Alterations in the production and concentration of selected alkaloids as a function of rising atmospheric carbon dioxide and air temperature: implications for ethno-pharmacology

The influence of recent and projected changes in atmospheric carbon dioxide concentration [CO₂] with and without concurrent increases in air temperature was determined with respect to growth characteristics and production of secondary compounds (alkaloids) in tobacco (Nicotiana tabacum L.) and jimson weed (Datura stramonium L.) over a ca. 50‐day period. Rising [CO₂] above that present at the beginning of the 20th century resulted in consistent, significant increases in leaf area, and above ground dry weight (both species), but decreased leaf area ratio (LAR) and specific leaf area (SLA) in jimson weed. Increased temperature resulted in earlier development and increased leaf area for both species, but increases in above ground final dry weight were observed only for jimson weed. The secondary compounds evaluated included the alkaloids, nicotine, atropine and scopolamine. These compounds are generally recognized as having impacts with respect to herbivory as well as human physiology. Rising [CO₂] reduced the concentration of nicotine in tobacco; but had no effect on atropine, and increased the concentration of scopolamine in jimson weed. However, because of the stimulatory effect of [CO₂] on growth, the amount of all three secondary compounds increased on a per plant basis in both species. Temperature per se had no effect on nicotine or scopolamine concentration, but significantly increased the concentration and amounts of atropine per plant. Overall, the underlying mechanism of CO₂ induced changes in secondary compounds remains unclear; however, these data suggest that the increase in [CO₂] and temperature associated with global climate change may have significant effects not only with respect to herbivory, but on the production of secondary compounds of pharmacological impact.     

Effect of Organic Effectors on Chromatin Solubility,DNA-Histone H1 Interactions,DNA and Histone HI Structures

Abstract

We have extended our previous investigations on the effect of organic osmolytes (glycine, proline, taurine, mannitol, sorbitol and trimethylammonium oxide (TMAO)) on chromatin solubility, to the study of their influence on DNA stability and DNA-histone interactions. Our aim was to understand the molecular origin of the protection effects observed.

To this end, we determined the amount of histone H1 required to precipitate DNA or H1-depleted chromatin, at various salt concentrations, in the presence of the above mentioned organic compounds. We found a shift of the H1/DNA ratio required to reach 50% precipitation, towards higher values. Taurine was the most efficient compound followed by mannitol and glycine, then sorbitol and proline. On the contrary, TMAO favoured the precipitation process. We attempted to interpret these results on the basis of Manning's counterion condensation theory.

Changes in histone H1 structure folding and in DNA melting temperature T_m were also analyzed. Glycine, taurine, sorbitol and TMAO increased the degree of secondary structure folding of the protein while mannitol and sorbitol had no effect. Taurine, glycine and proline decreased the T_m of DNA TMAO largely destabilized DNA but mannitol and sorbitol had no effect

Measurements of NaC1 activity in the presence of organic osmolytes did not reveal sufficiently large changes to account for their protection effect against chromatin precipitation. The osmotic coefficient j of the organic effectors solutions increased in the order : taurine < glycine < sorbitol < mannitol < proline ? TMAO. For the two latter compounds, the j values increased above 1 at high concentration.

We consider that the organic compounds investigated maybe classified into three categories : (i) class I (zwitterionic compounds : glycine, proline, taurine) would produce sodium ions release from the DNA surface; (ii) class II (the very polar molecule TMAO) would increase sodium counterions condensation on DNA together with histone HI folding; (iii) class III compounds (mannitol and sorbitol) would possibly produce a modification of NaCl activity but no definite explanation could be found for the complex behavior of these compounds.     

STUDIES ON THE MECHANISM OF HYDROGEN TRANSPORT IN ANIMAL TISSUES : VI. INHIBITOR STUDIES WITH SUCCINIC DEHYDROGENASE

1. The mechanism of succinic dehydrogenase action was studied by means of inhibitors. 2. The enzyme is inhibited by a large number of diverse compounds whose only common denominator appears to be their ability to react with SH groups. These compounds include quinonoid structures, sulfhydryl reagents, sulfhydryl compounds, copper, zinc, selenite, and arsenite. 3. In contrast to the above inhibitors, the action of malonate does not appear to involve sulfhydryl groups and is explained on the basis of its affinity for the enzyme groups which react with the carboxyl groups of succinate. 4. The action of malonate and the sulfhydryl reactants is mutually exclusive, and this fact suggests the conclusion that the sulfhydryl group of the enzyme is located between the carboxyl affinity points. 5. On the basis of the deduced structure of the succinate-activating center of the enzyme, it is suggested that the enzyme may function by oscillating between the EnSH and EnS· forms, rather than by a thiol-disulfide equilibrium.     

