防治木材变色的植物精油优选

为了开发木材变色防治用的天然环保产品,选用19种植物精油,依据精油的挥发速率及其对培养基中变色菌的抑菌效力,筛选综合性能较优的精油产品。结果表明,植物精油的挥发速率为7.9~550.8g·m^-2·h^-1,迷迭香和丝柏精油挥发较快,而雪松、肉桂和安息香精油挥发较慢。随着植物精油的体积分数由0.01%提高至0.05%,其对可可球二孢和串珠镰刀菌的平均抑菌效力分别由19%和21%增加至50%和59%,抑菌性能明显增强。以抑菌效力为变量的聚类分析表明,肉桂、丁香花、柠檬草和百里香4种植物精油对两种变色菌表现出较优的抑菌特性,其在体积分数0.05%条件下的抑菌效力达到100%。综合考虑抑菌效力和作用持久性,肉桂、丁香花和柠檬草精油是防治可可球二孢和串珠镰刀菌的较优品种。     

植物精油对木材霉变菌的抑菌效力研究

【目的】植物精油是一类安全环保且具有抑菌特性的天然产物,在木材霉变防治领域的应用潜力很大。开展植物精油对我国常见木材霉菌及变色菌的综合抑菌效力的研究,可为天然环保型木材霉变防治剂的开发提供重要依据。【方法】配制经植物精油修正的马铃薯葡萄糖琼脂培养基,通过评价霉变菌在培养基中的生长状况,对比分析19种植物精油对6种木材霉变菌的抑菌效力。【结果】在体积分数为0.05%的条件下,19种植物精油对黑曲霉Aspergillus niger、桔青霉Penicillam citrinum、绿色木霉Trichoderma viride、可可球二孢Botryodiplodia theobromae、串珠镰刀菌Fusarium moniliforme和链格孢霉Alternaria alternata的抑菌效力分别为0~100%、0~100%、0~100%、0~100%、11%~100%和20%~100%。聚类分析表明,肉桂、丁香花和百里香精油的综合抑菌效力最高,在体积分数0.05%的条件下对6种霉变菌的抑菌效力均达到100%,而尤加利、甜橙和松树精油的综合抑菌效力最低。相关分析表明,植物精油对6种霉变菌的抑菌效力之间均表现出显著相关性(P=0.01),其Pearson相关系数为0.777~0.959。【结论】不同植物精油的抑菌效力之间表现出较大差异,肉桂、丁香花和百里香精油是可以用于木材霉变防治的较优品种。     

侧柏心材活性成分的提取及其抑菌性能

研究侧柏心材不同部位及正己烷和二氯甲烷依次提取的心材活性成分对白腐菌、褐腐菌、黑曲霉菌的抑菌作用,并采用GC/MS联用技术对提取物中的活性成分进行鉴定和分析.结果表明:侧柏心材从髓心向边材根据年轮所划分的3个部位对3种真菌都具有较好的抑菌效果,并且靠近边材的2部分抑菌效果更明显些.气质联机技术对正己烷和二氯甲烷提取物分析鉴定表明:侧柏心材正己烷提取物中有14种化合物,大部分化合物属于萜烯类物质及其衍生物,最高含量化合物为罗汉柏烯(25.564%)和雪松醇(19.743%);侧柏心材二氯甲烷提取物中鉴定出24种化合物,最高含量化合物也为罗汉柏烯(15.429%).侧柏心材正己烷提取物对褐腐菌、白腐菌和黑曲霉菌第14 d时的抑菌圈直径分别为10.0,9.3和8.3 mm,大于二氯甲烷提取物抑菌圈直径(0,2.7和1.3mm),表明正己烷提取物对3种真菌的抑制生长作用明显优于二氯甲烷提取物的抑菌作用.     

Antibacterial and antifungal activity of Erigeron breviscapus

The antibacterial and antifungal properties of the ethanol extract of Erigeron breviscapus whole plant was evaluated. The extract showed a moderate antibacterial activity and a high antifungal activity.     

