Terpenoids with quinoid structures are found as natural products. This includes steroidal quinones, quinones with a secosteroid structure and meroterpenoid quinones. Importantly, catechol estrogens as endogenous metab...Terpenoids with quinoid structures are found as natural products. This includes steroidal quinones, quinones with a secosteroid structure and meroterpenoid quinones. Importantly, catechol estrogens as endogenous metabolites of estradiol and estrone are precursors of reactive quinones and semiquinones, which are thought to contribute to estrogen-induced carcinogenesis. On the other hand, a number of quinones that include substituted naphthoquinones and anthraquinones are highly cytotoxic and have been used in cancer treatment. This makes the structures interesting synthetic targets. The following is a review of important natural and synthetic terpenoid and steroid quinone hybrids.展开更多
New reagents for immunofluorescence analysis of carbazole series containing fluorinated β-dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carb...New reagents for immunofluorescence analysis of carbazole series containing fluorinated β-dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carbazole scaffold have been developed. The markers in complex with Eu<sup>3+</sup> ions possess stability in the aqueous phase, intense and prolonged luminescence (τ 550 - 570 μs) with characteristic emission maxima in the region of 615 nm and excitation wavelengths in the region of 380 - 390 nm, which distinguishes them from most of the analogs used. In the study of marker conjugation with streptavidin, a reagent containing 4 - 5 europium labeling complexes based on spacer-containing carbazole tetraketone was obtained. The marker-doped silicate nanoparticles exhibit intense and long-lived luminescence in the characteristic region.展开更多
An operationally simple protocol was designed for the enantioselective silane reduction (ESR) of ketones using air- and moisture-stable [Ir(OMe)(cod)]<sub>2</sub> (cod = 1,5-cyclooctadiene) (3) as a metal ...An operationally simple protocol was designed for the enantioselective silane reduction (ESR) of ketones using air- and moisture-stable [Ir(OMe)(cod)]<sub>2</sub> (cod = 1,5-cyclooctadiene) (3) as a metal catalyst precursor. This reaction was driven by chiral hydroxyamide-functionalized azolium salt 2. The catalytic ESR reaction could be performed under benchtop conditions at room temperature. Treatment of 2 with 3 in THF yielded the monodentate IrCl(NHC)(cod) (NHC = N-heterocyclic carbene) complex 4 in 93% yield, herein the anionic methoxy ligand of 3 serves as an internal base that deprotonates the azolium ring of 2. The well-defined Ir complex 4 catalyzed the ESR reaction of propiophenone (6) with (EtO)<sub>2</sub>MeSiH using the pre-mixing reaction procedure. Based on this success, the catalytic ESR reaction was designed and implemented using an in situ-generated NHC/Ir catalyst derived from 2 and 3. Thus, a wide variety of aryl ketones could be reduced to the corresponding optically active alcohols in moderate to excellent stereoselectivities at room temperature without temperature control. Since the high catalytic activity of 3 was observed, we next evaluated several other transition metal catalyst precursors for the catalytic ESR reaction under the influence of 2. This evaluation revealed that Ir(acac)(cod) (acac = acetylacetonate) (28) and [IrCl(cod)]<sub>2</sub> (5) can be successfully used as metal catalyst precursors in the ESR reaction.展开更多
In the course of organic synthesis, particularly for multi-step synthesis or natural product total synthesis, the selection of appropriate protective groups for the intended functionality is crucial in order to achiev...In the course of organic synthesis, particularly for multi-step synthesis or natural product total synthesis, the selection of appropriate protective groups for the intended functionality is crucial in order to achieve chemoselective synthetic goals. The development of many useful protective groups has been reported based on the functionality of the anilino group. Herein, we discuss our study of various protective groups and the processes we used to establish compatibility with anilino functionality via the implementation of Oxone-mediated oxidative esterification in methanol. The results and the details of our experiments are reported herein.展开更多
