Māra Jure

Synthetic approaches to 4-(het)aryl-3,4-dihydroquinolin-2(1H)-ones

This review summarizes strategies for the synthesis of 4-(het)aryl-3,4-dihydroquinolin-2(1H)-ones which are of interest due to their biological activity. It covers methods elaborated particularly for obtaining the title heterocycles, as well as procedures where these compounds are formed as side products. 4-Aryl-3,4-dihydroquinolin-2(1H)-one derivatives have been used for the synthesis of valuable molecules, e.g., anticancer drug tipifarnib.

Nitroolefins as starting materials for 5-membered N-heterocycles

Nitroolefins are widely used for the synthesis of valuable cyclic and acyclic compounds. Synthesis of polysubstituted pyrrolidines and 1 H -pyrroles, as well as the skeleton of spiroindolinopyrrolidin-2-one starting from the title compounds is well known. Herein the recent (2013–2015) examples leading to five-membered nitrogen heterocycles (with exception of the above-mentioned structures) are focused. How to Cite Mieriņa, I.; Jure, M. Chem. Heterocycl. Compd. 2016 , 52 , 10. [ Khim. Geterotsikl. Soedin. 2016 , 52 , 10.] For this article in the English edition see DOI 10.1007/s10593-016-1823-9

ALKYLIDENE AND ARYLIDENE MELDRUM'S ACIDS AS VERSATILE REAGENTS FOR THE SYNTHESIS OF HETEROCYCLES

Meldrums acid and its derivatives are excellent building blocks for the synthesis of acyclic, carbocyclic and heterocyclic compounds. Herein recent (mainly 2010–2015) trends on applications of arylidene/alkylidene Meldrums acids (R 1 , R 2 = H, Ar, Alk, –(CH 2 ) n –) in the synthesis of heterocycles and multicomponent reactions (MCR) involving in situ formation of arylidene/alkylidene Meldrums acids are focused. How to Cite Mieriņa, I.; Jure, M. Chem. Heterocycl. Compd. 2016 , 52 , 7. [ Khim. Geterotsikl. Soedin. 2016 , 52 , 7.] For this article in the English edition see DOI 10.1007/s10593-016-1822-x

Synthesis and antioxidant activity of new analogs of Quin-C1

New derivatives of 4-oxo-1,2,3,4-tetrahydroquinazoline, analogs of Quin-C1, have been synthesized by the condensation of aroyl- and heteroaroylhydrazides of anthranilic acid with cinnamic, crotonic, and 4-hydroxy-3-methoxybenzoic aldehydes. The antioxidant activity of the obtained compounds has been determined.

Investigation of the oil and Meal of Japanese Quince (Chaenomeles Japonica) Seeds

Abstract Various extracts of Japanese quince (Chaenomeles japonica) seeds obtained using organic solvents were studied for their polyphenol content and antiradical activity. It was established that petroleum ether, hexane, ethyl acetate, acetone, as well as toluene and chloroform extracts, in comparison to synthetic antioxidant butylated hydroxytoluene (BHT), demonstrate better (or comparable) activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH). Methods for detoxification of seeds, meals and press-cakes are proposed. Phenolic composition of different extracts (80% ethanol, 70% acetone), both acid and alkali hydrolysates of seeds, as well as seed oil methanol/water extract were analysed by means of high performance liquid chromatography (HPLC): chlorogenic acid was found for the first time in seed extract; protocatechuic acid predominated in all extracts. The content of other major phenolic acids was detected; it was found that seed oil contains syringic acid. It was determined that Japanese quince seeds contain almost ten times more α -tocopherol than barley grain. Due to the presence of α -tocopherol and phenolic compounds, seed oil and lipophilic extracts of seeds could serve as antioxidants. Abstrakt Krūmcidoniju (Chaenomeles japonica) sēklu dažādu organisko šķīdinātāju ekstraktiem noteikts kopējais polifenolu saturs un antiradikāļu aktivitāte. Petrolētera, heksāna, etilacetāta, acetona, kā arī toluola un hloroforma ekstraktu spēja inhibēt 2,2-difenil- 1-pikrilhidrazilu (DPPH) ir augstāka (vai salīdzināma) nekā sintētiskajam antioksidantam BHT (butilēts hidroksitoluols). Izstrādātas cianīdus saturošo krūmcidoniju sēklu, spraukumu un spiedpalieku detoksifikācijas metodes. Izmantojot augstas izšķirtspējas šķidrumhromatogrāfijas metodi (HPLC), analizēta krūmcidoniju sēklu| dažādu ekstraktu (80% etanola un 70% acetona), skābo un bāzisko hidrolizātu, kā arī eļļas metanola/ūdens ekstrakta polifenolu kompozīcija: sēklu ekstraktā pirmo reizi konstatēta hlorogēnskābe. Visos ekstraktos kā dominējošais savienojums atrasta protokatehīnskābe; noskaidrots arī citu galveno fenolskābju daudzums, un sēklu eļļā atrasta sīringskābe. Eļļā ir daudz a-tokoferola, kura saturs krūmcidoniju sēklās ir gandrīz desmit reizes lielāks nekā miežu graudos. Tā kā sēklu eļļa un lipofilie ekstrakti satur a-tokoferolu un polifenolus, ekstraktus var izmantot kā antioksidantu avotus.

Antioxidant Properties of Camelina sativa Oil and Press-Cakes

Abstract Camelina sativa is well known due to high content of polyunsaturated fatty acids in its oil. Till now this oil has been studied mainly for applications as raw material for synthesis of resins, biodiesel and hydrocarbon fuels. This study examines the oxidative stability of cold-pressed Camelina sativa (also known as camelina, false flax or gold-of-pleasure) oil and its extracts of spices. Despite the high content of polyunsaturated fatty acids, Camelina sativa oil appeared more rigid against oxidation than rapeseed or flax oil. Extracts of different spices were prepared by maceration in camelina oil at room temperature for 24 h. The stability of extracts was determined under accelerated oxidation conditions and monitored by peroxide values. Most of the tested additives (e.g., bay leaves, allspice, clove, barley sprouts, coriander, ginger) did not influence or even decreased oxidative stability of the oil. However, oil with thyme additive demonstrated remarkably higher stability then Camelina sativa oil alone. Press-cakes of camelina seeds were extracted with two polar solvents (ethanol or water) and their mixtures under variable conditions (room temperature or reflux). Prepared polar extracts of press-cakes were characterised by total polyphenol content (Folin–Ciocalteu method) and antiradical activity against 1,1-diphenyl-2-picryl hydrazyl and galvinoxyl.