Rhus Succedanea Research Articles

Applied analysis of lacquer films based on pyrolysis-gas chromatography/mass spectrometry

Ancient lacquer film, a Nanban lacquer film, an old lacquer-ware object imported from an Asian country, and the Baroque and Rococo lacquer films were analyzed by pyrolysis-gas chromatography/mass spectrometry. Compared with the results of the natural lacquer film, it was revealed that the ancient lacquer film and Nanban lacquer film were made from Rhus vernicifera, and the old lacquer-ware imported from an Asian country was made from Melanorrhoea usitata. However, the Baroque and Rococo lacquer films obtained from the Doerner Institute in Munich, Germany were made from natural resins. 3-Pentadecylcatechol (MW = 320) (urushiol), 3-heptadecylcatechol (MW = 348) (laccol), and 4-heptadecylcatechol (MW = 348) (thitsiol) were the main products of the pyrolysis of R. vernicifera, Rhus succedanea, and M. usitata.

Free radical scavenging activity of aqueous extract of Rhus succedanea galls

Objective: To evaluate the free radical scavenging activity of aqueous extract of Rhus succedanea galls. Material and methods: Aqueous extract was prepared and free radical scavenging activity was studied using DPPH assay and nitric oxide scavenging assay. Result: Aqueous extract of R. succedanea galls showed remarkable and concentration dependent free radical scavenging activity comparable to that of standard ascorbic acid in the studied models. IC 50 was found to be 27.33μg and 32.63μg in DPPH assay and NO scavenging assay respectively. Conclusion: The present results indicate that aqueous extract of R. succedanea galls exhibit free radical scavenging activity.

Identification of Rhus succedanea L. Cultivars Using Elliptic Fourier Descriptors Based on Fruit Shape

Abstract We have developed a method to identify cultivars of Rhus succedanea L. based on their fruit contour shape. For this, we collected fruits of five cultivars from three different environments (differing in site and/or year of collection) and the horizontal contour shape of each fruit was expressed by 37 elliptic Fourier descriptors, normalized in terms of size, rotation, shift and starting point of contour tracing. The first six components derived from a principal component analysis of the elliptic Fourier descriptors explained 89% of the variance. The differences among cultivars, environments and the cultivar x environment interaction were significant at the 0.01% probability level for all six principal components according to ANOVA. UPGMA cluster analysis based on the six principal components showed a high degree of clustering and most (but not all) ramets from the same cultivar clustered together. However, results of a UPGMA cluster analysis of Mahalanobis’ generalized distances among cultivars and environments, based on the 37 elliptic Fourier descriptors, showed that samples from the same cultivars clustered together, regardless of the environmental factors. We then applied a ‘similarity probability’ test, based on Mahalanobis’ generalized distances and a randomization test. The similarity probabilities between descriptors in the database and sampled fruits, when the cultivars they represented were included in the database, were >97%. In contrast, for samples representing cultivars that were not included in the database, the probabilities were <46%. These figures also apply to pairs of samples included in the database that represented the same cultivar, and different cultivars, respectively. These results suggest that it is possible to identify R. succedanea cultivars based on fruit contour shape using elliptic Fourier descriptors and similarity probability analysis.

Anti-Bacterial activity of Rhus succedanea Galls

Objective : To evaluate the anti-bacterial activity of Rhus succedanea galls. Materials and methods : Aqueous extract was prepared and anti-bacterial activity was studied against five bacterial organisms by agar disc diffusion method. Results : Aqueous extract of Rhus succedanea galls exhibited significant anti-bacterial activity. Conclusion : The present results indicate the potential usefulness of aqueous extract of Rhus succedanea in the treatment of bacterial infections.

Antioxidative and cytotoxic compounds extracted from the sap of Rhus succedanea.

Two new antioxidative and cytotoxic compounds, 10'(Z),13'(E),15'(E)-heptadecatrienylhydroquinone (1) and 10'(Z),13'(E)-heptadecadienylhydroquinone (2), as well as the known 10'(Z)-heptadecenylhydroquinone (3), were isolated from an EtOH extract of the sap of Rhus succedanea. The structures were elucidated by spectral analyses. These compounds showed antioxidative and cytotoxic activities against five cancer cell lines.

