pinecone/core-2020-05-10-deduplication huggingface dataset:
The incorporation of plant materials in “Serra da Estrela” cheese improves antioxidant activity without changing the fatty acid profile and visual appearance

“Serra da Estrela” cheese is a Portuguese delicacy, which has been produced for centuries from the milk of cattle pasturing in the protected Serra da Estrela natural park. Transforming this cheese into a functional food would be a huge benefit for the market and the consumer. Decocted extracts and dried chestnut flowers and lemon balm plants were incorporated into the cheese to functionalize it, granting antioxidant activity to this foodstuff. The functionalized cheeses showed higher antioxidant activity, especially lipid peroxidation inhibition. The incorporation of dried plants appeared to be more effective than using decoctions, but the influence of the plant species was less observable. Furthermore, the fatty acids profile of the cheeses was also determined through gas chromatography. C18:1 and C16:0 were the most abundant fatty acids; saturated fatty acids prevailed over the unsaturated ones. Between the control and the incorporated samples no significant differences were found. In addition, the external color was measured through a spectrophotometer for lightness, yellowness and redness. There were some differences recorded for each samples’ color. In general, the results indicated that the functionalization of this exquisite dairy product with natural plant extracts provided beneficial characteristics, both for consumers (healthier product) and producers (added-value products).The authors are grateful to the companies Queijos Casa Matias, Lda and Mais Ervas, Lda. for providing the cheese and M. officinalis samples, respectively. The authors also acknowledge PRODER project No. 46577-Plant Lact., and the Foundation for Science and Technology (FTC, Portugal) for financial support to the research center CIMO (Pest-OE/AGR/UI0690/2011)
Improvement of sensorial and volatile profiles of olive oil by addition of olive leaves

The changes caused by the addition of olive leaves (0, 5, and 10%) during the extraction of olive oil and malaxation time (20, 30, and 30 min) in the volatile profile and sensory attributes of olive oil from cv. Cobrançosa were studied. To investigate such transformations, a central composite designs from the Response Surface Methodology (RSM) was used, retrieving 13 runs combining leaf percentages and malaxation times. Each run was extracted in triplicate (39 olive oils overall). Sensory attributes were improved to leaves addition, mainly green and fruitiness attributes in olfactory and gustatory-olfactory sensations, but high malaxation times ( > 30 min) reduced pungent and bitter notes. Leaves addition increased the amounts of total volatiles, particularly the GLV's (green leaves volatiles) (E)-2-hexenal, (Z)-3-hexenal, and (Z)-3-hexenyl acetate, directly correlated with the improved sensory attributes. RSM models a showed positive linear effect with leaves addition, but a negative effect with malaxation time. These results suggest the use of olive leaves as effective odorants for the olive mill industry, while enabling the reduction of malaxation times and by-product amounts. Practical applications: The results obtained clearly open new lines of research to use olive leaves, a sub-product of olive oil extraction, in a valuable way. Olive leaves can be used as natural sources of odorants for olive oils. Furthermore, their use during the extraction of olive oils from overmature olives may also lead to an improvement of the volatile fraction and provide enhanced sensory properties to the consumers, thus conferring an added value to these oils. Another important practical application is the extraction process. In our work, we advise to optimize both the percentage of leaves and the malaxation time as much as possible, as they facilitate both sensory and volatile fractions of the extracted olive oils. Sensory attributes are improved to leaves addition, mainly green and fruitiness attributes in olfactory 17 and gustatory-olfactory sensations, but high malaxation times ( > 30 min) reduced pungent and bitter 18 notes. Leaves addition increase the amounts of total volatiles, particularly the GLV's (green leaves 19 volatiles) (E)-2-hexenal, (Z)-3-hexenal, and (Z)-3-hexenyl acetate, directly cor related with the improved 20 sensory attributes. RSM models a show positive linear effect with leaves addition, but a negative effect 21 with malaxation time. These results suggest the use of olive leaves as effective odorants for the olive mill 22 industry, while enabling the reduction of malaxation times and by-product amounts.Ricardo Malheiro thanks FCT, POPH-QREN and FSE for the
Post-Doctoral grant (SFRH/BPD/111901/2015).info:eu-repo/semantics/publishedVersio
Cyclisation of Novel Amino Oxo Esters to Tetramic Acids - Density Functional Theory Study of the Reaction Mechanism

