Malonylated Glycerolipids from the Glandular Trichome Exudate of Ceratotheca triloba

Chemical investigation of the glandular trichome exudate from Ceratotheca triloba (Pedaliaceae) led to the identification of nine 1-O-acetyl-2-O-[(R)-3-acetyloxy-fatty acyl]-3-O-malonylglycerols. Among these, 1-O-acetyl-2-O-[(R)-3-acetyloxyicosanoyl]-3-O-malonylglycerol (7) was the most abundant constituent (41%), followed by 1-O-acetyl-2-O-[(R)-(3-acetyloxyoctadecanoyl)-3-O-malonylglycerol (2; 21%). Compounds having iso- and anteiso-type structures in the 3-acetyloxy-fatty acyl groups in the fatty acyl moiety were also characterized as minor constituents. This is the first report of the isolation of malonylated glycerolipids as natural products.     

Peroxyl Radical Scavenging Activity of Caffeic Acid and Its Related Phenolic Compounds in Solution

The esterase gene (est) of Pseudomonas putida MR-2068 was cloned into Escherichia coli JM109. An 8-kb inserted DNA directed synthesis of an esterase in E. coli. The esterase gene was in a 1.1-kb PstI-ClaI fragment within the insert DNA. The complete nucleotides of the DNA fragment containing the esterase gene were sequenced and found to include a single open reading frame of 828 bp coding for a protein of 276 amino acid residues. The open reading frame was confirmed by N-terminal amino acid sequence analysis of the purified esterase. A potential Shine-Dalgarno sequence is followed by the open reading frame. The esterase activity of the recombinant E. coli was more than 200 times higher than that of parental strain, P. putida MR-2068.     

Syntheses of Paromamine and Its Related Compounds

Paromamine and its related compounds were synthesized by a modified Königs-Knorr reaction of 3,4,6-tri-O-acetyl-2-(2′,4′-dinitroanilno)-α-d-glucopyranosyl bromide with isopropylidene derivatives of 2-deoxystreptamine, streptamine and dihydroconduramine F–4. The condensed products were isolated as their poly N-acetyl derivatives and proved to have α-configuration by PMR spectroscopy in D₂O.     

Fructosyl transferase and hydrolase activities in rhizophores and tuberous roots upon growth of Polymnia sonchifolia (Asteraceae)

The underground reserve organs of yacon (Polymnia sonchifolia Poep. Endl.), similarly to other economically important Asteraceae, accumulate more than 60%, on a DW basis, of inulin type β(2‐1) fructans, mainly oligomers (GF2–GF16). Although sucrose:sucrose 1‐fructosyl transferase (1‐SST), fructan:fructan 1‐fructosyl transferase (1‐FFT) and fructan 1‐exohydrolase (1‐FEH) were properly described and characterized from a number of plant species, detailed information about their activities in different organs during development are rather scarce in the literature. In the present work 1‐SST, 1‐FFT and 1‐FEH activities were measured monthly in rhizophores and tuberous roots of yacon plants during their complete growth cycle under field conditions. Results showed that 1‐SST activity in rhizophores was always higher than 1‐FFT activity and increased up to 8 months of cultivation, decreasing to initial values at the end of the growth period. In the tuberous roots 1‐SST activity was also higher than 1‐FFT but varied differently. The higher values were found at the beginning of tuberization (3‐month‐old plants) and at the flowering phase (7‐month‐old plants). Results also showed that synthesizing activities in yacon plants were always higher in rhizophores than in the tuberous roots, while hydrolysing activity predominated in the latter, mainly when 1‐kestose and nystose were used as substrates. 1‐FEH from yacon plants showed low efficiency when commercial inulin from Helianthus tuberosus was utilized as substrate. The analysis of the enzymatic activities performed during growth of yacon clearly indicated the most appropriate source organ and phase of development to obtain the highest enzymatic activities for purification purposes and for the production of fructo‐oligosaccharides (FOS). Furthermore, the results suggested that the relative levels of activities of 1‐SST, 1‐FFT and 1‐FEH could be involved in the chain length distribution of the fructan molecules found in rhizophores and in tuberous roots of this species.     