Synthesis and Identification of Laccol Components from Rhus succedanea Lacquer Sap.

Three lacquer saps (Rhus vernicifera, Rhus succedanea and Melanorrhoea usitata lacquer saps) are used for a surface coating in Asia. We previously reported the identification of urushiol components in Rhus vernicifera lacquer sap (Japan, China and Korea). In this study, laccol components in Rhus succedanea lacquer sap (Vietnam and Taiwan) were synthesized by Wittig reaction of ylides derived from alkyl- and alkenylphosphonium iodides with aromatic parts such as 3-(10-oxo-1-decyl)catechol diacetate and 3-(10-oxo-1-decyl)phenol acetate, followed by removal of acetate groups. Identification of natural laccol components from Rhus succedanea lacquer saps was carried out by GC and GC/MS and comparison with synthesized laccol components. Stereostructures and constituent of all laccol components in Rhus succedanea lacquer sap were clarified. By quantitative analysis using GC, the most abundant component was 3-[(10Z, 13E, 15E)-10, 13, 15-heptadecatrienyl]catechol except for red lacquer sap, but the abundance of trienyl components was not higher than that in the Japanese lacquer sap such as Rhus vernicifera. The amount of monoenyl components were higher than in Japanese lacquer sap.

The plasma membrane strength of the root-tip cells and root phenolic compounds are correiated with Al tolerance in several common woody plants

Ten species including one cultivar of common woody plants, i.e., Picea abies Karst. (Norway spruce), Gleditsia triacanthos L. (honey locust), Robinia pseudoacacia L. (black locust), Populus tremuloides Michx. (quaking aspen), Eucalyptus viminalis Labill. (eucalyptus), Cryptomeria japonica (Japanese cedar), Camellia sinensis L., cv. Yabukita (tea), Rhus succedanea L. (sumac), Pinus densiflora (Japanese red pine), and Pinus thunbergii Parl., cv. Sanshu (Sanshu black pine), and 2 species of marker crop plants, i.e., Oryza sativa L., cv. Sasanishiki (rice) and Hordeum vulgare L., cv. Manriki (barley), were cultured for 38 d at pH 4.3 in full nutrient solutions under three different stress conditions; 1) high AI, low P and low pH (combined stress), 2) low P and low pH, and 3) control. Soluble ionic Al and P concentrations in the media were maintained at almost 55 and 7 µM, respectively. P. thunbergii cv. Sanshu, C. sinensis, G. triacanthos, R. pseudoacacia, P. abies, and C. japonica were more tolerant to the combined stress than Oryza sativa known to be one of the most tolerant crop plants. Al tolerance obtained after the short-term stress for 24 h in CaCl2 solution at pH 4.7 was positively correlated with that obtained after the long-term combined stress, suggesting that a short-term screening technique can be used for the estimation of tolerance in acid soils. Under the combined stress conditions, low P stress was not expressed in any plant parts, Al stress was expressed primarily in roots and low pH stress was highly expressed in shoots. The roots of the AI-tolerant plants contained a significantly lower amount of Al with a higher K accumulation ratio. The plasma membrane strength (PMS), corresponding to the intactness of the PM permeability of root-tip cells during the re-elongation period without Al after temporary treatment with AI, was correlated with Al tolerance. Positive correlation between low pH tolerance and Al tolerance at pH 4.7 without H+ toxicity in both short-term experiments suggested that the PM of the root-tip cells was a common target for both stresses. Al tolerance of woody plants was positively correlated with the concentration of soluble phenolic compounds in roots irrespective of the treatment, but not with exuded phenolic compounds. In contrast to acidic conditions, in vitro binding affinity to Al ions at pH 7.0 was significantly higher at equimolar concentrations of quercetin, catechin, and chlorogenic acid but lower in the case of rutin, citric, oxalic, and malic acids. To our knowledge, this is the first report in which phenolic compounds in roots were quantitatively related to Al tolerance in woody plants. It was eventually suggested that AI-tolerant woody plants constitutively adopted a dual strategy involving a superior PMS and a higher amount of root phenolic compounds which can bind strongly with and detoxify Al ions in the cytoplasm.

