Synthesis and antioxidant activity of phenolic derivatives ofα-santonin

Phenolic derivatives of-santonin have been synthesized and their antioxidant effect has been studied.Institute of Phytochemistry, National Academy of Sciences of the Republic of Kazakhstan, Karaganda. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 247–249, March–April, 1997.     

Synthesis and characterization of water-swellableα,β-polyasparthydrazide derivatives

, -polyasparthydrazide (PAHy) was crosslinked by glutaraldehyde to form water-swellable materials possessing a three-dimensional molecular network. Different crosslinking degrees were prepared varying glutaraldehyde/PAHy ratio and samples containing 5-fluorouracil were obtained by incorporating the drug into the polymer networks during the crosslinking reaction. All samples were characterized by swelling tests, thermal, x-ray and SEM analysis. Their microstructure was observed through scanning electron microscopy. Furthermore, for samples containing the anticancer drug,in vitro release studies were performed in pH 7.4 buffer solution.     

Synthesis and characterization of water-swellableα,β-polyasparthydrazide derivatives

The synthesis of a new crosslinked polymer by reaction of , -polyasparthydrazide and glutaraldehyde is reported. Different crosslinking degrees were obtained by varying the ratio between the aldehyde and the starting polymer. The crosslinked polymer was characterized by water swelling tests and thermal analysis. In particular, the crosslinking density and its effects on the glass transition temperature of the material were studied. Finally, the microstructure of the obtained polymer was observed using scanning electron microscopy.     

Synthesis and anti-α-glucosidase activity evaluation of betulinic acid derivatives

In this article, a series of betulinic acid derivatives (3a ～ 3u, 4a ～ 4e) were synthesized through a stepwise structure optimization and evaluated for their anti-α-glucosidase activities. All synthesized derivatives exhibited stronger anti-α-glucosidase activities (IC₅₀: 0.56 ± 0.05 ～ 3.99 ± 0.23 μM) than betulinic acid (IC₅₀: 7.21 ± 0.58 μM) and acarbose (IC₅₀: 611.45 ± 15.51 μM). Compound 3q presented the outstanding inhibitory activity (IC₅₀: 0.56 ± 0.05 μM), which was ～ 1100 time stronger than that of acarbose. Compound 3q was revealed as a reversible and noncompetitive α-glucosidase inhibitor by inhibitory mechanism assay. Fluorescence spectra, 3D fluorescence and CD spectra results showed that the interaction of compound 3q with α-glucosidase caused the conformational and secondary structure content change of α-glucosidase. Finally, the molecular docking simulated the interaction between compound 3q with α-glucosidase and the physicochemical parameter was assessed using SwissADME software.     

Synthesis of nitrogen-containing derivatives of 17(20)-pregnenoic, 17β-hydroxypregnanoic,and 17α-hydroxypregnanoic acids as new potential antiandrogens

A general scheme for the synthesis of oxazoline and benzoxazole derivatives of [17(20)E]-21-norpregnene differing in the structure of the steroid moiety as well as amides of 17β-hydroxy-3-oxopregn-4-en-21-oic and 17α-hydroxy-3-oxopregn-4-en-21-oic acids was developed. The scheme involved synthesis of the steroid building blocks (appropriately protected derivatives of pregn-17(20)-en-21-oic, 17β-hydroxypregnan-21-oic, and 17α-hydroxypregnan-21-oic acids) and subsequent transformation of these building blocks into the target compounds. Following the developed scheme, synthesis of new nitrogen-containing steroid derivatives exhibiting antiandrogenic activity was enabled.     

Synthesis of (α-nitroalkyl-ONN-azoxy)furoxan derivatives

The first synthesis of 4-(α-nitroalkyl-ONN-azoxy)-3-methylfuroxans was accomplished by the reaction of 4-amino-3-methylfuroxans with pseudo nitrols in the presence of dibromoisocyanurate.     

