Crystal and molecular structure of 13-diethanolamino-deacetyllaurenobiolide. Macrocycle conformation in linear germacrolides

An x-ray structure analysis of the 13-diethanolamino derivative of deacetyllaurenobiolide, a germacrane sesquiterpene lactone, was performed. The germacrane macrocycle has the chairchair conformation with the ¹⁵D_5,1D¹⁴ configuration. The conformation of the macrocycle in linear germacrolides was analyzed.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 454–457, November–December, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis of Dihalocarbene Derivatives of Arglabin

Dibromocarbene and bisdichlorocarbene derivatives of the available sesquiterpene lactone arglabin were synthesized for the first time. The structures of the molecules were established by spectra methods and XSA. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 451–453, September–October, 2005.     

First synthesis of dialkyl phosphonate derivatives of sesquiterpene α-methylene-γ-lactone

The stereoselective synthesis of two phosphorus-containing derivatives of the known guaianolide arglabin was carried out for the first time. The molecular structures of these products were established based on the spectroscopic data and the results of X-ray diffraction analysis of one of these compounds.     

Synthesis of dihalocarbene derivatives of estafiatin guaianolide

Adducts of dihalocarbenes generated from chloroform and bromoform were prepared by reaction with estafiatin guaianolide. Their structures were established by XSA. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 453–455, September–October, 2007.     

Preparation and structure elucidation of two minor products from reaction of arglabin with chloroform in the presence of a crown ether

A pentachloro derivative, the structure of which was proved by x-ray structure analysis, in addition to a new dichlorocarbene derivative were obtained for the first time by dichlorocyclopropanation of arglabin guaianolide. The stereochemistry of the principal reaction product was established. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 450–452, September–October, 2007.     

Molecular structure of <Emphasis Type="Italic">N</Emphasis>-(<Emphasis Type="Italic">o</Emphasis>-and <Emphasis Type="Italic">p</Emphasis>-hydroxybenzyl)cytisine

The molecular structures of N-(o-and p-hydroxybenzyl)cytisine were investigated by NMR spectroscopy, x-ray structure analysis, and molecular modeling. It was found that NMR resonances of the OH and aromatic protons in N-(o-hydroxybenzyl)cytisine were doubled because of the presence of two conformers in solution. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 165–168, March–April, 2008.     

Crystal Structure of O,O'-Diphenyl N-(o-methylphenyl)-P-toluenesulfonamidomethylphosphonate

1INTR0DUCT10NThederivativesofaaminoph0sphonicacidhaveversatilebiologicalactivities-`13Inordertolookforhighlyeffectiveandselectivenewpesticides,aseriesofdiethyl1-(P-tohienesulfonamido)methylphosphonates1havebeensynthesizedbyathree-com-P0nentreacti0nofp-t0luenesulfonamide,formaldehydeandtriphenylphosphite.t2j'The1HNMRspectraoftheprbductsin-dicatethatthetwohydrogenatoms0ntheaCatomaremagneticallyequivalentwhenthesubstitutedgroupsonNatomareH,CH3andEt02CCHz'However,(R=H.Me,EtO,CCH,,o-me…     

Synthesis and crystal structure of a new methooytrichloro derivative of achillin

A new trichlorometoxy derivative of achillin was isolated from the mixture of chlorination products of achillin in MeOH. The structure of this product was established by X-ray diffraction analysis. This confirmed the previously proposed stereochemistry for the molecules of other two products of this reaction.     

13α-Hydroxymethylenedeacetyllaurenobiolide, a New Germacranolide from Tanacetopsis mucronata

The new sesquiterpene lactone 13-hydroxymethylenedeacetyllaurenobiolide was isolated from the aerial part of Tanacetopsis mucronata S. Koval. (Asteraceae). Its structure was established using spectral data and X-ray structure analysis. The germacranolide macrocycle has the chair-chair conformation with the configuration ₁D¹⁴, ¹⁵D₅.     

