Mannich碱的合成及作为汽油抗爆剂的研究

以苯甲醛为原料通过两步缩合反应合成了苄叉丙酮Mannich碱,对其在汽油中的溶解性、防腐性及抗爆性进行研究。结果表明:苄叉酮型Mannich碱油溶性、抗爆性好,在汽油中对铜片无明显腐蚀。     

Phaseoloidin, a homogentisic acid glucoside from Nicotiana attenuata trichomes, contributes to the plant's resistance against lepidopteran herbivores

Plant trichomes are known for their capability to produce and store secondary metabolites that protect plants from biotic and abiotic stresses. ¹H NMR studies on intact individual trichomes located on the leaf surface of Nicotiana attenuata revealed the presence of two major secondary metabolites: nicotine, the signature metabolite of the genus, and phaseoloidin, a homogentisic acid glucoside. This glucoside was reported originally from the seeds of Entada phaseoloides, and this is the first report of its occurrence in a Solanaceous plant. Artificial diet feeding bioassays with Manduca sexta and Spodoptera littoralis larvae, two important herbivores of N. attenuata, revealed that the ingestion of phaseoloidin negatively influenced caterpillar performance. This effect was more pronounced for the generalist, S. littoralis, than for the specialists, M. sexta.     

Methyl jasmonate as an allelopathic agent: sagebrush inhibits germination of a neighboring tobacco,Nicotiana attenuata

Artemisia tridentata ssp. tridentata is the dominant and defining shrub in the Great Basin Desert, with well-documented allelopathic tendencies that have generally been ascribed to its most abundantly released secondary metabolites. However, as a minor component, sagebrush releases a highly biologically active substance, methyl jasmonate (MeJA), which is known to function as both a germination inhibitor and promoter in laboratory studies. Nicotiana attenuata is a tobacco species native to the Great Basin Desert and grows in newly burned juniper–sagebrush habitats for 2–3 yr following a fire. With a combination of field and laboratory studies, we examined the role of MeJA release from sagebrush by both air and water transport in inhibiting N. attenuata seed germination. We demonstrated that sagebrush interacts allelopathically with the seed bank of N. attenuata through its release of MeJA. In the field, seeds buried 0–40 cm from sagebrush plants for 4 months in net bags had significantly reduced germination compared to seeds buried similarly but protected in plastic bags. Moreover, germination on soils collected from underneath sagebrush plants was reduced by 60% compared to seeds placed on soils collected between sagebrush plants or outside of the sagebrush population. Exposure to A. tridentata seeds and seedlings did not affect N. attenuata germination, suggesting that established sagebrush plants only influence the tobacco's seed bank. In the laboratory, exposure of seeds to sagebrush emissions resulted in germination delays of up to 6 d. Exposure to volatile and aqueous MeJA also inhibited germination of N. attenuata seeds at quantities that are released naturally by sagebrush: 3.5 g/hr and 1.12 g/seed cup (56 ng/seed), respectively. A. tridentata seeds were significantly more resistant to MeJA, being inhibited at 336 g MeJA (16.8 g/seed), 300 times greater than the level of aqueous MeJA required to inhibit N. attenuata seeds. MeJA inhibited N. attenuata germination regardless of the seed's dormancy state and the specific epimer (trans- or cis-) of MeJA. Germination on sagebrush chaff that had been heated to reduce MeJA content was negatively correlated with the amount of MeJA remaining in the chaff. Germination of a nondormant, conspecific tobacco, N. trigonophylla, which grows in the same area but is not associated with fire, is less sensitive than N. attenuata to the extracts of sagebrush litter, but similarly sensitive to MeJA. Additionally, four of five other tobacco species that are not known to be associated with sagebrush are less sensitive to MeJA, suggesting an evolved sensitivity to MeJA. To determine the proportion of germination inhibition of a sagebrush extract that could be attributed to MeJA, we serially diluted sagebrush extracts with water and restored the quantity of MeJA of the original extract by adding appropriate quantities of synthetic MeJA; 16–60% of the inhibitory activity of the original extract could be attributed to the MeJA. We conclude that MeJA release from sagebrush plays an allelopathic role for N. attenuata seed banks, but other unidentified compounds are also involved.     

