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The aim of this work was to study the physicochemical and kinetic properties of chlorogenate hydrolase (CHase) (EC 3.1.1.42) of Aspergillus niger AKU 3302 by induction in the presence of yerba mate extract. The data obtained could be applicable directly to mass processing for a plant scale production of quinic acid (QA) and caffeic acid (CA) with koji CHase. It is fundamentally significant to accumulate catalytic properties of CHase as much as possible with crude CHase, when koji CHase is directed to practical industrial processing of breakdown of chlorogenate (CGA). CHase exhibited a high thermal stability without appreciable loss after standing for 6 h at 50 °C and was stable in wide pH ranges from 2.0 to 9.0. The optimum pH and temperature of CHase activity were found at 6.5–7.0 and 45 °C, respectively. The Vmax and Km values for CGA hydrolysis were 1.996 unit mg−1 and 0.72 mM, respectively. The activation energy of CHase was estimated to be 26 kJ mol−1. Thus, CHase induced with CGA revealed successful for the production of CA and QA, fine chemicals of high interest and commercial values, from natural plant resources rich in CGA such as yerba mate. Several advantageous merits obtained with a crude CHase for the practical formation of QA and CA from yerba mate or yerba mate extract are discussed. Fil: Butiuk, Ana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina Fil: Maidana, Silvana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina Fil: Martos, María Alicia. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina Fil: Akakabe, Yoshihiko. Yamaguchi University; Japón Fil: Adachi, Osao. Yamaguchi University; Japón Fil: Hours, Roque Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentina

Chlorogenic acid (CGA) and its hydrolysis products, quinic and caffeic acids are considered as fine chemicals and have a high commercial value. Yerba mate stems, useless residue from yerba mate processing, contains significant amounts of CGA. The goal of this study was to determine the best conditions for maximizing the CGA aqueous extraction from residues of yerba mate processing and to fit the extraction kinetics to empirical models. The effect of single factors such as solid-liquid ratio, numbers of extraction, temperature and time were studied for two particle sizes, using one factor at a time method and Response Surface Methodology (RSM). The highest and almost instantaneous CGA extraction (1.051 ± 0.015 gCGA L−1) was obtained using O particle size particle size >1 × 5 mm) the optimized conditions were 85 ± 5 °C and 25 ± 5 min, solid-liquid ratio of 1:20 and double stage extraction. For these last particles, the applied models of Pilosof et al. and Spiro and Jago showed a good agreement with the experimental and model calculated data. In the present study, it was possible to optimize the CGA extraction conditions for two particle sizes of yerba mate stems, in order to obtain extracts with high content of CGA that can be used in the production of others fine chemicals of interest in pharmaceutical industries.

Eight-carbon (C8) volatiles, such as 1-octen-3-ol, octan-3-one, and octan-3-ol, are ubiquitously found among fungi and bryophytes. In this study, it was found that the thalli of the common liverwort Marchantia polymorpha, a model plant species, emitted high amounts of C8 volatiles mainly consisting of (R)-1-octen-3-ol and octan-3-one upon mechanical wounding. The induction of emission took place within 40min. In intact thalli, 1-octen-3-yl acetate was the predominant C8 volatile while tissue disruption resulted in conversion of the acetate to 1-octen-3-ol. This conversion was carried out by an esterase showing stereospecificity to (R)-1-octen-3-yl acetate. From the transgenic line of M. polymorpha (des6(KO)) lacking arachidonic acid and eicosapentaenoic acid, formation of C8 volatiles was only minimally observed, which indicated that arachidonic and/or eicosapentaenoic acids were essential to form C8 volatiles in M. polymorpha. When des6(KO) thalli were exposed to the vapor of 1-octen-3-ol, they absorbed the alcohol and converted it into 1-octen-3-yl acetate and octan-3-one. Therefore, this implied that 1-octen-3-ol was the primary C8 product formed from arachidonic acid, and further metabolism involving acetylation and oxidoreduction occurred to diversify the C8 products. Octan-3-one was only minimally formed from completely disrupted thalli, while it was formed as the most abundant product in partially disrupted thalli. Therefore, it is assumed that the remaining intact tissues were involved in the conversion of 1-octen-3-ol to octan-3-one in the partially disrupted thalli. The conversion was partly promoted by addition of NAD(P)H into the completely disrupted tissues, suggesting an NAD(P)H-dependent oxidoreductase was involved in the conversion.

Plant fatty acid alpha-dioxygenases (DOXs) catalyze the stereospecific conversion of fatty acids into the corresponding (R)-2-hydroperoxy fatty acids. In several plant species the corresponding gene was shown to be induced by pathogen infection, herbivore attack and environmental stresses. The precise signaling pathway accountable for the induction remains unidentified. In the present study, the effects of bacterial infection, oxidative- and heavy metal-stresses, and plant signaling molecules such as jasmonate, salicylic acid (SA), and ethylene (ET) on expression of a fatty acid alpha-DOX (OsDOX) gene in rice seedlings were investigated. The rice blight bacteria, Xanthomonas oryzae, elicited the accumulation of OsDOX transcripts in the leaves in both the incompatible and compatible interactions. Treating the seedling with CuSO4 also significantly enhanced the OsDOX expression. The degree of induction was shown to be mostly parallel to the level of endogenous jasmonic acid (JA) in the leaves. In contrast, SA was little effective and ET down-regulated not only the OsDOX expression but also the endogenous level of JA in rice seedlings. These results suggested that the OsDOX gene expression by a variety of stress-related stimuli was activated through jasmonate signaling and was negatively regulated by ET.

