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1.
Heartwoods of 22 African tropical wood species were extracted with methanol and the contents of total phenolic compounds in these extracts were measured. Three bioassays were conducted to evaluate the antioxidant activity, tyrosinase inhibitory activity, and antifungal activity of the methanol extracts. The results indicated that the extracts from 13 species exhibited high antioxidant potential, and their inhibitory concentrations that caused 50% scavenging of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (IC50) were less than 10 μg/ml. The crude extract from Cylicodiscus gabunensis showed the highest antioxidant activity, and was even higher than that of (+)-catechin, which is known as a potent antioxidant. There was a good correlation between the antioxidant activity and the content of total phenolic compounds, indicating that phenolic compounds played a predominant role in the antioxidant property of the wood extracts. Among all 22 species, only 1 species, Milicia excelsa, contained extractives that showed very high tyrosinase inhibitory activity. The extracts from 9 species showed high antifungal activity. No consistent relationship was observed between the tyrosinase inhibitory activity or antifungal activity and the content of total phenolics in the extracts. Part of this article was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, August 2006  相似文献   

2.
Indonesian medicinal plants were screened as potential sources of antiacne agents. The screening methods were performed using antibacterial assay against Propionibacterium acnes, lipase inhibitor assay, and antioxidant assay. The results showed that from 40 plant materials extracted with methanol and 50% ethanol in water, Caesalpinia sappan was the best extract based on the combined activities: antibacterial (minimum inhibitory concentration 0.13 mg/ml; minimum bactericidal concentration 0.25 mg/ml), lipase inhibitory [50% inhibitory concentration (IC50) 120.0 μg/ml], and antioxidative (IC50 6.47 μg/ml). Another prospective extract is Intsia palembanica based on its lipase inhibitory activity (IC50 4.1 μg/ml) and antioxidant activity (IC50 3.87 μg/ml). Part of this report was presented at the 58th Annual Meeting of the Japan Wood Research Society, Tsukuba, March 2008  相似文献   

3.
An extract of Empetrum hermaphroditum Hagerup leaves was examined for germination inhibitors using an assay based on germination of Populus tremula L. seeds. The substances were extracted in water and purified by solvent partitioning. The acidic ethyl acetate fraction, containing the major part of the inhibitory activity was purified by reversed‐phase high‐performance liquid chromatography. Two zones of inhibitory activity were detected, combined and further purified by normal‐phase HPLC. One major zone of inhibitory activity was thereafter detected and the substance in this fraction was crystallized and identified by nuclear magnetic resonance and gas chromatography‐mass spectrometry as 5‐methoxy‐3,3´‐dihydroxy‐dihydrostilbene or batatasin III. Ca. 100 mg of the substance was then, by sequential HPLC, isolated in crystalline form from E. hermaphroditum leaves. The inhibitory activity of the pure substance was compared with a crude water extract of E. hermaphroditum leaves. It was concluded that the pure substance exhibited ca. 28 % of the inhibitory activity of the crude extract. The difference in inhibitory activity might be explained by the presence of a glucosidic conjugate of 5‐methoxy‐3,3´‐dihydroxy‐dihydrostilbene in the crude extract.  相似文献   

4.
In screening experiments for antiacne activity, methanolic and 50% ethanolic extracts of Caesalpinia sappan wood showed the most potent activity out of 28 species of plants extracts. These extracts showed inhibition of Propionibacterium acnes growth, lipase inhibitory activity, and antioxidant activity. In order to isolate the active compound from C. sappan, separation of the extract components was performed by column chromatography and preparative high-performance liquid chromatography (HPLC). Brazilin, protosappanin A, and sappanone B were isolated from methanolic extracts. Brazilin showed better antibacterial activity [minimum inhibitory concentration (MIC) = minimum bactericidal concentration (MBC) = 0.50 mg/ml] than protosappanin A (MIC = MBC = 1.00 mg/ml) and sappanone B (MIC = MBC > 2.00 mg/ml). The 50% inhibitory concentration (IC50) for lipase inhibition was lowest for brazilin (6 μM), which showed strong inhibition compared with protosappanin A (100 μM) and chloramphenicol (677 μM, positive control). The antioxidant activity of brazilin (IC50 8.8 μM) was not significantly different from protosappanin A (9.1 μM) and (+)-catechin (10.2 μM). The antioxidant activity of brazilin and protosappanin A were higher than sappanone B (IC50 14.5 μM). Brazilin is considered to have suffi ciently potent activity for use as an antiacne agent.  相似文献   

