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1.
The first-formed flower primordium on determinate varieties(plants with terminal inflorescences) of Phaseolus vulgarishas been identified and located. Irrespective of the numberof leaves on the main stem, it is formed directly in the axilof the uppermost leaf. The physiological significance of thisis discussed.  相似文献   

2.
Background: Lonicera caerulea L. (blueberry honeysuckle, Caprifoliaceae) is a traditional crop in northern Russia, China, and Japan. Its fruits are little known as edible berries in North America and Europe. This review deals with the botany and chemical composition of L. caerulea and the biological activity of its main constituents, focusing on the potential health benefits of the berries. Methods and Results: PubMed, Science Direct and ISI Web of Knowledge(SM) databases were used for this paper. Literature sources include the period 1935-2007. L. caerulea berries a are rich source of phenolic compounds such as phenolic acids as well as anthocyanins, proanthocyanidins and other flavonoids, which display potential health promoting effects. Chemopreventive, antimicrobial, anti-adherence and antioxidant benefits, among others are described for these compounds. Conclusions: The potential of L. caerulea berries to prevent chronic diseases such as diabetes mellitus, cardiovascular diseases and cancer seems to be related above all to their phenolic content.  相似文献   

3.
In the last few years gold(III) complexes have attracted growing attention in the medicinal chemistry community as candidate anticancer agents. In particular some organogold(III) compounds manifested quite attractive pharmacological behaviors in preclinical studies. Here we compare the chemical and biological properties of the novel organogold(III) complex [Au(bipydmb?H)(NH(CO)CH3)][PF6] (Aubipyaa) with those of its parent compounds [Au(bipydmb?H)(OH)][PF6] (Aubipyc) and [Au2(bipydmb?H)2)(μ?O)][PF6]2 (Au2bipyc), previously synthesized and characterized. The three study compounds were comparatively assessed for their antiproliferative actions against HCT-116 cancer cells, revealing moderate cytotoxic effects. Proapoptotic and cell cycle effects were also monitored. Afterward, to gain additional mechanistic insight, the three gold compounds were challenged against the model proteins HEWL, RNase A and cytochrome c and reactions investigated through UV–Vis and ESI–MS analysis. A peculiar and roughly invariant protein metalation profile emerges in the three cases consisting of protein binding of {Au(bipydmb?H)} moieties. The implications of these results are discussed in the frame of current knowledge on anticancer gold compounds.  相似文献   

4.
Summary Pollen samples from Brassica napus cvs Arran and Herkules were incubated for 1 h in a germination medium or in a medium to which 20 mg ml–1 of a toxic extract from Alternaria brassicicola had been added. The pollen samples were then used to pollinate cv Primor. A number of the plants, obtained from pollinations using pollen incubated in the toxic extract, produced pollen with a significantly increased ability to germinate in medium containing 10 mg ml–1 of the extract, evidence that some selection for resistance to the toxic compounds produced by A. brassicicola had occurred. The potential application of in vitro pollen selection and conditions necessary for its success are discussed.  相似文献   

5.
Five widely documented mechanisms of chloride transport across plasma membranes are: anion-coupled antiport; sodium and hydrogen-coupled symport; Cl- channels; and an electrochemical coupling process. No genetic evidence has yet been provided for primary active chloride transport despite numerous reports of cellular Cl(-)-stimulated ATPases co-existing, in the same tissue, with uphill chloride transport that could not be accounted for by the five common chloride transport processes. Cl(-)-stimulated ATPase activity is a common property of practically all biological cells with the major location being of mitochondrial origin. It also appears that plasma membranes are sites of Cl(-)-stimulated ATPase activity. Recent studies of Cl(-)-stimulated ATPase activity and active chloride transport in the same membrane system, including liposomes, suggest a mediation by the ATPase in net movement of chloride up its electrochemical gradient across plasma membranes. Further studies, especially from a molecular biological perspective, are required to confirm a direct transport role to plasma membrane-localized Cl(-)-stimulated ATPases.  相似文献   