In vitro antifungal activities of longan (Dimocarpus longan Lour.) seed extract

Longan, Dimocarpus longan Lour., contains polyphenolic compounds which exhibit several pharmacological properties. This study aims to evaluate antifungal activities of longan fruit extract in comparison to its active compounds. The results showed that longan seed exhibited antifungal activity against the opportunistic yeasts (Candida species and Cryptococcus neoformans). In contrast, longan pulp and whole fruit did not demonstrate any inhibitory effects. Ellagic acid showed the most potent antifungal activity followed by corilagin and gallic acid, respectively. Ellagic acid inhibited Candida parapsilosis and C. neoformans more effectively than Candida krusei and also some Candida albicans clinical strains. Baidam cultivar possessed higher antifungal activity (MIC=500-4000 μg/ml) as it contained higher contents of ellagic acid and gallic acid than Edor (MIC=1000-8000 μg/ml). For antibacterial activity, only corilagin and gallic acid possessed weak to moderate inhibitory effects against Staphylococcus aureus and Streptococcus mutans, respectively. Longan seed was then applied in the oral care products. Longan effervescent granule (5% extract) significantly reduced adhesion of C. albicans to acrylic strips. Mouthwash containing 0.5% extract exhibited good antifungal activity compared to a commercial product. These findings indicated that longan seed extract and its polyphenolic compounds can be used as an antifungal agent in oral care products for the treatment of opportunistic yeast infection.     

Sensitivity of fungi isolated from onychomycosis to Eugenia cariophyllata essential oil and eugenol

The antifungal activity of Eugenia cariophyllata essential oil and eugenol, its major constituent, on fungal strains isolated from onychomycosis was evaluated. The natural products presented prominent antifungal action with MIC of 1% and 4%, respectively.     

Antifungal activity of Piper guineense of Cameroon

The antifungal activity of the ethanol extract of the seeds of Piper guineense and some of its fractions obtained by column chromatography was investigated using filamentous fungi and yeasts. The results indicated a significant antifungal effect. No toxic effect was observed in mice treated per os with the extract.     

Antifungal activities of the leaves of three Pistacia species grown in Turkey

The crude extracts obtained from the leaves of Pistacia vera, Pistacia terebinthus and Pistacia lentiscus were tested for antifungal activities against three pathogenic agricultural fungi, Phythium ultimum, Rhizoctania solani and Fusarium sambucinum. The extracts significantly inhibited the growth of P. ultimum and R. solani. However, the antifungal activity was not observed against F. sambucinum.     

Antifungal constituent from Gordonia dassanayakei.

The hexane extract of the stem bark of Gordonia dassanayakei showed high antifungal activity against plant pathogenic fungi Curvularia sp., Colletotrichum gloeosporioides, Rhizoctonia solani, Corynespora cassiicola, and Fusarium sp. A compound responsible for the antifungal activity was isolated and identified as 3-formyl-2,4-dihydroxy-6-methylbenzoic acid 3-hydroxy-4-(methoxycarbonyl)-2,5-dimethylphenyl ester (1).     

Synthesis of N-substituted dimethylmaleimides and their antifungal activities against Sclerotinia sclerotiorum

Compounds with maleimide, both natural and synthesized, have good biological activities, especially the antifungal activity. In order to investigate the antifungal activity of dimethylmaleimides, 17 N-substituted dimethylmaleimides were prepared from the reactions of 2,3-dimethyl maleic anhydride and amines using a facile synthetic method in this paper. These compounds were evaluated for antifungal activities against Sclerotinia sclerotiorum by the mycelium growth rate method. They exhibited minimum inhibitory concentrations (MICs) ranging from 0.01–50.0 μg/mL, with N-(2-benzimidazole)-3,4-dimethylmaleimide being the most active one with an MIC of 0.01 μg/mL. The structure and activity relationship on these compounds indicated that the hydrophobicity of the N-substituents is associated with their antifungal activity. Compared to current antifungals, most of N-substituted dimethylmaleimides have a perfect activity for S. sclerotiorum control and low toxicity.     

