Home About us Contact
|
Home About us Contact | ||
|
|
||
Cinnamic Acid (cinnamic + acid)
Terms modified by Cinnamic Acid Selected AbstractsSynthesis of Cholesteryl Esters of Heterocyclic Analogues of Cinnamic Acid and Hetaroyloxycinnamic Acids by the Wittig Reaction.CHEMINFORM, Issue 34 2003V. N. Listvan Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Electrochemical Methoxylation of Cinnamic Acid and Its Derivatives.CHEMINFORM, Issue 26 2002I. B. Il'chibaeva Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] p-Toluenesulfonic Acid Mediated Hydroarylation of Cinnamic Acids with Anisoles and Phenols under Metal and Solvent-Free Conditions.CHEMINFORM, Issue 43 2007Arun R. Jagdale Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis of Cinnamic Acids and Related Isosteres as Potent and Selective ,v,3 Receptor Antagonists.CHEMINFORM, Issue 29 2004Thomas D. Penning Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Condensation of o-Phenylenediamine with Cinnamic Acids.CHEMINFORM, Issue 6 2002P. K. Dubey Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Structure,hepatoprotective activity relationship of 3,4-dihydroxycinnamic acid (caffeic acid) derivativesJOURNAL OF APPLIED TOXICOLOGY, Issue 6 2001V. Pérez-Alvarez Abstract 3,4-Dihydroxycinnamic acid (caffeic acid, CAF) is a natural product containing a catechol group with an ,,,-unsaturated carboxylic acid chain that has shown hepatoprotective properties. The aim of this work was to determine the importance of the 4-hydroxy, 3-hydroxy, 3,4-dihydroxy substituents and the double bond moiety on the hepatic pharmacological effects of the molecule. We compared the ability of the caffeic, 4-hydroxycinnamic, 3-hydroxycinnamic, cinnamic and 3,4-dihydroxyhydrocinnamic (a caffeic acid analogue without the double bond) acids at a dose of 50 mg kg,1, p.o., to reduce the liver damage produced by CCl4 (4 g kg,1, p.o.) intoxication in the rat. Cinnamic acid, the non-hydroxylated analogue, only modestly protected the experimental animals challenged with CCl4, suggesting that hydroxyl groups participate in the pharmacological properties of CAF. The 3,4-dihydroxyhydrocinnamic derivative did not show any significant differences when compared with the CAF effect in this model, suggesting that the double bond does not account for the liver pharmacological properties of CAF. In contrast, the 4-hydroxy substituent seems to be very important for hepatoprotective activity because the 4-hydroxy analogue improved almost every hepatic injury marker altered by CCl4, and in a better way than CAF did. Copyright © 2001 John Wiley & Sons, Ltd. [source] Alterations in Taxol Production in Plant Cell Culture via Manipulation of the Phenylalanine Ammonia Lyase PathwayBIOTECHNOLOGY PROGRESS, Issue 6 2002Michelle C. Brincat One approach to increasing secondary metabolite production in plant cell culture is to manipulate metabolic pathways to utilize more resources toward production of one desired compound or class of compounds, such as diverting carbon flux from competing secondary pathways. Since phenylalanine provides both the phenylisoserine side chain and the benzoyl moiety at C-2 of Taxol, we speculated that blockage of the phenylpropanoid pathway might divert phenylalanine into Taxol biosynthesis. We used specific enzyme inhibitors to target the first enzyme in the phenylpropanoid pathway, phenylalanine ammonia lyase (PAL), the critical control point for conversion of l -phenylalanine to trans -cinnamic acid. Cinnamic acid acted quickly in reducing PAL activity by 40,50%, without affecting total protein levels, but it generally inhibited the taxane pathway, reducing Taxol by 90% of control levels. Of the taxanes produced, 13-acetyl-9-dihydro-baccatin III and 9-dihydrobaccatin III doubled as a percentage of total taxanes in C93AD and CO93P cells treated with 0.20 and 0.25 mM cinnamic acid, when all other taxanes were lowered. The PAL inhibitor ,-aminooxyacetic acid (AOA) almost entirely shut down Taxol production at both 0.5 and 1.5 mM, whereas l -,-aminooxy-,-phenylpropionic acid (AOPP) had the opposite effect, slightly enhancing Taxol production at 1 ,M but having no effect at 10 ,M. The discrepancy in the effectiveness of AOA and AOPP and the lack of effect with addition of phenylalanine or benzoic acid derivatives further indicates that the impact of cinnamic acid on Taxol is related not to its effect on PAL but rather to a specific effect on the taxane pathway. On the basis of these results, a less direct route for inhibiting the phenylpropanoid