Over the past decades, different software programs have been developed for the Computer-Assisted Structure Elucidation (CASE) with NMR data using with various approaches. WebCocon is one of them that has been continuously improved over the past 20 ye...
In the fungus Fusarium fujikuroi, carotenoid production is up-regulated by light and down-regulated by the CarS RING finger protein, which modulates the mRNA levels of carotenoid pathway genes (car genes). To identify new potential regulators of car...
Band-selective (bs) HSQC, improving spectral resolution by restriction of the heteronuclear dimension without inducing spectral folding, has been recently used for polymer tacticity determination. Herein is reported an evaluation of various bs-HSQC a...
Synthesis, the complete 1H- and 13C-NMR assignments, and the long-range C,H coupling constants (nJC,H) of some hydrogen-deficient carbazolequinones, assessed by a J-HMBC experiment, are reported. In these molecules, the protons, used as entry points...
The structure of a representative pyrazolo[3,4]pyran derivative was determined by 1D and 2D NMR techniques. Complete 1H and 13C chemical shifts for this compound are reported. Careful analysis of the HMBC (Heteronuclear Multi-Bond Correlation) spectr...
2-Substituted 1,4-benzodioxanes bearing one or more substituents at benzene are important templates in the design and synthesis of a large variety of biologically active compounds. One of the most straightforward synthetic strategies to prepare them...
A variety of biological active compounds can be classified as 2-substituted 1,4-benzodioxanes bearing one or more substituents at the benzene. The synthesis of these important templates can be approached by different strategies. The most straightforw...
A simple route to 3-oxoalkanonitrile 5, aprecursor of the title compounds is described. Reaction of enaminones 2 with hydroxylamine hydrochloride in ethanol yielded aldoximes 3 that were converted readily into 5 in basic medium. This method has been...
Highly purified 5-vinyl-1H-tetrazole was synthesized, which is in great demand in modern medicine and industry as a monomer for obtaining nitrogen-rich macromolecular compounds and a reagent for the complete synthesis of biological compounds. The mol...
A convenient, broadly applicable and durable wood protection was recently published by Kaufmann and Namyslo. This procedure efficiently allows for esterification of wood hydroxyl groups with (1H-benzotriazolyl)-activated functionalized benzoic acids....
A combination of selective 1D Total Correlation Spectroscopy (TOCSY) and 1H-13C Heteronuclear Multiple Bond Correlation (HMBC) NMR techniques has been employed for the identification of methyl linolenate primary oxidation products without the need fo...
Experimental parameters that influence the resolution of 1H-NMR phenol OH signals are critically evaluated with emphasis on the effects of pH, temperature and nature of the solvents. Extremely sharp peaks (Δν1/2 ≤ 2 Hz) can be obtained under optimize...
Qualitative and quantitative analysis of complex mixtures and structure elucidation is generally impeded by the intrinsic complexity of the NMR spectra and the extensive signal overlap. The conventional approach to characterizing individual metabolit...
A series of novel monoazo-disperse dyes containing pyrazolo[1,5-a]pyrimidine structures were synthesized starting with the coupling reaction between ethyl cyanoacetate and 4-hydroxybenzenediazonium chloride, followed by treatment of the resulting hyd...
4-Heteroarylidene-2-phenyl-1,3-oxazol-5(4H)-ones were prepared by reactions of hippuric acid with substituted furan-2-carboxaldehydes or furo[b]pyrrole type aldehydes. The reactivity of various furan-2-carboxaldehyde derivatives in this reaction is d...
Vegetable oils are bio−based and sustainable starting materials that can be used to develop chemicals for industrial processes. In this study, the functionalization of three vegetable oils (grape, hemp, and linseed) with maleic anhydride was ca...
Recent findings demonstrate that concentrated sulfuric acid supports rich organic chemistry, including the stability of the canonical DNA bases adenine, thymine, guanine and cytosine. Yet, due to full protonation in concentrated sulfuric acid, these...
6-Hydroxy-2-methylbenzofuran-4-carboxylic acid was synthesized in two steps, starting from 3,5-dihydroxybenzoate. The product was obtained through a direct thermal one-pot cyclization with propargyl bromide, followed by a base-catalyzed hydrolysis. I...