天然防腐剂在果蔬保鲜涂料中的应用

采用适当的方法从中草药中提取有效成分，并将其与被膜剂复合。针对各种常见水果病菌，采用平板抑菌试验筛选出５种具有显著抑菌能力的药种，进而用最低抑制发育浓度试验比较了各药种对不同病菌的抑制作用，为天然防腐剂在果蔬保鲜涂料中应用提供了依据。     

Antibacterial and antifungal activity of Indonesian ethnomedical plants

Methylene chloride and methanol extracts of 20 Indonesian plants with ethnomedical uses have been assessed for in vitro antibacterial and antifungal properties by disk diffusion method. Extracts of the six plants: Terminalia catappa, Swietenia mahagoni Jacq., Phyllanthus acuminatus, Ipomoea spp., Tylophora asthmatica and Hyptis brevipes demonstrated high activity in this bioassay system. These findings should stimulate the search for novel, natural product such as new antibacterial and antifungal agents.     

超声-抗菌石蜡处理对竹材防霉性能的影响

为增强竹材的防霉性能,以毛竹作为研究材料,先对竹材进行超声预处理,制备了抗菌石蜡乳液对竹材进行浸渍改性处理,并对改性后竹材的含水率、吸水率、防水效率和防霉性能进行了测试。选用天然植物中的2-羟基-1,4萘醌作为防霉剂,选用司班80(Span80)和吐温80(Tween80)作为58号食品级石蜡的复配乳化剂,考虑了亲水亲油平衡(HLB)值对石蜡乳化的影响,制得稳定的抗菌石蜡乳液。利用抗菌石蜡乳液对超声处理后的竹片进行浸渍处理,采用L₉(3³)正交试验设计,以石蜡乳液固含量、干燥温度和干燥时间为因子,以含水率和浸泡768 h后的防水效率为测试指标。结果表明,当Span80和Tween80的质量比为2∶3、HLB值为10.72时,石蜡乳液的稳定性最好。对改性后竹材含水率的影响从大到小依次是石蜡乳液固含量、干燥温度、干燥时间。当石蜡乳液固含量为5%、干燥温度为70℃、干燥时间为1.5 h时,试件含水率最低为4.11%。浸泡768 h后对竹材防水效率影响从大到小依次是干燥温度、石蜡乳液固含量、干燥时间;当石蜡乳液固含量为15%、干燥温度为40℃、干燥时间为1.5 h时,试件防水效率最高为32.15%。超声处理并不能有效阻止竹材的霉变,超声联合抗菌石蜡乳液改性后的竹材防霉性能有明显提高,改性竹材在28 d霉变试验后表面无菌丝、霉点。     

洋葱伯克霍尔德菌C23抗真菌活性多肽的分离纯化

为了深入研究洋葱伯克霍尔德菌C23(Burkholderia cepacia C23)菌株产生的抗真菌活性物质,以立枯丝核菌(Rhizoctonia solani)为指示菌进行生物活性跟踪,采用有机沉淀法、超滤法、Sephadex G25分子凝胶过滤法对活性物质进行分离纯化。结果表明,洋葱伯克霍尔德菌C23菌株产生的抗真菌活性物质为分子量5 000～10 000 Da的多肽类物质;建立了用超滤、分子凝胶过滤快速有效分离纯化伯克霍尔德菌C23菌株活性多肽的技术方法,为进一步制备单一的活性多肽成分奠定了基础。     

Analysis of compounds in dichloromethane extractives for Sawara Falsecypress （Chamaecyparis pisifera） outer heartwood

The chemical components of dichloromethane extractives for Sawara Falsecypress heartwood were analyzed with GC/MS except for basic chemical composition analysis for heartwood with Chinese standard method. 14 kinds of compounds were idenfifjed according to the computer compounds library data. The major compounds in dichloromethane extractives comprised of terpene and naphthalene derivafives. The experiments of antifungal effects of the dichloromethane extractive on Aspergillus niger were also carded out. The result showed that the dichloromethane extractive from Sawara Falsecypress has no or weak antifungal capability.     

