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1.
The chemical composition of a hydrodistilled oil of Stachys inflata Benth. growing wild in Iran was examined by GC/MS. Thirty-nine constituents were identified. The major components of the oil were germacrene-D (16.9%), bicyclogermacrene (16.6%), -pinene (11.3%), -phellandrene (9.8%), bicycloelemene (6.6%), -pinene (5.6%), and spathulenol (3.2%).  相似文献   

2.
Water-distilled essential oil from the aerial parts ofS. Boissieriwas analyzed by GC/MS. Forty - five components were characterized representing 97% of the oil. The main components were identified as carvacrol (40.8%),-terpinene (26.4%), andp-cymene (14.5%).  相似文献   

3.
Water-distilled essential oil from Ononis viscosa L. subsp. breviflora (DC.) Nyman was analyzed by GC/MS. Forty compounds were characterized representing 81.3% of the oil. Hexahydrofarnesylacetone (12.5%), carvacrol (10.0%), lauric acid (8.3%), nonanal (5.5%), E-geranylacetone (4.8%), and dodecanal (4.8%) were identified as the major constituents.  相似文献   

4.
Several halomethyl-arylcarbinols were prepared, and the influence of substituents on enantiomer selectivity in the acetalisation reaction with [2S-(2,3a,4,7,7a)]-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-ol was examined.
Unserem sehr verehrten Lehrer, Herrn Prof. Dr.Otto Hromatka, mit den besten Wünschen zum 80. Geburtstag gewidmet.  相似文献   

5.
Effects of -tocopherol (Toc) and -tocopherol acetate (TocA) on the hydrolysis activity of phospholipase D (fromStreptomyces chromofuscus) were studied in small unilamellar vesicles (SUV) of egg yolk phosphatidylcholine (PC). Choline produced in the reaction was monitored by use of a choline oxidase — oxygen electrode. Addition of 18 mol% Toc into SUV (2 mM PC) brought about a twofold rate of choline production. On the other hand, the effect of 18 mol% TocA in SUV was very small. The apparent maximum velocity,V max(app), increased by addition of Toc in SUV. The apparent Michaelis constant,K m(app), was unchanged by addition of Toc and TocA in SUV. The Toc and TocA molecules did not have significant effects when PC was solubilized in the micelles of heptaethylene glycol dodecyl ether. The effects of Toc and TocA are, therefore, not due to specific ones on the enzyme itself, but rather upon the bilayer-organization of the substrate. Measurements of spreading pressure showed complete miscibility of PC and Toc, and limited mutual solubility of PC and TocA, suggesting stronger attractive interactions between Toc and PC than those between TocA and PC in the bilayers.  相似文献   

6.
The catalytic potential of dealuminated faujasite in the hydration of turpentine oil was investigated. The main product was the monocyclic alcohol -terpineol (44%) being the non-alcoholic isomerization co-product only 24 %.  相似文献   

7.
Procedures for the synthesis of 4,5-bis[2,5-dimethyl(3-thienyl)]-1,3-azoles based on 1,2-bis[2,5-dimethyl(3-thienyl)]-2-hydroxyethan-1-one, 2-chloro-1,2-bis[2,5-dimethyl(3-thienyl)]ethan-1-one, and 1,2-bis[2,5-dimethyl(3-thienyl)]ethane-1,2-dione were developed. Dithienylethenic compounds in which the thienyl rings are linked through the azole rings exhibit photochromic properties.  相似文献   

8.
The condensation of dichloromethyl tert-butyl ketone (1) with benzaldehyde, para-bromobenzaldehyde, and 2,4-dichlorobenzaldehyde under conditions for the Darzens reaction gives 1-aryl-1-chloro-4,4-dimethyl-2,3-pentanediones (2–4). In the case of nitrobenzaldehydes, the reaction products are 1-aryl-2-chloro-1,2-epoxy-4,4-dimethylpentanones (5 and 6), which isomerize to -chloroketones (7 and 8) upon prolonged storage or heating at reflux in benzene.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Science Center, Russian Academy of Sciences, 420083 Kazan. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 438–441, February, 1992.  相似文献   

9.
Elemental sulfur reacts with ketones and gaseous ammonia at room temperature yielding thiazoline-3 in excellent yields. Under the same conditions elemental selenium does not react at all. Attempts using the known techniques which have been applied in improving the reactivity of slowly reacting ketones in thiazoline-3-synthesis have been unsuccessful (Exp. No. 1–17). The reaction of -halogenketones with sodiumhydrogenselenide to synthesize -hydroselenoketones gives only the original ketones and selenium in almost quantitative yields (No. 18–23). The same is observed with -haloketones and sodium ore magnesium-diselenides (No. 24–45). The explanation of these unexpected results is the strong reducing power of the hydrogenselenide (No. 46–52). Even -bromoketones with activated bromine (i.g. by phenyl groups) were reduced by sodiumhydrogensulfide giving red undefinite oils. However, -chloroketones give -mercaptoketones in excellent yields (No. 53–61). Hydrogenselenide reduces -mercaptoketones to sulfur and ketones in the presence of triethylamine (No. 62–67). Also the transformation of -selenocyanketones to ,-diketodisenides by alkali or the oxidative hydrolysis of selenium-BUNTE salts does not work and gives elementary selenium only. Studies about the concomitant reaction of elementary selenium and ethylenimine on ketones were continued (No. 68–82).
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10.
Copyrolysis of 4-chlorotetrafluorobenzotrichloride with chlorodifluoromethane (as the source of difluorocarbene) gave 4-chlorodifluoromethyl--chlorohexafluorostyrene, 1,4-dichlorotetrafluorobenzene, and 4-(chlorodifluoromethyl)chlorotetrafluorobenzene along with 4-chloro--chlorohexafluorostyrene. Possible routes for the formation of these products have been offered.For Part 30, see Ref. 1.Translated fromIzevstiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2199–2202, December, 1994.  相似文献   