Crystal structure and theoretical calculations of Julocrotine,a natural product with antileishmanial activity

Julocrotine, N‐(2,6‐dioxo‐1‐phenethyl‐piperidin‐3‐yl)‐2‐methyl‐butyramide, is a potent antiproliferative agent against the promastigote and amastigote forms of Leishmania amazonensis (L.). In this work, the crystal structure of Julocrotine was solved by X‐ray diffraction, and its geometrical parameters were compared with theoretical calculations at the B3LYP and HF level of theory. IR and NMR spectra also have been obtained and compared with theoretical calculations. IR absorptions calculated with the B3LYP level of theory employed together with the 6‐311G+(d,p) basis set, are close to those observed experimentally. Theoretical NMR calculations show little deviation from experimental results. The results show that the theory is in accordance with the experimental data. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008     

Tryptophan-derived peptides. 1: Crystal structure and solution conformation of Boc-Gly-Trp-Ala-OtBu

The solid-state structure of Boc-Gly-Trp-Ala-OBu^t was determined by single-crystal X-ray diffraction analysis. The tripeptide gave crystals belonging to the orthorhombic systemP2₁2₁2₁ and at 122.0(5) K:a=11.0663(12),b=14.107(2),c=17.275(2) Å,V=2697.0(5) ųZ=4,R(F)=0.0259, andR _w(F)=0.0695. The peptide adopts a type-I-turn in the solid state with a single, rather weak, intramolecular hydrogen bond between the Boc-CO and Ala-NH groups (NO 3.082(1) Å, <NHO 167(1)°). The conformation of the Boc-Gly-Trp-Ala-OBu^t peptide has also been studied by¹H NMR spectroscopy. The solvent and temperature dependencies of NH chemical shifts suggests that this hydrogen bond is broken and that all amide protons are solvent exposed in CDCl₃ and (CD₃)₂SO.     

邻菲咯啉镉配合物的合成、晶体结构及抑菌活性

合成了以邻菲咯啉为配体的金属镉的配合物,利用红外光谱、元素分析、单晶衍射和热重分析等手段对其结构及性质进行了表征和分析,并研究了金属配合物对金黄色葡萄球菌、大肠杆菌、酵母菌的抑菌活性.结果表明,此类配合物对三类菌种均有不同程度的抑制作用.     

Stereochemistry and conformations of natural 1,2-epoxy-guaianolides based on 1D and 2D NMR data and semiempirical calculations

From detailed study of 1D and 2D NMR spectra of ten natural 1,2-epoxyguaianolides (bis-1,2:3,4-epoxyguaianolides and guaianolide-1,2-epoxychlorohydrins), we identified general spectral traits helpful for stereochemical assignment of such sesquiterpene lactones. We found that the chemical shifts of certain (1)H and (13)C nuclei are consistently dependent on the configuration of 1,2-epoxy-ring which could be used as a simple rule for establishing this configuration. Then, from 1D and 2D (COSY, NOESY, HMQC, HMBC) NMR data, applying the observed rule, the structure and stereochemistry of two new, diastereomeric guaianolide-1,2-epoxychlorohydrins, isolated from Achillea serbica, are determined. The NMR data, namely, nuclear overhauser enhancement (NOE) correlations, pointed out two conformations of guaianolide's cycloheptane ring. The semiempirical calculations (AM1 and PM3 methods), performed in order to gain additional information regarding conformations, resulted in three geometries of investigated lactones. Even so, the conformations derived from the NMR data agreed well with those calculated by semiempirical methods.     

Crystal and molecular structure of 4-chloro-7-diethylaminocoumarin

An x-ray study of 4-chloro-7-diethylaminocoumarin was carried out. The introduction of an electron-withdrawing substituent at C⁴ leads to localization of the double bond in the pyran ring and equalization of the bond lengths in the benzene ring.A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, 117813 Moscow. K. A. Timiryazev All-Union Agricultural Academy, 127550 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 445–448, February, 1992.     