The synthesis of new indoloannulated thiopyranethiones is reported. The key-step is a rhodium-catalyzed [2 + 2 + 2]-cycloaddition of alkynyl-ynamides with carbon disulfide to close the pyrrole and the thiopyranethione...The synthesis of new indoloannulated thiopyranethiones is reported. The key-step is a rhodium-catalyzed [2 + 2 + 2]-cycloaddition of alkynyl-ynamides with carbon disulfide to close the pyrrole and the thiopyranethione rings simultaneously. A violet idolothiopyrane thione or a mixture of the violet and a red isomer result from [RhCl(C<sub>8</sub>H<sub>14</sub>)<sub>2</sub>]<sub>2</sub>/3BINAP catalyzed cycloadditions, the regiochemistry is controlled by the substitution pattern on the alkynyl-ynamide.展开更多
A new phloretin derivative 1 3-[2-(4-hydroxy-phenyl)-ethyl]-benzo[d] isoxazole-4,6-diol (yield 63%) was synthesized from phloretin by carbonyl nucleophilic addition condensation reaction. Its structure was characteriz...A new phloretin derivative 1 3-[2-(4-hydroxy-phenyl)-ethyl]-benzo[d] isoxazole-4,6-diol (yield 63%) was synthesized from phloretin by carbonyl nucleophilic addition condensation reaction. Its structure was characterized by 1H NMR, 13C NMR and HR-MS. The phloretin, compound 1, resveratrol and acetylated resveratrol were determined by comparing them with paclitaxel. Anti-tumor activity of alcohol on SPC-A1, EC109, A549, MCF-7 and MDA-MB-231 cell lines. Compound 1 showed better antitumor activity than docetaxel against A549 tumor cells.展开更多
A new electrophilic polymer, 2,4-dinitrophenyl ether of polyvinyl alcohol (PVA-DNP), having a degree of substitution of 0.5 was prepared from polyvinyl alcohol (PVA) and 1-fluro-2,4-dinitrobenzene (DNFB). The PVA-DNP ...A new electrophilic polymer, 2,4-dinitrophenyl ether of polyvinyl alcohol (PVA-DNP), having a degree of substitution of 0.5 was prepared from polyvinyl alcohol (PVA) and 1-fluro-2,4-dinitrobenzene (DNFB). The PVA-DNP polymer was characterized by NMR, IR, and UV-visible spectroscopy. The reaction of PVA-DNP with sodium methoxide was followed by NMR and UV-visible spectroscopy. Evidence of polymer bound spirocyclic SIGMA complex, C-1 and C-3 polymer bound DNP-methoxy SIGMA complexes and the formation and C-1 methoxy complex of 2,4-dinitroanisole was observed.展开更多
A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition m...A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K<sub>3</sub>PO<sub>4</sub>) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .展开更多
Hirshfeld surface analysis has been widely used in recent years as a means to quantify and visualize various types of intermolecular interactions in molecular crystals. This review article introduces intermolecular in...Hirshfeld surface analysis has been widely used in recent years as a means to quantify and visualize various types of intermolecular interactions in molecular crystals. This review article introduces intermolecular interactions discussed with Hirshfeld surface analysis and 2D fingerprint plots. In addition, using CIF files obtained from our previous results, Hirshfeld surface analysis was newly performed, and the resulting 3DHirshfeld surfaces, 2D print plots, molecular structural features, and crystal structure relationships were described. Classification of their intermolecular interactions, statistical discussion focused on crystalline water and perspective on ligand-protein docking are also mentioned.展开更多
The aim of this study was to investigate the chemical composition of the essential oils of “Covid-Organics” of Madagascar (62% Artemisia annua and two other undisclosed medicinal plants) used as curative and prevent...The aim of this study was to investigate the chemical composition of the essential oils of “Covid-Organics” of Madagascar (62% Artemisia annua and two other undisclosed medicinal plants) used as curative and preventive treatments of Covid-19, to identify its constituent species. The essential oils isolated by hydro-distillation from two samples (curative and preventive) were analyzed by GC-FID and GC-MS. These essential oils (curative and preventive) were mainly dominated by camphor (17.9% and 11.9%, respectively), spathulenol (4.8% and 11.8%, respectively), α-acorenol (4.3% and 3.7%, respectively), (E)-β-caryophyllene (3.4% and 4.2%, respectively), 1,8-cineole (3.1% and 3.6%, respectively), hexadecanoïc acid (3.8% and 3.2%, respectively) and caryophyllene oxide (3.4% and 2.4%, respectively). From the chemical composition, two species were identified, A. annua characterised by camphor and Cinnamomumcamphora (Ravintsara) characterised by 1,8-cineole and sabinene. However, we were unable to identify the third species.展开更多
