GC-MS and FTIR analysis of methanolic leaf extract of Rhynchosia minima (L.) DC.

The current analysis was carried out to determine the chemical components in the leaves of R. minima (L.) DC. The GC-MS analysis of methanolic leaves extract of R. Minima indicated the presence of 19 compounds. The prevailing compounds of R. minima leaves were 1Pentadecene (14.31), alpha. Bisabolol (10.39%), 1Heptadecene (9.78%), Cyclohexene,4 (1,5dimethyl1,4hexadienyl (7.06%), 3Hexadecene (Z) (8.10%), Caryophyllene (6.58%), Neophytadiene (5.16%), Humulene (1.91%), Naphthalene,1,2,3,5,6,8 a-hexahydro-4,7-dimethyl (3.72%), Hexadecanoic acid, methyl ester (2.09%), Pentadecanone (3.13%), 8-Octadecanone (4.02%),1-Nonadecene (4.16%), Spiro[4.5]dec-6-en-8-one,1,7-dimethyl-4-(1-methylethyl (2.97%), Neophytadiene (2.24%),(E)-. beta.-Famesene (1.92%), Cyclohexene,4-[(1E)-1,5-dimethyl-1,4-hexadien (1.80%), Cyclohexane,octyl (1.45%), beta Bisabolene (9.21%). These compounds have antibacterial, antifungal, antioxidant, hemolytic, insecticidal, and lubricant activity. Fourier Transform Infra-Red Spectroscopy (FTIR) leaf anlysis of R. minima shows lipid, protein, phosphate ion, carboxylic acid, hydroxy compound, aliphatic bromo compounds. The present study revealed that R. minima leaves represent various types of bioactive compounds. 1-Heptadecene with antibiotic activity, 8-Octadecanone shows antimicrobial activity and hexadecanoic acid, nematicide, antibiotic, antioxidant, hypocholesterolemic production of methyl ester.

High-efficiency cathodic electrochemiluminescence of the tris(2,2′-bipyridine)ruthenium(ii)/N-hydroxy compound system and its use for sensitive “turn-on” detection of mercury(ii) and methyl blue

N-Hydroxysuccinimide (NHS) and N-hydroxysulfosuccinimide (NHSS) were exploited as efficient coreactants for cathodic Ru(bpy)32+ electrochemiluminescence (ECL) in neutral medium.

BF3·Et2O-Promoted Decomposition of Cyclic α-Diazo-β-Hydroxy Ketones: Novel Insights into Mechanistic Aspects

We report novel insights into the cascade rearrangement of destabilized vinyl cations deriving from the BF3·Et2O-induced decomposition of cyclic α-diazo-β-hydroxy ketones in turn prepared by aldol-type condensation of cycloalkanones with diazoacetone. Complexation of the hydroxy group of the α-diazo-β-hydroxy compound with the Lewis acid is the first event, followed by the generation of the cycloalkanylidenediazonium salt that, after nitrogen loss, produces the highly reactive vinyl cation. The subsequent ring expansion results in the formation of a cycloalkenyl vinyl cation that affords the allylic cation by 1,2-methylene shift and ring contraction. The cation can then trap the solvent, the fluoride or the hydroxide released from the [BF3OH]− to afford different reaction products. The effect of both solvent and substrate ring size on products types and ratios were analyzed and discussed from a mechanistic point of view.

An efficient synthesis of 3β,14β-dihydroxy-5α-androst-15-en-17-one

An efficient four-step method has been developed for the synthesis of 3 β,14 β-dihydroxy-5 α-androst-15-en-17-one from a common androstane derivative. The X-ray crystal structures of the alkenes, the epoxide and the 14-hydroxy compound have been determined.

Formation and Fragmentation of 4-Diazo-1,2-diphenyl-3-oxo-butyl Acetate

threo-4-Diazo-1,2-diphenyl-3-oxo-butyl acetate (15) could be prepared via the classical route 6→8→10→12→13→15. However, its alkaline hydrolysis to the bifunctional hydroxy compound 17 led to a spontaneous dehydration to the diazoketone (E)-18 and to a fragmentation to acetic acid, benzaldehyde (8) and diazoketone 19.