Synthesis of γ-benzyltert-butoxycarbonyl-L-alanyl-D-glutamate and its derivatives

A convenient method of obtaining Boc-L-Ala-D-iGln-OBzl and its amide analogs by condensing the N-hydroxysuccinimidyl ester of Boc-L-Ala with the -benzyl ester ofD-Glu in the presence of NaHCO₃, followed by amidation of the resulting Boc-L-Ala-D-Glu--OBzl, is proposed. The use of l-adamantylamine and octadecylamine as amino components has enabled the corresponding -adamantylamide and octadecylamide of the dipeptide to be obtained.Simferopol' State University, 4 Yaltinskaya ul., Simferopol', Crimea, Ukraine 333036. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 101–103, January–February, 1998.     

Synthesis and electroluminescent properties of naphthalimide derivatives

Naphthalimide derivatives, N-ethyl-4-acetylamino-l ,8-naphthalimide (EAAN) and polymer with N-propyl-4-acetylamino-l,8-naphthalimide (PAAN) side-chain (P-PAAN) were successfully synthesized. Electroluminescent devices of ITO/PVK(120nm)/EAAN(50nm)/Al(150nm) (Ⅰ) and ITO/PVK P-PAAN( 10:1) (50nm)/Al(150nm) (Ⅱ) constructed with EAAN and P-PAAN as the emitting layer were investigated, whereas the single-layer devices of ITO/EAAN or P-PAAN(50nm)/Al(l50nm) (Ⅲ) were not observed to have any e-mission light. The emission results revealed that the exciton recombination formed by positive and negative charge carriers injected from electrodes of devices Ⅰ and Ⅱ was much more balanced than that of devices Ⅲ, which implied that naphthalimide derivatives are a new type of electron-transporting materials with high performance. The electron-transporting properties of naphthalimide derivatives were also elucidated by investigation of the electroluminescent behaviors from both devices of ITO/PPV (80nm)/Al and ITO/P     

Synthesis and transformations of the 20-substituted derivatives of 16α,17α-epoxy-5α-pregnane-3Β,21-diol-20-ones

A new and more effective sequence of reactions is proposed for the production of 16,17-isopropylidenedioxy-5-pregnane-3,21-diol-20-one. It uses methods previously unused for 5-H-steroids and involves 21-hydroxylation of 16,17-epoxy-5-pregnan-3-ol-20-one with diacetoxyiodobenzene and cis-opening of the obtained 21-hydroxy-16,17-epoxy-5-pregnane-3,21-diol-20-one by acetic acid in the presence of epoxycarbonylhydrazine, followed by condensation of the obtained product with acetone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1185–1188, May, 1991.     

Synthesis of furanyl- and triazolyl-containing α-CF3-α-hydroxy acids and their derivatives

Russian Chemical Bulletin - Starting from methyl trifluoropyruvate, α-CF3-substituted α-methoxy-α-(furan-2-yl) acetic acids and their derivatives and also methyl...     

Synthesis ofα-substitutedα-amino acids by the alkylation of 5-oxazolinone derivatives

Methods have been developed for the alkylation of 5-oxazolinone derivatives in DMF in the presence of K₂CO₃, KOH, or diisopropylethylamine and a phase transfer catalyst as well as for the preparation of-methyl-phenylalanine,-methylalanine,-methylalanine, and the methyl ester of N-benzoyl--methylalanine. Increasing the initial concentration of the starting 5-oxazolinone in the reaction mixture leads to a sharp drop in the yield of reaction products due to side condensation reactions. The reaction of 2-phenyl-4-benzyl-5- oxazolinone with ethyl iodide gave a dimer namely, 3-(benzoylamino)-3,5-dibenzylpyrrolidine-2,4-dione.Latvian Institute of Organic Chemistry, LV-1006 Riga. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 829–833, June, 1994. Original article submitted January 21, 1994.     

