The Mills-Nixon effect. IV. Base-catalysed cleavage of Trimethylsilyl-veratrol, -1,3-benzodioxole and -1,4-benzodioxan derivatives

1974 ◽  
Vol 27 (4) ◽  
pp. 895 ◽  
Author(s):  
LJ Brocklehurst ◽  
KE Richards ◽  
GJ Wright
Keyword(s):  
Sodium Hydroxide ◽  
Dimethyl Sulphoxide ◽  
The Other ◽  
Ring Junction

The rates of cleavage for 4-trimethylsilyl-veratrol, 5-trimethylsilyl-1,3-benzodioxole and 6-trimethyl- silyl-1,4-benzodioxan have been measured at 30�C in 1 : 9 water-dimethyl sulphoxide containing sodium hydroxide. The benzodioxole derivative is more reactive than the other two substrates; this enhanced reactivity arises from hybridization changes enforced on the ring junction carbons by the strained dioxole ring.

scholarly journals Interaction of solvents with membranal and soluble potassium ion-dependent enzymes

1970 ◽  
Vol 116 (1) ◽  
pp. 49-54 ◽  
Author(s):  
M. Mayer ◽  
Y. Avi-Dor
Keyword(s):  
Enzyme Activity ◽  
Pyruvate Kinase ◽  
Solvent Effects ◽  
Adenosine Triphosphatase ◽  
The State ◽  
Dimethyl Sulphoxide ◽  
The Other ◽  
Enzyme Structure ◽  
Wide Range ◽  
Muscle Pyruvate Kinase

The effects of dimethyl sulphoxide and glycerol on ox brain microsomal Na++K+-stimulated adenosine triphosphatase (EC 3.6.1.3), K+-stimulated p-nitrophenyl phosphatase and K+-dependent muscle pyruvate kinase (EC 2.7.1.40) were studied. Dimethyl sulphoxide at concentrations below 20% (v/v) was found to stimulate the p-nitrophenyl phosphatase and pyruvate kinase by increasing their affinity for K+ but to inhibit the Na++K+-stimulated adenosine triphosphatase. The latter enzyme activity was also inhibited by glycerol, which like dimethyl sulphoxide, stimulated the K+-activated p-nitrophenyl phosphatase at a wide range of concentrations. The solvent effects were promptly reversed by dilution. Similarity was found between glycerol and dimethyl sulphoxide, on one hand, and ATP, on the other, in their stimulatory effect and their ability to increase the ouabain- and oligomycin-sensitivity of the K+-stimulated p-nitrophenyl phosphatase. However, only the solvents, not the ATP, increased the binding of K+ by the microsomes. From the above findings it is suggested that solvents may act on K+-dependent enzymes by altering the state of solvation of the activating cation as well as by changing the enzyme structure.

Organic sulfur compounds. VII. Some reactions of benzothiazine hydroxamic acids

1970 ◽  
Vol 48 (23) ◽  
pp. 3727-3732 ◽  
Author(s):  
R. T. Coutts ◽  
Sharon J. Matthias ◽  
E. Mah ◽  
N. J. Pound
Keyword(s):  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Unsaturated Acid ◽  
Hydroxamic Acids ◽  
Sulfur Compounds ◽  
The Other ◽  
Complex Reaction ◽  
Organic Sulfur Compounds ◽  
Derivatives Of

Treatment of (3,4-dihydro-4-hydroxy-3-oxo-2H-1,4-benzothiazin-2-yl)acetic acid (1a) with sodium hydroxide yields the corresponding lactam, i.e. (3,4-dihydro-3-oxo-2H-1,4-benzothiazin-2-yl)acetic acid, together with the α,β-unsaturated acid, 3,4-dihydro-3-oxo-2H-1,4-benzothiazine-Δ2,α-acetic acid. The 6-methyl- and 6-bromo-derivatives of 1a behaved similarly when reacted with sodium hydroxide but when 3,4-dihydro-4-hydroxy-3-oxo-2H-1,4-benzothiazine was so treated a more complex reaction occurred.Methyl (6-bromo-3,4-dihydro-4-hydroxy-3-oxo-2H-1,4-benzothiazin-2-yl)acetate was also treated with hydrochloric acid. The two products isolated were (6-bromo-3,4-dihydro-3-oxo-2H-1,4-benzothiazin-2-yl)acetic acid and (6-bromo-7-chloro-3,4-dihydro-3-oxo-2H-1,4-benzothiazin-2-yl)acetic acid.The action of hydrochloric acid on 3,4-dihydro-4-hydroxy-7-methyl-3-oxo-2H-1,4-benzothiazine also gave two products. One was the corresponding lactam; the other was unexpected and has been tentatively identified as bis[2-(3,4-dihydro-7-methyl-3-oxo-2H-1,4-benzothiazine].