6.
The femoral chordotonal organ (FCO) of Locusta migratoria and Valanga sp. (Orthoptera : Acrididae) is a leg stretch receptor containing scolopophorous sensory neurones embedded in a ligament, which emerges distally from the body of the organ and connects to a distal apodeme. The ligament is pulled when the tibia is flexed. Thus the FCO bridges the femur-tibia joint. The ligament is divided into separate strands, each of which is composed of several or more, long attachment cells. These cells link individual scolopidia to the apodeme. An additional unloading strand connects the body of the FCO to a static point on the femoral integument. Because the strands are inserted along the apodeme in a sequential array, and because the unloading strand holds all the tension on the FCO when the ligament is relaxed (tibia extended), a mechanism for gradual, sequential uptake of tension by the ligament strands exists when the ligament is pulled (tibia flexed). This leads to a range fractionation of stretch-sensitive neurone responses during tibial flexion, and of relaxation-sensitive neurone responses during tibial extension. Observations on the ultrastructural distribution of desmosomes suggest that groups of attachment cells may be functionally connected and may collectively transmit force to specific groups of neurones.  相似文献   

7.
Fungi of the genus Penicillium isolated from little studied habitats are able to synthesize both previously known and new physiologically active compounds with diverse structures. They include secondary metabolites of alkaloid nature, i.e., ergot alkaloids, diketopiperazines, quinolines, quinazolines, benzodiazepines, and polyketides. We discuss the use of profiles of secondary metabolites for taxonomy purposes. Studying the physicochemical characteristics of producers of biologically active compounds showed that the biosynthesis of alkaloids is initiated on the first days of cultivation and proceeds simultaneously with growth. The cyclic character of alkaloid accumulation was recorded related to the processes of alkaloid biosynthesis, excretion from cells, degradation in culture fluid, and consumption by cells. Synchronic variations in the concentrations of intracellular tryptophan and alkaloids are necessary for the regulation of the optimal quantity of tryptophan necessary for the culture.  相似文献   

8.
D Kantoci 《Life sciences》1999,65(12):1305-1315
A non-linear algorithm, ACE (Algorithm for Cross-Evaluation), was developed to correlate the activity of anti-cancer drugs against human cell lines. ACE evaluates the relationships among compounds and cell lines and displays the resulting clusters on a 3-D surface plot. This plot along with a frequency plot and rank graph provides clear information regarding the sensitivity of groups of cell lines to particular compounds. The program was tested on published anti-cancer data sets and found associations useful in the selection and design of chemotherapy drugs for pre-clinical trials. ACE may be applied to other situations where details of groupings and relationships need to be extracted from large sets of data.  相似文献   

9.
Sponges (Porifera) currently represent one of the richest sources of natural products and account for almost half of the pharmacologically active compounds of marine origin. However, to date very little is known about the pharmacological potential of the sponges from polar regions. In this work we report on screening of ethanolic extracts from 24 Antarctic marine sponges for different biological activities. The extracts were tested for cytotoxic effects against normal and transformed cell lines, red blood cells, and algae, for modulation of the activities of selected physiologically important enzymes (acetylcholinesterase, butyrylcholinesterase, and α-amylase), and for inhibition of growth of pathogenic and ecologically relevant bacteria and fungi. An extract from Tedania (Tedaniopsis) oxeata was selectively cytotoxic against the cancer cell lines and showed growth inhibition of all of the tested ecologically relevant and potentially pathogenic fungal isolates. The sponge extracts from Isodictya erinacea and Kirkpatrickia variolosa inhibited the activities of the cholinesterase enzymes, while the sponge extracts from Isodictya lankesteri and Inflatella belli reduced the activity of α-amylase. Several sponge extracts inhibited the growth of multiresistant pathogenic bacterial isolates of different origins, including extended-spectrum beta-lactamase and carbapenem-resistant strains, while sponge extracts from K. variolosa and Myxilla (Myxilla) mollis were active against a human methicillin-resistant Staphylococcus aureus strain. We conclude that Antarctic marine sponges represent a valuable source of biologically active compounds with pharmacological potential.  相似文献   

10.
《Journal of Asia》2020,23(1):260-267
The increasing risk of insecticide resistance in mosquito populations has led to the search for new larvicidal agents. Evaluation of bioassay-guided fractionation of the rhizome extract of Alpinia galanga (L.) Willd against Aedes aegypti was assessed. Bioactive fractions were isolated from the rhizome extract of A. galanga using a Soxhlet extractor and chromatography techniques, and subsequently tested against the fourth instar of Culex pipiens. The lethal concentration (LC) was calculated via log-probit analysis. The active fraction was evaluated by gas chromatography-mass spectroscopy (GC–MS) and infrared (IR) analysis. The highest larvicidal potential obtained from bioassays using the Soxhlet apparatus was observed in dichloromethane (DCM) and ethyl acetate (EtoAc) extracts, with LC50 values of 124.49 and 176.30 ppm, respectively, after 24 h of exposure. Subsequently, the DCM extract was subjected to column and thin-layer chromatography. Results of the DCM extraction and the active TLC fraction (F133) of the Rf value 0.5 revealed that LC50 and LC90 values decreased over time. The F133 fraction of A. galanga exhibited zero hatchability (100% mortality) at LC50 (63.416 ppm) and LC25 (31.70 ppm) against Cx. pipiens eggs. GC–MS analysis of the active thin-layer chromatography TLC fraction (F133) revealed the presence of phenol 2 4-bis (1 1-dimethylethyl), which was identified as the major compound. Alpinia galanga extract is a promising candidate for the control of mosquito populations. Further study is required to determine the effect of the extracts on non-target organisms.  相似文献   