5.
The methanol (MeOH) extract of Populus ussuriensis Kom. bark was analyzed for antioxidant assessing by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging potential. Among fractions using several solvents, the ethyl acetate (EtOAc) soluble fraction, which showed strong antioxidant activity (IC50 2.02 ± 0.01 μg/ml), was further purified by Thin layer chromatography (TLC) guided Sephadex LH-20 column chromatography. Three known phenolic glucosides, picein (I), salicortin (II), grandidentatin (III), and that of a new, 2-hydroxycyclohexyl-4′-O-p-coumaroyl-β-d-glucopyranoside (isograndidentatin A), were isolated and their structures were elucidated on the basis of physiochemical and spectroscopic methods. This was the first report of the chemical composition of P. ussuriensis bark. Phenolic glucosides III and IV exhibited strong antioxidant activities, with IC50 values 6.73 ± 0.01 and 6.69 ± 0.01 μM, respectively, comparable to the control (α-tocopherol, IC50 6.80 ± 0.01 μM). P. ussuriensis bark EtOAc-soluble fraction and compounds III and IV could be used as biopreservatives in food applications as well as for cosmetic and medicinal preparations, to alleviate oxidative stress.  相似文献   

6.
Constituents of tars formed during the aging of bamboo (Phyllostachys pubescens), oak (Quercus serrata), and pine (Pinus densiflora) wood crude vinegars were analyzed by pyrolysis-gas chromatography (Py-GC) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) to investigate their origination. The pyrolysate of tars obtained from the wood and bamboo crude vinegars were almost identical and were primarily composed of phenolic compounds and aromatic hydrocarbons. In addition, during the aging of model wood vinegar that was prepared for comparison with the wood and bamboo vinegars, a marked decrease was observed in the levels of phenolic compounds (phenol; o-, p-, and m-cresol; and syringol). Furthermore, the Py-GC-MS results of the tars produced during the aging of the model wood vinegar revealed that phenolic compounds were primarily responsible for the formation of tar during the aging of wood and bamboo crude vinegars. Pyrroles, which may be derived from the primary pyrolysate of amino acids, nitrogen-containing extracts, or both, were also partially involved in the formation of tar during the aging period.  相似文献   

7.
The present study examined the chemical composition, in vitro antioxidant, anti-hyaluronidase and antifungal activities of essential oils of Melaleuca leucadendron Linn. from Gundih-Central Java, Indonesia in different plant ages of 5, 10 and 15 years old. The Chemical composition of essential oils were analyzed by GC/MS. Twenty-six components were identified, of which 1,8-cineole (49.22–55.04 %), α-terpineol (8.79–10.70 %), d-limonene (5.58–6.39 %), and β-caryophyllene (5.03–7.64 %) were the main compounds in these oils. The antioxidant assay and anti-hyaluronidase assay showed that M. leucadendron leaf oils possess mild antioxidant activity with IC50 between 7.21 and 9.23 mg/ml and anti-hyaluronidase activity with IC50 between 1.94 and 3.03 mg/ml. The antifungal assay showed the effectiveness of these essential oils against Fomitopsis palustris (IC50 0.12–3.16 mg/ml), Trametes versicolor (IC50 0.01–0.06 mg/ml), Cladosporium cladosporioides (IC50 0.03–0.49 mg/ml), and Chaetomium globosum (IC50 0.06–0.15 mg/ml).  相似文献   