Buoyed by the extensive research on the wide-range biological activities of aminophosphonates, a novel class of aminated (cyclopropylmethyl)phosphor-nates compounds was synthesized from diethyl ((1-(3-chloropropyl)cyc...Buoyed by the extensive research on the wide-range biological activities of aminophosphonates, a novel class of aminated (cyclopropylmethyl)phosphor-nates compounds was synthesized from diethyl ((1-(3-chloropropyl)cyclopropyl)methyl)phosphonate and various amines in the presence of Hunig’s base. Upon biological activity screening these compounds demonstrated encouraging anti-pancreatic cancer properties at low micromolar concentrations.展开更多
In the present work, for the first time, the main details of the electronic mechanism of the synergistic antioxidant interaction between different pairs: phenolic food acid and glutathione and the stable radical catio...In the present work, for the first time, the main details of the electronic mechanism of the synergistic antioxidant interaction between different pairs: phenolic food acid and glutathione and the stable radical cation ABTS<sup>+·</sup> were revealed on the basis of a rigorous analysis of the DFT calculated data. It was shown that among all the studied food acids, only caffeic acid exhibits a clear-cut significant synergistic effect with glutathione. It established the electronic and structural factors underlying the mechanism of the synergistic interaction of the mixture caffeic acid and glutathione in its reaction with ABTS<sup>+·</sup>. The main causes of this considered synergistic effect are, firstly, the presence of the 3-OH and 4-OH hydroxyl groups in the structure of caffeic acid, secondly, the greater stability of its anion which contains the deprotonated 4-OH hydroxyl group. All other phenolic food acids under study do not possess the given structural particularity and therefore do not show such synergistic effects with glutathione.展开更多
Electrochromic materials are of great interest for their potential in eyewear protection and data storage devices, as they change colors in response to electrochemical switching. While many of the systems currently us...Electrochromic materials are of great interest for their potential in eyewear protection and data storage devices, as they change colors in response to electrochemical switching. While many of the systems currently used are based on inorganic materials, organic materials such as triazenes have emerged as viable alternatives due to their unique properties, including optical properties. Triazenes are a class of organic compounds with three consecutive nitrogen atoms in an acyclic arrangement, and they have been used for a variety of applications in medicinal and synthetic chemistry. However, the effects of solvents on the UV-visible absorption spectrum of triazenes have not been fully investigated. The neutral molecules of 3,3-diisopropyl-1-phenyltriazene and 1-(4-chlorophenyl)-3-cyclopentyltriazene in acetonitrile, the UV-visible spectra corresponded respectively to HOMO → LUMO transitions with a large maximum absorption at 299.74 nm (4.1364 eV) and 299.57 nm (4.1387 eV) and the most intense oscillator strength (f = 0.6988) and (f = 0.7372). These results suggest that the electronic transitions of the compounds are highly influenced by the nature of the substituents on the triazene unit, as well as the solvent used in the experiment. The redox couple 0.92 and -0.44 V/Ag/AgCl is attributed to the phenyl group. Compound III showed an oxidation and reduction peak respectively -0.27 and -0.8 V/Ag/AgCl attributed to the phenyl molecule. The study concluded that all three compounds were electroactive and exhibited reversible characteristics with oxidizing/reducing couples. This study aims to contribute to research on the optical properties of triazenes compounds and the application of quantum chemical calculation methods for understanding their molecular structures. By investigating the solute-solvent interactions occurring in the solvation shell of the solutes, we aim to gain insights into the effects of solvents on the UV-visible absorption spectrum of triazenes. Our findings may have implications for the development of functionalized triazenes as potential electrochromic materials.展开更多
An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byprod...An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byproduct was recovered in high yield by simple filtration. Some aromatic acids have been transformed into the corresponding acid chlorides in good yields by employing the isolated VH. Treatment of primary or secondary alcohols with VH gave alkyl formates or alkyl chlorides by depending on the reaction conditions.展开更多