The synthesis of novel N-urethane-protected gamma-methylamino-beta-oxo esters and their use as precursors for the preparation of N-methyltetramic acids is described. The presence of the bulky urethane protecting group on the nitrogen atom gives rise to rotational isomers detectable in the NMR spectra of the compounds, along with the keto/enol tautomerism. The mechanism of the cyclisation reaction of gamma-amino-beta-oxo esters to tetramic acids was studied theoretically by the B3LYP hybrid density functional method. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Sonogashira cross-couplings of dehydroamino acid derivatives and phenylacetylenes

Several phenylacetylenes were coupled under Sonogashira cross coupling conditions  with the methyl esters of N-(tert-butoxycarbonyl)-(E)-beta-bromo or beta, beta-dibromodehydroalanine to give respectively beta-substituted or beta,beta-bis-substituted dehydroalanines.  The beta-substituted dehydroalanines were obtained in good to high yields (60-90%) under the usual Sonogashira conditions (1 equiv. of the phenylacetylene, 1 mol% Pd(PPh3)4, 2 mol% CuI 18 equiv. NEt3 in  acetonitrile, 24h at rt) with maintenance of the stereochemistry. The beta,beta-bis-substituted dehydroalanines were in turn obtained in moderate to good yields (44-63%) requiring modified Sonogashira conditions (4 equiv. of the phenylacetylene,10 mol% PdCl2(PPh3)2, 20 mol% CuI, 1.4 equiv. Cs2CO3, 2h at reflux of acetonitrile). In the latter reactions some phenylacetylene dimer and the (E)-isomer of the mono substituted coupled products were also isolated in some extent. 
The Sonogashira products which were obtained from the 4-bromophenylacetylene were reacted with functionalized benzo[b]thiophenes under C-C or C-N palladium-catalyzed cross-coupling conditions.
Preliminary fluorescence studies were performed for mono and disubstituted 4-aminophenylacetylenic dehydroamino acids and for the benzo[b]thiophene derivatives. The results showed that some of the dehydroalanines prepared can be used as fluorescent probes.Fundação para a Ciência e Tecnologia - POCTI/99/QUI/32689, SFRH/BD/4709/2001
Selenium-Containing Heterocycles From Isoselenocyanates: Synthesis of 1,3-Selenazolidine and Perhydro-1,3-selenazine Derivatives

Treatment of ω-halo alkylamines 9 and 10 with aryl and alkyl\ud
isoselenocyanates 6a–g in the presence of triethylamine in\ud
dichloromethane gave the corresponding 1,3-selenazolidines\ud
11a–g and perhydro-1,3-selenazines 12a–g, respectively, in\ud
good to excellent yields. Chemical and spectroscopic evidence\ud
for the structures of all new compounds are presented, and in selected examples the molecular structures have been established by X-ray crystallography. The analogous reactions with isothiocyanates have been used for the preparation\ud
of 1,3-thiazolidines and perhydro-1,3-thiazines
A highly selective synthesis of the indolo[2,3-a]quinolizine ring system and application to natural product synthesis

This article has been published in the journal, European Journal of Organic Chemistry [© Wiley-VCH Verlag].  The definitive version, ALLIN, S. et al., 2005. A highly selective synthesis of the indolo[2,3-a]quinolizine ring system and application to natural product synthesis. European Journal of Organic Chemistry, 19, pp.4179-4186, is available at: https://doi.org/10.1002/ejoc.200500412.We present a facile and highly stereoselective approach to the indolo[2,3-a]quinolizine ring\ud
system from a readily available, non-racemic chiral template. We demonstrate the potential for\ud
application of this methodology to natural product synthesis through conversion of the\ud
template to some representative indole alkaloids with high enantiomeric purity in both\ud
enantiomeric series
2-arylthienyl-substituted 1,3-benzothiazoles as new nonlinear optical chromophores