pathway may be required to avoid unwanted side effects and potentially enhance Taxol production. [source] Cell wall phenolics of white and green asparagusJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2005Rocío Rodríguez Abstract Cinnamic acids influence physical and textural attributes of plant foods as they play an important role in lignification and cross-linking of cell-wall polymers. Several trans -cinnamic acids have been detected in asparagus cell wall (CW), and, of these, amounts of ferulic acid (FA) and its dehydrodimers have been found to increase significantly during post-harvest storage. The distribution of these compounds along the different sections of white and green spears, as well as their modifications during postharvest storage, has been investigated. It has been observed that the cell walls from the apical, middle and lower sections of the green spears contain equivalent amounts of FA derivatives (about 400 µg g,1 CW), while these compounds are mainly located in the middle (681 µg g,1 CW) and lower section (975 µg g,1 CW) of the white ones. During asparagus post-harvest storage a general increase of FA monomers and dimers took place that affected every section of both green and white spears. Major changes occurred in the middle and lower sections of the white asparagus, where the amounts of ferulic derivatives increased to 1700 and 1678 µg g,1 CW after storage. A similar but less pronounced trend was observed for the green spears. Copyright © 2005 Society of Chemical Industry [source] Selective bio-availability of phenolic acids from Scottish strawberriesMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue S1 2009Wendy R. Russell Abstract Scottish strawberries were found to be a rich source of phenolic acids, namely benzoic (1287.95 ± 279.98 mg/kg) and cinnamic (1159.40 ± 233.96 mg/kg) acids, both free and attached to other plant components. Studies suggest a chemopreventative role for such compounds in several major clinical conditions, but the anticipated benefits are likely to be affected by their bio-availability and metabolic fate. In this pilot study, strawberries (750 g) was consumed by four healthy human volunteers (32 ± 6 years). Only the benzoic acids were detected in the plasma. Of these, the major free (gentisic, protocatechuic and p -hydroxybenzoic acid) and conjugated (syringic acid) benzoic acids were 26,27% recovered in the urine within 5 h. Cinnamic acids were completely undetected in plasma and only trace amounts were found in the urine. Since, the cinnamic acids escaped absorption early in the gastrointestinal tract, their release and/or metabolism is dependant on the host colonic microbiota. Results indicate that there is a high degree of selective absorption of strawberry phenolic acids into the systemic circulation. If selective absorption of phenolic acids is observed with consumption of other plant-based foods, this is likely to have implications for the bioactive role of these compounds in chronic disease prevention. [source] Willow genotype, but not drought treatment, affects foliar phenolic concentrations and leaf-beetle resistanceENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2004Carolyn Glynn Abstract In a greenhouse experiment we examined the effect of willow genotype and irrigation regime (moderate drought and well-watered) on plant growth parameters, foliar nitrogen, and phenolic concentrations, as well as on the preference and performance of the blue leaf beetle, Phratora vulgatissima (L.) (Coleoptera: Chrysomelidae). The 10 vegetatively propagated willow genotypes in the experiments were F2 full-sibling hybrids, originated from a cross between Salix viminalis (L.) (Salicaceae) (high in condensed tannins) and Salix dasyclados (L.) (Salicaceae) (rich in phenolic glycosides). Insect bioassays were conducted on detached leaves in Petri dishes as well as with free-living insects on intact potted plants. The 10-week long irrigation treatments caused statistically significant phenotypic differences in the potted willow saplings. Total biomass was somewhat higher in the well-watered treatment. The root to total biomass ratio was higher in the drought-treatment plants. There was significant genotypic variation in foliar nitrogen concentrations, and they were higher in the drought-treatment plants. There was also a strong genotypic variation in each of the phenolic substances analyzed. Condensed tannins, which accounted for the greatest proportion of total phenolic mass, were higher in the well-watered