New fluorine substituted 6-(5’-fluoro-2’-triphenylphosphiniminophenyl) 3-thioxo-1,2,4-triazin-5 (2H, 4H) one (2) was obtained via Wittig’s reaction of the corresponding 6-(5’-fluoro-2’-amino-phenyl)-3-thioxo-1,2,...New fluorine substituted 6-(5’-fluoro-2’-triphenylphosphiniminophenyl) 3-thioxo-1,2,4-triazin-5 (2H, 4H) one (2) was obtained via Wittig’s reaction of the corresponding 6-(5’-fluoro-2’-amino-phenyl)-3-thioxo-1,2,4-triazinone (1). Behavior of compound 2 towards alkylating agents and/or oxidizing agents was studied were, N-hydroxyl (3), Mannich base (4,5), S-alkyl (6,7,8) and thiazolo [3,2-b][1,2,4] triazinones (10-14) and or 3-disulfide (18), 3-sulfonic acid 19 and 1,2,4-triazin-3,5-Dionne (20) derivatives obtained. Structures of the new products are established by elemental and spectral data. The new targets obtained screened as Molluscicidalagents against Biomophlaria Alexandrina snails responsible for Bilharziasis diseases, in compare with Baylucide as standard drug.展开更多
The Phellinus mushrooms have been known for its immunomodulatory, hypolipidemic, and anticancer activities. In the current work, the chemical constituents of two Phellinus mushrooms, Phellinus pini 141016# and Phellin...The Phellinus mushrooms have been known for its immunomodulatory, hypolipidemic, and anticancer activities. In the current work, the chemical constituents of two Phellinus mushrooms, Phellinus pini 141016# and Phellinus sp. 150802#, which were collected in Foshan city, Guangdong province, were investigated preliminarily by pre-test tube method and by comparison with the known natural compounds from Phellinus pini, and their antioxidant activities were evaluated by the biochemical assay of hydroxyl and 2,2-diphenyl-1-pricylhydrazyl (DPPH) radicals scavenging activity in vitro. The results show that both the two Phellinus mushrooms contain phenolics, alkaloids, lactones, steroids and terpenoids, and have potent antioxidant activities. The IC50 values of DPPH radicals and hydroxyl radicals for Phellinus pini 141016# were 74.37 μg/mL and 59.69 μg/mL, respectively, and the IC50 values of DPPH radicals and hydroxyl radicals for Phellinus sp. 150802# were 98.95 μg/mL and 165.47 μg/mL, respectively. They are comparable to the antioxidant activity of the standard antioxidant ascorbic acid.展开更多
Novel 6-(5’-fluoro-2’-diphenylphosphorylanilido)-3-hydrazino-1,2,4-trizin-5 (2H) one (3) is achieved from hydrozinolysis of the corresponding 3-thioxo-analoges 2. Compound 2 is also obtained from phosphorylation of ...Novel 6-(5’-fluoro-2’-diphenylphosphorylanilido)-3-hydrazino-1,2,4-trizin-5 (2H) one (3) is achieved from hydrozinolysis of the corresponding 3-thioxo-analoges 2. Compound 2 is also obtained from phosphorylation of 6-(5’-fluoro-2’-aminophenyl)-3-thioxo-1,2,4-triazin-5(2H) one (1). Novel fluorine substituted isolated and/or fused heterobicyclic nitrogen systems bearing and/or containing, 6-phosphoryl anilido-1,2,4-trizin-5 (2H) one moiety (4 - 22) have been synthesized from ring closure reactions of compound 3 with π-acceptors activated carbon compounds in different medium and conditions. Structures of the products are characterized by MS, IR, UV-VIS, CH, N, and 1H/13CNMR spectral data. The new products have been evaluated as potential inhibitors towards HIV-1 activity.展开更多
A highly efficient and convenient procedure for the enantioselective synthesis of (S)-Rivastigmine, a cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer’s type and dementia due to Parki...A highly efficient and convenient procedure for the enantioselective synthesis of (S)-Rivastigmine, a cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer’s type and dementia due to Parkinson’s disease, is accomplished by the treatment of versatile, readily accessible (S)-(-)-2-methyl-2-propanesulfinamide with 3-hydroxyacetophenone. This protocol provides high yield and excellent enantiomeric excess in short step synthesis.展开更多
Pyrrolidines are well known for their versatile pharmacological activities such as antimicrobial [1] [2] [3] [4], antitumor [5], anti HIV [6], anticonvulsant [7] [8], human melanocortin-4 receptor agonists [9], etc. M...Pyrrolidines are well known for their versatile pharmacological activities such as antimicrobial [1] [2] [3] [4], antitumor [5], anti HIV [6], anticonvulsant [7] [8], human melanocortin-4 receptor agonists [9], etc. Moreover, indole nucleus is an important element of many natural and synthetic molecules that covers some of the relevant and recent achievement in the biological, chemical and pharmaceutical activity of important indole derivatives [10]. In view of these observations, the intention is directed to synthesize some new bisindole derivatives of expected biological interest.展开更多