A series of nonlinear optical chromophores 6 containing a substituted benzothiazole ring have  been synthesized and characterized. 1,3-Benzothiazoles 6 were prepared by reacting various  formyl derivatives of thienyl compounds with ortho-aminobenzenethiol in fair to excellent  yields. These in turn were prepared by Suzuki coupling between aryl and thienyl precursors.  The electronic interactions between donor and acceptor end groups in the conjugated 1,3-benzothiazoles 6 are expressed in the intense and markedly solvatochromic CT transitions.  The  solvatochromic  behaviour  of  compounds  6  was  determinated  by  linear  regression  analyses of absorption maxima in several solvents, whereby benzothiazole 6f was found to be  a  very  appropriate  indicator  dye  whose  absorption  wavenumbers  (νmax=  1590  cm –1)  in  aliphatic and dipolar aprotic and in aromatic and chlorinated solvents excellently correlate  with  the  π*  values  defined  by  Kamlet  and  Taft.  Hyper-Rayleigh  scattering  was  used  to  measure the first hyperpolarizabilities β of the mentioned compounds. Thermo gravimetric  analysis (TGA) was used to evaluate their thermal stability. The experimental results indicate  that good nonlinearity–thermal stability is well balanced for chromophores 6, making them  good candidates for device applications.Fundação para a Ciência e Tecnologi
Synthesis of Alkaloid Analogues from β-Amino Alcohols by β-Fragmentation of Primary Alkoxyl Radicals

10 pages, 1 table, 12 schemes.-- Available online Nov 6, 2006.Supporting information available at: http://www.wiley-vch.de/contents/jc_2046/2007/o200600720_s.pdfThe fragmentation of primary alkoxyl radicals is usually a minor process with respect to hydrogen abstraction and other competing reactions. However, when β-amino alcohols were used as substrates, the scission proceeded in good to excellent yields and no side reactions were observed. The fragmentation can be coupled with an allylation or alkylation reaction, to give alkaloid analogues and functionalized nitrogen heterocycles.This work was supported by the Investigation Programs PPQ2000-0728 and PPQ2003-01379 (Plan Nacional de I+D, Ministerios de Ciencia y Tecnología and Educación y Ciencia, Spain) and Proyecto Intramural del CSIC 2004-8-0E211. We also acknowledge financial support from FEDER funds. D. H. thanks the Ministerio de Educación y Ciencia for an FPU fellowship. A. M. thanks the\ud
C.S.I.C. for an I3P fellowship
SN2' alkylation of chiral allylic cyanohydrin o-phosphates with organocuprates

Enantiomerically enriched cyanohydrin O-phosphates, prepared
by enantioselective cyanophosphorylation of α,β-unsaturated
aldehydes, react regioselectively at the γ-position
with organocuprates derived from alkyl Grignard reagents
and CuCN to afford chiral γ-alkyl-substituted α,β-unsaturated
nitriles. The configuration of the new C–C double bond
is mainly (E) when the reaction is performed at –78 °C and
(Z) when it is carried out at higher temperatures (0 °C). A
high level of transfer of the chirality in the new stereocentre,
corresponding to a stereospecific anti attack onto the cyanophosphate, is observed. Enantiomerically enriched (E)-γ-alkylated
α,β-unsaturated esters are prepared after subsequent
methanolysis in a three-step sequence from the corresponding
α,β-unsaturated aldehydes. In addition, the synthesis of
(R)-4-methylnonan-1-ol, also known as the sex pheromone of
the yellow mealworm Tenebrio molitor L, and its (S) enantiomer
have been carried out in a four-step route from (E)-oct-2-enal.This work has been supported by the DGES of the Spanish Ministerio
de Educación y Ciencia (MEC) (CTQ2004-00808/BQU), the
Generalitat Valenciana (CTIOIB/2002/320, GRUPOS03/134 and
GV05/144) and the University of Alicante
Asymmetric conjugate addition of ketones to β-nitrostyrenes by means of 1,2-amino-alcohol-derived prolinamides as bifunctional catalysts

