Inhibition of Clostridium botulinum 62A by Saturated n-Aliphatic Acids, n-Alkyl Formates, Acetates, Propionates and Butyrates

1982 ◽  
Vol 45 (12) ◽  
pp. 1117-1119 ◽  
Author(s):  
M. DYMICKY ◽  
H. TRENCHARD
Keyword(s):  
Chain Length ◽  
Alkyl Group ◽  
Clostridium Botulinum ◽  
Mathematical Relationship ◽  
Aliphatic Acids ◽  
Minimum Inhibitory Concentrations ◽  
Alkyl Groups ◽  
Maximum Inhibition

Saturated aliphatic acids (C1 to C20) and n-alkyl formate, acetate, propionate and butyrate esters (C1 to C20) were evaluated to determine the minimum inhibitory concentrations (MIC) necessary to inhibit the growth of Clostridium botulinum 62A in a bacteriological medium. The C1 to C7 and C16 to C20 acids and esters were relatively inactive (MIC > 200 μg/ml). The C8 to C15 acids exhibited some antibotulinal acitivity (MIC = 100 μg/ml), whereas C8 to C15 esters were substantially more inhibitory. The n-alkyl formates, acetates and propionates having C13 to C14 groups gave the highest inhibition, with MIC's of 3.1, 6.3 and 6.3 μg/ml, respectively. The maximum inhibition for the butyrates (MIC = 12.4 μg/ml) was associated with C11 to C12 alkyl groups. A mathematical relationship between activity and alkyl group chain length was derived.

scholarly journals Gemini (dimeric) surfactant perturbation of the human erythrocyte.

2000 ◽  
Vol 47 (3) ◽  
pp. 651-660 ◽  
Author(s):  
M Dubnicková ◽  
M Bobrowska-Hägerstrand ◽  
T Söderström ◽  
A Iglic ◽  
H Hägerstrand
Keyword(s):  
Cell Surface ◽  
Chain Length ◽  
Human Erythrocyte ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Single Chain ◽  
Inner Membrane ◽  
Phosphatidylserine Exposure ◽  
Alkyl Groups ◽  
Dimeric Surfactant

We studied the ability of di-cationic gemini surfactantsdi (amphiphiles), i.e. 1,4-butanediammonium-N,N-dialkyl-N,N,N',N'-tetramethyl bromides (Di-Cm-di-QAS (s = 4), where m = 8, 11, 13, 16 and s = the number of alkyl groups in the spacer) to induce shape alteration, vesiculation, haemolysis and phosphatidylserine exposure in human erythrocytes, and to protect erythrocytes against hypotonic haemolysis. At high sublytic concentrations the Di-Cm-di-QAS (s = 4) amphiphiles rapidly induced echinocytic (spiculated) shapes and a release of exovesicles, mainly in the form of tubes, from the cell surface. Following 60 min incubation erythrocytes were sphero-echinocytic and a few cells with invaginations/endovesicles were observed. No phosphatidylserine exposure was detected. The haemolytic potency increased with an increase of the alkyl chain length. At sublytic concentrations the Di-Cm-di-QAS (s = 4) amphiphiles protected erythrocytes against hypotonic haemolysis. It is suggested that the Di-Cm-di-QAS (s = 4) amphiphiles perturb the membrane in a similar way as single-chain cationic amphiphiles, but that they do not easily translocate to the inner membrane leaflet.

The Hantzsch pyrrole synthesis

1970 ◽  
Vol 48 (11) ◽  
pp. 1689-1697 ◽  
Author(s):  
M. W. Roomi ◽  
S. F. MacDonald
Keyword(s):  
Carboxylic Acids ◽  
Ethyl Acetoacetate ◽  
Alkyl Group ◽  
Ethyl Esters ◽  
Hantzsch Synthesis ◽  
Butyl Esters ◽  
Alkyl Groups