8.
The effect of crude extracts (CEs) of virulent (V‐E4) and hypovirulent (H‐E13) Cryphonectria parasitica strains on growth and physiological activities of chestnut calli was investigated on cell cultures obtained from either a susceptible Castanea sativa or a resistant Castanea mollissima chestnut species. The V‐E4 CEs significantly reduced calli fresh weight in both species when used at 50 and 500 μg g–1 and, in general, showed an inhibitory effect on either O2 uptake and H+‐ATPase activity. Only the highest (500 μg g–1) concentration of H‐E13 CEs had a detrimental effect on callus growth, whereas the lowest one (5 μg g–1) induced a slight, but significant early increase in callus fresh weight of both genotypes. The O2 uptake and H+‐ATPase activity were enhanced by the presence of H‐E13 CEs. The decrease of callus growth and physiological activities, caused by V‐E4 CEs, was attributed to toxic compounds produced by the C. parasitica virulent strain, whereas the stimulatory effects of H‐E13 CEs on the overall callus metabolism seemed to be due either to the lack or very reduced amount of phytotoxic compounds and to growth‐regulating substances produced only by the hypovirulent strain of the fungus.  相似文献   

9.
Hiba (Thujopsis dolabrata) wood was treated with supercritical carbon dioxide (scCO2) at stepwise temperature increments from 50° to 400°C continuously so that extractives (dichloromethane-soluble and -insoluble phases) and solid residues were obtained. The yield of extractives from hiba wood increased with increasing extraction temperature. The volatile compounds in the dichloromethane-soluble phase from scCO2 extraction at 50°C contained only terpenoids. However, the volatile compounds in the dichloromethane-soluble phase from scCO2 extraction at 300°C not only contained terpenoids but also phenols, furans, hydrocarbons, and organic acids. The yield of β-thujaplicin, which is a useful compound in hiba wood, increased with increasing extraction temperature from 50°C to 300°C; the optimal conditions for extracting β-thujaplicin were 300°C and 19.61 MPa. Further study of degradated compounds from the cellulosic and lignic materials of hiba wood after stepwise high-temperature scCO2 treatment above 300°C may provide clues to its efficient use.  相似文献   

10.
The methanolic extract of the root of Garcinia multiflora and its derived soluble fractions, namely those soluble in ethyl acetate (EtOAc), n-butanol, and water, were screened for their antioxidant activities. Among them, the EtOAc-soluble fraction exhibited the highest scavenging activity against the 1,1-dipheny1,2-picrylhydrazyl radical, the highest superoxide radical scavenging activity, and the strongest reducing power. In addition, according to the bioactivity-guided isolation, 26 specific phytocompounds, including 3 aromatics, 3 benzophenones, 3 flavonoids, 3 isocoumarins, 1 phloroglucinol, 6 steroids, and 7 xanthones, were isolated from the EtOAc-soluble fraction and identified. Of these, 2,4,3′,4′-tetrahydroxy-6-methoxybenzophenone and 1,3,6,7-tetrahydroxyxanthone were found to be the major bioactive constituents, present in the crude extract in concentrations of 3.9 and 15.6 mg/g, respectively. These two compounds had similar antioxidant activities to (+)-catechin, a well-known antioxidant.  相似文献   