Antimutagenicity in Euglena gracilis

The genotoxic effect of N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) and furadantine (Fu) was significantly decreased by standard antimutagens (ascorbic acid, α-tocopherol, chlorophyllin and sodium selenite) in the unicellular flagellate Euglena gracilis. The effects of these compounds were verified also by a bacterial test in which three strains of Salmonella typhimurium, TA97, TA100 and TA102, were used. The above compounds were antimutagenic in strains of bacteria used, except for chlorophyllin which had no effect on strain TA102.     

Correlation of alkylating and mutagenic activities of allyl and allylic compounds: Standard alkylation test vs. kinetic investigation

Thirty-nine allylic and non-allylic compounds have been tested in the standard 4-(p-nitrobenzyl)pyridine (NBP) alkylating procedure and the Salmonella typhimurium mutagenicity assay. Fourteen of these were found directly mutagenic (without addition of S-9 mix activating enzyme system). With twelve of these compounds, a good correlation of alkylating and mutagenic potencies was established; the remaining two do not meet the chemical conditions of the NBP procedure on account of HCl elimination with these two compounds. The other 25 substances were inactive in both systems. The quantitative correlation proved to be almost linear in the lower activity ranges (E ～ 2; revertants/μmol ～ 600). The reasons for some deviations from the linear relationship have been analyzed and discussed on the basis of structural features. In addition to the standard alkylation test, a modified NBP-test was performed in order to obtain kinetic data and activation energy values. The results with 6 representative allylic compounds show that the overall correlation is not substantially improved above that of the standard procedure; nonetheless, additional information on reaction characteristics is obtained with some substances.     

Selective pharmacological blocking of synaptic transmission through the parasympathetic ganglia: Effects on the cardiovascular system

In acute experiments on rats and dogs, compounds IEM-1556 and IEM-1678, the blockers of transmission through the parasympathetic ganglia, reduced the negative chronotropic effect of stimulation of the vagus nerve (VN), while practically not changing the heart rate (HR). In chronic experiments on dogs, these compounds increased the HR, substantially reduced the respiratory heart arrhythmia, did not change the arterial blood pressure (AP), and reduced the chronotropic effects of VN stimulation. IEM-1556 exerted more strong and long-lasting blocking effects on vagal heart control than IEM-1678 did, but in anesthetized animals could evoke a drop in the AP. Acetylcholine, if administered during the action of the above compounds, inhibited heart activity. It is concluded that both IEM-1678 and IEM-1556 are selective parasympatholytics (although IEM-1556 may produce a side effect). The above compounds block synaptic transmission through the intracardiac parasympathetic ganglia and do not affect neuro-effector transmission in the heart.Neirofiziologiya/Neurophysiology, Vol. 28, No. 2/3, pp. 151–159, March–June, 1996.     

Effect of different antioxidants and free radical scavengers on aflatoxin production

Different antioxidants and free radical scavengers on aflatoxin production are analysed. The different compounds at different concentration were used: buthylated hydroxyanisole (BHA), buthylated hydroxytoluene (BHT), α-tocopherol (vitamin E), ascorbic acid (vitamin C), reduced glutathione, cysteine, cysteamine. The above compounds were tested in culture ofAspergillus parasiticus supplemented with carbon tetrachloride, a potent stimulating agent of aflatoxin biosynthesis. Cysteamine and BHA highly inhibited the aflatoxin production induced by carbon tetrachloride, the inhibition decreased by lowering the concentration. On the contrary, vitamin E, vitamin C, reduced glutathione and cysteine further enhanced the carbon tetrachloride stimulating effect. The addition of the above compounds did not significantly affect the growth of the fungal mycelia.     

Low organotin contamination of harbour sediment in Svalbard

Arctic sea routes are opening up for maritime transport due to sea ice retreat leading to increasing human activities in the Arctic and concomitant pressures on the environment. Organotin compounds are used in antifouling paints of large seagoing vessels and are known to leach into the marine environment and accumulate in sediments and biota. As organotin levels in Svalbard sediments have not been documented in peer-reviewed literature before, this study describes the levels in sediment of harbours around Svalbard (Ny-Ålesund, Longyearbyen, Svea, Pyramiden and Barentsburg). Organotin levels in sediments of Svalbard harbours were low (below the detection limit up to 14 ng Sn/g dw sum-butyltin) compared to other Arctic regions with a longer history of shipping. Levels were below known no effect levels and in accordance, no imposex was found in marine whelks from Ny-Ålesund harbour. Of all other analysed compounds in sediments of Kongsfjorden (polycyclic aromatic hydrocarbon (PAHs), polychlorinated biphenyls, polybrominated diphenylethers and perfluorinated compounds) PAH levels were highest and in one sample above action levels. It is advised to continue monitoring contaminant levels, for which the current results form a good basis. If contaminant levels rise, mitigation measures can be taken in time.     