Antiviral activities of biflavonoids.

Biflavonoids such as amentoflavone (1), agathisflavone (2), robustaflavone (3), hinokiflavone (4), volkensiflavone (5), rhusflavanone (7), succedaneflavanone (9), all isolated from Rhus succedanea and Garcinia multiflora, as well as their methyl ethers and acetates, volkensiflavone hexamethyl ether (6), rhusflavanone hexaacetate (8), and succedaneflavanone hexaacetate (10) were evaluated for their antiviral activities. The inhibitory activities against a number of viruses including respiratory viruses (influenza A, influenza B, respiratory syncytial, parainfluenza type 3, adenovirus type 5, and measles) and herpes viruses (HSV-1, HSV-2, HCMV, and VZV) were investigated. The results indicated that robustaflavone exhibited strong inhibitory effects against influenza A and influenza B viruses with EC50 values of 2.0 micrograms/ml and 0.2 microgram/ml, respectively, and selectivity index values (SI) of 16 and 454, respectively. Amentoflavone and agathisflavone also demonstrated significant activity against influenza A and B viruses. Amentoflavone and robustaflavone exhibited moderate anti-HSV-1 anti-HSV-2 activities with EC50 values of 17.9 micrograms/ml (HSV-1) and 48.0 micrograms/ml (HSV-2) and SI values of > 5.6 (HSV-1) and > 2.1 (HSV-2) for amentoflavone; EC50 values of 8.6 micrograms/ml (HSV-1) and 8.5 micrograms/ml (HSV-2), and SI values of > 11.6 (HSV-1) and > 11.8 (HSV-2) for robustaflavone. Rhusflavanone demonstrated inhibitory activities against influenza B, measles, and HSV-2 viruses with SI values of 9.3, 8 and > 6.4, respectively. Succedaneaflavanone exhibited inhibitory activities against influenza B virus and VZV with SI values of 15 and < 3.0, respectively.

Total Synthesis of Robustaflavone, a Potential Anti-Hepatitis B Agent

Robustaflavone, a naturally occurring compound, is an inhibitor of hepatitis B virus replication in vitro. Robustaflavone is a biflavanoid composed of two units of apigenin (5,7,4‘-trihydroxyflavone) joined via a biaryl linkage between the 6-position of one unit and the 3‘-position of the other (I6,II3‘-biapigenin). The natural material was isolated from the seed-kernels of Rhus succedanea. To provide ready access to sufficient quantities of material for continued biological studies, as well as to provide a general route for the preparation of structural analogues, a total synthesis of robustaflavone was pursued. The total synthesis was approached by constructing apigenin ethers containing functionalities at the 6- and 3‘-positions which could be cross-coupled using transition metal catalysis. Key steps of the synthesis included development of a regioselective iodination of an apigenin derivative at the 6-position. Also key was the formation of an apigenin 3‘-boronate using a palladium-catalyzed exchange of the corresponding 3‘-iodide with a diboron reagent. Finally, identification of appropriate reaction conditions for Suzuki coupling to form the sterically congested 6−3‘‘‘ biaryl bond of robustaflavone provided access to the desired biflavanoid system. This work represents the first total synthesis of robustaflavone.

Robustaflavone, a potential non-nucleoside anti-hepatitis B agent

Robustaflavone, a naturally occurring biflavanoid isolated from Rhus succedanea, was found to be a potent inhibitor of hepatitis B virus (HBV) replication in 2.2.15 cells, with an effective concentration (EC 50) of 0.25 μM, and a selectivity index (SI, IC 50/EC 90) of 153. Robustaflavone hexaacetate inhibited HBV replication with an EC 50 of 0.73 μM, but exhibited no cytotoxicity at concentrations up to 1000 μM. Combinations of robustaflavone with penciclovir and lamivudine displayed synergistic anti-HBV activity, having the most pronounced effects when the combination ratios were similar to the ratio of EC 50 potencies. Thus, a 1:1 combination of robustaflavone and penciclovir exhibited an EC 50 of 0.11 μM and an SI of 684, while a 10:1 combination of robustaflavone and lamivudine exhibited an EC 50 of 0.054 μM and an SI of 894. Statistical analyses of the combination data using the Combostat® program confirmed that robustaflavone exhibited synergism with both penciclovir and lamivudine.