11.
In our investigation to find out new anti-acne agent, we focused on Terminalia laxiflora Engl & Diels (Combretaceae) methanolic wood extract, which has been selected during previous screening experiments for anti-acne agents, which included 29 species of Sudanese medicinal plants. Based on the biologically guided fractionation using an antibacterial assay against Propionibacterium acnes, a lipase inhibitory assay and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity assay; five tannin-related compounds were isolated, such as ellagic acid, flavogallonic acid dilactone, terchebulin and gallic acid. Terchebulin showed good antibacterial activity; minimum inhibitory concentration (MIC) = 125 μg/ml and minimum bactericidal concentration (MBC) = 250 μg/ml. Gallic acid exhibited lipase inhibitory activity with IC50 value of 149.3 μM, which showed strong inhibition compared with terchebulin, IC50 260.7 μM. However, all compounds exhibited better or equal DPPH radical scavenging activity to (+)-catechin as positive control. Ellagic acid and terchebulin showed the best DPPH radical scavenging activities, IC50 4.86 and 4.90 μM, respectively. This study demonstrated that terchebulin has potentiality as an anti-acne agent.  相似文献   

12.
Trembling aspen (Populus tremuloides Michx) bark was extracted with water and the crude extract fractionated with tert-butyl-methyl ether (TBME), ethyl acetate (EtOAc) and n-butanol (BuOH) to obtain four different fractions. The antioxidant properties of the bark hot water extracts and its fractions were determined by three in vitro experiments: DPPH assay, phosphomolybdenum assay and canola oil thermoxidation assay by DSC analysis. Most of the results of the reported tests showed that the crude hot water extract and its fractions exhibited a strong antioxidant activity, higher than the synthetic antioxidant BHT. The results of this study confirm that antioxidant activity is a property that strongly depends on the oxidation conditions used in the particular oxidation test. Among the fractions separated from the aqueous extracts of bark, BuOH, TBME and EtOAc soluble fractions exhibited the best antioxidant efficiency, in phosphomolybdenum assay, DPPH assay and canola oil thermoxidation, respectively. Total phenol, flavonoid and flavanol contents were also evaluated and the results confirmed that the polyphenols contained in the hot water extract of this bark are mainly composed of non-flavonoid compounds.  相似文献   

13.
The effects of physical properties of wood, including specific gravity, porosity, and water retention, on the water activity (a w) of wood meal media for the cultivation of edible mushrooms were examined. Five species of wood, selected from an initial set of 11 species, and six species of fungi popularly cultivated in Japan were used. The water activity of each fungal species was measured using liquid media in which a w had been reduced by adding NaCl, KCl, sucrose, or ethylene glycol. From the water activities of the media and fungi, we estimated the most suitable wood species for the cultivation of each edible mushroom in wood meal media. Suitable wood species for the wood meal cultivation of shiitake, nameko, and maitake, which had relatively high a w, was limited to hardwoods like arakashi, konara, and irohakaede because of their higher water activities. Edible mushrooms with lower levels of a w, like hiratake, enokitake, and bunashimeji, could be cultivated in all kinds of wood species used in this experiment, but especially in sugi.Parts of this report were presented at the 49th, 50th, 51st, and 52nd Annual Meetings of the Japan Wood Research Society, in Kyoto (April 2000), Tokyo (April 2001), Gifu (April 2002), and Fukuoka (March 2003), Japan  相似文献   

14.
Twenty plant materials collected from the islands of Java and Kalimantan in Indonesia were extracted with 50% aqueous ethanol (crude extract). The crude extracts were assayed for antimicrobial activities against Streptococcus sobrinus and for glucosyltransferase (GTase) inhibition. Fourteen extracts inhibited the growth of S. sobrinus by more than 50% and six extracts inhibited GTase activity by more than 50% at a concentration of 100 μg/ml. Koompassia malaccensis (kempas) extracts showed 90% depression of S. sobrinus growth and 80% inhibition of GTase activity at a concentration of 100 μg/ml. Kempas crude extracts were subjected to column chromatography using Sephadex LH-20 and then preparative high-performance liquid chromatography to isolate four compounds A, B, C, and D. These compounds were identified as taxifolin and the flavanonol rhamnoside isomers neoastilbin, astilbin, and isoastilbin, respectively, from 1H and 13C nuclear magnetic resonance (NMR) spectra and other two-dimensional NMR techniques (COSY, HMBC, and HMQC). Each compound depressed the growth of S. sobrinus over a concentration range of 9.3242.7 μg/ml and showed GTase inhibitory activity with IC50 values in the range 27.4–57.3 μg/ml. Taxifolin and flavanonol rhamnoside isomers isolated for the first time from kempas could be potent compounds for preventing dental caries. Part of this report was presented at the 57th Annual Meeting of the Japan Wood Research Society Conference, Hiroshima, 2007  相似文献   