Comparative study of SCE induction and cytostatic effects by homo-azasteroidal esters of N,N-bis(2-chloroethyl)aminobenzoic acid in human lymphocytes

The effect of homo-azasteroidal esters of benzoic acid mustard isomers and the 4-methyl derivatives, which have steroidal lactams as a biological basis, on cytogenetic damage was studied. Twenty compounds were comparatively studied, on a molar basis, as regards their ability to induce sister-chromatid exchanges (SCEs) and cell division delays.A correlation between potency for SCE induction, effectiveness in cell division delay and previously established antitumor activity of these compounds was observed.     

复方中药制剂在寒冷诱导机体损伤中作用及其机制

目的:研究寒冷所诱导的机体损伤作用,明确寒冷引发机体损伤的部分机制以及预防性药物对机体处于寒冷环境中的保护作用。方法:通过低温试验、ATP检测、电镜观察等确定寒冷对机体造成的损伤;通过总抗氧化能力、CAT含量、谷胱甘肽过氧化物酶含量、SOD水平、MDA水平等的检测确定氧化应激在寒冷暴露对机体损伤中的作用及机制;并确证复方中药制剂在寒冷损伤氧化应激状态下对机体的保护作用。结果:1.急性-15±1℃寒冷环境暴露可引起机体内肝脏组织能量代谢障碍,ATP生成减少,肝细胞线粒体损伤,溶酶体增多等机体损伤的现象;2.寒冷应激可导致机体的总抗氧化能力、CAT显著减少,而氧化应激终产物之一的丙二醛(malondialdehyde,MDA)显著增多(说明肝脏组织出现明显的氧化应激过程),并且出现抗氧化能力下降。3.预先给予药物干预后,机体抗氧化能力显著增加。结论:1.寒冷可以诱导机体肝脏明显损伤。2.氧化应激是寒冷诱导机体损伤的关键机制之一。3.复方中药制剂可以增加机体在寒冷应激条件下的抗氧化能力,从而产生保护作用。     

Photo‐mechanical effect in luminescent polymeric materials

The photomechanical effect was found for the first time in a polymer composition on the basis of polymethylmethacrylate with embedded molecules of the luminophor dibenzoylmethanate of boron difluoride incapable of undergoing photochemical isomerization, unlike other compounds. A thermal mechanism of photochemical displacement was suggested. Copyright © 2009 John Wiley & Sons, Ltd.     

The spreading of monolayers of myosin

The spreading of the muscle proteins myosin and actomyosin depends both on the salt solution in which the proteins are dissolved and on the solution on which they are spread. The spreading is more complete the lower the concentration of the salt solution in which the proteins are dissolved and the higher the salt concentration of the solutions on which the proteins are spread. This effect seems to be due partially to the difference in density allowing the spread droplets a longer life on the surface, and partially to the effect of salt on the charge of the protein. A change in the pH of the substrate has a smaller effect than a change in the salt concentration. Heavy metals like Cu⁺⁺ or Zn⁺⁺, inhibit spreading almost completely. The dependence of spreading on these salts and on time was investigated in detail.The effect of the different salts was also compared with the effect of different phosphate compounds. It was noted that the above substances, including the different salts, phosphate compounds, and heavy metals, affect the mechanism of spreading but not films already spread. The viscosity of these fibrillar proteins was compared with other proteins in the monomolecular film state and in myosin an unusually high viscosity was found.     

The Movement of Organic Nitrogen Compounds in Plants: With two Figures in the Text

The hypothesis that the movement of organic nitrogen, like thatof carbohydrate, is governed by the prevailing concentrationgradients for the mobile compounds in the phloem has been testedby determining the effect on nitrogen distribution when normaltranslocation was interrupted by ringing in Pelargonium spp.and Vicia faba plants. Nitrogen compounds in the plant tissue were fractionated intoprotein, soluble protein, amide, amino-acid, peptide, nitrate,and ammonia nitrogen. The presence of short-chain peptides inthe extracts was confirmed by paper chromatography. Results showed that accumulation above the ringed zone was confinedto the soluble nitrogen fractions and that amino-acids and possiblypeptides were involved in translocation. The direction of movementmay be determined by the prevailing concentration gradientsof these compounds in the phloem tissue.     