Recent advances in the discovery and development of flavonoids and their analogues as antitumor and anti-HIV agents.

Antitumor and anti-HIV flavonoids and their analogues will be reviewed with emphasis on those discovered in our laboratory. The active antitumor compounds include the antileukemic tricin (1) and kaempferol-3-O-beta-D-glucopyranoside (2) from Wikstroemia indica, the cytotoxic hinokiflavone (3) from Rhus succedanea, the cytotoxic isoflavone (8) from Amorpha fruticosa, two dihydroxypentamethoxyflavones (9, 10) from Polanisia dodencandra. The development of synthetic 2-phenyl-4-quinolones as potent cytotoxic antimitotic flavonoid analogues and 2-phenylthiochromen-4-ones as potent antitumor flavonoid analogues will be presented. Selected results from other laboratories and antitumor-related biological studies also will be discussed. Flavonoids have also been investigated as potential anti-HIV agents. In our laboratory, acacetin-7-O-beta-D-galactopyranoside (131) from Chrysanthemum morifolium and chrysin (102), as well as apigenin-7-O-beta-D-glucopyranoside (130), from Kummerowia striata, have been found to exhibit anti-HIV activity. In other studies, some flavonoids and related compounds have been investigated as inhibitors of HIV-1 reverse transcriptase, protease, and integrase. The isolation and structural modification of such plant-derived active principles provide a continuing source of potential antitumor and anti-HIV agents.

In vitro anti-HIV activity of biflavonoids isolated from Rhus succedanea and Garcinia multiflora.

Eleven biflavonoids, including amentoflavone (1), agathisflavone (2), robustaflavone (3), hinokiflavone (4), volkensiflavone (5), morelloflavone (7), rhusflavanone (9), succedaneaflavanone (10), GB-1a (11), GB-1a 7"-O-beta-glucoside (13), and GB-2a (14) isolated from Rhus succedanea and Garcinia multiflora, as well as their methyl ethers, volkensiflavone hexamethyl ether (6), morelloflavone heptamethyl ether (8), and GB-1a hexamethyl ether (12), were evaluated for their anti-HIV-1 RT activity. The results indicated that compounds 3 and 4 demonstrated similar activity against HIV-1 reverse transcriptase (RT), with IC50 values of 65 microM. Compounds 1, 2, 7, 11, and 14 were moderately active against HIV-1 RT, with IC50 values of 119 microM, 100 microM, 116 microM, 236 microM, and 170 microM, respectively. Morelloflavone (7) also demonstrated significant antiviral activity against HIV-1 (strain LAV-1) in phytohemagglutinin-stimulated primary human peripheral blood mononuclear cells at an EC50 value of 6.9 microM and a selectivity index value of approximately 10. The other biflavonoids were either weakly active, inactive, or not selective against HIV-1 in human lymphocytes.

Robustaflavone, a naturally occurring biflavanoid, is a potent non-nucleoside inhibitor of hepatitis B virus replication in vitro

Robustaflavone, a naturally occurring biflavanoid isolated from the seed kernel extract of Rhus succedanea, was found to be a potent in vitro inhibitor of hepatitis B, with an effective concentration (EC50) of 0.25 μM and an in vitro selectivity index (IC50EC90) of 153. Further studies suggested that inhibition of HBV DNA polymerase is the mechanism of action.

