Structure-activity relations in thymidine phosphorylase inhibitors. A correlation using substituent constants and regression analysis

1970 ◽  
Vol 13 (5) ◽  
pp. 913-919 ◽  
Author(s):  
Eugene Coats ◽  
W. R. Glave ◽  
Corwin Hansch
Keyword(s):  
Regression Analysis ◽  
Thymidine Phosphorylase ◽  
Structure Activity ◽  
Structure Activity Relations ◽  
Substituent Constants

Lead optimization: quantitative structure-activity relations

1981 ◽  
Vol 295 (1076) ◽  
pp. 45-55 ◽  
Keyword(s):  
Quantitative Analysis ◽  
State Of The Art ◽  
Crop Protection ◽  
Regression Equations ◽  
Quantitative Structure ◽  
Structure Activity ◽  
Structure Activity Relations ◽  
Substituent Constants ◽  
Significant Regression ◽  
Essential Prerequisite

The optimization of bioactivity in a series is one of the aims in the design of crop protection chemicals. The approach of Hansch is the most developed model in this area. Here electronic, hydrophobic, and steric substituent constants are used for a quantitative analysis of the possible ways in which substitution may modulate bio- activity in a congeneric series (quantitative structure-activity relations; q.s.a.r.). An essential prerequisite of this approach is the availability of reliable substituent constants. The present state of the art is reviewed, with emphasis on steric parameters where several new approaches have been developed recently, and based upon recent q.s.a.r. studies from the literature as well as from our own laboratories. Q.s.a.r. may lead to significant regression equations, which can be used in different ways: the correlation between pesticidal activity and substituent properties provides the possibility of predicting the most favourable member of the class concerned. The resulting equations can also be given a physical interpretation in terms of the mode of action of the series studied. The scope and limitations of these applications are discussed.

New Groups of Potential Antituberculotics: Bis(1-aryltetrazol-5-yl) Disulfides. Structure Activity Relationship

1994 ◽  
Vol 59 (1) ◽  
pp. 234-238 ◽  
Author(s):  
Karel Waisser ◽  
Jiří Kuneš ◽  
Alexandr Hrabálek ◽  
Želmíra Odlerová
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Antimycobacterial Activity ◽  
Activity Relationship ◽  
Active Derivative ◽  
Structure Activity ◽  
Medium Activity ◽  
Substituent Constants ◽  
Atypical Strains

Oxidation of 1-aryltetrazole-5-thiols afforded bis(1-aryltetrazol-5-yl) disulfides. The compounds were tested for antimycobacterial activity against Mycobacterium tuberculosis, M. kansasii, M. avium and M. fortuitum. In the case of M. tuberculosis, the logarithm of minimum inhibitory concentration showed a parabolic dependence on hydrophobic substituent constants. Although the compounds exhibited low to medium activity, the most active derivative, bis(4-chlorophenyltetrazol-5-yl) disulfide (III) was more effective against atypical strains than are the commercial tuberculostatics used as standards.

Structure-activity relations and β-lactamase resistance

1980 ◽  
Vol 289 (1036) ◽  
pp. 197-205 ◽  
Keyword(s):  
Broad Spectrum ◽  
Product Inhibition ◽  
Sulphur Atom ◽  
Chemical Modifications ◽  
Gram Negative ◽  
Structure Activity ◽  
Broad Spectrum Resistance ◽  
Structure Activity Relations ◽  
Minor Influence ◽  
A Minor

β-Lactam antibiotics resistant to β-lactamase degradation can be produced by many chemical modifications, but often at the expense of antibacterial activity. Substitution onto several positions in the molecule produces different and often selective resistance; for instance, heavily sterically hindered acyl groups give staphylococcal P-lactamase resistance to penicillins, and resistance to some enzymes from Gram-negative pathogens to both penicillins and cephalosporins. 6-α- or 7-α-substituents respectively confer a broad spectrum of resistance (e.g. cefoxitin), but changes at positions 2 or 3 have only a minor influence on enzyme susceptibility. Changes in the ring condensed with the β-lactam, such as changing ceph-3-em to ceph-2-em may greatly enhance stability. Small improvements can occur when the nuclear sulphur atom is oxidized, but a much better effect is obtained when it is replaced by another atom such as oxygen, as in clavulanic acid. This compound appears to have broad spectrum resistance which is actually due to susceptibility and subsequent product inhibition.

Compound 48/80. Structure-activity relations and poly-THIQ [tetrahydroisoquinoline], a new, more potent analog

1973 ◽  
Vol 16 (11) ◽  
pp. 1292-1295 ◽  
Author(s):  
George W. Read ◽  
Edgar F. Kiefer ◽  
James F. Weber
Keyword(s):  
Structure Activity ◽  
Structure Activity Relations
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