In vivo Volatile Emissions from Peanut Plants Induced by Simultaneous Fungal Infection and Insect Damage

Peanut plants, Arachis hypogaea, infected with white mold, Sclerotium rolfsii, emit a blend of organic compounds that differs both quantitatively and qualitatively from the blend emitted from plants damaged by beet armyworm (BAW; Spodoptera exigua) larvae or from uninfected, undamaged plants. Attack by BAW induced release of lipoxygenase products (hexenols, hexenals, and hexenyl esters), terpenoids, and indole. The plant-derived compound methyl salicylate and the fungal-derived compound 3-octanone were found only in headspace samples from white mold infected plants. White mold-infected plants exposed to BAW damage released all the volatiles emitted by healthy plants fed on by BAW in addition to those emitted in response to white mold infection alone. When BAW larvae were given a choice of feeding on leaves from healthy or white mold-infected plants, they consumed larger quantities of the leaves from infected plants. Exposure to commercially available (Z)-3 hexenyl acetate, linalool, and methyl salicylate, compounds emitted by white mold-infected plants, significantly reduced the growth of the white mold in solid-media cultures. Thus, emission of these compounds by infected plants may constitute a direct defense against this pathogen.     

由月桂烯合成香叶基丙酮的研究

以月桂烯为原料,与氯化氢反应生成香叶基氯及其同分异构体,产物与乙酰乙酸乙酯发生取代反应,经水解脱羧制得香叶基丙酮。月桂烯的加成反应是整个反应过程的关键步骤,对合成香叶基丙酮有决定性影响;重点探讨了催化剂种类及用量、反应温度及原料配比对月桂烯与氯化氢加成反应的影响。得到最适宜反应条件:以CuCl和四丁基溴化铵为催化剂,用量为月桂烯摩尔分数的1%,温度为10 ℃,n(月桂烯):n(氯化氢)=1:1。该条件下,氯化物的产率可达92.86%,且香叶基氯和橙花基氯占氯化物总量的75.71%。氯化物经取代反应,水解脱羧后得到香叶基丙酮,产率为76.62%。     

Floral Scent Contributes to Interaction Specificity in Coevolving Plants and Their Insect Pollinators

Chemical defenses, repellents, and attractants are important shapers of species interactions. Chemical attractants could contribute to the divergence of coevolving plant-insect interactions, if pollinators are especially responsive to signals from the local plant species. We experimentally investigated patterns of daily floral scent production in three Lithophragma species (Saxifragaceae) that are geographically isolated and tested how scent divergence affects attraction of their major pollinator—the floral parasitic moth Greya politella (Prodoxidae). These moths oviposit through the corolla while simultaneously pollinating the flower with pollen adhering to the abdomen. The complex and species-specific floral scent profiles were emitted in higher amounts during the day, when these day-flying moths are active. There was minimal divergence found in petal color, which is another potential floral attractant. Female moths responded most strongly to scent from their local host species in olfactometer bioassays, and were more likely to oviposit in, and thereby pollinate, their local host species in no-choice trials. The results suggest that floral scent is an important attractant in this interaction. Local specialization in the pollinator response to a highly specific plant chemistry, thus, has the potential to contribute importantly to patterns of interaction specificity among coevolving plants and highly specialized pollinators.     

以丙酮为原料的乙烯酮法制乙酰丙酮

乙酰丙酮是制备医药的中间体 ,同时作为催化剂在日本发展较快。由于生产技术等原因使得我国目前该产品在成本及质量上达不到国外进口产品水平 ,本文充分利用我国丰富的丙酮资源 ,开发了以丙酮为原料的乙烯酮法制乙酰丙酮工艺。     

利用野生淀粉资源——木薯、芭蕉芋发酵生产丙酮

提出了以木薯、芭蕉芋替代玉米作为生产丙酮的发酵原料 ,先后利用豆饼、玉米粉等 10余种辅料进行了实验 ,以改善木薯、芭蕉芋原料蛋白质不足[4 ] 。并通过实验筛选了适合木薯、芭蕉芋发酵的优良菌株。实验表明 ,以木薯、芭蕉芋为原料 ,只需添加少量辅料 ,利用筛选出的优良菌株发酵 ,结果可达到现有玉米发酵水平     

苯和甲醛在择形催化剂上合成苯甲醇和甲苄醚的新路线

研究了以苯和甲醛水溶液 (工业级 )为原料 ,在用P、B改性的中孔沸石HZSM 5催化剂上进行羟甲基化和醚化反应 ,在 2 0 0～ 2 10℃、常压、n(苯 )∶n(甲醛 ) =1 0∶2 6的优化工艺条件下 ,以w (P) =2 %的PZSM 5为催化剂 ,苯的转化率能达到 5 1 98% ,苯甲醇的选择性可达到 5 3 10 % .     