treatment. There was, however, no difference in levels of the other phenolics (salicylates, cinnamic acid, flavonoids, and chlorogenic acid) between irrigation treatments. The sum of these phenolics was higher in the well-watered treatment. There was a strong variation in P. vulgatissima larval development on different willow genotypes, and larval performance was negatively correlated with levels of salicylates and cinnamic acid. There was, however, no effect of irrigation treatment on larval performance. Phratora vulgatissima preferred to feed on well-watered plants, and we found a preference for oviposition there, but neither feeding nor oviposition site preference was affected by willow genotype. Adult feeding and oviposition preferences were not correlated with larval performance. [source] Genetically engineered Pseudomonas: a factory of new bioplastics with broad applicationsENVIRONMENTAL MICROBIOLOGY, Issue 10 2001Elías R. Olivera Summary New bioplastics containing aromatic or mixtures of aliphatic and aromatic monomers have been obtained using genetically engineered strains of Pseudomonas putida. The mutation (,) or deletion (,) of some of the genes involved in the ,-oxidation pathway (fadA,, fadB,,fadA or ,fad,BA mutants) elicits a strong intracellular accumulation of unusual homo- or co-polymers that dramatically alter the morphology of these bacteria, as more than 90% of the cytoplasm is occupied by these macromolecules. The introduction of a blockade in the ,-oxidation pathway, or in other related catabolic routes, has allowed the synthesis of polymers other than those accumulated in the wild type (with regard to both monomer size and relative percentage), the accumulation of certain intermediates that are rapidly catabolized in the wild type and the accumulation in the culture broths of end catabolites that, as in the case of phenylacetic acid, phenylbutyric acid, trans -cinnamic acid or their derivatives, have important medical or pharmaceutical applications (antitumoral, analgesic, radiopotentiators, chemopreventive or antihelmintic). Furthermore, using one of these polyesters (poly 3-hydroxy-6-phenylhexanoate), we obtained polymeric microspheres that could be used as drug vehicles. [source] Volatile constituents of benzoin gums: Siam and Sumatra.FLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2003Part Abstract The volatile extract composition of two different benzoin gums, Siam and Sumatra, were analysed by GC,MS. Twenty components representing more than 99.1% of the oil from Siam and 29 components representing more than 97.4% of the oil from Sumatra were analysed. The major components were benzyl benzoate (76.1,80.1%) for the two oils and benzoic acid (12.5%), methyl benzoate (1.5%) and allyl benzoate (1.5%) for Siam, and styrene (2.3%), cinnamic acid (3.5%) and benzyl cinnamate (3.3%) for Sumatra. Volatile compounds of oils and crushed benzoins were also studied using solid-phase microextraction (SPME) employing carboxen/polydimethylsiloxane and carbowax/divinylbenzene ,bres. Copyright © 2003 John Wiley & Sons, Ltd. [source] Oxidative behavior and relative reactivities of some unsaturated compounds towards hexachloroiridate(IV) in perchloric acid mediumINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 7 2002Kalyan K. Sen Gupta The kinetics of the oxidation of styrene, cinnamic acid, and some of their substituted derivatives by hexachloroiridate(IV) in dimethyl formamide,water mixtures and in the presence of perchloric acid have been investigated. The reactions appear to proceed via the formation of an unstable intermediate 1:1 complex between iridium(IV) and the substrate, followed by the decomposition of the complex in the rate-determining step. Correlation with , yielded , values of ,4.0 and ,3.5 which suggests the formation of a cationic intermediate in the rate-determining step of the reaction. Subsequent cleavage of the carbon,carbon bond yielded the product aldehydes. Thermodynamic and activation parameters associated with the equilibrium and the rate-determining steps were also evaluated. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 411,417, 2002 [source] Reduction of dissolved oxygen in boiler water using new redox polymersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2010Christophe Waterlot Abstract New polymers were used as catalysts for the removal of dissolved oxygen in boiler water. These polymers, based upon hydroquinone-quinone redox system, were prepared by polymerization of methyl 4-(2,5-dimethoxybenzyl)cinnamate and copolymerization of this monomer with 4-(4,-vinylphenethyl)-1,10-phenanthroline. The resulting product was used to synthesize polymers containing transition metal ions. Nuclear magnetic resonance, infrared spectroscopy, and elemental analysis were achieved to characterize monomers and/or electron-transfer polymers. These polymers were used for the removal of oxygen from water. It was shown that the oxygen content was reduced to less than 0.1 mg L,1 in , 70 s. Based on the obtained results, the redox capacity of two polymers were determined. It was established that the poly-4-(2,5-dihydroxybenzyl)cinnamic acid reached a redox capacity of 69.7 mg of O2 per gram of polymer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Catalytic performance of cellulose supported palladium complex for Heck reaction in waterJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Ying Xu Abstract Cellulose supported palladium complex was synthesized and characterized by XPS, TG/DTA etc. The complex was found to be an efficient catalyst for Heck reaction of acrylic acid or styrene with aryl iodides at low temperature in water under atmospheric condition, the substituted trans -cinnamic acid or 1,2-stilbene was obtained in stereoselectivity. Repeated tests showed that the catalyst have good reusability. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Comparison of specific interactions in P4VP/PSCA and PS4VP/PSCA blends and complexesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Naima Bouslah Abstract The compatibilization of an immiscible polymer system polystyrene/poly(4-vinylpyridine) has been induced by the introduction of carboxylic acid groups within the polystyrene chains. Poly(styrene- co -cinnamic acid), PSCA, copolymers were used to prepare blends and complexes with poly(4-vinylpyridine), P4VP, and in a second time with poly(styrene- co -4-vinylpyridine), PS4VP, copolymer in order to reduce the density of the interacting groups. The miscibility of the systems has been ascertained by DSC, which revealed that both blends and complexes exhibit a single glass transition temperature indicating their single phase nature. The Tgs of the complexes of PS4VP with PSCA15, containing 15 mol % of cinnamic acid content, were higher than those of the corresponding blends indicating that stronger interpolymer interactions were developed in the complexes. Furthermore, the application of the Kwei equation suggested that P4VP interacts more strongly with PSCA15 than does PS4VP. FTIR spectra revealed the development of hydrogen bonding within the PS4VP/PSCA system and both hydrogen bonding and ionic interaction in the P4VP/PSCA blends whereas the same interactions were expected in both systems. This observation confirmed the stronger ability of P4VP to interact with PSCA copolymer. The viscosimetric study showed both positive and negative deviations of the reduced viscosity of the blends from the additivity law confirming the presence of specific interactions within the blend solutions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Permeability studies of alkylamides and caffeic acid conjugates from echinacea using a Caco-2 cell monolayer modelJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 1 2004A. Matthias Summary Background:, Echinacea is composed of three major groups of compounds that are thought to be responsible for stimulation of the immune system , the caffeic acid conjugates, alkylamides and polysaccharides. This study has focussed on the former two classes, as these are the constituents found in ethanolic liquid extracts. Objective:, To investigate the absorption of these two groups of compounds using Caco-2 monolayers, which are a model of the intestinal epithelial barrier. Results:, The caffeic acid conjugates (caftaric acid, echinacoside and cichoric acid) permeated poorly through the Caco-2 monolayers although one potential metabolite, cinnamic acid, diffused readily with an apparent permeability (Papp) of 1 × 10,4 cm/s. Alkylamides were found to diffuse through Caco-2 monolayers with Papp ranging from 3 × 10,6 to 3 × 10,4 cm/s. This diversity in Papp for the different alkylamides correlates to structural variations, with saturation and N-terminal methylation contributing to decreases in Papp. The transport of the alkylamides is not affected by the presence of other constituents and the results for synthetic alkylamides were in line with those for the alkylamides in the echinacea preparation. Conclusion:, Alkylamides but not caffeic acid conjugates are likely to cross