This study optimized corncob-derived magnetic biochar (MBC) with tailored iron content for laccase immobilization to boost nonylphenol (NP) degradation in water. Low-iron MBC (LMBC) and high-iron MBC (HMBC) from corncob were prepared via impregnation...
Here we describe a full structural elucidation of the diethyl (2-(4-phenyl-1H-1,2,3-triazol-1-yl)benzyl) phosphate. This compound is a common by-product present in the synthetic protocols to access the α-hydroxy phosphonate compounds through of a Pho...
A new alkaloid, geissospermiculatine was characterized in Geissospermum reticulatum A. H. Gentry bark (Apocynaceae). Here, following a simplified isolation protocol, the structure of the alkaloid was elucidated through GC-MS, LC-MS/MS, 1D, and 2D NMR...
Two forms were found in the NMR spectra of N6-substituted 2-chloroadenosines. The proportion of the mini-form was 11–32% of the main form. It was characterized by a separate set of signals in COSY, 15N-HMBC and other NMR spectra. We assumed tha...
The zoanthids Palythoa caribaeorum and Protopalythoa variabilis are among the most abundant marine species along the Brazilian coast. We now report the isolation and structure elucidation of two unprecedented sulfonylated ceramides, palyosulfonoceram...
Herein, a novel fluorescent method for the determination of d-panthenol (DP) level in solutions with no separate hydrolysis step has been revealed based on the utilization of citric acid (CA) as a derivatizing agent. Consequently, the essential param...
A flavanone and a flavanone glycoside, together with vomifoliol, have been isolated for the first time from the aerial parts of the plant Echiochilon fruticosum and identified. Their structures were established on the basis of spectroscopic measureme...
From the aerial parts of Hypericum perforatum L. we have isolated phloroglucinol 1 (see the formula), a homologue of 2, the latter isolated previously from the same extract and identified by 2D NMR (DQF COSY, PS NOESY, TOCSY, HSQC and HMBC) [1].[...]
Derivatives of 3-(1H-1,2,3-triazol-1-yl)quinoline-2,4(1H,3H)-dione unsubstituted on quinolone nitrogen atom, which are available by the previously described four step synthesis starting from aniline, were exploited as intermediates in obtaining the t...
A novel usnic acid derivative with 2-chlorothiazole substituent was obtained by a three-step synthesis from usnic acid. The structure of the product was proved by a set of physical methods, including 1H, 13C, HRMS, HSQC, HMBC and IR spectroscopy.
The synthesis of previously unknown 4,5-dimethylfuro[3,4-d]pyridazin-1(2H)-one has been proposed and structurally characterized via a single-crystal X-ray diffraction analysis, 1H, 13C–{1H}, 1H–13C HMQC, and 1H–13C HMBC NMR spectros...
The previously unknown compounds—3-(dichloromethyl)-2-nitro-6,7-dihydro-1-benzofuran-4(5H)-ones—have been synthesized and structurally characterized via single-crystal X-ray diffraction, 1H, 13C–{1H}, 1H–13C HMQC and 1H–...
A new dimer of the food-relevant mycotoxin zearalenone was isolated after electrochemical and chemical oxidation. The structure was determined as a 16-O-15′-biaryl ether-linked dimer based on spectroscopic analyses (1H- and 13C-NMR, COSY, HMBC,...
The epimeric sesquiterpene alcohols (14R)-β-oplopenol and (14S)-β-oplopenolwere obtained by LiAlH4 reduction of β-oplopenone. The complete 1H- and 13C-NMRassignments of these two new sesquiterpene alcohols have been made using 1D and 2DNMR techniques...
Two new cembrane diterpenes, sicrassarines A and B (compounds 1 and 2), were isolated from the Taiwanese soft coral Sinularia crassa. The structures of the new metabolites were determined on the basis of extensive spectroscopic analysis, particularly...
New substituted [30]trithiadodecaazahexaphyrines (hemihexaphyrazines) were synthesized by a crossover condensation of 2,5-diamino-1,3,4-thiadiazole with 4-chloro-5-(2,6-diisopropylphenoxy)- or 4,5-bis-(2,6-diisopropylphenoxy)phthalonitriles. The comp...