Extraktionen von Ginsenosiden aus Ginseng-Wurzeln mit flüssigem Ammoniak, Methanol-Wasser oder Wasser/ Extractions of Ginsenosidesj from Ginseng Roots with Liquid Ammonia, Methanol-Water or Water

2000 ◽  
Vol 55 (3-4) ◽  
pp. 326-332 ◽  
Author(s):  
In-Ho Cho ◽  
Eberhard Hohaus ◽  
Axel Lehnen ◽  
Harro Lentz
Keyword(s):  
Sodium Hydroxide ◽  
Liquid Ammonia ◽  
Sodium Hydroxide Solution ◽  
Extraction Methods ◽  
The Other ◽  
Simultaneous Increase ◽  
Hydroxide Solution ◽  
High Yields

Abstract Extractions of ginsenosides from ginseng roots with liquid ammonia, methanol/water (60:40; v/v) or water were carried out. The extracts have been analyzed qualitatively and quantitatively to valuate yield and selectivity of extractions of ginsenosides. Water supplied the lowest yield. The yields of extracts with liquid ammonia were higher than those with m ethanol-water (60%). Yields of the ginsenosides Rb1, Rb2, Rc and Rd by extracting with liquid ammonia are about twice as much as those of the extraction with methanol-water (60%). It was proved by HPLC that malonyl-ginsenosides m -Rb1 m-Rb2, m-Rc and m-Rd were converted to the corresponding neutral ginsenosides by extraction with liquid ammonia. Because of high yields of extracts and simultaneous increase of the contents of Rb1, Rb2, Rc and Rd the extraction with liquid ammonia is obviously superior to the other extraction methods. Furtherm ore, ginsenosides from ginseng roots were extracted by alkaline methanol-water (60%) solutions. Alternatively, the extracts of the methanol-water (60%) extraction were treated with sodium hydroxide solution. Both methods convert also the malonyl-ginsenosides to neutral ginsenosides

Elaeocarpus alkaloids. I. The structures of (±)-elaeocarpine, (±)-isoelaeocarpine, and (±)-isoelaeocarpicine, three new indolizidine alkaloids from Elaeocarpus polydactylus

1969 ◽  
Vol 22 (4) ◽  
pp. 775 ◽  
Author(s):  
SR Johns ◽  
JA Lamberton ◽  
AA Sioumis ◽  
RI Willing
Keyword(s):  
Sodium Hydroxide ◽  
Sodium Hydroxide Solution ◽  
Acetyl Derivative ◽  
Spectroscopic Properties ◽  
Crystal Structure Analysis ◽  
Hydroxide Solution ◽  
Total Alkaloids ◽  
Ring Junction ◽  
Relative Stereochemistry ◽  
A Minor

