Metabolite Profiles, Bioactivity, and HPLC Fingerprint of Different Varieties of Eucommia ulmoides Oliv.: Towards the Utilization of Medicinal and Commercial Chinese Endemic Tree.

Eucommia ulmoides Oliv. is widely regarded in China as a precious medicinal and commercial endemic tree. Due to cross-breeding or natural variation of E. ulmoides, the metabolite composition may vary significantly, making control of the medical quality difficult. In order to improve the rational development and utilization, the quality of seven varieties of E. ulmoides were evaluated based on metabolite profiles (total phenolic, total flavonoid, gutta-percha, aucubin, geniposidic acid, chlorogenic acid, geniposide, pinoresinol diglucoside, rutin, hyperoside, and astragalin), bioactivities (in vitro, in vivo antioxidant activities, and antibacterial activities) and HPLC fingerprint combined with chemometrics analysis. On this basis, the differences of medicinal parts (leaf and bark) were further carried out. For the traditional use of bark, Purple-leaf E. ulmoides was the most suitable. For the use of leaf, Qinzhong 1 and Purple-leaf E. ulmoides were appropriate. HPLC fingerprint analysis showed that significant differences in metabolite profiles exist among seven varieties of E. ulmoides. Combined with chemometrics analysis, seven varieties of E. ulmoides were divided into three groups from the use of leaf and bark. The analysis not only evaluated quality of seven varieties of E. ulmoides, but also could distinguish different varieties and different regions of origin. The results can provide theoretical basis for E. ulmoides resources utilization and cultivation of fine varieties.

Comparison of hand and rotary instrumentation for removing gutta-percha from previously treated curved root canals: a microcomputed tomography study.

AIM: To compare the efficacy of hand and rotary nickel-titanium (NiTi) instruments in removing filling material from curved root canals of root filled teeth with unknown preparation parameters. METHODOLOGY: Ninety mandibular molars with root fillings in curved root canals and homogenous root canal filling extending to 0-2 mm short of the radiographic apex were selected. Root canal curvatures and radii were measured in two directions and microcomputed tomography (micro-CT) scans were used to determine preoperative volumes of the filling material. Subsequently, the teeth were assigned to two identical groups (n = 14). The root fillings were removed with Hedström files or FlexMaster NiTi rotary instruments. Postoperative micro-CT imaging was used to assess the percentage of residual filling material as well as the amount of dentine removal. Working time and procedural errors were recorded. Data were compared using analysis of covariance and analysis of variance procedures. RESULTS: Root canals retreated with Hedström files were associated with less remaining filling material compared with FlexMaster instruments (P < 0.05). Both retreatment techniques removed similar amounts of dentine with no significant differences (P > 0.05). FlexMaster instruments were significantly faster than Hedström files (P < 0.05). No procedural errors were detected in the Hedström group, whilst three instruments fractured in the FlexMaster group. CONCLUSIONS: Hand instrumentation resulted in significantly less residual filling material than retreatment with rotary NiTi instruments. Dentine removal was not significantly different for both techniques. FlexMaster NiTi rotary files were significantly faster than Hedström files, but were associated with a higher risk of instrument fracture.

Efficacy of reciprocating and rotary techniques for removing filling material during root canal retreatment.

AIM: To compare the efficacy of reciprocating and rotary techniques with that of hand files for removing gutta-percha and sealer from root canals. METHODOLOGY: The root canals of fifty-four human extracted maxillary central incisors were cleaned and shaped using a crown-down technique to a size 40 and filled with gutta-percha and a zinc oxide-eugenol-based sealer using a lateral compaction technique. Teeth were divided into three groups according to the technique used for removing the root filling material: group I - Gates-Glidden burs and stainless steel hand files up to size 50; group II - rotary technique with NiTi Mtwo R files and additional Mtwo files to size 50, 0.04 taper; group III - reciprocating technique with the Reciproc instrument R50, size 50, 0.05 taper. Chloroform was used as a solvent in all groups. Teeth were then split longitudinally and photographed under 8× magnification. The images were transferred to a computer, and the total canal space and remaining filling material were quantified. The ratio of remaining filling material to root canal periphery was computed with the aid of Image Tool 3.0 software. The mean percentages of remaining filling material and time required to remove it were compared using the Kruskal-Wallis and Mann-Whitney tests (P < 0.05). RESULTS: The mean percentage of remaining filling material was significantly higher (P < 0.05) in group II, with Mtwo rotary files (12.17%), than in group I, with the hand file technique (7.19%), and group III, with Reciproc instruments (4.57%), which were statistically similar (P > 0.05). The time required to remove filling material was significantly shorter (P < 0.05) in group III (194 s), followed by group II (365 s) and group I (725 s) (P < 0.05). CONCLUSION: Remaining endodontic filling material was observed on the canal walls of all teeth regardless of the technique used. Hand files combined with Gates-Glidden burs (group I) and the reciprocating technique (group III) removed more filling material from the canal walls than the Mtwo R files. The reciprocating technique was the most rapid method for removing gutta-percha and sealer, followed by the rotary technique and the hand file technique.

The composition of the essential oil from Cyperus distans rhizome.

The essential oil from the rhizomes of Cyperus distans L.f. obtained by hydrodistillation was analyzed by capillary GC and GC/MS techniques. Eight constituents were identified, representing 99.6% of the total oil. The major components of the oil were cyperene (47.6%), alpha-pinene (18.8%), 1,8-cineole (14.5%) and caryophyllene oxide (7.3%).

Effect of alkali and enzymatic pretreatments of Eucommia ulmoides leaves and barks on the extraction of gutta percha.

This paper exploited a novel method of single solvent recycling plus enzymatic pretreatment. Petroleum ether (60-90 degrees C) was an ideal solvent to extract Eucommia gum at high temperature (approximately 80 degrees C) and to precipitate the gum (flocculent) as the temperature of the solution fell to below 40 degrees C. The gutta percha was almost completely precipitated from solution as the temperature cooled down to below 0 degree C. After filtration and recovery of the precipitated gum, the filtrate, petroleum ether, was applied to an activated carbon column to remove dissolved impurities and reused for next gutta percha extraction. Because impurities were kept in solution, the precipitated gutta percha was highly pure. In an experiment of enzyme hydrolyzing the plant cell wall, cuticle layers on the surfaces of leaves prevented cellulase from approaching to and hydrolyzing the cellulose of the cell wall. NaOH (1%) at 70 degrees C efficiently degraded the cuticle layer, which greatly improved the enzymatic hydrolysis of cellulose within eucommia leaves. Gutta percha that was extracted from the alkali- and cellulase-treated leaves had a degree of polymerization as high as in the leaves, and the yield increased from 2.5% of milled leaves up to over 3.2%. The tensile strength of obtained gutta percha increased from 0.02 MPa of milled Eucommia leaves to 60.5 MPa, the breakage extensibility ranged from about 0 to 24%, and the tearing strength ranged from 0.5 to 36 kN/m.