15.
Identification and evaluation of antioxidant activities of bamboo extracts   总被引：2，自引：0，他引：2  
The antioxidant activity of solvent extracts from two main bamboo species, moso bamboo (Phyllostachys pubescens) and madake bamboo (P bambusoides) in Japan, was first evaluated by scavenging free radical of 1,1-diphenyl-2-picrylhydrazyl (DPPH), the inhibition activity for peroxidation of linoleic acid, and the reduction power. The methanol-extracts of moso bamboo culms and madake bamboo leaves presented stronger antioxidant activity compared with DPPH scavenging activity. Methanol-extract of moso bamboo culms was further fractionated by different solvents and n-butanol soluble fraction exhibited the most significant activity in the DPPH scavenging assay. The fractionation of n-butanol soluble extract was isolated by silica gel column with gradient mixture solvent of chloroform and methanol. The isolated fractions were directed by the antioxidant activity measured by scavenging the stable DPPH free radical. It was observed that most of the eluted fractions showed the antioxidative activity. Fractions acquired from elution with the mixture solvent of chloroform and methanol (10:1-5:1) showed stronger antioxidant activity than the other fractions.  相似文献   

16.
The phenolic composition of pine bark from a variety of Pinus species was estimated by measuring Klason lignin, acid-soluble lignin, and a 1% NaOH extract. Polyphenol contents of hot water extracts from pine bark were determined by the Folin-Ciocalteu assay and the vanillin-H2SO4 assay. Among the pine bark varieties investigated, Pinus radiata bark showed the highest polyphenol content and potent antioxidant activity. Pinus rigida bark was also a usable polyphenol-rich source, whereas Pinus densiflora bark had a low yield (5.1%) of hot water extract, although it showed potent antioxidant activity. Correlations between proanthocyanidin content in pine bark and antioxidant activity were observed. The results suggested that proanthocyanidin was the crucial contributor to potent antioxidant activity in pine bark. The publication of this article was made possible by an Emachu Research Fund. The authors are grateful for the fund.  相似文献   

17.
A method for screening wood extractives was developed using cellulose thin-layer chromatography plate (Cell-TLC) separation and was directly applied to bioassays. Wood meal (60 mesh) from nangka (Artocarpus heterophyllus Lamk) heartwood was extracted with hot methanol. The crude extract was separated using a Cell-TLC plate (50 × 50mm). Two broad bands with Rf values of 0.46 and 0.96 were found, and the bands showed completely different effects against the pest termite Coptotermes formosanus Shiraki and the decay fungus Fomitopsis palustris. The band with Rf 0.46 was preferentially consumed by workers of C. formosanus, and it did not show any growth inhibition against F. palustris when the Cell-TLC plate was directly exposed to the organism. In contrast, the band with Rf 0.96 appeared to repel strongly the feeding by C. formosanus and inhibited the growth of F. palustris. It was concluded that the Cell-TLC system was applicable for screening wood extracts consisting of many compounds.  相似文献   