Different L-prolinamides 21, prepared from L-proline and chiral
β-amino alcohols are active bifunctional catalysts for the
direct nitro-Michael addition of ketones to β-nitrostyrenes. In
particular, catalyst 21e, prepared from L-proline and (1S,2R)-
cis-1-amino-2-indanol, exhibits the highest catalytic performance
working in polar aprotic solvents such as NMP, especially
in the presence of 20 mol-% of acid additives such
as p-nitrobenzoic acid or under microwave heating. High syn
diastereoselectivities (up to 94% de) and good enantioselectivities
(up to 80%ee) are obtained at room temp. Moreover,
catalyst 21e can be easily recovered and reused. ESIMS
studies are used to characterize the intermediates assumed for the catalytic cycle. The stereochemical control attending
Michael addition reactions between ketones and nitrostyrenes
catalyzed by prolinamide derivatives 21 has been
investigated with computational density functional methods.
Transition-state energies for the rate-limiting C–C bondforming
step are calculated. Analysis of these structures indicates
that hydrogen bonding plays an important role in catalysis,
and that the energy barrier for Re-face attack to form
syn-(4S,5R) products is lower than that for Si-face attack
leading to syn-(4R,5S) products.This work has been supported by the Dirección General de Investigación
of the Ministerio de Educación y Ciencia (CTQ2004-00808/BQU), by the Generalitat Valenciana (CTIOIB/2002/320,
GRUPOS03/134, GRUPOS05/11 and GV05/157) and the University
of Alicante
Epoxidation of (E,E)-cinnamylideneacetophenones with hydrogen peroxide and iodosylbenzene with salen-mnIII as the catalyst

(E,E)-Cinnamylideneacetophenones 3a–j were epoxidized
under mild conditions with Jacobsen’s catalyst 4 and hydrogen
peroxide or iodosylbenzene as oxidants. γ,δ-Monoepoxides
and a diastereomeric mixture of α,β:γ,δ-diepoxides were
obtained in each case, and only the α,β-monoepoxide of 4-
nitrocinnamylideneacetophenone (3d) was isolated. The
presence of a methyl group in the vinylic moiety of substrates
3i,j allowed the formation of two γ,δ-monoepoxide diastereomers.
The epoxidation of (E,E)-2 -hydroxycinnamylid-
Introduction
Salen MnIII complexes are efficient catalysts for the epoxidation
of various olefinic compounds.[1–3] Since the pioneering
work of Kochi et al.,[4] many contributors have reviewed
a wide range of applications of these powerful and
selective catalysts.[5–7] Several oxidants have been used as
effective oxygen donors in these epoxidations, with iodosylbenzene[
8–11] and sodium hypochlorite[12–14] being the
most frequently reported. Among other common olefin oxidants
hydrogen peroxide,[15–17] oxone®,[18] dimethyldioxirane
(DMD),[19–23] m-chloroperbenzoic acid (MCPBA),[24]
molecular oxygen[25] and more recently also tetrabutylammonium
monosulfate[24,26,27] and tetrabutylammonium periodate[
28] have been used. Alkene epoxidation can also be
achieved with simple co-catalysts such as imidazoles, pyridines
and tertiary amine N-oxides, which act as axial ligands
and, in some cases, as phase-transfer catalysts.[29–31]
[a] Department of Agro-Industries, Escola Superior Agrária de
Bragança,
5301-855 Bragança, Portugal
Fax: +351-273-325405
E-mail: clems@ipb.pt
[b] Department of Chemistry, University of Aveiro,
3810-193 Aveiro, Portugal
Fax: +351-234-370084
E-mail: arturs@dq.ua.pt
[c] Department of Organic Chemistry, University of Debrecen,
4010 Debrecen, Hungary
Fax: +36-52-453836
E-mail: alevai@puma.unideb.hu
Eur. J. Org. Chem. 2007, 2877–2887 © 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 2877
eneacetophenones 3h,j led to the formation of the corresponding
γ,δ-monoepoxides as well as (E)-2,3-trans-3-hydroxy-
2-styryl-4-chromanones, which originated from the in
situ cyclisation of 2,3-epoxy-1-(2-hydroxyphenyl)-5-phenyl-
4-penten-1-ones. The structures of all new compounds and
the stereochemistry of the mono- and diepoxide diastereomers
were established by NMR studies
Hydrophobically directed aldol reactions: polystyrene-supported L-proline as a recyclable catalyst for direct asymmetric aldol reactions in the presence of water