the intestinal barrier. [source] ANTIOXIDANT ACTIVITY AND PHENOLIC ACID CONSTITUENTS OF CHESTNUT (CASTANIA SATIVA MILL.) HONEY AND PROPOLISJOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2009ALI OSMAN SARIKAYA ABSTRACT This study describes the constituents of phenolic acids and antioxidant activities of chestnut (Castania sativa Mill.) honeys and propolis in Turkey. Antioxidant activity of the chestnut honeys and propolis were examined by three different methods, namely scavenging of free radical 2, 2-diphenyl-1-picrylhydrazyl, FRAP, and cupric reducing antioxidant power. Total phenolic contents were determined by using Folin,Ciocalteu reagent as GA equivalent. The phenolic constituents were also determined by HPLC. The antioxidant activities were compared with standard antioxidants such as catechin, BHT and Trolox. The antioxidant activities of all the samples were found high and related to the sample concentrations. The ethanolic propolis extracts showed the highest antioxidant activity. The major phenolic acids of the chestnut honeys and propolis identified by HPLC with PDA detection were coumaric acid, FA, cinnamic acid, CA and ChA. PRACTICAL APPLICATIONS In this study, some phenolic acid components and antioxidant capacity of chestnut (Castania sativa Mill.) honey and propolis were measured. The comparative findings from antioxidant activities and phenolic acid analyses of honey and propolis samples of chestnut origin provide important criteria for considering their nutritional and nutraceutical potentials. Comparison of our results with literature data also ranks the chestnut honey and propolis as better sources of antioxidants among those from other floral origins. [source] Synthesis of carbon-14 labeled [1- 14C]-, and [2- 14C]- L -tyrosineJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 8 2001W. Augustyniak Abstract Two labeled isotopomers of L -tyrosine, L -Tyr, have been synthesized using specific properties of the enzymes phenylanine ammonia lyase, PAL, and L -phenylalanine hydroxylase. In an intermediate step [1- 14C]-, and [2- 14C]- L -phenylalanine, L -Phe, have been obtained from [1- 14C]-, and [2- 14C]cinnamic acid, prepared from potassium [14C]cyanate or [2- 14C]malonic acid, and by addition of ammonia in the presence of enzyme PAL. The labeled isotopomers of L -Phe have been converted into [1- 14C]-, and [2- 14C]- L -Tyr using the enzyme L -phenylalanine hydroxylase. Copyright © 2001 John Wiley & Sons, Ltd. [source] Improved pharmacokinetics of AMG 517 through co-crystallization part 1: Comparison of two acids with corresponding amide co-crystalsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2010Mary K. Stanton Abstract The dissolution and pharmacokinetics (PK) of two carboxylic acid co-crystals (cinnamic acid and benzoic acid) with the corresponding amide co-crystals (cinnamamide and benzamide) of AMG 517 were investigated. Powder and intrinsic dissolution studies were performed in fasted simulated intestinal fluid (FaSIF). Suspension formulations in 1% polyvinylpyrrolidone K25 in water were administered orally at 100,mg/kg to rats. The four co-crystals were found to have faster intrinsic and powder dissolution rates in FaSIF than the free base. This correlated with a 2.4- to 7.1-fold increase in the area under the concentration,time curve in rat PK investigations. When contrasting the acid to its corresponding amide co-crystal, cinnamamide shows improvement over cinnamic acid, while benzamide and benzoic acid perform similarly. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:3769,3778, 2010 [source] Inhibition of browning by antibrowning agents and phenolic acids or cinnamic acid in the glucose,lysine modelJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2005Eun-Jung Kwak Abstract The effects of antibrowning agents and phenolic acids or cinnamic acid on the inhibition of browning were investigated with a glucose,lysine model. Six antibrowning agents (cysteine, glutathione, sodium sulfite, pentasodium tripolyphosphate, citric acid and oxalic acid) and four phenolic acids (ferulic, hydroxybenzoic, syringic and vanillic acids) were used. In order to investigate the antibrowning capacity of these agents, model solutions containing glucose, lysine and an antibrowning agent were heated at 50 °C in the presence of FeCl2, before being stored in nitrogen or air at 4 °C or 30 °C. Browning was accelerated to some degree during storage in air at 30 °C. In the case of storage at 4 °C, however, no browning was detected in nitrogen after