青藏高原植物香芸火绒草挥发油的超临界CO2萃取及GC-MS分析

通过对高原植物香芸火绒草超临界CO2萃取的研究，获得了温度45℃、压力18MPa为其相对较佳提取条件，提取产物为黄绿色浸膏，得率为0．87％。将该浸膏精制成净油，其得率为60．2％。进一步通过气相色谱-质谱联用技术（GC—MS）对净油分析，鉴定出其中的15种化学成分，并通过峰面积归一法确定了它们的相对含量。挥发油成分主要为：邻苯二甲酸异辛酯、高良姜素黄烷酮、α-甜没药萜醇、橙花叔醇、胡萝卜醇、棕榈酸等。通过对香芸火绒草挥发油成分的研究，为高原特有植物资源的进一步开发利用提供了试验依据。     

Allelopathic potential of watermelon tissues and root exudates

Allelopathic potential of watermelon in hydroponic culture was investigated using the continuous root exudates trapping system (CRETS). Laboratory bioassays and high-performance liquid chromatography (HPLC) were used for quantification of phytotoxins in different plant tissues and root exudates collected using XAD-4 resin. Seedling growth of both watermelon and lettuce was significantly inhibited by watermelon root exudates and the degree of inhibition increased with increasing concentration of exudates. Root exudates had inhibitory effects throughout the experiment and these were most pronounced during the period 41–50 days after transplanting. Inhibitory effects of various plant tissues were demonstrated using the bioassay tests. Frulic acid was the dominant component found using HPLC and the amounts of allelochemicals found in the plant extracts were correlated with the bioassay results using the Petri dish test. The results indicate that the allelopathic potential of watermelon may play an important role in the phenomenon referred to as ‘soil sickness’.     

Concentrations of constitutive alk(en)ylresorcinols in peel of commercial mango varieties and resistance to postharvest anthracnose

Mature green mango fruits of commercially important varieties were screened to investigate the levels of constitutive antifungal compounds in peel and to assess anthracnose disease after inoculation with Colletotrichum gloeosporioides. High-pressure liquid chromatography was used to quantify the levels of 5-n-heptadecenylresorcinol and 5-n-pentadecylresorcinol in the peel extracts. The fruit peel of the varieties ‘Kensington Pride’ and ‘Keitt’ were observed to have the highest levels of both 5-n-heptadecenylresorcinol (107.3–123.7 and 49.9–61.4 μg/g FW, respectively) and 5-n-pentadecylresorcinol (6.32–7.99 and 3.30–6.05 μg/g FW, respectively), and the fruits of the two varieties were found to have some resistance to postharvest anthracnose. The varieties ‘Kent’, ‘R2E2’, ‘Nam Doc Mai’, ‘Calypso’ and ‘Honey Gold’ contained much lower concentrations of resorcinols in their peel and three of these varieties were found to be more susceptible to anthracnose. Concentrations of 5-n-heptadecenylresorcinol were significantly lower at the ‘sprung’ and ‘eating ripe’ stages of ripening compared to levels at harvest. Concentrations of 5-n-pentadecylresorcinol did not differ significantly across the three stages of ripening. The levels of these two resorcinols were found to be strongly inter-correlated (P<0.01, r²=0.71), with concentrations of 5-n-heptadecenylresorcinol being an average 18 times higher than those of 5-n-pentadecylresorcinol. At the ‘eating ripe’ stage, significant relationships were observed between the concentrations of each type of alk(en)ylresorcinol and anthracnose lesion areas following postharvest inoculation, P<0.001, r²= 0.69 for 5-n-pentadecylresorcinol, and P<0.001, r²= 0.44 for 5-n-heptadecenylresorcinol.     

常用国产阳离子季胺盐在蚕业消毒中的性能与应用

本文作了若干国产季胺盐对蚕业病原物的杀灭效果试验,并探讨了环境中的pH、温度,有机物,作用时间,无机离子,纤维物等对季胺盐药效的影响,及添加1％新鲜石灰后季胺盐的杀菌情况变化,认为季胺盐石灰浆在蚕业消毒中应该与漂白粉类互相补充,作为蚕业环境的常用消毒剂。文中还对季胺盐消毒效果测定中的若干问题进行了分析与讨论。     

Spontaneous postharvest fermentation of açai (Euterpe oleracea) fruit

Açai (Euterpe oleracea) fruit (EOF) are widely commercialized in the Brazilian Amazon. These fruit contain a high bacterial load and are transported on boards stowed inside or outside the holds of small boats. In this context, postharvest parameters were assessed under conditions that simulated these two methods of EOF transport: stowage in closed polystyrene boxes, simulating the inside of cargo holds, i.e., transport in a closed system; and open baskets, simulating transport in an open environment, i.e., transport in the prow or bow of the boat. EOF suffered spontaneous fermentation of alcoholic, acetic, and lactic types in the closed system, which is the most common type of transportation of this fruit. In the closed system, there was a predominance of lactic acid bacteria over acetic acid bacteria, with 82% and 95% of the initial content of d-glucose and d-fructose being consumed, respectively, after 27 h of experiment. The weight loss reached 1.7% and there was a logarithmic decrease of the major phenolic compounds of the fruit in the closed system, with losses of 78% of cyanidin-3-rutinoside, 88% of cyanidin-3-glucoside, 78% of homorientin, and 72% of orientin after 27 h, which was higher than in the open system (58%, 66%, 73% and 62%, respectively). Analyses on EOF stowed in a closed system indicated that the respiratory rate was characteristic of a non-climacteric fruit, i.e., it showed a logarithmic decay in the production of CO₂ (R² = 0.995; P < 0.05). Thus, transport in a closed system results in more drastic nutritional and functional changes on EOF than when transport is carried out in an open system, suggesting that transportation in continuous aerobic conditions and a short period of time between picking and processing are preferable.     