The data on the synthesis of N-aminomorpholine hydrazones are presented. It is shown that the interaction of N-aminomorpholine with functionally substituted benzaldehydes and 4-pyridinaldehyde in isopropyl alcohol leads to the formation of correspond...
A new phenolic glucoside, isoconiferoside (1), was isolated from the seeds of Panax ginseng (Araliaceae). The structure was determined to be 9-O-[b-D-glucopyranosyl-(1®6)-b-D-glucopyranosyl]-trans-coniferyl alcohol based on spectroscopic analyses (1H...
Copper phosphido compound Cu4(μ-PPh2)4(PtBu3)2 was synthesized by three synthetic methods and structurally characterized by X-ray diffraction and 1H, 31P, 13C and 31P HMBC NMR spectroscopy. Cu4(μ-PPh2)4(PtBu3)2 was also demonstrated to be a hyd...
A nickel complex with a Schiff base Ni(3-tert-butyl-salophen) was synthesized and structurally characterized by single-crystal X-ray diffraction, 1H, 13C{1H}, 1H–13C HMQC, 1H–13C HMBC, 1H-1H dqf-COSY and 1H-1H NOESY NMR spectroscopy, and...
A number of 1D and 2D NMR techniques, such as 1H, 13C, DEPT 135, 1H-1H COSY, HSQC, and HMBC, were utilized for the structure verification of 4-(8-propyl-2,4-dithioxo-1,3-diazaspiro[4.5]decan-3-yl)spiro[1,5-dihydro-1,5-benzodiazepine-2,3′-indoli...
The reaction of 5-amino-3-(cyanomethyl)-1H-pyrazole-4-carbonitrile with 3-aryl-2,4-di (ethoxycarbonyl)-5-hydroxy-5-methylcyclohexanones in boiling acetic acid leads to the formation of new 4,5,6,7,8,9-hexahydropyrazolo[1,5-a]quinazolines. The mechani...
Thiopyrimidines represent one of the most active classes of compounds, possessing a wide spectrum of biological activities. Herein, we report the synthesis of 2-(heptylthio)pyrimidine-4,6-diamine (HPDA) via S-alkylation. The structure of HPDA was elu...
Usnetic acid is a dibenzofuran-2-ylacetic acid that can be obtained by alkaline degradation of a secondary lichen metabolite—usnic acid. In the present paper, the product of the reaction of usnetic acid with a mild fluorinating agent, Selectflu...
Five new iridoids, salvialosides A–E (compounds 1–5), together with fifty known compounds were isolated from the roots of Salvia digitaloides. The structures of the new compounds were completely elucidated using a combination of 2D NMR techniques (CO...
Phytochemical constituents of Vitis wenchowensis were investigated for the first time. A new resveratrol trimer, wenchowenol (1), was isolated from the roots and stems of Vitis wenchowensis along with four known stilbenoids 2–5. The structure and rel...
The synthesis of three novel, valuable bioconjugates obtained by coupling cholesterol bromoacetate with pyridine derivatives via an SN2 reaction was successfully carried out. Each of the products was fully characterized by magnetic nuclear resonance...
Diols represent a structurally diverse class of compounds with considerable biological and functional significance. Herein, we describe the synthesis of 1,1-bis(4-ethylphenyl)propan-1,2-diol (BEPP) via a Grignard reaction. The structure of BEPP was u...
Phytochemical investigations of the leaves of Garcinia paucinervis resulted in the isolation of three new xanthones 1–3 and five known analogues 4–8. Structural elucidations of 1–3 were performed by spectral methods such as 1D and 2D (HMQC, HMBC, and...
Phytochemical investigation of the flowers of Acmella oleracea had resulted in the isolation of one new alkylamide, (2E,5Z)-N-isobutylundeca-2,5-diene-8,10-diynamide (1), together with four known analogues (2-5). The structures of these compounds wer...
The 7-C60-adduct of N,N-(tetrachlorophthaloyl)dehydroabietylamine was synthesized for the first time and characterized by IR, UV-vis, mass and NMR spectral studies. The 1H-NMR and 13C-NMR resonance signals of the new compound are unambiguously assign...
The synthesis of tetra- and pentanorlabdane compounds with rearranged cycle B based on commercially available (+)-sclareolide is reported. Desired compounds were prepared from intermediate ketones via Baeyer–Villiger oxidation. The structures o...
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