four weeks. Citric acid was the most efficient antibrowning agent during storage in air at 30 °C and inhibited browning to 36% after four weeks. However, its antibrowning capacity was increased by 8,15% in the presence of any of the phenolic acids or cinnamic acid, essentially independently of concentration in the range 10 µM to 10 mM or the type of phenolic acid. Copyright © 2005 Society of Chemical Industry [source] Photoluminescent Color and Polarized Light Emission Tuning of Fluorene Derivatives Using a Photoreactive H-Bonded Liquid Crystalline PolymerMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 16 2010Nobuhiro Kawatsuki Abstract Three fluorene (FL) derivatives with pyridine end groups were synthesized to control the photoluminescence (PL) wavelength and polarized light emission using a photoreactive H-bonded polymer containing cinnamic acid side groups (P6CAM). The FL derivatives, which possessed pyridine end groups, formed H-bonds with cinnamic acid, and changed the PL behavior of the derivatives. The controllability ,max of the PL depended on the position of the N-atom at the pyridine end group and the degree of the photoreaction of the P6CAM. For F1, ,max of the PL was tuned from 470 to 518,nm. Employing P6CAM as the photoalignment layer to reorient the cinnamic acid side groups realized polarized PL up to PL||/PL,,=,3.9. Furthermore, photopatterning of the PL color and the direction of the polarized light emission using patterned P6CAM films were demonstrated. [source] Off-line liquid chromatography-MALDI by with various matrices and tandem mass spectrometry for analysis of glycated human serum albumin tryptic peptidesMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 4 2007Annunziata Lapolla Abstract Advanced glycation end-product (AGE)/peptides, arising from in vivo digestion of glycated proteins, are biologically important compounds, due to their reactivity against circulating and tissue proteins. For information on their possible structure, in vitro glycation of HSA and its further enzymatic digestion were performed. The resulting digestion product mixture was analysed directly by MALDI MS with various matrices [2,5-dihydroxy benzoic acid (DHB) and ,-cyano-4-hydroxy cinnamic acid (CHCA)]. Alternatively, offline microbore LC prior to MALDI analysis was used, and showed that 63% of the free amino groups prone to glycation are modified, indicating the contemporary presence of unglycated peptides. This result proves that, regardless of the high glucose concentration employed for HSA incubation, glycation does not go to completion. Further studies showed that the collisionally activated decomposition of singly charged glycated peptides leads to specific fragmentation pathways, all related to the condensed glucose molecule. These unique product ions can be used as effective markers to establish the presence of a glucose molecule within a peptide ion. [source] Control of Aspergillus growth and aflatoxin production using natural maize phytochemicals under different conditions of water activityPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2006Andrea V Nesci Abstract The effects of the natural phytochemicals trans -cinnamic acid (CA) and ferulic acid (FA) alone at concentrations of 1,25 mM and in 16 combinations (M: mixtures) on growth and aflatoxin B1 production by Aspergillus flavus Link and A. parasiticus Speare were evaluated. Studies on growth rate and aflatoxin B1 production were carried out in vitro in relation to a water activity aw of 0.999, 0.971, 0.955 and 0.937. Overall, CA at concentrations of 10 and 20 mM and FA,CA mixtures M3 (20 + 5 mM respectively), M8 (25 + 5 mM), M9 (1 + 10 mM), M10 (10 + 10 mM), M11 (20 + 10 mM), M12 (25 + 10 mM), M13 (1 + 20 mM), M14 (10 + 20 mM), M15 (20 + 20 mM) and M16 (25 + 20 mM) were the treatments most effective at inhibiting growth of the four species assayed. All strains were much more sensitive to all natural phytochemicals tested on growth rate at aw = 0.937. CA and the FA,CA mixtures M1 (1 + 1 mM respectively), M4 (25 + 1 mM), M5 (1 + 5 mM), M6 (10 + 1 mM), M7 (20 + 1 mM), M8 (25 + 5 mM), M9 (1 + 10 mM), M10 (10 + 10 mM), M11 (20 + 10 mM), M12 (25 + 10 mM), M13 (1 + 20 mM), M14 (10 + 20 mM), M15 (20 + 20 mM) and M16 (25 + 20 mM) completely inhibited aflatoxin B1 production by all strains at aw = 0.999, 0.971, 0.955 and 0.937. Decreased aflatoxin B1 levels in comparison with the control were observed with FA at 1, 10, 20 and 25 mM with the strains RCM89, RCM108 and RCM38 at aw = 0.971, 0.955 and 0.999 