Characterization of Rhus vernicifera and Rhus succedanea lacquer films and their pyrolysis mechanisms studied using two-stage pyrolysis-gas chromatography/mass spectrometry

Rhus vernicifera and Rhus succedanea lacquers, which are used as a surface coating for wood, porcelain and metalware in Japan, were investigated using two-stage pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). Urushiol and laccol components were detected in each lacquer film by pyrolysis at 400 °C. These are the monomers, and are characteristic of Rhus vernicifera and Rhus succedanea lacquer films. In addition, alkenes, alkanes, alkenylphenols and alkylphenols were detected by pyrolysis at 500 °C after pyrolysis at 400 °C. Based on these results, the pyrolysis mechanisms of the respective lacquer films were considered. The pyrolysis products were from the urushiol and laccol polymers. These pyrolysis products clearly reflect the structure of each lacquer film.

Aroma Compounds from Aqueous Solution of Haze (Rhus succedanea) Honey Determined by Adsorptive Column Chromatography

Aroma concentrate separated from an aqueous solution of Haze honey by adsorptive column chromatography had a stronger aroma intensity than that separated by a combination of a preliminary extraction with acetone and separation of volatile compounds from acetone extract by steam distillation extraction. A total of 130 compounds were identified, including 27 alcohols, 19 aldehydes, 9 ketones, 12 esters, 8 acids, 35 hydrocarbons, 10 furanoids or pyranoids, and 10 miscellaneous compounds. The sensory importance of the volatile compounds was investigated by sniffing the fractions separated by preparative gas chromatography. As a result, benzeneacetaldehyde, linalool, phenethyl alcohol, p-cresol, p-anisaldehyde, methyl-p-anisaldehydes, trimethoxybenzene, 5-hydroxy-2-methyl-4H-pyran-4-one, and lilac aldehydes seemed to contribute to Haze honey aroma. Keywords: Aroma compounds; flavor components; honey; column concentration

Rhus succedanea peroxidase and its compounds I and II

In order to explore the process in which lacquer latex is oxidized and polymerized, peroxidase (RSP) was purified from Taiwanese lacquer ( Rhus succedanea) latex and characterized. The absorption and magnetic circular dichroism (MCD) spectra of ferric and ferrous peroxidase are quite similar to those of Chinese lacquer ( Rhus vernicifera) peroxidase (RVP), while spectral features of laccase contained in Taiwanese and Chinese lacquer are considerably different. Exogenous small ligands such as NO, CN −, and CO gave the MCD spectra characteristic to low-spin heme, indicating that these molecules can occupy an axial position. In addition, the electron spin resonance (ESR) spectra of NO-ferrous enzyme provided strong support for an imidazole group as the proximal (fifth) ligand. The treatment of native enzyme with H 2O 2 gave rise to compound I with a half-life of 10 min. Compound I was relatively stable (τ 1 2 = 10 min) but changed to compound II, giving the isosbestic points at 394 and 580 nm. This compound II returned to the resting state with a half-life of 165 min, giving the isosbestic point at 413 nm. The MCD spectra of compounds I and II were similar to those reported for horseradish peroxidase (HRP).

Litterfall in a secondary forest with special reference to the relationships between leaf‐fall rate, basal area and relative growth rate on a species basis

AbstractTotal basal area (BA), mean relative growth rate of individual basal area (RGRbam), annual leaf‐fall rate (L), and number of trees (N) on a species basis were measured in a secondary forest mixed with evergreen and deciduous trees in the warm‐temperate zone of Japan. Every species had a characteristic tree size and composed the tree and the shrub layers. The layer for each species, and the tree size of the species were represented by the species mean basal area per tree (BA/N or bam). A power form equation was obtained for the relation between the species mean leaf‐fall rate per tree (L/N or lm) and bam. RGRbam was correlated with leaf‐fall rate per unit basal area (L/BA) rather than with bam. This suggested that RGRbam is associated less with mean tree size (bam) and dominance as total basal area (BA), and more with annual leaf production per unit basal area, provided that L is equal to the annual leaf production per species. Rhus succedanea, the most dominant species in the forest plot, was typical in that it showed lower values of RGRbam and L/BA than other tree species. This would suggest a decline of R. succedanea in a secondary forest.