Synthesis,structure and biological activity of four new picolinohydrazonamide derivatives

Four new picolinohydrazonamide derivatives, namely, 6‐methyl‐N′‐(morpholine‐4‐carbonothioyl)picolinohydrazonamide, C₁₂H₁₇N₅OS, 6‐chloro‐N′‐(morpholine‐4‐carbonothioyl)picolinohydrazonamide methanol monosolvate, C₁₁H₁₄ClN₅OS·CH₃OH, 6‐chloro‐N′‐(4‐phenylpiperazine‐1‐carbonothioyl)picolinohydrazonamide, C₁₇H₁₉ClN₆S, and 6‐chloropicolinohydrazonamide, C₆H₇ClN₄, have been synthesized and characterized by NMR spectroscopy and single‐crystal low‐temperature X‐ray diffraction. In addition, their antibacterial and anti‐yeast activities have been determined. The first three compounds adopt the zwitterionic form in the crystal structure regardless of the presence or absence of solvent molecules in the structure. They also adopt the same symmetry, i.e. P2₁/c (P2₁/n), unlike the fourth structure which is chiral and has the space group P2₁2₁2₁. For all the studied cases, intermolecular N—H…O and N—H…N hydrogen bonds play an essential role in the formation of the structures.     

酵母甘露聚糖硫酸酯化前后结构与生物活性比较研究

对酵母甘露聚糖及硫酸酯化酵酯母甘露聚糖的相对分子质量、红外光谱、离子色谱、比旋光度、IO4^-氧化、SO4^2-含量、Smith降解、电泳及THP－1细胞分泌IL-la的水平等进行了测定，结果表明，硫酸酯化后相对分子质量增加，IR光谱[α]D^20均有明显变化，电泳迁移加快，IO4^-氧化甲酸生成量减少，硫酸酯化位置在非还原末端，C（3）对碱位置稳定，Smith降解结果表明硫酸化前后基本结构无明显变化。硫酸酯化前后样品对THP－1细胞分泌IL－1a水平影响差异显，对IL-6,IL-8,TNFa,IL-2亦有影响。     

Electronic structure and biological activity of chosen DDT-type insecticides studied by 35Cl-NQR

A correlation between the electronic structure and biological activity of chosen dichlorodiphenyltrichloroethane (DDT)-type insecticides: 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane, 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane, 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene, 2,2-bis(4-chlorophenyl)ethanoic acid and 4,4'-dichlorobenzophenone (used in agriculture) has been analysed on the basis of the (35)Cl-nuclear quadrupole resonance (NQR) spectroscopy. The (35)Cl-NQR resonance frequencies measured at 77 K have been correlated with the lethal dose (LD(50)) parameter that characterises the biological activity of these insecticides.     

Triterpenoids fromAbies species 18. NMR spectra of abieslactone and its dehydro derivative

The contradictions in the interpretations of the¹³C NMR spectrum of a natural lanostanoid, abieslactone, and of the 1H NMR spectrum a its 9,11-dehydro derivative reported in the literature were resolved by two-dimensional¹H-¹H and¹³C-¹H (COSY) NMR spectroscopy.Translated fromIzvestiya Akademi Nauk. Seriya Khimicheskaya, No. 11, pp.2780–2784, November,1996     

Synthesis of thiourea derivatives of the alkaloid anabasine and crystal structure of <Emphasis Type="Italic">N</Emphasis>-(anabasino1-thiocarbonyl)furan-2-carboxamide

A series of new N-acylsubstituted thioureas, the compositions and structures of which were determined by IR and PMR spectroscopy and mass spectrometry, were synthesized from the alkaloid anabasine. The crystal structure of one of the products, N-(anabasino-1-thiocarbonyl)furan-2-carboxamide, was confirmed by x-ray structure analysis. It was also shown that this compound exhibited moderate antibacterial activity. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 183–185, March–April, 2009.     

双乙酰二茂铁缩肼基二硫代甲酸甲酯Schiff碱的合成、晶体结构和生物活性(英文)

用双乙酰二茂铁和肼基二硫代甲酸甲酯为起始原料,制备了含二茂铁的Schiff碱配体[(CH3)SSCNHN=C(CH3)(C5H4)]2Fe.利用元素分析以及红外光谱和单晶X射线衍射分析了产物的组成、化学特征及晶体结构,并测定了其生物活性.结果表明,标题化合物对Ec9706食管癌细胞株具有适度的生长抑制活性.