respectively. The data show that CA and FA can be considered as effective fungitoxicants for A. flavus and A. parasiticus in in vitro assay. The information obtained is part of an ongoing study to determine their application at the storage level. Copyright © 2006 Society of Chemical Industry [source] A new catalytic activity from tobacco converting 2-coumaric acid to salicylic aldehydePHYSIOLOGIA PLANTARUM, Issue 3 2007Jacek Malinowski Salicylic acid (SA) mediates plant response to pathogen invasion, resulting in hypersensitive response and in the formation of systemic acquired resistance. It is well known that Nicotiana tabacum and other plants respond to Tobacco Mosaic Virus (TMV) infection by increasing the content of SA but the details of SA biosynthesis are still not fully understood. Generally, SA may originate directly from isochorismate (Arabidopsis thaliana), or its C6,C1 skeleton could be synthesized via the phenylpropanoid pathway by ,-oxidation of trans -cinnamic acid (N. tabacum), 2-coumaric acid (OCA) (Gaulteria procumbens, Lycopersicum esculentum) or by retro-aldol reaction of trans -cinnamoyl-CoA (Hypericum androsaemum). We report here a novel putative enzyme activity from tobacco, salicylic aldehyde synthase (SAS), catalysing non-oxidative formation of salicylic aldehyde (SALD) directly from OCA. This chain-shortening activity is similar to that of 4-hydroxybenzaldehyde synthase from Vanilla planifolia, Lithospermum erythrorhizon, Daucus carota, Solanum tuberosum and Polyporus hispidus but the enzyme differs in the kinetics of the reaction, substrate specificity and requirements for reducing cofactors. SAS activity is constitutively expressed in healthy tobacco leaves and doubles as a result of infection with TMV. Moreover, the product of SAS activity,SALD, applied exogenously on tobacco leaves, stimulates peroxidase activity and enhances resistance to consecutive infection with TMV. These observations could suggest a contribution of SAS and SALD to the response of tobacco to TMV infection. [source] Mutations in the cinnamate 4-hydroxylase gene impact metabolism, growth and development in ArabidopsisTHE PLANT JOURNAL, Issue 5 2009Anthony L. Schilmiller Summary The initial reactions of the phenylpropanoid pathway convert phenylalanine to p -coumaroyl CoA, a branch point metabolite from which many phenylpropanoids are made. Although the second enzyme of this pathway, cinnamic acid 4-hydroxylase (C4H), is well characterized, a mutant for the gene encoding this enzyme has not yet, to our knowledge, been identified, presumably because knock-out mutations in this gene would have severe phenotypes. This work describes the characterization of an allelic series of Arabidopsis reduced epidermal fluorescence 3 (ref3) mutants, each of which harbor mis-sense mutations in C4H (At2g30490). Heterologous expression of the mutant proteins in Escherichia coli yields enzymes that exhibit P420 spectra, indicative of mis-folded proteins, or have limited ability to bind substrate, indicating that the mutations we have identified affect protein stability and/or enzyme function. In agreement with the early position of C4H in phenylpropanoid metabolism, ref3 mutant plants accumulate decreased levels of several different classes of phenylpropanoid end-products, and exhibit reduced lignin deposition and altered lignin monomer content. Furthermore, these plants accumulate a novel hydroxycinnamic ester, cinnamoylmalate, which is not found in the wild type. The decreased C4H activity in ref3 also causes pleiotropic phenotypes, including dwarfism, male sterility and the development of swellings at branch junctions. Together, these observations indicate that C4H function is critical to the normal biochemistry and development of Arabidopsis. [source] Trans -cinnamic acid and coumarin-3-carboxylic acid: experimental charge-density studies to shed light on [2,+,2] cycloaddition reactionsACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2009Judith A. K. Howard As part of an ongoing series of experimental charge-density investigations into the intra- and intermolecular interactions present in compounds which undergo solid-state [2,+,2] cycloaddition reactions, the charge-density analyses of trans -cinnamic acid and coumarin-3-carboxylic acid are reported. Thus, high-resolution single-crystal X-ray diffraction data were recorded at 100,K for trans -cinnamic acid (sin,,/,max = 1.03,Å,1) and coumarin-3-carboxylic acid (sin,,/,max = 1.19,Å,1). In addition to the anticipated O,H...O hydrogen