Hinokiflavone, a Cytotoxic Principle fromRhus succedaneaand the Cytotoxicity of the Related Biflavonoids1

Hinokiflavone (1) was isolated as the cytotoxic principle from the drupes of Rhus succedanea L. A comparison of the cytotoxicity of 1 and other related biflavonoids, including amentoflavone (2), robustaflavone (3), agathisflavone (4), rhusflavone (5), rhusflavanone (6) and its hexaacetate (7), succedaneaflavanone (8) and its hexaacetate (9), cupressuflavone (10), neorhusflavanone (11), volkensiflavone (12) and its hexamethyl ether (13), spicataside (14) and its nonaacetate (15), morelloflavone (16) and its heptaacetate (17) and heptamethyl ether (18), GB-1a (19) and its hexamethyl ether (20) and 7"-O-beta-glucoside (21), and GB-2a (22), indicates that an ether linkage between two units of apigenin as seen in 1 is structurally required for significant cytotoxicity. Compounds 13 and 20 also demonstrated significant cytotoxicity.

Smodingium allergenic Anacardiaceae in South Africa

The first case reports of genuine poison ivy dermatitis in South Africa appeared in 1959.1 Eight patients were seen who had developed the rash following contact with a creeper in a hedge in Olifantsfontein near Pretoria. The creeper was identified as Toxicodendron radicans and had presumably been imported from North America, since it is not indigenous to South Africa. Similar cases have been seen since then in Johannesburg.2In 1963, seven patients from Pretoria and Johannesburg with a unique dermatitis of “poison-ivy type” were reported.3 These patients had not been exposed to imported American poison ivy but had reacted to an indigenous plant identified as Smodingium argutum, known by various common names, including tovana and rainbow leaf. It transpired that Smodingium dermatitis had been recognized by tribal blacks, foresters, botanists, horticulturists, and amateur gardeners for many years before the medical profession became aware of it. In subsequent years, this type of dermatitis became widely recognized and many more cases were seen, leading to further case studies2 and investigations.4,5In 1971. four South African patients were reported with a similar type of “poison ivy” dermatitis who had been exposed to the wax tree, Toxicodendron succedanea, an oriental sumac.2 It became clear from cross-sensitivity reactions in certain patients that there were antigenic similarities between the oleoresins from S. argutum, T. radicans and T. succedanea, all members of the family Anacardiaceae.2 An identical dermatitis is produced by all three plants.

The effect of pH on the oxygen intermediate and the dioxygen reducing site in blue oxidases

A new method for the preparation of laccase (monophenol, dihydroxyphenylalanine:oxygen oxidoreductase, EC 1.14.18.1) from acetone powder from the latex of the Vietnamese lacquer tree Rhus succedanea is described. The spectral and catalytic properties resemble more those of the fungal laccase from Polyporus versicolor than those of the lacquer tree enzyme from Rhus vernicifera. Laccase from R. succedanea and human ceruloplasmin form similar types of oxygen intermediates, shown by EPR, as the laccases from R. vernicifera and P. versicolor. The oxygen intermediate formed in the reoxidation of anaerobically-reduced R. vernicifera laccase shows pH-dependent characteristics, suggesting the presence of at least one protonable group in the dioxygen reducing site. At pH 7.4 a broad line is formed which at pH 4.0 becomes much more narrow and rather similar to that obtained from P. versicolor. Protons can exchange rapidly with the oxygen intermediate or its near surroundings as shown by the fast change in line shape of the intermediate EPR signal, when pH is rapidly dropped from 7.4 to 4.0 or increased from 4.0 to 7.4. The decay of the oxygen intermediate in R. vernicifera laccase is pH dependent with a t 1 2 = 13 s at pH 7.4 and a t 1 2 = 1 s at pH 4.0. With R. succedanea and P. versicolor laccase the decay of the oxygen intermediates has a t 1 2 = 1 s at pH 5.5. There is a linear correlation between the decrease of the oxygen intermediate and the reoxidation of the Type 2 copper. This suggests that the oxygen intermediate can accept only one electron and water is formed.