A Novel Isoindoline,Porritoxin Sulfonic Acid,from Alternaria porri and the Structure-phytotoxicity Correlation of Its Related Compounds

Novel zinniol-related compound 3, named porritoxin sulfonic acid, with an isoindoline skeleton was isolated from the culture liquid of Alternaria porri. The structure was determined to be 2-(2″-sulfoethyl)-4-methoxy-5-methyl-6-(3′-methyl-2′-butenyloxy)-2,3-dihydro-1H-isoindol-1-one. The phytotoxic activities of three isoindolines (1-3) were evaluated in a seedling-growth assay against stone leek and lettuce.     

Efficient Preparation of Browning-Free Glandular Trichome Tissues from the Surface of Leaves of Rosa rugosa Thunb.

An improved technique for separation of glandular trichomesfrom leaves of rugosa rose (Rosa rugosa Thunb.) was developed.The glandular hairs that had been tightly attached to the tissueof leaf veins via rigid cells were efficiently detached by shakingwith quartz sand dispersed in a solution of mannitol and sodiumascorbate. The mixture of the glandular and simple trichomessuspended in the separation solution was collected by filtrationover nylon mesh (150 mesh), and then it was centrifuged in asolution that contained glycerol. The glandular trichome tips,which were not susceptible to browning, were used for preliminarystudies of cell-free conversions of sesquiterpenes. The glandulartrichomes were found to be a potential source of enzymes associatedwith the biosynthesis and/or bioconversion of sesquiterpenesof R. rugosa. (Received July 28, 1994; Accepted November 11, 1994)     

Metabolism of Glutamic Acid and N-Acetylglutamic Acid in Leaf Discs and Cell-free Extracts of Higher Plants

Radioactive glutamic acid and N-acetylglutamic acid have been incubated with normal and wilted leaf discs and radioactivity recovered in uncombined proline. The discs which had been placed under moisture stress incorporated considerably more label in uncombined proline than did normal discs.     

Semi-automated 3D Leaf Reconstruction and Analysis of Trichome Patterning from Light Microscopic Images

Trichomes are leaf hairs that are formed by single cells on the leaf surface. They are known to be involved in pathogen resistance. Their patterning is considered to emerge from a field of initially equivalent cells through the action of a gene regulatory network involving trichome fate promoting and inhibiting factors. For a quantitative analysis of single and double mutants or the phenotypic variation of patterns in different ecotypes, it is imperative to statistically evaluate the pattern reliably on a large number of leaves. Here we present a method that enables the analysis of trichome patterns at early developmental leaf stages and the automatic analysis of various spatial parameters. We focus on the most challenging young leaf stages that require the analysis in three dimensions, as the leaves are typically not flat. Our software TrichEratops reconstructs 3D surface models from 2D stacks of conventional light-microscope pictures. It allows the GUI-based annotation of different stages of trichome development, which can be analyzed with respect to their spatial distribution to capture trichome patterning events. We show that 3D modeling removes biases of simpler 2D models and that novel trichome patterning features increase the sensitivity for inter-accession comparisons.     

22种植物提取物及其6种化合物对鱼类指环虫的杀灭研究

将感染有指环虫的金鱼投放在加有一定浓度的植物提取物或化合物的水体中,控制一定的水体条件,显微镜下定期观察鱼鳃上的指环虫数量,统计杀虫率。结果表明:22种植物中蛇床提取物的杀灭指环虫效果最好,其最高杀灭率为100%;其次是两面针、木通、吴茱萸、牛心朴子,最高杀虫率均为80%;夹竹桃、徐长卿的最高杀虫率均为70%;草果、苦木、北乌头、滨蒿、蒺藜、白芷、山柰、榧的最高杀虫率在48 h内均在20%~50%;在测试浓度范围内,生姜、辣椒、仙茅、大风子、泽漆、相思子和雷丸没有明显杀虫活性。6种植物化合物作用48 h时川楝素的杀灭指环虫活性最高,最高杀灭率为100%;其次是鬼臼毒素、烟碱和槟榔碱,杀虫率在30%~50%;青蒿素和苦参碱在鱼中毒浓度下对指环虫仍然没有杀灭效果。根据以上结果,蛇床、两面针、木通、吴茱萸、牛心朴子、夹竹桃、徐长卿等植物和化合物川楝素对鱼类指环虫具有较好的杀灭作用。     

Synthesis of Configurational Isomers of Verbenyl Carboxylic Acid and Related Compounds

Configurational isomers of verbenyl carboxylic acid and its derivatives were synthesized from (+)-α-pinene via a key intermediate, phenyl verbenyl sulfone. Configurations of the compounds were determined from stereochemical features in the reactions and the ¹H- and ¹³C-NMR spectral properties.     