11.
12.
The keys to identifying different species normally rely heavily on morphological characteristics. However, when an animal has been killed for food or sport, these markers are often destroyed or intentionally removed from the animal. This presents a problem for government agencies who are involved in determining the species origin of an animal or products derived from it in order to enforce conservation and/or health-related regulations. The problem is compounded if the meat of the animal has been processed in any way. We have developed a procedure called FINS (Forensically Informative Nucleotide Sequencing) that overcomes these problems. FINS has four components. First, methods have been developed that can isolate DNA from a wide range of biological samples including processed foods (e.g., canned, partially cooked, pickled, salted or smoked). Second, a specific segment of DNA is amplified using PCR. Third, the nucleotide sequence of the amplified segment of DNA is determined. Fourth, this nucleotide sequence is subjected to a phylogenetic analysis using a database, and the most closely related species is identified. FINS is a rapid, reliable and reproducible procedure that is based on established techniques. This procedure fills the need for an accurate method of determining the species identity of a specimen when this is not possible by conventional means.  相似文献   

13.
This review considers the methods of investigation proposed by L. A. Piruzyan in the field of preclinical trials of physiologically active compounds: (1) the search for new physiologically active compounds illustrated by analysis of the developmental mechanisms of some diseases, such as jaundice of the newborn, renal and liver insufficiency, acute drug-induced intoxication, discoid and systemic lupus erythematosus, and lupus-like syndrome; (2) experimental studies on safety of medicinal substances—the testing of substances for mutagenicity and embryotoxicity, the preparation of compounds with antimutagenic and anticarcinogenic properties, the determination of preserved blood characteristics; (3) the stabilization of medicinal preparations for use—with drug oxidation inhibitors, and substances contained in liposomes. The ligand pathology concept is presented. The necessity of an individualized approach for assessment of chemical compound safety for humans in emphasized: it should be based on the activity determination of certain enzymes in each subject. Deceased.  相似文献   

14.
Cap liners were found to be a major source of plasticizer contamination of high-purity extraction solvents. Plasticizer concentrations found ranged from 0.1–5 ppm; this can produce substantial interference in biological analysis because of the rather high concentration factors obtained in the final extracts.  相似文献   

15.
16.
This study was initiated to characterize Rhizobium isolates obtained from root nodules of ineffectively nodulated, field-grown alfalfa (Medicago sativa L.) plants. The purpose was to determine if these isolates possessed characteristics which would explain either their ineffectiveness in N(2) fixation or their apparent ability to tolerate the moderately acid soil conditions from which they originated. Isolates were characterized by analysis of growth rate, 39 degrees C tolerance, acid production on conventional media, and symbiotic performance. All isolates were ineffective in N(2) fixation on alfalfa, and they contained one or more anomalous characteristics. These included either slow growth rate, lack of 39 degrees C tolerance, or lack of acid production on conventional media. Infectiveness tests on a broad range of legumes revealed that the isolates formed root nodules on M. sativa, Medicago lupulina L., and Phaseolus vulgaris (L.) Savi. (common bean). These results provide evidence that, in some situations, ineffective nodulation of M. sativa in the field may be due to the presence of promiscuous, native Rhizobium species.  相似文献   

17.
Summary and conclusion Lex (13 fucosylated type 2 chain) functions as an adhesion molecule capable of Ca2+-mediated homotypic binding. Cells with high surface expression of Lex therefore exhibit strong self-aggregation (based on Lex-Lex interaction) in the presence of Ca2+. In this review, I have summarized several lines of supporting data for this concept, and the role of Lex-Lex interaction in the process of embryo compaction and autoaggregation of F9 teratocarcinoma cells. In general, cell adhesion events based on Lex-Lex interaction may be followed and reinforced by integrin- or Ig receptor-based adhesion systems.SLex, the 23 sialosyl derivative of Lex, and its positional isomer SLea, have been identified as the target molecules for selectin-dependent cell adhesion. Adhesion of leukocytes or tumour cells to ECs or platelets, which express E-selectin and P-selectin respectively, is initiated by this process. The target epitopes SLex and SLea are presented mainly on transmembrane glycoproteins having many clusters of O-linked carbohydrate chains. Therefore, inhibition of O-glycosylation may be effective for blocking selectin-mediated cell adhesion. The abundant presence of Lex epitope in the central nervous system, and the physiological changes of Lex expression as described in this monograph, reflect the adhesive properties of this molecule and its sialyosylated and/or fucosylated derivatives.  相似文献   