Basing on the DFT calculations we propose the new theoretical model which describes both the surface tension σ of the short chain n-alkanes at their normal boiling points and their reaction rate constants with hydrox...Basing on the DFT calculations we propose the new theoretical model which describes both the surface tension σ of the short chain n-alkanes at their normal boiling points and their reaction rate constants with hydroxyl radicals OH<span style="white-space:nowrap;">•</span> (at 297 ± 2 K) on the basis of their molecular orbital electronic characteristics. It has been shown that intermolecular dispersion attraction within the surface liquid monolayer of these compounds, as well as their reaction rate constants k with OH<span style="white-space:nowrap;">•</span> radicals are determined by the energies <em>E<sub>orb</sub></em> of the specific occupied molecular orbitals which are the same in the determination of both the above physico-chemical characteristics of the studied n-alkanes. The received regression equations confirm the theoretically found dependences between the quantities of σ and k and the module |<em>E<sub>orb</sub></em>|. For the compounds under study this fact indicates the key role of their electronic structure particularities in determination of both the physical (surface tension) and the chemical (reaction rate constants) properties.展开更多
文摘Terpenoids with quinoid structures are found as natural products. This includes steroidal quinones, quinones with a secosteroid structure and meroterpenoid quinones. Importantly, catechol estrogens as endogenous metabolites of estradiol and estrone are precursors of reactive quinones and semiquinones, which are thought to contribute to estrogen-induced carcinogenesis. On the other hand, a number of quinones that include substituted naphthoquinones and anthraquinones are highly cytotoxic and have been used in cancer treatment. This makes the structures interesting synthetic targets. The following is a review of important natural and synthetic terpenoid and steroid quinone hybrids.
文摘New reagents for immunofluorescence analysis of carbazole series containing fluorinated β-dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carbazole scaffold have been developed. The markers in complex with Eu<sup>3+</sup> ions possess stability in the aqueous phase, intense and prolonged luminescence (τ 550 - 570 μs) with characteristic emission maxima in the region of 615 nm and excitation wavelengths in the region of 380 - 390 nm, which distinguishes them from most of the analogs used. In the study of marker conjugation with streptavidin, a reagent containing 4 - 5 europium labeling complexes based on spacer-containing carbazole tetraketone was obtained. The marker-doped silicate nanoparticles exhibit intense and long-lived luminescence in the characteristic region.
文摘An operationally simple protocol was designed for the enantioselective silane reduction (ESR) of ketones using air- and moisture-stable [Ir(OMe)(cod)]<sub>2</sub> (cod = 1,5-cyclooctadiene) (3) as a metal catalyst precursor. This reaction was driven by chiral hydroxyamide-functionalized azolium salt 2. The catalytic ESR reaction could be performed under benchtop conditions at room temperature. Treatment of 2 with 3 in THF yielded the monodentate IrCl(NHC)(cod) (NHC = N-heterocyclic carbene) complex 4 in 93% yield, herein the anionic methoxy ligand of 3 serves as an internal base that deprotonates the azolium ring of 2. The well-defined Ir complex 4 catalyzed the ESR reaction of propiophenone (6) with (EtO)<sub>2</sub>MeSiH using the pre-mixing reaction procedure. Based on this success, the catalytic ESR reaction was designed and implemented using an in situ-generated NHC/Ir catalyst derived from 2 and 3. Thus, a wide variety of aryl ketones could be reduced to the corresponding optically active alcohols in moderate to excellent stereoselectivities at room temperature without temperature control. Since the high catalytic activity of 3 was observed, we next evaluated several other transition metal catalyst precursors for the catalytic ESR reaction under the influence of 2. This evaluation revealed that Ir(acac)(cod) (acac = acetylacetonate) (28) and [IrCl(cod)]<sub>2</sub> (5) can be successfully used as metal catalyst precursors in the ESR reaction.