bonds weak C,H...O interactions were identified in both structures along with very weak intermolecular interactions between pairs of molecules that undergo solid-state [2,+,2] cycloaddition reactions upon irradiation. [source] Intake of phytochemicals among Japanese, calculated by the new FFF databaseBIOFACTORS, Issue 1-4 2004Junko Kita Abstract Effects of phytochemicals on human health are suggested from various animal experiments, but human studies remain insufficient. We have constructed a database of various phytochemicals (polyphenols, carotenoids, and sulphur compounds) (http://www.life-science.jp/fff/) and estimated the amount of intake among Japanese population. The subjects were volunteers (16 males and 63 females, averagely aged 71 and 61, respectively) in Iwate city. Average BMI was 23 in both sexes. Intake of 36 phytochemicals was calculated from one-day dietary records of all intake, by multiplying concentrations of each phytochemical in foods. Phytochemicals with average intake of at least 10 ,mole per day were catechin, isoflavones, isothiocyanate, ferulic acid, quercetin, cinnamic acid and chlorogenic acid. Chief component analysis yielded 12 factors (80%). [source] Alterations in Taxol Production in Plant Cell Culture via Manipulation of the Phenylalanine Ammonia Lyase PathwayBIOTECHNOLOGY PROGRESS, Issue 6 2002Michelle C. Brincat One approach to increasing secondary metabolite production in plant cell culture is to manipulate metabolic pathways to utilize more resources toward production of one desired compound or class of compounds, such as diverting carbon flux from competing secondary pathways. Since phenylalanine provides both the phenylisoserine side chain and the benzoyl moiety at C-2 of Taxol, we speculated that blockage of the phenylpropanoid pathway might divert phenylalanine into Taxol biosynthesis. We used specific enzyme inhibitors to target the first enzyme in the phenylpropanoid pathway, phenylalanine ammonia lyase (PAL), the critical control point for conversion of l -phenylalanine to trans -cinnamic acid. Cinnamic acid acted quickly in reducing PAL activity by 40,50%, without affecting total protein levels, but it generally inhibited the taxane pathway, reducing Taxol by 90% of control levels. Of the taxanes produced, 13-acetyl-9-dihydro-baccatin III and 9-dihydrobaccatin III doubled as a percentage of total taxanes in C93AD and CO93P cells treated with 0.20 and 0.25 mM cinnamic acid, when all other taxanes were lowered. The PAL inhibitor ,-aminooxyacetic acid (AOA) almost entirely shut down Taxol production at both 0.5 and 1.5 mM, whereas l -,-aminooxy-,-phenylpropionic acid (AOPP) had the opposite effect, slightly enhancing Taxol production at 1 ,M but having no effect at 10 ,M. The discrepancy in the effectiveness of AOA and AOPP and the lack of effect with addition of phenylalanine or benzoic acid derivatives further indicates that the impact of cinnamic acid on Taxol is related not to its effect on PAL but rather to a specific effect on the taxane pathway. On the basis of these results, a less direct route for inhibiting the phenylpropanoid pathway may be required to avoid unwanted side effects and potentially enhance Taxol production. [source] Enzymatic Synthesis of Enantiopure ,- and ,-Amino Acids by Phenylalanine Aminomutase-Catalysed Amination of Cinnamic Acid DerivativesCHEMBIOCHEM, Issue 2 2009Bian Wu Abstract The phenylalanine aminomutase (PAM) from Taxus chinensis catalyses the conversion of ,-phenylalanine to ,-phenylalanine, an important step in the biosynthesis of the N -benzoyl phenylisoserinoyl side-chain of the anticancer drug taxol. Mechanistic studies on PAM have suggested that (E)-cinnamic acid is an intermediate in the mutase reaction and that it can be released from the enzyme's active site. Here we describe a novel synthetic strategy that is based on the finding that ring-substituted (E)-cinnamic acids can serve as a substrate in PAM-catalysed ammonia addition reactions for the biocatalytic production of several important ,-amino acids. The enzyme has a broad substrate range and a high enantioselectivity with cinnamic acid derivatives; this allows the synthesis of several non-natural aromatic ,- and ,-amino acids in excellent enantiomeric excess (ee >99,%). The internal 5-methylene-3,5-dihydroimidazol-4-one (MIO) cofactor is essential for the PAM-catalysed amination reactions. The regioselectivity of amination reactions was influenced by the nature of the ring substituent. [source] | |||||||||||||||||||||||||||||||