and acceptable OAR sparing, the dose to the hippocampus should be considered when high doses are prescribed.

The effect of multileaf collimator leaf width on the radiosurgery planning for spine lesion treatment in terms of the modulated techniques and target complexity.

PURPOSE: We aim to evaluate the effects of multileaf collimator (MLC) leaf width (5 mm vs. 2.5 mm) on the radiosurgery planning for the treatment of spine lesions according to the modulated techniques (intensity-modulated radiotherapy [IMRT] vs. volumetric-modulated arc therapy [VMAT]) and the complexity of the target shape. METHODS: For this study, artificial spinal lesions were contoured and used for treatment plans. Three spinal levels (C5, T5, and L2 spines) were selected, and four types of target shapes reflecting the complexity of lesions were contoured. The treatment plans were performed using 2.5-mm and 5-mm MLCs, and also using both static IMRT and VMAT. In total, 48 treatment plans were established. The efficacy of each treatment plan was compared using target volume coverage (TVC), conformity index (CI), dose gradient index (GI), and V(30%). RESULTS: When the 5-mm MLC was replaced by the 2.5-mm MLC, TVC and GI improved significantly by 5.68% and 6.25%, respectively, while CI did not improve. With a smaller MLC leaf width, the improvement ratios of the TVC were larger in IMRT than VMAT (8.38% vs. 2.97%). In addition, the TVC was improved by 14.42-16.74% in target type 4 compared to the other target types. These improvements were larger in IMRT than in VMAT (27.99% vs. 6.34%). The V(30%) was not statistically different between IMRT and VMAT according to the MLC leaf widths and the types of target. CONCLUSION: The smaller MLC leaf width provided improved target coverage in both IMRT and VMAT, and its improvement was larger in IMRT than in VMAT. In addition, the smaller MLC leaf width was more effective for complex-shaped targets.

Production of ginsenoside Rd from ginsenoside Rc by α-L-arabinofuranosidase from Caldicellulosiruptor saccharolyticus.

Ginsenoside Rd was produced from ginsenoside Rc using a thermostable recombinant alpha-L-arabinofuranosidase from Caldicellulosiruptor saccharolyticus. The optimal reaction conditions for the production of ginsenoside Rd from Rc were pH 5.5, 80 degrees C, 227 U enzyme/ml, and 8.0 g/l ginsenoside Rc in the presence of 30% (v/v) n-hexane. Under these conditions, the enzyme produced 7.0 g/l ginsenoside Rd after 30 min, with a molar yield of 100% and a productivity of 14 g l(-1) h(-1). The conversion yield and productivity of ginsenoside Rd are the highest reported thus far among enzymatic transformations.