文摘In the course of organic synthesis, particularly for multi-step synthesis or natural product total synthesis, the selection of appropriate protective groups for the intended functionality is crucial in order to achieve chemoselective synthetic goals. The development of many useful protective groups has been reported based on the functionality of the anilino group. Herein, we discuss our study of various protective groups and the processes we used to establish compatibility with anilino functionality via the implementation of Oxone-mediated oxidative esterification in methanol. The results and the details of our experiments are reported herein.
文摘The synthesis of new indoloannulated thiopyranethiones is reported. The key-step is a rhodium-catalyzed [2 + 2 + 2]-cycloaddition of alkynyl-ynamides with carbon disulfide to close the pyrrole and the thiopyranethione rings simultaneously. A violet idolothiopyrane thione or a mixture of the violet and a red isomer result from [RhCl(C<sub>8</sub>H<sub>14</sub>)<sub>2</sub>]<sub>2</sub>/3BINAP catalyzed cycloadditions, the regiochemistry is controlled by the substitution pattern on the alkynyl-ynamide.
文摘A new phloretin derivative 1 3-[2-(4-hydroxy-phenyl)-ethyl]-benzo[d] isoxazole-4,6-diol (yield 63%) was synthesized from phloretin by carbonyl nucleophilic addition condensation reaction. Its structure was characterized by 1H NMR, 13C NMR and HR-MS. The phloretin, compound 1, resveratrol and acetylated resveratrol were determined by comparing them with paclitaxel. Anti-tumor activity of alcohol on SPC-A1, EC109, A549, MCF-7 and MDA-MB-231 cell lines. Compound 1 showed better antitumor activity than docetaxel against A549 tumor cells.
文摘A new electrophilic polymer, 2,4-dinitrophenyl ether of polyvinyl alcohol (PVA-DNP), having a degree of substitution of 0.5 was prepared from polyvinyl alcohol (PVA) and 1-fluro-2,4-dinitrobenzene (DNFB). The PVA-DNP polymer was characterized by NMR, IR, and UV-visible spectroscopy. The reaction of PVA-DNP with sodium methoxide was followed by NMR and UV-visible spectroscopy. Evidence of polymer bound spirocyclic SIGMA complex, C-1 and C-3 polymer bound DNP-methoxy SIGMA complexes and the formation and C-1 methoxy complex of 2,4-dinitroanisole was observed.
文摘A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K<sub>3</sub>PO<sub>4</sub>) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .
文摘Hirshfeld surface analysis has been widely used in recent years as a means to quantify and visualize various types of intermolecular interactions in molecular crystals. This review article introduces intermolecular interactions discussed with Hirshfeld surface analysis and 2D fingerprint plots. In addition, using CIF files obtained from our previous results, Hirshfeld surface analysis was newly performed, and the resulting 3DHirshfeld surfaces, 2D print plots, molecular structural features, and crystal structure relationships were described. Classification of their intermolecular interactions, statistical discussion focused on crystalline water and perspective on ligand-protein docking are also mentioned.
文摘The aim of this study was to investigate the chemical composition of the essential oils of “Covid-Organics” of Madagascar (62% Artemisia annua and two other undisclosed medicinal plants) used as curative and preventive treatments of Covid-19, to identify its constituent species. The essential oils isolated by hydro-distillation from two samples (curative and preventive) were analyzed by GC-FID and GC-MS. These essential oils (curative and preventive) were mainly dominated by camphor (17.9% and 11.9%, respectively), spathulenol (4.8% and 11.8%, respectively), α-acorenol (4.3% and 3.7%, respectively), (E)-β-caryophyllene (3.4% and 4.2%, respectively), 1,8-cineole (3.1% and 3.6%, respectively), hexadecanoïc acid (3.8% and 3.2%, respectively) and caryophyllene oxide (3.4% and 2.4%, respectively). From the chemical composition, two species were identified, A. annua characterised by camphor and Cinnamomumcamphora (Ravintsara) characterised by 1,8-cineole and sabinene. However, we were unable to identify the third species.