Infrared study of some 2-substituted-6-hydroxy-4-pyrimidine carboxylic acids: Correlation with MO-calculations

The IR spectra of a series of 2-substituted-6-hydroxy-4-pyrimidine carboxylic acids (substituent = OH, SH, CH3, CH3S and NH2) were studied from the aspect of the influence of the subsitutent on the polarizability of some bonds, keto-enol tautomerism and hydrogen bond formation. The spectra were taken using solids due to the low solubility of the acids. Theoretical calculations were done using the MNDO-AM1 semiempirical molecular-orbital method. The stabilities of various tautomers were calculated simulating the dielectric continuum using the COSMO facility of the MOPAC program package. Theoretical calculations were made for all the possible tautomers of the 2-substituted-6-hydroxy-4-pyrimidine carboxylic acids. For the most stable isomers, the vibrational spectra were calculated. For the majority of the compounds the most stable isomer was identified having the structure 2-Y-6-oxo-4-carboxy-3H-pyrimidine. Besides this structure, for the 2-amino-, and 2-methyl- derivatives the zwitterionic forms have very similar stability. The 2-hydroxy compound is most stable as the 2,6-dioxo-1H, 3H isomer. The calculated vibrations for the compounds with a single stable structure correlate very well with the experimental frequencies. For the 2-methyl- and 2-amino- compounds the correlation is considerably less satisfactory. The most probable reason for this deviation is the existence of two or more tautomets in equilibrium. The correlation of the measured frequencies and the pKa values of the acids, indicate that the same tautomers exist in the solid state and in the solution.

Dielectric Spectroscopy of Some Multihydroxy Compound Solutions in Water/Tetrahydrofuran Mixtures

The dielectric spectra up to 72 GHz have been measured at 20 °C for solutions of glucose and sorbitol (max. 1 mol/1) in the mixed solvent water/tetrahydrofuran (THF) as a function of the THF content (max. volume fraction 0.4). There is no significant difference in the relaxation behaviour of corresponding glucose and sorbitol systems. The spectra of binary water/THF as well as hydroxy compound/water systems show that the respective minor components influence the structure and dynamics of water. The ternary systems hydroxy compound/water/THF, however, exhibit merely a superposition of those effects, thus there is no evidence for an interaction between the hydroxy compound and THF in aqueous environment.

Darstellung und Einkristall-Röntgenstrukturanalyse einiger Fluorphosphite und Phosphitester / Preparation and Single Crystal X-Ray Diffraction Study of Some Fluorophosphites and Phosphite Esters

The synthesis of some monofluorophosphite esters from the appropriate hydroxy compound and PCl2F in the presence of a tertiary amine is described. The reaction of 2,2′-dihydroxy-biphenyl with PCl3 in the presence of triethylamine did not furnish the expected chlorophosphite 9; instead, the bridged bisphosphite ester, 10, was obtained. Reaction of the fluorophosphite ester 8 with 3,5-di-tert-butyl-benzoquinone furnished the spiromonofluorophosphorane 12 in which λ5P is part of a five-membered and a seven-membered ring system. Single crystal X-ray diffraction studies were conducted on compounds 2, 10 and 13. In the case of 2, crystallographic 2/m symmetry and short intermolecular P · · · O distances were observed. Compound 10 shows short intramolecular P · · · O contacts. The catechyl phosphate 13, similarly to other dialkylphosphate esters, was found to be a hydrogen-bonded dimer.

Bicyclo[2.2.2]octane-2-spirocyclohexanes, Part 4. Birch Reduction of Spirodiisophor-6-ones

Birch reduction of spirodiisophorones by sodium in liquid ammonia - t-butanol reduces their normally inert 6-keto-group, producing the corresponding secondary alcohols, the 6-hydroxygroup of which assumes the endo- or exo-configuration. 3´-Oximinospirodiisophor-6-one is converted predominantly into the 6-endo-hydroxy-compound , from which the 3´,6-endo-ketol is obtainable by the action of sodium bisulphite. 3´-eq(and ax)-Hydroxyspirodiisophor-6-one each yield a pair of stereoisomeric 3´,6-diols, distinguished by their spectral characteristics and derivatives. Spirodiisophora-3´,6-dione yields a mixture of the same four diols, three of which are isolable in low yield. The structure of selected compounds is correlated with their assigned 13C NMR spectra.