18.
For reasons of unequal distribution of more than one nematode species in wood, and limited availability of wood samples required for the PCR‐based method for detecting pinewood nematodes in wood tissue of Pinus massoniana, a rapid staining‐assisted wood sampling method aiding PCR‐based detection of the pine wood nematode Bursaphelenchus xylophilus (Bx) in small wood samples of P. massoniana was developed in this study. This comprised a series of new techniques: sampling, mass estimations of nematodes using staining techniques, and lowest limit Bx nematode mass determination for PCR detection. The procedure was undertaken on three adjoining 5‐mg wood cross‐sections, of 0.5 × 0.5 × 0.015 cm dimension, that were cut from a wood sample of 0.5 × 0.5 × 0.5 cm initially, then the larger wood sample was stained by acid fuchsin, from which two 5‐mg wood cross‐sections (that adjoined the three 5‐mg wood cross‐sections, mentioned above) were cut. Nematode‐staining‐spots (NSSs) in each of the two stained sections were counted under a microscope at 100× magnification. If there were eight or more NSSs present, the adjoining three sections were used for PCR assays. The B. xylophilus– specific amplicon of 403 bp ( DQ855275 ) was generated by PCR assay from 100.00% of 5‐mg wood cross‐sections that contained more than eight Bx NSSs by the PCR assay. The entire sampling procedure took only 10 min indicating that it is suitable for the fast estimation of nematode numbers in the wood of P. massonina as the prelimary sample selections for other more expensive Bx‐detection methods such as PCR assay.  相似文献   

19.
Heartwood, sapwood, and inner and outer bark of Port Orford cedar were extracted with methanol, and the extracts evaluated for antioxidant activity. The total phenol content (TPC) of the extracts was determined by the Folin-Ciocalteu method and expressed as gallic acid equivalent (GAE). Butylated hydroxytoluene was used as a positive control in the free-radical-scavenging activity tests and ethylenediaminetetraacetic acid dihydrate disodium salt served as a positive control in the metal-chelating activity assay. All wood extracts showed significant freeradical-scavenging activity. In the radical-scavenging assay of 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (the ABTS assay), the inner bark extracts exhibited the strongest free-radical-scavenging activity. The 50% inhibitory concentrations (IC50) in the radical-scavenging assay against 1,1-diphenyl-2-picrylhydrazyl hydrate radical (DPPH) of the heartwood, sapwood, and inner and outer bark extracts were 64.77, 29.03, 10.31, 19.87 μg·ml−1, respectively. In the metal-chelating activity system, the sapwood extract demonstrated significant activity. The greatest TPC, 537.5 mg GAE/g dry extract, was detected in the inner bark. The lowest TPC of 136.9 mg GAE/g dry extract was observed in the heartwood dry extract. The results indicate that the antioxidant activities of the extracts are in accordance with the amounts of phenolics present; the inner and outer barks of Port Orford cedar are rich in phenolics and may provide good sources of antioxidants.  相似文献   

20.
Study aim was to investigate discoloration and associated fungi in 50‐ to 70‐year‐old stems of Betula pendula damaged by logging. Investigated wounds (on 70 stems) were inflicted 4–18 years previously, and all of them had discoloration with mean radial spread (±SD) 2.9 ± 2.9 cm and longitudinal spread 50.3 ± 24.0 cm. Both wound area and length had a strong impact on a total length of discoloration (r = 0.665 and r = 0.745, respectively; p < 0.001), but had no influence on its spread beyond wound margins (r = ?0.035 and r = ?0.079). There was no correlation between the age of an injury and spread of the discoloration neither in vertical (r = ?0.110) nor in radial (r = ?0.280) direction. Average wound closure rate was 1.2 ± 0.5 cm year ?1. The difference between discoloration length in stems with open and occluded injuries was insignificant (t‐test, p = 0.769). The principal fungi isolated from the wounds were ascomycetes (Epicoccum, Cadophora, Neonectria, Alternaria spp.) that were able to cause discoloration of wood with little effect on its mechanical properties and capable only for limited spread inside a stem of a living tree. In conclusion, results of the present study demonstrate that the amount of discoloured wood beyond logging wounds in B. pendula is mainly restricted to the damaged portion of a stem and that the associated loss of wood production remains low during about 10 years since the damage.  相似文献   

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