圆柏枝叶对小鼠自发行为及生理生化指标的影响

选择城市绿化重要树种圆柏为研究对象,探讨北美圆柏枝叶对小鼠自发活动及其生理生化指标的影响及挥发性物质与环境间的关系。采用旷场分析法,将入组的30只昆明小鼠分成3组:对照组、低剂量组和高剂量组,低剂量组和高剂量组分别对应地暴露于210 g和420 g圆柏枝叶中,每天4 h,连续处理6 d,观察小鼠各行为指标,结合医学手段分析小鼠相应的生理生化指标。结果表明,小鼠的中央格运动路程、总路程及中央格运动时间都呈现一定的剂量反应;体质量呈稳定增长趋势;生理指标正常,生化指标有部分超出正常范围。经低浓度枝叶挥发物处理的小鼠兴奋性增强,探究和认知能力增强,且其食欲没有受到影响,但是引起部分生化指标的异常,其作用机制还需进一步的探索。研究结果为圆柏作为生态保健树用于城市森林人居环境建设绿化配置提供科学依据。     

光肩星天牛对干旱胁迫下复叶槭挥发物的嗅觉反应

对干旱胁迫下3a生复叶槭的挥发物进行了鉴定。当复叶槭受到干旱胁迫时，9种化合物释放量升高(包括：丁醇、戊醇、反—2—己烯—1—醛、顺—3—己烯—1—醇、戊醛、戊酸、己醛、己酸、苯乙酮)，而长叶烯释放量降低：复叶槭复水后苯乙酮升高，但其他挥发物释放量降低。通过GC—EAD检测了光肩星天牛对其中某些化合物的触角电位反应，并使用诱捕器和人工合成单体进行了田间生测实验。丁醇、戊醇和顺—3—己烯—1—醇能引起光肩星天牛的触角反应，这一结果在田间实验中得到了证实。这表明干旱胁迫在光肩星天牛选择寄主植物方面起着重要作用。     

Composition of pyrolyzate from Japanese green tea

Green tea is a beverage that is produced by hot-water extraction of the leaves of tea (Camellia sinensis L.). As the amount of green tea consumption has increased, the importance of using the residue has grown. To address this problem, chemical compositions of two pyrolyzates obtained with an electric kiln, L and G, which were obtained from the tea leaf product and its hot-water extraction residue, respectively, were examined. Both pyrolyzates were alkaline, in contrast to the acidic pHs that are typical of pyrolyzates from wood materials. The major constituents were nitrogen-containing compounds, which accounted for up to about 70% (based on gas chromatography-mass spectrometry peak area). Caffeine was the main compound in both samples, although it might not be a pyrolysis product but actually sublimates from the samples and then condenses back into the pyrolyzates. Other nitrogen-containing compounds were formed mainly from proteins and amino acids. Acids and phenols, which are typical components in pyrolyzates obtained from wood materials and contribute to acidic pH, were rare in both samples. Other neutral compounds are known as compounds in pyrolyzates from wood materials. The pyrolyzates obtained in this experiment were novel and may have new uses.Contents of this report was presented in the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, 2002     

桉木抽出物中多酚化合物的特性研究

采用化学分析和光谱分析相结合的方法，从制浆造纸的角度，重点对雷林一号桉木的多酚化合物的特性进行了研究。结果表明：幼龄材的抽出物含量较少，适宜于制浆的采伐期为５～７年。１５年生雷林一号桉木心材中的多酚类化合物以水解单宁为主（占原料的５．９８％），其次为缩合单宁（１．９１％）。稀碱预处理桉木，可除去大部分多酚类化合物。存放过久的桉木中多酚化合物大部分变成‘黄粉’，既不溶于水也不溶于丙酮，只溶于稀碱或亚硫酸钠。桉木制浆前采用碱预处理可减轻多酚化合物对制浆产生的不良影响。     

大叶冬青叶抗肿瘤活性初步研究

用MTT法对大叶冬青叶不同提取物和挥发油抗肿瘤活性的测定表明,大叶冬青提取物具有一定的抗肿瘤活性.其中老叶乙醇提取物和鲜叶挥发油抗肿瘤活性最高,老叶乙醇提取物对胃癌细胞株SGC-7901的抑制率为62.40%,鲜叶挥发油对肺癌细胞株NCI-H460抑制率为93.33%.进一步实验表明大叶冬青挥发油对NCIH460(肺癌)细胞的IC50为42.86μg/mL.研究结果为大叶冬青叶保健、药用产品的开发提供了科学依据.