A simple synthetic methodology for the preparation of a polystyrene-\ud
supported L-proline material is reported, and this\ud
material has been used as catalyst in direct asymmetric aldol\ud
reactions between several ketones and arylaldehydes to furnish\ud
aldol products in high yields and stereoselectivities.\ud
Screening of solvents showed that these reactions take place\ud
only in the presence of water or methanol, at lower levels of\ud
conversion in the latter case. This solvent effect, coupled\ud
with the observed high stereoselectivities, has been ex-\ud
Introduction\ud
In the last decade organocatalysis has became a field of\ud
great interest.[1] Organocatalysts are metal-free small organic\ud
molecules that are able to function as efficient and\ud
selective catalysts for a large variety of enantioselective\ud
transformations. In this context, -proline and its derivatives\ud
have emerged as powerful organocatalysts.[2] -Proline\ud
can be regarded as the simplest “enzyme” and it has been\ud
successfully applied in many reactions, such as Robinson\ud
annulations,[3] aldol reactions,[4] Mannich reactions,[5]\ud
Michael reactions,[6] direct electrophilic α-aminations,[7] Diels–\ud
Alder reactions,[8] Baylis–Hillman reactions,[9] aza-Morita-\ud
Baylis–Hillman reactions,[10] α-selenenylation,[11] oxidation,[\ud
12] chlorination,[13] and others.[14]\ud
Among all these processes, -proline-mediated aldol reactions\ud
affording β-hydroxy ketones have been investigated\ud
in great depth. Indeed, the aldol reaction is one of the most\ud
important C–C bond-formation methods in organic synthesis.[\ud
15] Proline and its derivatives operate by bifunctional catalysis\ud
and play the role of a simplified version of the type I\ud
[a] Dipartimento di Chimica Organica “E.Paternò”, Università di\ud
Palermo,\ud
Viale delle Scienze, Pad. 17, 90128 Palermo, Italy\ud
Fax: +39-091-596825\ud
E-mail: mgrutt@unipa.it\ud
© 2007 Wiley-VCH Verlag GmbH 4688 & Co. KGaA, Weinheim Eur. J. Org. Chem. 2007, 4688–4698\ud
plained in terms of the formation of a hydrophobic core in\ud
the inner surface of the resin, whereas the hydrophilic proline\ud
moiety lies at the resin/water interface. Such a microenvironment\ud
both promotes the aldol reaction and increases the\ud
stereoselectivity. Recycling investigations have shown that\ud
this material can be reused, without loss in levels of conversion\ud
and stereoselectivity, for at least five cycles
Isoflavone glycosides: Synthesis and evaluation as α-glucosidase inhibitors

On the basis of the structure of 4′,7,8-trihydroxyisoflavone 7-O-α-D-arabinofuranoside (namely A-76202, 1), a Rhodococcus metabolite showing potent inhibitory activities against the α-glucosidases of rat liver microsome (IC 50 = 0.46 ng/mL), 26 analogs, each with minor variations at the sugar moiety and the isoflavone A and B rings, were readily synthesized. Notably, a new and efficient method was developed for the divergent synthesis of the B-ring congeners of the isoflavone glycosides by using Suzuki-Miyaura coupling as the final step. Modifications at the sugar moiety and the isoflavone A ring significantly diminish the activity, whereas variations at the B ring are largely tolerated for retaining the potent α-glucosidase inhibitory activity. © Wiley-VCH Verlag GmbH & Co. KGaA, 2008.postprin
Pyrenylamino acids : synthesis, photophysical and electrochemical studies