Three new interrelated alkaloids have been isolated from Elaeocarpus poly-dactylus Schltr. (family Elaeocarpaceae). Two of these alkaloids, (�)-elaeocarpine (I) and (�)-isoelaeocarpine (II), are isomeric and the structure and complete stereochemistry of (�)-elaeocarpine have been established from an X-ray crystal structure analysis of (�)- elaeocarpine hydrobromide.1 From a detailed analysis of the spectroscopic properties of (�)-elaeocarpine and (�)-isoelaeocarpine, and in particular of their 100-Mc/s n.m.r. spectra, it has been shown that the alkaloids are epimeric at C7 and that (�)-isoelaeocarpine has a cis ring junction at C7,C8, whereas (�)-elaeocarpine is known to have a C7,C8 trans configuration. In methanolic sodium hydroxide solution (�)-elaeocarpine and (�)-isoelaeocarpine are interconvertible. (�)-Isoelaeocarpicine (VIa) is closely related to (�)-elaeocarpine and (�)-iso-elaeocarpine, and has been so named because the configuration at C7,C8 corresponds to that of (�)-isoelaeocarpine. (+)- Isoelaeocarpicine is phenolic, differs from (�)-elaeocarpine and (�)- isoelaeocarpine in molecular composition by the elements of water, and is converted into a mixture of elaeocarpine and isoelaeocarpine by the action of methanolic sodium hydroxide solution. Study of the 100-Mc/s n.m.r. spectrum of (+)-isoelaeocarpicine has established the complete stereochemistry shown in (VIa). The structures indicated for the three alkaloids (I), (II), and (VIa) depict relative stereochemistry only and are not intended to imply a particular absolute configuration. Study of the reaction between (+)-isoelaeocarpicine (VIa) and acetic anhydride shows that an O-acetyl derivative (VIb) is formed rapidly, but that with longer reaction periods the amide (VIIIa) is obtained. The steric requirements of the borohydride reduction of (I) and (II) have been studied, and it has been found that the n.m.r. spectra of solutions of the alcohol (XIIa) in CD3CO2D or of its hydro- chloride in CD3OD indicate an equilibrium between two deuteronated forms of (XIIa), one of which is considered to have a cis and the other a trans ring junction for the indolizidine ring. A minor alkaloid, C17H21N3, amounts to <1% of the total alkaloids, and a minor non-alkaloidal constituent has been identified as 2- hydroxy-6-methylacetophenone.

Preservation of viable flexibacteria at low temperatures

1970 ◽  
Vol 16 (6) ◽  
pp. 441-444 ◽  
Author(s):  
Annika Sanfilippo ◽  
Ralph A. Lewin
Keyword(s):  
Liquid Nitrogen ◽  
Low Temperatures ◽  
Extreme Temperature ◽  
Dimethyl Sulphoxide ◽  
The Other

Most of the 28 species (91 strains) of flexibacteria tested without additives survived after freezing in liquid nitrogen (−196 °C): they included all six Microscilla spp., all three Cytophaga spp., both of the Herpetosiphon spp. tested, Flexithrix dorotheae, and seven (most strains) of the eight species of Flexibacter spp. All but 2 of the 19 strains of Saprospira grandis, but neither of the two other tested species of Saprospira, survived freezing to −196° without additives.Incorporation of 10% glycerol before freezing permitted survival of three of the sensitive strains of Flexibacter (F. aurantiacus copepodarum, F. flexilis iolanthae, and F. giganteus), but adversely affected two other species (F. elegans and F. ruber). Incorporation of 10% dimethyl sulphoxide (DMSO) had some similar effects. Freezing to −196° with glycerol conserved viable cultures of all 19 S. grandis strains, of S. toviformis, and of 2 of the 3 strains of S. thermalis.A less extreme temperature was less satisfactory. Stored at −22°, some or all strains of 6 species died out in less than 1 week; most strains of 12 others died after a few weeks; and 7 species survived for at least 21 weeks. (The other three were not tested.)

scholarly journals The relative effectiveness of commonly used disinfectants in inactivation of echovirus 11

1978 ◽  
Vol 81 (1) ◽  
pp. 77-87 ◽  
Author(s):  
Murray Drulak ◽  
Alfred M. Wallbank ◽  
Ingrid Lebtag
Keyword(s):  
Sodium Hydroxide ◽  
Fetal Calf Serum ◽  
Relative Effectiveness ◽  
Calf Serum ◽  
Skim Milk ◽  
The Other

SUMMARYEchovirus 11 in the presence of fetal calf serum was exposed to six commonly used disinfectants for times of 10, 20 and 30 s. At the end of such exposure times, skim milk neutralized disinfectant activity and residual virus was assayed using the plaque technique. The six disinfectants studied were Javex, sodium hydroxide, ethanol, Wescodyne, One Stroke Ves-Phene, and Sonacide. Although 0·25% (w/v) sodium hydroxide and 95% (v/v) ethanol were equally virucidal and significantly more so than the other four disinfectants, causing 106reduction in 20 s, they may not be practical to use in many instances. Javex at a dilution of 1/50 (1200 parts/106chlorine) proved to be virucidal causing 103·5reduction of echovirus 11 in 30 s. Wescodyne (1/50) and undiluted Sonacide were relatively ineffective causing 10 reduction or less of echovirus 11 in 30 s. One Stroke Ves-Phene (1/50) was ineffective causing no significant inactivation in 30 s.