Ethyl esters of 2-alkyl- and 2,4-dialkylpyrrole-3-carboxylic acids are obtained generally by extensions of the Hantzsch synthesis, benzyl and t-butyl esters when the 2-alkyl group is methyl. Hemopyrrole is obtained from butanal and ethyl acetoacetate in three steps. Pyrroles bearing higher alkyl groups or carbobenzoxy groups are reductively alkylated like the corresponding methylpyrroles and carbethoxy derivatives; t-butyl esters do not survive.

scholarly journals Cytotoxicity against HL60 Cells of Ficifolidione Derivatives with Methyl, n-Pentyl, and n-Heptyl Groups

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4081
Author(s):  
Hisashi Nishiwaki ◽  
Megumi Ikari ◽  
Satomi Fujiwara ◽  
Kosuke Nishi ◽  
Takuya Sugahara ◽  
...  
Keyword(s):  
Insecticidal Activity ◽  
Alkyl Group ◽  
Caspase 3 ◽  
Biological Activities ◽  
Mosquito Larvae ◽  
Leukaemia Cell ◽  
Leukaemia Cell Line ◽  
Hl60 Cells ◽  
Flow Cytometric ◽  
Alkyl Groups

Ficifolidione, a natural insecticidal compound isolated from the essential oils of Myetaceae species, is a spiro phloroglucinol with an isobutyl group at the C-4 position. We found that ficifolidione showed cytotoxicity against cancer cells via apoptosis. Replacement of the isobutyl group by n-propyl group did not influence the potency, but the effect of the replacement of this group by a shorter or longer alkyl group on the biological activity remains unknown. In this study, ficifolidione derivatives with alkyl groups such as methyl, n-pentyl, and n-heptyl group—instead of the isobutyl group at the C-4 position—were synthesized to evaluate their cytotoxicity against the human promyelocytic leukaemia cell line HL60 and their insecticidal activity against mosquito larvae. The biological activities of their corresponding 4-epimers were also evaluated. As a result, the conversion of the isobutyl group to another alkyl group did not significantly influence the cytotoxicity or insecticidal activity. In HL60 cells treated with the n-heptyl-ficifolidione derivative, the activation of caspase 3/7 and the early stages of apoptosis were detected by using immunofluorescence and flow cytometric techniques, respectively, suggesting that the cytotoxicity should be induced by apoptosis even though the alkyl group was changed.

The Alkyl Inductive Effect, II Theoretical Calculation of Inductive Parameters

1979 ◽  
Vol 34 (2) ◽  
pp. 321-326 ◽  
Author(s):  
Harry F. Widingand ◽  
Leonard S. Levitt
Keyword(s):  
Electric Field ◽  
Alkyl Group ◽  
Bond Model ◽  
Chemical Effects ◽  
Alkyl Groups ◽  
Alkyl Substitution ◽  
Internal Induction ◽  
Experimental Values ◽  
Physical And Chemical ◽  
Calculated Distance

AbstractThree models of alkyl groups, “derealization”, “through-the-bond”, and “electric field” models, are presented, all of which enable the calculation of σI (R) from first principles, and excellent agreement is demonstrated for the calculated and experimental values of σI (R) . For the “delocalization” model it is found that - σI (R) = 0.0455 + 0.0232(1-1/n), where n is the number of C atoms in an n-alkyl group, and for an infinite C-chain R group, σI( R∞) is - 0.0687, identical to the value found b y a different method in Part I of this series. The “through-the-bond” model gives - σI(R) = - 0.0559 +, where Ci is the number of C-atoms in the i th position from X in RX; and for the “electric field” model, we obtain - σI(R) = 0.0463 + 0.0102 , where di is the calculated distance from C1 to Cn in the most probable conformation of the R-group. It is concluded that Taft's σI(R) values have a real significance whether or not the physical and chemical effects of alkyl substitution reside ultimately in an internal induction mechanism, or in alkyl group polarization by charged centers in the molecule, or a combination of the two.