Allantoin and Allantoic Acid in Tissues and Stem Exudate from Field-grown Soybean Plants

Samples of stem exudate and plant tissue collected from field-grown soybean (Glycine max [L.] Merr.) plants were analyzed for allantoin and allantoic acid. Nitrogen in nitrate plus amino acids exceeded ureide N concentration in stem exudate prior to flowering. During all of reproductive development (from about 40 days after planting until maturity), ureide N concentration was two to six times greater than amino acid plus nitrate N concentration. Allantoin and allantoic acid, not asparagine, are the principal forms of nitrogen transported from nodulated roots to shoots of the soybean plant. During pod and seed development ureide N comprised as high as 2.3, 37.7, and 15.8% of total N in leaf blades, stems + petioles, and fruits, respectively. The concentration of ureide in stems and fruits declined to nearly zero at maturity.     

Interaction of Mineral Deficiency and Nitrogen Source on Acid Phosphatase Activity in Leaf Extracts

Plants were grown in sand cultures to observe the effects ofmineral deficiencies, with different sources of nitrogen supply,on leaf acid phosphatase activity using phenolphthalein phosphateas substrate. Large increases ranging from 7 to 18 times normal (on freshweight or protein basis) occurred with deficiency of phosphoruswith nitrate, nitrite or ammonia nitrogen; increases from 4to 8 times normal occurred with deficiencies of zinc with nitriteor ammonia; and of copper with nitrite. Less pronounced increases,from 2 to 3 times normal on a protein basis, occurred with deficiencyof zinc with nitrate; of boron with all nitrogen sources; ofmanganese and of iron with nitrite. Activities on both proteinand fresh-weight basis were often greater with nitrite or ammoniumsulphate than with nitrate. Effects of phosphorus, zinc, copper,boron, and nitrogen sources were significant. Molybdenum deficiency caused approximately 2 times normal activityon a protein basis in tomato, tobacco, sunflower, cauliflower,lucerne, mustard, spinach beet, and lettuce when nitrate wasgiven. Effects with ammonia nitrogen were not consistent inmolybdenum-deficient plants but 50 per cent. increases occurredin the first 5 species listed. Activities varied widely betweenspecies. It was concluded that the increases in activity were causedby increases in amounts of the enzyme produced during growth,and that different combinations of deficiencies and nitrogensupplies produce different specific responses in terms of enzymesynthesis.     

Studies on Production of Nucleic Acid and its Related Compounds by Microorganisms

Adenosine was produced from adenine by means of fermentation using Bacillus subtilis Marburg 160-88 (st^r, try^-, pur^-). For the study on adenosine production, experiments concerning with pre-culture age, inoculum size, fermentation period, concentration of adenine, carbon source, nitrogen source and supplement of vitamins were carried out by test tube shaker. Furthermore the time course of fermentation was observed using jar fermentor. And it was proved that adenosine was produced about 1 mg/ml during the first 40 hrs of fermentation in the glucose mineral medium containing 1~2 mg/ml of adenine. This fermentation procedure seems to be one of economical methods for adenosine production.     

Studies on Production of Nucleic Acid and its Related Compounds by Micro-organisms

In the course of studies on biochemical production of adenosine and its related substances, the authors developed new simplified methods for determination of adenine, hypoxanthine, and some of their nucleosides and nucleotides. The methods are; (i) paper chromatography for detection of adenine, hypoxanthine and their nucleosides with a new solvent system, methylisobutylketone-acetic acid-water, in short running of 17 cm, and for detection of 5′-nucleotides with two dimensional development utilizing borate complex formation, (ii) charcoal column method for quantitative determination of adenine, hypoxanthine and adenosine in cultured broth with stepwise elution technique, and (iii) simplified ion-exchange column methods for quantitative determination of adenine nucleotides in phosphorylation mixtures of adenosine with yeast cells.     