Several beta-pyrenyldehydroamino acids and a pyrenylalanine derivative were synthesized in good to high yields from dehydroamino acids using several types of reactions. A beta-[(pyren-1-yl)methylamino]alanine was prepared treating the methyl ester of N,N-(di-tert-butoxycarbonyl)dehydroalanine with 1-pyrenemethylamine hydrochloride in the presence of an excess of potassium carbonate. The methyl esters of N-(tert-butoxycarbonyl)-beta-(1,2,4-triazol-1-yl) dehydroalanine and dehydroaminobutyric acid were reacted with 1-pyrenemethylamine hydrochloride in the presence of triethylamine to give the E-isomers of the beta-aminomethylpyrene dehydroalanine and dehydroaminobutyric acid derivatives in 84% and 45% yield, respectively. Beta-(Pyren-1-yl) dehydrophenylalanine and dehydroaminobutyric acid derivatives were obtained from the pure stereoisomers of the corresponding beta-bromodehydroamino acids and 1-pyrene boronic acid using Suzuki cross-couplings.  This reaction was also applied successfully to beta-bromodehydrodipeptides. The electrochemical behaviour of some of the compounds prepared was studied by cyclic voltammetry. The peak potentials for oxidation and reduction of pyrenylalanine were similar to those referred for pyrene. However, it was found that, when the pyrene ring was conjugated with the dehydroamino acid moiety, the compounds were more difficult to oxidize and easier to reduce than pyrene.
The fluorescence properties of four of the pyrenylamino acids synthesized were evaluated in cyclohexane and alcohols. The of methyl ester of N,N-bis(tert-butoxycarbonyl)-beta-[(pyren-1-yl)methylamino] alanine presented high fluorescence quantum yield in cyclohexane and ethanol (0.45 and 0.35, respectively).Fundação para a Ciência e a Tecnologia (FCT)A.S.A - SFRH/BPD/24548/2005Fundo Europeu de Desenvolvimento Regional (FEDER) - POCTI-SFA-3-686, POCI/QUI/59407/200
Bifunctional Binols: Chiral 3,3'-Bis(aminomethyl)-1,1'-bi-2-naphthols (Binolams) in asymmetric catalysis

3,3'-Bis(dialkylaminomethyl)-1,1'-binaphth-2-ols (Binolams) have emerged during the last five years as very efficient chiral ligands in many enantioselective processes. Enantiomerically pure Binolams are easily accessible by means of a variety of methods, the most widely used being the so-called chiral Binol route. In most cases, Binolam-metal complexes behave as bifunctional catalysts: that is, they are characterized by their dual action on the reagents, being able to activate both the nucleophilic and the electrophilic species involved in the reaction. The most successful transformations carried out with complexes of this type include cyanation of aldehydes and ketones and enantioselective nucleophilic additions of enolate derivatives and organometallic compounds to C=O or C=N double bonds. As a final bonus, the basic natures of these ligands allow their recovery in high yields in numerous transformations.This work has been supported by the DGES of the Spanish Ministerio de Ciencia e Innovación (MICINN) and the Ministerio de Educación y Ciencia (MEC) (Consolider INGENIO 2010 CSD2007-00006, CTQ2007-62771/BQU, CTQ2007-62952/BQU, CTQ2004-00808/BQU, CTQ2004-02375/BQU, BQU2001-0724-C02, PB96-0203, and PB97-0123), the Generalitat Valenciana (GVDOC00-14-02, CTIOIB/2002/320, GRUPOS03/134, and GV05/144), and by the University of Alicante
The synthesis of novel isoindoline nitroxides bearing water-solubilising functionality

A range of novel tetramethyl- and tetraethylisoindolinenitroxides, possessing aryl-linked carboxylic acids, amines, alcohols and phosphonic acids were prepared. Notably, the chemistry established for the aromatic dibromination of the tetramethylisoindolines was not easily transferred to the corresponding tetraethylisoindoline system. Instead, various tetraethylisoindoline analogues were accessed by the oxidation of methyl groups attached to the aromatic ring to give the carboxylic acids. The increased steric bulk of the tetraethyl structures should limit bio-reduction and these compounds may have potential as antioxidants