Chemistry of the Podocarpaceae. XXIII. Preparation and reactions of some lactone derivatives of 12-Methoxypodocarpa-8,11,13-trien-19-oic acid

1969 ◽  
Vol 22 (9) ◽  
pp. 1989 ◽  
Author(s):  
RC Cambie ◽  
WA Denny
Keyword(s):  
Sodium Hydroxide ◽  
Convenient Method ◽  
Potassium Hydroxide ◽  
Potential Method ◽  
Fragmentation Reaction ◽  
Ring Junction ◽  
Benzilic Acid ◽  
Derivatives Of

The parent lactone (V) of a series of 12-methoxypodocarpa-8,11,13- trien-19-oic acid derivatives has been prepared by successive dehydration and hydrogenation of the 7α- and 7β-hydroxy lactones (VII) and (VIII), and also by reduction of the 7-keto lactone (IV) with diborane. Attack by nucleophiles on the 7β-hydroxy lactone (VIII) is a convenient method for the preparation of less readily available 7α- substituted lactones. Treatment of the 7-keto lactone (IV) with sodium hydroxide in methanol effects a fragmentation reaction to give the diosphenol (XXIV), providing a potential method for the formation of hitherto inaccessible 6,7-diketones with a trans-fused A/B ring junction. Treatment of the diosphenol (XXV) with potassium hydroxide affords the cis-fused A/B ring junction diketo acid (XXXI) rather than the product of an expected benzilic acid rearrangement.

Copper(II)-promoted solvolyses of nickel(II) complexes. I. N,N-Dialkyldithiocarbamates

1973 ◽  
Vol 26 (6) ◽  
pp. 1207 ◽  
Author(s):  
WW Fee ◽  
DE McElholum ◽  
AJ McPherson ◽  
DL Rundle
Keyword(s):  
Dimethyl Sulphoxide ◽  
The Other ◽  
Nickel Ions ◽  
Rate Law ◽  
Significant Contributor ◽  
Low Dielectric ◽  
Dielectric Media ◽  
Reaction Stoichiometry ◽  
Kinetics Of ◽  
Negligible Contribution

The kinetics of copper(II)-promoted solvolyses of bis(N,N- dibutyldithiocarbamato)nickel(II) in dimethyl sulphoxide (dmso), N,N- dimethylacetamide (dma), acetone, and chloroform, and bis(N,N- dicyclohexyldithiocarbamato)nickel(II) in dmso and dma have been examined. Although the reaction stoichiometry differs in chloroform compared with the other solvents, in all media the two-term rate law ����������������� -d[Ni(dtc)2]/dt = (k1+k2[Cu2+])[Ni(dtc)2] is obeyed. However, in the absence of added sodium and nickel ions, experiments in dmso at low [Cu2+]O, indicate a negligible contribution from the k1 path. Results are discussed in the light of a mechanism involving primary dissociative (k1) and associative (k2) steps. Although the ratios k2/k1 indicate overall importance for the associative pathways of reaction in the low dielectric media cf. dmso and dma, the k1 term also appears as a significant contributor to the reaction of the dibutyldithiocarbamate complex in the former solvents.

Property Evaluation of Polypropylene/Glass Fiber Complex Braids under a Base/Salt Environment

2011 ◽  
Vol 236-238 ◽  
pp. 3001-3004 ◽  
Author(s):  
Ching Wen Lou ◽  
Jin Mao Chen ◽  
Ching Wen Lin ◽  
Wen Hao Hsing ◽  
Hsien Chang Liao ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Sodium Chloride ◽  
Glass Fiber ◽  
Sodium Hydroxide ◽  
Glass Fibers ◽  
The Other ◽  
The Earth ◽  
Property Evaluation ◽  
Base Salt ◽  
Experimental Group

The earth can be strengthened by embeding geogrids within. Glass fibers, used in geogrids, are heat-resistant and have stable size and chemistry; however, they tend to break from the clefts on the surface. This project created complex braids for geogrids by wrapping glass fibers (GF) with polypropylene (PP) filaments, preventing the geogrids’ outer friction and combining two materials as a bind. An 8-spindle braid machine and a 16-spindle braid machine were employed for braiding process. The experimental group was divided into two subjects, one was PP/ GF complex braids heat-set and the other non-heat-set. Then PP/ GF complex braids were measured with tensile strength after being immersed in sodium hydroxide (NaOH) solutions and sodium chloride (NaCl) solutions.

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