乙醇催化转化制丙酮的研究初报

以 Fe Cl3 制得的 Fe2 O3 / γ- Al2 O3 催化剂在 42 0～ 430℃气相条件下催化乙醇转化为丙酮 ,转化率可达5 4.5 % ,选择性为 86.8%。     

From Floral Induction to Blooming: The Molecular Mysteries of Flowering in Woody Plants

Flowering is a pivotal developmental process in response to the environment and determines the start of a new life cycle in plants. Woody plants usually possess a long juvenile nonflowering phase followed by an adult phase with repeated flowering cycles. The molecular mechanism underlying flowering regulation in woody plants is believed to be much more complex than that in annual herbs. In this review, we briefly describe the successive but distinct flowering processes in perennial trees, namely the vegetative phase change, the floral transition, floral organogenesis, and final blooming, and summarize in detail the most recent advances in understanding how woody plants regulate flowering through dynamic gene expression. Notably, the florigen gene FLOWERING LOCUS T(FT) and its antagonistic gene TERMINAL FLOWER 1 (TFL1) seem to play a central role in various flowering transition events. Flower development in different taxa requires interactions between floral homeotic genes together with AGL6 conferring floral organ identity. Finally, we illustrate the issues and corresponding measures of flowering regulation investigation. It is of great benefit to the future study of flowering in perennial trees.     

由氯化苄制备苯甲醛工艺的研究

采用环流反应器、以氯化苄和氯气为原料进行光氯化反应 ,制备苄叉二氯 ;将制得的苄叉二氯粗品进行真空精馏得到高纯度的精品 ;然后用一种新型醇胺类相转移催化剂 ,分别以盐酸和水作为介质 ,在 90～ 110℃水解后得到了高纯度的苯甲醛。考察了反应温度、通氯量对氯化苄转化率的影响 ,并对影响水解反应的温度、介质选择和介质用量进行了研究 ,确定了较适宜的工艺条件。     

钛修饰的锆基-金属有机框架材料催化苯甲硫醚制备苯甲砜

本文以UiO-66型Zr-MOFs为基础,通过后合成修饰的方法合成了UiO-66(Zr,Ti).以水为绿色溶剂,在相对温和的条件下,UiO-66(Zr,Ti)高效绿色催化双氧水分解,进而促使苯甲硫醚选择性氧化制备苯甲砜.研究发现,当原料苯甲硫醚用量为1mmol,最佳反应温度为60℃,反应时间为12h,UiO-66(Zr...     

Phytochemical and Biological Studies of Agave attenuata

The present study was conducted to examine various biological activities of a methanol extract of Agave attenuata leaves. GC-MS analysis of the n-hexane fraction from the extract revealed the presence of 31 compounds, with mono-2-ethylhexyl phthalate (11.37%), 1,2-benzenedicarboxylic acid (6.33%), n-docosane (6.30%) and eicosane (6.02%) as the major components. The leaves contained appreciable levels of total phenolic contents (10.541-39.35 GAE, mg/100 g) and total flavonoid contents (43.35-304.8 CE, mg/100 g). The extract and some of its fractions showed moderate antimicrobial effects. Leaves extract and fractions also exhibited a good antioxidant potential when measured by DPPH radical scavenging activity and inhibition of lipid peroxidation assays. The hemolytic effect of the plant was found to be in a range of 1.01%-2.64%. From the present study it is concluded that this plant could be used as a source of natural antioxidants and functional food nutraceutical applications.     

丙酮提取菠萝皮抑菌物的条件研究

采用正交试验法研究丙酮提取菠萝皮抑菌物质的工艺条件。实验结果表明,提取物对大肠杆菌、黑曲霉、金黄色葡萄球菌具有明显的抑制作用,对桔青霉则无抑制作用。对大肠杆菌和黑曲霉的抑菌效果最佳的提取工艺条件为：料液比1∶30,丙酮浓度75%,提取时间40 min,提取温度70℃。对金黄色葡萄球菌最佳的提取工艺条件为：料液比1∶10,丙酮浓度65%,提取时间40 min,提取温度50℃。在优化条件下,菠萝皮的丙酮提取物对大肠杆菌、黑曲霉、金黄色葡萄球菌的MIC分别为60、100、250mg·m L^-1。     

燃煤电厂超低排放改造前后汞污染排放特征

燃煤电厂在日常经营管理过程中,主要是通过燃煤的方式实现对电力的供应。但是这种方式,很有可能会对大气造成严重的污染,因此对燃煤电厂超低排放改造前后的汞污染情况进行分析,为大气环境提供良好的保护措施。