Long-chain fatty acids can be metabolized to C n −1 aldehydes by α-oxidation in plants. The reaction mechanism of the enzyme has not been elucidated. In this study, a complete nucleotide sequence of fatty acid α-oxygenase gene in rice plants (Oryza sativa) was isolated. The deduced amino acid sequence showed some similarity with those of mammalian prostaglandin H synthases (PGHSs). The gene was expressed in Escherichia coli and purified to apparently homogenous state. It showed the highest activity with linoleic acid and predominantly formed 2-hydroperoxide of the fatty acid (C n ), which is then spontaneously decarboxylated to form corresponding C n −1 aldehyde. With linoleic or linoleic acids as a substrate, rice α-oxygenase formed no product having aλ max at approximately 234 nm, which indicated that the enzyme could not oxygenize the pentadiene system in the substrate. The spectroscopic feature of the purified enzyme in its ferrous state is similar to that of mammalian PGHS, whereas that of dithionite-reduced state showed significant difference. Site-directed mutagenesis revealed that His-158, Tyr-380, and Ser-558 were essential for the α-oxygenase activity. These residues are conserved in PGHS and known as a heme ligand, a source of a radical species to initiate oxygenation reaction and a residue involved in substrate binding, respectively. This finding suggested that the initial step of the oxygenation reaction in α-oxygenase has a high similarity with that of PGHS. The rice α-oxygenase activity was inhibited by imidazole but hardly inhibited by nonsteroidal anti-inflammatory drugs, such as aspirin, ibuprofen, and flurbiprofen, which are known as typical PGHS inhibitors. In addition, peroxidase activity could not be detected with α-oxygenase when palmitic acid 2-hydroperoxide was used as a substrate. From these findings, the catalytic resemblance between α-oxygenase and PGHS seems to be evident, although there still are differences in their substrate recognitions and peroxidation activities.

When palmitic acid was incubated with crude enzyme of marine green alga Ulva pertusa, (R)-2-hydroperoxyhexadecanoic acid was formed in high enantiomeric purity (>99%ee).

Long-chain aldehydes (LCA), such as pentadecanal (PD), (8Z,11Z)-heptadecadienal (HDD) and (8Z,11Z,14Z)-heptadecatrienal (HDT), were identified in the essential oils obtained from fresh green tobacco leaves (Nicotiana tabacum cv. BY2 and N. tabacum cv. MC). PD, HDD and HDT were found to be produced enzymatically from palmitic acid (PA), linoleic acid and α-linolenic acid, respectively. LCA-forming activity for PA changed during growth of tobacco leaves and was highest at flowering time.

(−)-( 3R,4R )-3-Butyl-4-vinylcyclopentene [(−)- 1 ] was synthesized via (+)-( 1S,5R )-3-oxabicyclo [3,3,0] oct-6-en-2-one. Synthetic (−)- 1 coincided with the peak with later retention time of racemic (±)- 1 in a chiral GC (CP-Cyclodex 236M), while the natural 1 in essential oils from the marine brown algae, Dictyopteris prolifera and D . sp. was identical with the earlier retention time peak. Thus, the absolute configuration of the natural product in Dictyopteris oils was determined as (+)-( 3S,4S ) with ca 100% enantiomeric excess.

Immobilized cells of Daucus carota transformed acetophenone into (S)-α-phenethyl alcohol by a stereoselective reduction pathway. Immobilized cells of Nicotiana tabacum also transformed the same substrate into the (S)-alcohol, but neither stereoselective reduction nor stereoselective oxidation was observed in the biotransformation process. (R)- and (S)-α-phenethyl alcohol of a high enantiomeric purity of > 99% ee can be prepared by the biotransformation of acetophenone with immobilized cells of Gardenia jasminoides and Daucus carota.

When linoleic and linolenic acid were incubated with a crude enzyme of marine green alga Ulva conglobata, the corresponding (R)-9-hydroperoxy-(10E, 12Z)-10, 12-octadecadienoic acid [(R)-9-HPODE] and (R)-9-hydroperoxy-(10E, 12Z, 15Z)-10, 12, 15-octadecatrienoic acid [(R)-9-HPOTrE] were formed with a high enantiomeric excess (>99%), respectively.

The essential oil from the shoots of the marine embryophyte, Zostera marina was prepared by simultaneous distillation-extraction. Volatile compounds in the oil were identified by GC and GC-mass spectrometry. The major constituents were phytol, hexadecanamide, octadecanamide, pentadecane, heptadecane, nonadecane, (8 Z , 11 Z )-heptadecadienal (HDD), (8 Z )-heptadecenal (HD), (9 Z , 12 Z , 15 Z )-octadecatrienal and (9 Z , 12 Z )-octadecadienal. HDD and HD were shown to be formed enzymatically from linoleic acid and oleic acid, respectively.

Immobilized cells of Gardenia jasminoides enantioselectively transformed acetophenone into the corresponding ( R )-alcohol by a two-step pathway involving initial reduction of the aromatic ketone to produce a mixture of ( R )- and ( S )-α-phenethyl alcohol followed by stereoselective oxidation of the ( S )-aromatic alcohol to produce acetophenone.

Immobilized cells of Daucus carota enantioselectively transformed aromatic ketones such as acetophenone and propiophenone, into the corresponding ( S )-alcohols with an optical purity of 89–99% ee in a chemical yield of 54–70%. Immobilized Gardenia jasminoides cells yielded the ( R )-alcohols with a 63–91% ee.