Inhibitory Activities of 3-Thiophenecarboxylic Acid and Related Compounds on Plant Growth

3-Thiophenecarboxylic acid (1) showed strong growth-inhibitory activity toward the following plants but not Glycine max Merrill; Brassica campestris subsp. rapa Hook. fil. et Anders, Sesamum indicum L., Lactuca sativa L. var. longifolia Lam, Echinochloa utilis Ohwi et Yabuno and Allium tuberosum Rottler. Compound 1 strongly inhibited the growth of roots of S. indicum and L. sativa even at the low concentration of 5.0 × 10^?5 m. The growth-inhibitory activity of 1-related compounds (2–6) on S. indicum was also studied. Among the compounds, 3-thiopheneacetic acid (6) showed the strongest inhibitory activity, but 3-thiophenecarboxaldehyde (2), 3-thiophenemethanol (3), and 3-thiophenecarboxamide (5) showed no activity. The radicles of plants treated with these active compounds showed negative geotropism.     

Bioassay-Guided Fractionation of Extracts from Codiaeum variegatum against Entamoeba histolytica Discovers Compounds That Modify Expression of Ceramide Biosynthesis Related Genes

Leaves of Codiaeum variegatum (“garden croton”) are used against bloody diarrhoea by local populations in Cameroon. This study aims to search for the active components from C. variegatum against Entamoeba histolytica, and thereby initiate the study of their mechanism of action. A bioassay-guided screening of the aqueous extracts from C. variegatum leaves and various fractions was carried out against trophozoites of E. histolytica axenic culture. We found that the anti-amoebic activity of extracts changed with respect to the collection criteria of leaves. Thereby, optimal conditions were defined for leaves'' collection to maximise the anti-amoebic activity of the extracts. A fractionation process was performed, and we identified several sub-fractions (or isolated compounds) with significantly higher anti-amoebic activity compared to the unfractionated aqueous extract. Anti-amoebic activity of the most potent fraction was confirmed with the morphological characteristics of induced death in trophozoites, including cell rounding and lysis. Differential gene expression analysis using high-throughput RNA sequencing implies the potential mechanism of its anti-amoebic activity by targeting ceramide, a bioactive lipid involved in disturbance of biochemical processes within the cell membrane including differentiation, proliferation, cell growth arrest and apoptosis. Regulation of ceramide biosynthesis pathway as a target for anti-amoebic compounds is a novel finding which could be an alternative for drug development against E. histolytica.     

黑穗醋栗叶片衰老过程中抗坏血酸含量及相关酶活性的变化特征

该试验以3个不同黑穗醋栗品种‘亚德’(Adelinia)、‘布劳德’(Brodtrop)和‘黑丰’(Heifeng)为材料,分析黑穗醋栗8个不同发育时期叶片(幼叶到衰老叶)中的抗坏血酸(AsA)含量、合成与代谢相关酶活性,以明确叶片生长发育及自然衰老过程中AsA含量与代谢合成相关酶之间的关系,为寻找黑穗醋栗最佳叶片采摘时期、AsA含量调控及延缓叶片衰老进程研究奠定基础。结果表明:(1)不同品种黑穗醋栗叶片中AsA含量和AsA相关代谢物水平存在明显的多样性;在叶片生长发育过程中,叶片总抗环血酸(T-AsA)和AsA含量在3个品种中变化趋势一致,均在成熟期叶中达到最高,其中‘亚德’成熟期叶片中AsA含量最高(98.33μmol/g),之后随着叶片的衰老而迅速下降,在衰老后期降至34.57μmol/g。(2)在叶片生长发育进程中,L-半乳糖途径中的关键酶L-半乳糖-1,4-内酯脱氢酶(GalLDH)活性变化与AsA含量变化趋势一致;AsA-GSH循环再生代谢中,脱氢抗坏血酸还原酶(DHAR)、单脱氢抗坏血酸还原酶(MDHAR)、谷胱甘肽还原酶(GR)活性在展叶期最高,之后随着叶片的衰老而降至最低,这与AsA含量变化趋势相似,而抗坏血酸过氧化物酶(APX)活性变化与之正好相反;叶片H2O2含量则随着叶片的衰老逐渐增加,至衰老期达到最高。(3)GalLDH与T-AsA、AsA、氧化型抗坏血酸(DHA)、DHAR和MDHAR呈现极显著正相关关系,即叶片中GalLDH活性越高,叶片中AsA含量也越高;DHAR与T-AsA、AsA和DHA也存在极显著正相关关系。研究认为,黑穗醋栗叶片中AsA含量于成熟期达到最高,且品种间存在显著差异;GalLDH、DHAR可能是黑穗醋栗叶片AsA合成代谢的关键酶,可通过增强GalLDH和AsA-GSH循环系统相关酶活性来提高黑穗醋栗叶片中的AsA含量,进而延缓其衰老。