文摘Buoyed by the extensive research on the wide-range biological activities of aminophosphonates, a novel class of aminated (cyclopropylmethyl)phosphor-nates compounds was synthesized from diethyl ((1-(3-chloropropyl)cyclopropyl)methyl)phosphonate and various amines in the presence of Hunig’s base. Upon biological activity screening these compounds demonstrated encouraging anti-pancreatic cancer properties at low micromolar concentrations.
文摘In the present work, for the first time, the main details of the electronic mechanism of the synergistic antioxidant interaction between different pairs: phenolic food acid and glutathione and the stable radical cation ABTS<sup>+·</sup> were revealed on the basis of a rigorous analysis of the DFT calculated data. It was shown that among all the studied food acids, only caffeic acid exhibits a clear-cut significant synergistic effect with glutathione. It established the electronic and structural factors underlying the mechanism of the synergistic interaction of the mixture caffeic acid and glutathione in its reaction with ABTS<sup>+·</sup>. The main causes of this considered synergistic effect are, firstly, the presence of the 3-OH and 4-OH hydroxyl groups in the structure of caffeic acid, secondly, the greater stability of its anion which contains the deprotonated 4-OH hydroxyl group. All other phenolic food acids under study do not possess the given structural particularity and therefore do not show such synergistic effects with glutathione.
文摘Electrochromic materials are of great interest for their potential in eyewear protection and data storage devices, as they change colors in response to electrochemical switching. While many of the systems currently used are based on inorganic materials, organic materials such as triazenes have emerged as viable alternatives due to their unique properties, including optical properties. Triazenes are a class of organic compounds with three consecutive nitrogen atoms in an acyclic arrangement, and they have been used for a variety of applications in medicinal and synthetic chemistry. However, the effects of solvents on the UV-visible absorption spectrum of triazenes have not been fully investigated. The neutral molecules of 3,3-diisopropyl-1-phenyltriazene and 1-(4-chlorophenyl)-3-cyclopentyltriazene in acetonitrile, the UV-visible spectra corresponded respectively to HOMO → LUMO transitions with a large maximum absorption at 299.74 nm (4.1364 eV) and 299.57 nm (4.1387 eV) and the most intense oscillator strength (f = 0.6988) and (f = 0.7372). These results suggest that the electronic transitions of the compounds are highly influenced by the nature of the substituents on the triazene unit, as well as the solvent used in the experiment. The redox couple 0.92 and -0.44 V/Ag/AgCl is attributed to the phenyl group. Compound III showed an oxidation and reduction peak respectively -0.27 and -0.8 V/Ag/AgCl attributed to the phenyl molecule. The study concluded that all three compounds were electroactive and exhibited reversible characteristics with oxidizing/reducing couples. This study aims to contribute to research on the optical properties of triazenes compounds and the application of quantum chemical calculation methods for understanding their molecular structures. By investigating the solute-solvent interactions occurring in the solvation shell of the solutes, we aim to gain insights into the effects of solvents on the UV-visible absorption spectrum of triazenes. Our findings may have implications for the development of functionalized triazenes as potential electrochromic materials.
文摘An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byproduct was recovered in high yield by simple filtration. Some aromatic acids have been transformed into the corresponding acid chlorides in good yields by employing the isolated VH. Treatment of primary or secondary alcohols with VH gave alkyl formates or alkyl chlorides by depending on the reaction conditions.
文摘New fluorine substituted 6-(5’-fluoro-2’-triphenylphosphiniminophenyl) 3-thioxo-1,2,4-triazin-5 (2H, 4H) one (2) was obtained via Wittig’s reaction of the corresponding 6-(5’-fluoro-2’-amino-phenyl)-3-thioxo-1,2,4-triazinone (1). Behavior of compound 2 towards alkylating agents and/or oxidizing agents was studied were, N-hydroxyl (3), Mannich base (4,5), S-alkyl (6,7,8) and thiazolo [3,2-b][1,2,4] triazinones (10-14) and or 3-disulfide (18), 3-sulfonic acid 19 and 1,2,4-triazin-3,5-Dionne (20) derivatives obtained. Structures of the new products are established by elemental and spectral data. The new targets obtained screened as Molluscicidalagents against Biomophlaria Alexandrina snails responsible for Bilharziasis diseases, in compare with Baylucide as standard drug.