An evaluation of cryoprotective compounds on bovine spermatozoa

The potentially cryoprotective properties of 72 higher-molecular-weight polymeric additives and 69 low-molecular-weight compounds were evaluated. The polymeric compound selection was based on solubility in semen extender, toxicity and finally, on the cryoprotective effect on bull spermatozoa as measured by progressive motility. Five compounds showed cryoprotection to the cell, but with no significant improvement over that of TESNaK yolk, TEST yolk, or TEST yolk glycerol extenders used as controls. Low-molecular-weight compounds were selected on the basis of colligative properties particularly that of freezing-point depression. Elimination was based on precipitation of proteins in the extender, toxicity, and cryoprotection to bovine spermatozoa as measured by progressive motility. Nineteen compounds that yielded protection during cryopreservation of bovine spermatozoa were compared using post-thaw motility and membrane integrity using glutamic-oxaloacetic transaminase enzyme retained in the spermatozoa after freezing as an indicator. Semen was diluted with extender containing selected compounds at 35 or 5 °C to determine the effect of temperature at which the cryoprotective compound was added. Glycerol yielded the highest recovery. Diethylene glycol, dimethylsulfoxide, N-methylacetamide, and triethylene glycol appeared not to be different in freezing bovine spermatozoa. The temperature or method of addition of cryoprotective compound did not reveal a significant difference.     

Norbergenin derivatives from the stem bark of Diospyros sanza-minika (Ebenaceae) and their radical scavenging activity

Three new norbergenin derivatives, 11-O-p-hydroxybenzoylnorbergenin, 4-O-(3′-methylgalloyl)norbergenin and 4-O-syringoylnorbergenin were isolated from the stem bark of Diospyros sanza-minika, along with three known compounds: norbergenin, 4-O-galloylnorbergenin and quercitol. Their structures were established on the basis of 1D and 2D NMR experiments and mass spectrometry. Some of the above compounds showed radical scavenging properties in a DPPH solution assay.     

Inhibiting the color formation by gradient temperature‐elevating Maillard reaction of soybean peptide‐xylose system based on interaction of l‐cysteine and Amadori compounds

Light color and savory flavor enhancer are attractive for consumers and food producers. The effect of addition time of l ‐cysteine on inhibiting color formation was investigated in soybean peptide‐xylose system, and the possible pathway was explored. Once dicarbonyl compounds were formed during the Maillard reaction, the addition of l ‐cysteine had no color‐inhibiting effect; if l ‐cysteine was added immediately after the Amadori compound was formed, the extraordinary color‐inhibiting effect was observed. Therefore, an improved way to inhibit color formation was proposed on the basis of the interaction of l ‐cysteine and Amadori compounds by controlling the addition time of l ‐cysteine through gradient temperature‐elevating Maillard reaction. The system was heated at 80 °C for 60 min to form Amadori compounds, followed by the addition of L‐cysteine, and the temperature was raised to 120 °C and held for 110 min. Compared with traditional products, the lightest color product was found desirable by GC/MS analysis and sensory evaluation. The novel method proposed can be a guide for the industrial preparation of light‐colored products. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.     

Scavenging effect of benzophenones on the oxidative stress of skeletal muscle cells.

Benzophenone is an ultraviolet (UV)-absorbing agent that has been used in industry and medicine for more than 30 years. Consumers of cosmetics and sunscreens containing UV-absorbers are exposed to benzophenones on a daily basis, owing to the widespread use of these compounds. However, the efficacy of these compounds as scavengers of oxidative stress is still not well established. In the present study, we investigate the antioxidative capacity of six sunscreen benzophenone compounds. A primary myoblast culture was mixed in vitro with 100 microM menadione. The cytotoxic effect by menadione-induced oxidative stress was monitored by the lucigenin- or luminol-amplified chemiluminescence, methylthiotetrazole (MTT) assay, and the antioxidative effects of various benzophenone compounds were evaluated. The results showed that the addition of menadione can induce oxidative stress on myoblasts by superoxide and hydrogen peroxide production, which can be eradicated by superoxide dismutase (SOD) and catalase, respectively, in a dose-dependent mode. The catalase has a protective effect on the cytotoxicity induced by menadione as measured by the MTT assay, while the SOD does not. The selected benzophenones also have a significant scavenging effect on the menadione-induced cell death on the myoblasts. The ortho-dihydroxyl structure and other hydroxy groups in the same ring have a stronger scavenging effect on the superoxide anion on myoblasts; thus, a stable penoxy radical may be formed. The mechanism of this effect remains to be clarified.     

Mechanism of the antistressor and antiradiation action of plant phenol compounds]

The article analyses critically the date from literature as well as own date concerning appropriateness and mechanisms of antiradiation, capillary strengthening and antistress effect of plant phenolic compounds. Knowledge on antioxidant effect as the most fundamental mechanism being in the basic of the above mentioned biologic effects of plant phenolic compounds is grounded.