Synthesis and structure of penta-platinum σ-bonded derivatives of corannulene

The synthesis of a new class of Pt(II) complexes with corannulene by way of either oxidative addition or reductive coupling is reported and their crystal structures are investigated. The crystal structure for {trans-Pt(PEt₃)₂Cl}₄{cis-Pt(PEt₃)₂Cl}C₂₀H₅ (1) consists of two enantiomers in a unit cell and shows cis- and trans-configuration around Pt(II) due to bulky PEt₃ ligands. The pentanuclear Pt(II) complex, 1, readily reacts with 1-ethynyl-4-nitrobenzene to afford the penta-alkynyl substituted Pt(II) complex (2). Although there are still bulky PEt₃ ligands around the Pt atoms in 2, all five Pt(II) have trans-configurations. The bowl of corannulene in 2 is shallower than that of 1. Therefore, the bowl depth of corannulene plays a key role in the determination of molecular geometry of σ-bonded pentanuclear complexes bearing corannulene.     

Synthesis of phosphorylated derivatives of furoylglycine and furoyl-β-alanine

Chloromethylfuroyl chlorides react with alkyl glycinates and β-alanates to form the corresponding chloromethylfuroyl amides. The compounds obtained are phosphorylated with triethyl phosphite under the conditions of the Arbuzov reaction to give (diethoxyphosphorylmethylfuroyl amides. Alkaline hydrolysis of these compounds proceeds only at the carboxy group leading to (diethoxyphosphorylmethyl)furoylglycine and furoyl-β-alanine. Selectivity of hydrolysis does not depend on the position of carboxamide and diethoxyphosphorylmethyl groups in the furan ring.     

Synthesis and antitumor activity of derivatives of 23-hydroxybetulinic acid

A series of natural product 23-hydroxybetulinic acid derivatives were prepared.In the preparation of mono-O-benzoyl ester derivative,it was observed that benzoyl group migrated from 3-O-to 23-O-position during the detritylation.     

Synthesis and spectral properties of arylmercury derivatives of α-thiopicolinanilide

A series of thirteen arylmercury derivatives of α-thiopicolinanilide have been synthesizedand characterized by elemental analysis,IR,~1H NMR and MS.The intramolecular coordination andthe substituent effects on the MS and ~(199)Hg NMR behaviours have been studie6.It has been shownthat a linear correlation exists between the ~(199)Hg chemical shifts and the Hammett-Brown constantsσ~+,and the electron-donating groups cause the chemical shift to move upfield.     

Autooxidation of Δ17(20)-20-hydroxy derivatives of steroids. Synthesis of 3β-acetoxy-17α-hydroperoxy-16α-methylpregn-5-en-20-one and its reduction to 17α-hydroxy derivative

An efficient procedure was proposed for the synthesis of 3β-acetoxy-17α-hydroperoxy-16α-methylpregn-5-en-20-one. Optimal conditions were found for the combined process including 1,4-addition of methylmagnesium bromide at the Δ¹⁶-20-oxo fragment of dehydropregnenolone acetate and autooxidation of resulting bromomagnesium 3β-acetoxy-16α-methylpregna-5,17(20)-dien-20-olate. The subsequent reduction of the 17α-hydroperoxy group and hydrolysis of the 3β-acetoxy group afforded 17α-hydroxy-16α-methyl-substituted dehydropregnenolone acetate and its 3-hydroxy analog in high yield.     

Synthesis and characterization of novel β-amino acid derivatives

In the work discussed in this paper, novel β-amino acid derivatives were prepared by Michael addition between 3-substituted-2-propenic acid and hydrazine hydrate. The optimum reaction conditions were determined by analyzing the effects of the ratio of the starting materials, temperature, and reaction time. The conclusions were: reaction temperature 80 °C, reaction time 8 h, n (3-substituted-2-propenic acid)/n (hydrazine hydrate) = 1:15. Products were characterized by measurement of melting point, elemental analysis, and IR and ¹H NMR spectroscopy.     

Aryl-ONN-azoxy-α,α-dinitroalkanes and some of their derivatives

Previously unknownN-dinitroalkyl-NNO-azoxybenzenes have been prepared (by nitration ofN-(-hydroximino) alkyl-NNO-azoxybenzenes) and transformed to some derivatives.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1972–1975, November, 1994