11.
Effects of polymer additives on the formation of microfibrils of bacterial cellulose have been examined by transmission electron microscopy. Among additives with different degrees of polymerization (DP) or substitution (DS), carboxymethyl cellulose sodium salt (CMC) with DP = 80 and DS = 0.57 is the most effective in producing separate, smaller-size microfibrils. By increasing the concentration of this CMC from 0.1 to 1.5%, the percentage of microfibrils measuring 3–7 nm wide is increased and levels off at around 1.0%. Other polymer additives such as xyloglucan are less effective than CMC in producing microfibrils with smaller sizes and the resulting microfibrils still tend to aggregate. The number of charged substituents and the molecular weight seem to be important factors in the production of highly separate smaller-size microfibrils. The reduction in average microfibril size is well correlated to the decrease in mass fraction of cellulose I in bacterial cellulose crystals. On the basis of these results, the mechanism of the crystallization of celluloses I and I is discussed. The effect of colony types, smooth and rough, on the formation of microfibrils in the presence of CMC is also described.  相似文献   

12.
Summary. Glycosylated -hydroxy and -mercapto acids have been synthesized starting from malic/citramalic/thiomalic acid and Ac4--D-Glc-NH2/Bzl4--D-Glc-NH2 using hexafluoroacetone as protecting and activating reagent.Dedicated to Prof. Dr. Horst Wilde on the occasion of his 65th birthday  相似文献   

13.
A new type of macrocyclic receptor able to bind organic substrates containing carboxy and carboxylate groups was designed on the basis of 1,3-disubstituted calix[4]arenes. A series of disubstitited calix[4]arenes were prepared in 60—80% yields by selective 1,3-alkylation of p-tert-butylcalix[4]arene. The compounds obtained were tested as carriers for dl-tartaric, glycolic, dl-amygdalic, and dl-glutamic acids through liquid membranes immobilized on a polymer matrix. The structural factors favorable for the transport of these hydrophilic substrates through lipophilic membranes were established.  相似文献   

14.
15.
The new triterpene glycoside zygoeichwaloside G was isolated from the roots of Zygophyllum eichwaldii C.A.M. by column chromatography. Acid hydrolysis and PMR and 13C NMR spectroscopy using twodimensional COSY, TOCSY, and HSQC and analysis of HMBC and ROESY spectra established that glycoside G is 19--hydroxyursolic acid 3-O--L-(2-O-sulfo)-arabinopyranoside.  相似文献   

16.
The analysis of the experimental data for the energy of the longest wavelength optical transitions n,opt of substituted polymethines X (CH)2n+1 X shows that in the asymptotic case (n) ,opt does not tend to zero, as it follows from the empirically established correlations, but has a finite, non-zero value. It is shown that the energy gap of odd polymethines is the same as that of the even polymethines - the polyenes (E 2 eV). The substituents (X N, O, B) are responsible for the appearance of levels in the gap. These, depending on the substituent character, are vacant (X B) or occupied (X N, O). The transition from or to such a level determines the longest wavelength optical transition energy of polymethines.  相似文献   

17.
An improved procedure was developed for asymmetric reduction of acetophenone and propiophenone by the chiral reagent NaAl(IPTOLate)H2. This procedure is based on isolation of the chiral alcohol that formed as a crystalline host—guest complex with the IPTOL ligand. The enantiomeric enrichment of the product was as high as 97% ee. The ability of IPTOL and its analogs to form host—guest complexes with a number of ether-type solvents, 1-phenylethanol, and 1-phenylpropan-1-ol as well as thermal stabilities of IPTOL-containing complexes with these alcohols were studied.  相似文献   

18.
The two hydroxyls of yuccagenin can be glycosylated by Koenigs-Knorr condensation with acetobromorhammose in dichloroethane in the presence of mercuric cyanide. The bisrhamnoside of yuccagenin markedly lowers the cholesterol and triglyceride content in blood serum of healthy animals and animals with experimental hyperlipidemia.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 242–243, May–June, 2000.  相似文献   

19.
The electronic structure of the benzaldehyde molecule has been studied by X-ray emission spectroscopy. The gas-phase O-K- and C-K-spectra of this compound have been obtained. MNDO quantum-chemical calculations have been carried out. The structure of the MO's of benzaldehyde has been compared with those of benzene and formaldehyde molecules. The character of the p-p interaction of the phenyl and formyl fragments has been considered. The contribution of the latter to the highest occupied molecular orbitals of the-system has been shown to be small.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1033–1037, June, 1994.  相似文献   

20.
The eight solid complexes of zinc with L--methionine or L--histidine were prepared. The thermal decomposition processes of these complexes were determined by means of TG-DTG. The results show that their decomposition processes can be divided into three steps except for the complex Zn(Met)2 the decomposition of which is completed in one step. All the final products are ZnO.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

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