文摘The Phellinus mushrooms have been known for its immunomodulatory, hypolipidemic, and anticancer activities. In the current work, the chemical constituents of two Phellinus mushrooms, Phellinus pini 141016# and Phellinus sp. 150802#, which were collected in Foshan city, Guangdong province, were investigated preliminarily by pre-test tube method and by comparison with the known natural compounds from Phellinus pini, and their antioxidant activities were evaluated by the biochemical assay of hydroxyl and 2,2-diphenyl-1-pricylhydrazyl (DPPH) radicals scavenging activity in vitro. The results show that both the two Phellinus mushrooms contain phenolics, alkaloids, lactones, steroids and terpenoids, and have potent antioxidant activities. The IC50 values of DPPH radicals and hydroxyl radicals for Phellinus pini 141016# were 74.37 μg/mL and 59.69 μg/mL, respectively, and the IC50 values of DPPH radicals and hydroxyl radicals for Phellinus sp. 150802# were 98.95 μg/mL and 165.47 μg/mL, respectively. They are comparable to the antioxidant activity of the standard antioxidant ascorbic acid.
文摘Novel 6-(5’-fluoro-2’-diphenylphosphorylanilido)-3-hydrazino-1,2,4-trizin-5 (2H) one (3) is achieved from hydrozinolysis of the corresponding 3-thioxo-analoges 2. Compound 2 is also obtained from phosphorylation of 6-(5’-fluoro-2’-aminophenyl)-3-thioxo-1,2,4-triazin-5(2H) one (1). Novel fluorine substituted isolated and/or fused heterobicyclic nitrogen systems bearing and/or containing, 6-phosphoryl anilido-1,2,4-trizin-5 (2H) one moiety (4 - 22) have been synthesized from ring closure reactions of compound 3 with π-acceptors activated carbon compounds in different medium and conditions. Structures of the products are characterized by MS, IR, UV-VIS, CH, N, and 1H/13CNMR spectral data. The new products have been evaluated as potential inhibitors towards HIV-1 activity.
文摘A highly efficient and convenient procedure for the enantioselective synthesis of (S)-Rivastigmine, a cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer’s type and dementia due to Parkinson’s disease, is accomplished by the treatment of versatile, readily accessible (S)-(-)-2-methyl-2-propanesulfinamide with 3-hydroxyacetophenone. This protocol provides high yield and excellent enantiomeric excess in short step synthesis.
文摘Pyrrolidines are well known for their versatile pharmacological activities such as antimicrobial [1] [2] [3] [4], antitumor [5], anti HIV [6], anticonvulsant [7] [8], human melanocortin-4 receptor agonists [9], etc. Moreover, indole nucleus is an important element of many natural and synthetic molecules that covers some of the relevant and recent achievement in the biological, chemical and pharmaceutical activity of important indole derivatives [10]. In view of these observations, the intention is directed to synthesize some new bisindole derivatives of expected biological interest.
文摘Basing on the DFT calculations we propose the new theoretical model which describes both the surface tension σ of the short chain n-alkanes at their normal boiling points and their reaction rate constants with hydroxyl radicals OH<span style="white-space:nowrap;">•</span> (at 297 ± 2 K) on the basis of their molecular orbital electronic characteristics. It has been shown that intermolecular dispersion attraction within the surface liquid monolayer of these compounds, as well as their reaction rate constants k with OH<span style="white-space:nowrap;">•</span> radicals are determined by the energies <em>E<sub>orb</sub></em> of the specific occupied molecular orbitals which are the same in the determination of both the above physico-chemical characteristics of the studied n-alkanes. The received regression equations confirm the theoretically found dependences between the quantities of σ and k and the module |<em>E<sub>orb</sub></em>|. For the compounds under study this fact indicates the key role of their electronic structure particularities in determination of both the physical (surface tension) and the chemical (reaction rate constants) properties.