Antifungal agents from heartwood extract of <Emphasis Type="Italic">Taiwania cryptomerioides</Emphasis> against brown root rot fungus <Emphasis Type="Italic">Phellinus noxius</Emphasis>

Taiwania (Taiwania cryptomerioides Hayata) is a native and plantation species in Taiwan, and its heartwood has demonstrated excellent decay resistance. Brown root rot fungus Phellinus noxius has caused severe damage to more than 100 tree species in Taiwan. The aims of this study were to investigate the antifungal activities of Taiwania heartwood extracts against P. noxius and to identify the antifungal compounds. Antifungal activities were examined using the agar dilution method (a direct contact assay) and the inverted lid method (a vapor contact assay). Active compounds were purified using liquid–liquid partition, open-column chromatography and HPLC. Among four soluble fractions (n-hexane, ethyl acetate, n-butanol and water soluble fractions), results showed that n-hexane soluble fraction (HSF) can significantly inhibit the growth of P. noxius via the agar dilution method. Moreover, active compounds present in HSF were obtained using antifungal assay-guided fractionation. Results showed that ferruginol, T-cadinol, α-cadinol and T-muurolol were found to exhibit excellent antifungal activities against P. noxius, and their IC₅₀ values were 16.9, 25.8, 33.8 and 50.6 μg/mL, respectively. According to the current findings, phytochemicals (ferruginol, T-cadinol, α-cadinol and T-muurolol) of Taiwania heartwood had the potential to be used as environmentally benign antifungal agents against P. noxius in place of synthetic or inorganic fungicides.     

Antifungal activity of Agapanthus africanus extractives

The ethanolic extract of the rhizomes of Agapanthus africanus showed antifungal activity. In bioassay guided fractionation, n-butanol fraction exhibited significant activity against human pathogens. A saponin, (25R)-spirost-7-en-2alpha,3beta,5alpha-triol-3-O-[alpha-L-rhamnopyranosyl(1-->2)-[beta-D-galactopyranosyl (1-->3)] beta-D-glucopyranoside (1), responsible for the antifungal activity and having MIC value of 15.6 microg/ml against Trychophyton mentagrophytes and Sporothrix schenekii, was isolated and identified as active constituent of the plant.     

山苍子油活性成分对木材真菌的抑制作用

为筛选出新的对绵腐卧孔菌、绿色木霉和彩绒革盖菌3种常见木材真菌有效的杀菌剂,采用菌丝生长速率法,测定了山苍子油主成分及其衍生物共10种化合物对这3种常见木材真菌的抑制率,建立毒力方程并分析其活性。结果表明:10种化合物对3种常见木材真菌的生长均表现出一定的抑制作用,而且随着浓度的升高,抑制作用增强;通过10种化合物对3种常见木材真菌的毒力回归分析,并与三唑酮相比较,依次筛选出对绵腐卧孔菌、绿色木霉和彩绒革盖菌的抑制作用最强的分别为柠檬醛1,2-丙二醇缩醛、β-紫罗兰酮和鸢尾酮,其半数有效抑制质量浓度(EC50)依次分别为18.69、23.50和32.21 mg/L。3种真菌分别经柠檬醛1,2-丙二醇缩醛、β-紫罗兰酮和鸢尾酮处理后,菌体细胞膜的相对渗透率发生变化,表明山苍子油活性成分的木材防腐作用与菌体细胞膜遭破坏有关。     

解淀粉芽孢杆菌TF28抗菌粗蛋白的初步研究

解淀粉芽孢杆菌TF28是从大豆根部分离得到的一株具有广谱高效拮抗作用的内生细菌,其发酵上清液经20％～40％硫酸铵盐析后获得抗菌粗蛋白。为明确该粗蛋白的理化性质,研究了温度、pH值、UV照射和蛋白酶对其稳定性的影响。结果表明：该粗蛋白具有一定的热稳定性,100℃处理30rain后抑茵活性仍为原有抑菌活性的85．9％;且在较广pH（3～11）范围内比较稳定,活性均能保持在95％以上;对紫外线、胰蛋白酶不敏感,对蛋白酶K具有一定的耐受性。初步研究了抗茵粗蛋白的抑菌作用,结果显示,对所测定的12种病原真菌均有抑制作用,其中对大豆根腐病菌和水稻恶苗病菌的抑制作用尤为明显。其对水稻恶苗病菌病原茵孢子的萌发起到抑制作用,有效抑制中浓度（EC50）为138．32μg／mL。此外,该抗茵粗蛋白能破坏病原茵菌丝结构导致畸形。     

Antimicrobial activity of Ximenia americana

Extracts of the bark, leaves, root and stem of Ximenia americana were tested for their antimicrobial and antifungal activity.