18.
The aim of this study was to assess the phytotoxic potential of Cleome arabica L, as well as to isolate the main bioactive compounds. Phytotoxicity was evaluated on germination and seedling growth of Lactuca sativa, Raphanus sativus, Peganum harmala and Silybum marianum, through testing aqueous and organic extracts of different C. arabica organs (roots, shoots, siliquae and seeds). Results showed that siliquae methanol extract caused the greatest negative effect on lettuce germination and growth. For the bioactive subfractions (petroleum ether, ethyl acetate and methanol–water), the ethyl acetate induced highly significant reduction, showing 100% inhibition of lettuce growth at 6 g/L. The bioactive ethyl acetate subfraction was chromatographed and subjected to NMR techniques. Based on bio-guided chromatographic fractionation, five bioactive allelochemical compounds were isolated from ethyl acetate extract of siliquae of C. arabica. The most inhibitory compound on lettuce seedling growth was elucidated as 11-α-acetylbrachy-carpone-22(23)-ene.  相似文献   

19.
The aim was to investigate the phenolic content, antioxidant capacity, and antibacterial activity of Dalmatian sage (Salvia officinalis L.) leaves collected during different vegetation periods. Separation and quantification of the individual phenols were performed by reversed-phase (RP)-HPLC coupled with a PDA (photodiode array) detector and using an internal standard, while the contents of total phenols, flavonoids, flavones, and flavonols were determined spectrophotometrically. The antioxidant properties of the sage leaf extracts were evaluated using five different antioxidant assays (FRAP, DPPH, ABTS, Briggs-Rauscher reaction, and β-carotene bleaching). The antimicrobial activity of the extracts was tested against two Gram-positive (Bacillus cereus and Staphylococcus aureus) and two Gram-negative (Salmonella Infantis and Escherichia coli) bacterial reference strains. All extracts were extremely rich in phenolic compounds, and provided good antioxidant and antibacterial properties, but the phenophase in which the leaves were collected affected the phenolic composition of the sage extracts and consequently their biological activity. The May Extract, the richest in total flavonoids, showed the best antioxidant properties and the highest antimicrobial activity. Thus, collection of the plants during May seems the best choice for further use of them in the pharmaceutical and food industry.  相似文献   

20.
Acyloxydiene–Fe(CO)3 complexes act as enzyme-triggered CO-releasing molecules (ET-CORMs) and can deliver CO intracellularly via esterase-mediated hydrolysis. The protective properties of structurally different ET-CORMs on hypothermic preservation damage and their ability to inhibit VCAM-1 expression were tested on cultured human umbilical vein endothelial cells (HUVEC) and renal proximal tubular epithelial cells (PTEC) using a structure–activity approach. Cytotoxicity of ET-CORMs, protection against hypothermic preservation damage, and inhibition of VCAM-1 expression were assessed. Cytotoxicity of 2-cyclohexenone and 1,3-cyclohexanedione-derived ET-CORMs was more pronounced in HUVEC compared to PTEC and was dependent on the position and type of the ester (acyloxy) substituent(s) (acetate>pivalate>palmitate). Protection against hypothermic preservation injury was only observed for 2-cyclohexenone-derived ET-CORMs and was not mediated by the ET-CORM decomposition product 2-cyclohexenone itself. Structural requirements for protection by these ET-CORMs were different for HUVEC and PTEC. Protection was affected by the nature of the ester functionality in both cell lines. VCAM-1 expression was inhibited by both 2-cyclohexenone- and 1,3-cyclohexanedione-derived ET-CORMs. 2-Cyclohexenone, but not 1,3-cyclohexanedione, also inhibited VCAM-1 expression. We demonstrate that structural alterations of ET-CORMs significantly affect their biological activity. Our data also indicate that different ET-CORMs behave differently in various cell types (epithelial vs endothelial). These findings warrant further studies not only to elucidate the structure–activity relation of ET-CORMs in mechanistic terms but also to assess if structural optimization will yield ET-CORMs with restricted cell specificity.  相似文献   

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