Synthesis and characterization of some octaalkyl substituted lead phthalocyanines and unexpected variations in lead lability arising from the position of substituents and their chain length

2013 ◽  
Vol 17 (06n07) ◽  
pp. 511-521 ◽  
Author(s):  
Lydia X. Sosa-Vargas ◽  
Isabelle Chambrier ◽  
Colin J. MacDonald ◽  
Simon J. Coles ◽  
Graham J. Tizzard ◽  
...  
Keyword(s):  
Chain Length ◽  
Alkyl Chain ◽  
Lead Ion ◽  
X Ray ◽  
H Nmr ◽  
Alkyl Groups ◽  
Nmr Spectrometry ◽  
Acid Catalyzed ◽  
Chain Lengths

The preparation of some peripherally substituted (2,3,9,10,16,17,23,24) and non-peripherally substituted (1,4,8,11,15,18,22,25) octaalkyl lead(II) phthalocyanines with different alkyl chain lengths (6, 7, 8 or 9 carbons) is described and a comparison of some of their properties reported. X-ray structure analyses of the isomeric peripheral and non-peripheral octakis(octyl)phthalocyaninato lead(II) compounds reveal a greater degree of distortion of the ligand ring system from planarity in the former derivative. The series of peripherally substituted octaalkyl lead(II) phthalocyanines exhibit columnar liquid crystal behavior whereas the non-peripherally substituted isomers do not. The lability of the lead ion was investigated using 1 H NMR spectrometry under a specific set of conditions (8.8 × 10-4 M solutions of the phthalocyanine in d8-toluene containing d4-acetic acid 2.06 × 10-5 M). All the compounds underwent acid catalyzed demetalation at rates dependent upon the location of the substituents and, more surprisingly, the chain length of the alkyl groups. Under these conditions the lead ion within each of the peripherally substituted octaalkyl lead phthalocyanines was more labile than that in the non-peripherally substituted isomer.

Organoplatinum(IV) complexes with functional alkyl groups and their use in supramolecular chemistry

2009 ◽  
Vol 87 (7) ◽  
pp. 904-916 ◽  
Author(s):  
Richard H.W. Au ◽  
Lisa J. Findlay-Shirras ◽  
Neil M. Woody ◽  
Michael C. Jennings ◽  
Richard J. Puddephatt
Keyword(s):  
Supramolecular Chemistry ◽  
Self Assembly ◽  
Alkyl Group ◽  
Oxidative Addition ◽  
Alkyl Groups ◽  
Alkyl Bromides ◽  
Diimine Ligand

The oxidative addition of alkyl bromides RCH2Br (R = C5H4N, C6H4CN, CH2C6H4CO2H, or CH2C6H4CH2CO2H) to dimethylplatinum(II) complexes [PtMe2(LL)] (LL = diimine ligand) gives the corresponding organoplatinum(IV) complexes [PtBrMe2(CH2R)(LL)] containing functionality in the alkyl group RCH2. The pyridyl derivatives can be protonated, while abstraction of the bromide ligand from [PtBrMe2(CH2R)(LL)] can form cationic complexes, which can react with water or form oligomers by self-assembly.

Effect of Alkyl Group Structure on Cure Characteristics of N,N-Dialkylthio-Carbamyl-N′,N′-Dialkylsulfenamide Vulcanization Accelerators

1974 ◽  
Vol 47 (4) ◽  
pp. 906-910 ◽  
Author(s):  
R. D. Taylor
Keyword(s):  
Carbon Atom ◽  
Steric Hindrance ◽  
Alkyl Group ◽  
Group Structure ◽  
Substituent Effects ◽  
Steric Effects ◽  
Alkyl Groups ◽  
Inductive Effects ◽  
Cure Rates ◽  
Alpha Carbon

Abstract Wide variations in scorch times and cure rates can be attained with tetraalkylthiocabamylsulfenamides through variation in alkyl groups. Substituent effects are substantial on either the carbamate nitrogen or on the sulfenamide nitrogen. Both inductive effects and steric effects influence the scorch times and cure rates. Positive inductive effects shorten scorch times and increase cure rates. Steric hindrance at the sulfenamide nitrogen increases the scorch time. Branching at the carbon atom beta to the nitrogen has a larger effect on scorch time than branching at the alpha carbon. Thiocarbamylsulfenamides can give appreciably higher cure rates and cure efficiencies than their benzothiazole sulfenamide analogs.

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