Variation homology

Analogues Produced by Homologous Variations 1.1.1.1 Homology Through Monoalkylation... 

Simple homologous variations applied on a neuramidase-inhibiting lead [8] achieved a 6300-fold increase in potency (Fig. 1.1). 

Substituent variation R, = Methyl or ethyl Homology variation R2 = Alkyl Position variation R3 = Amino Frequency variation m = 1-3... 

Ring enlargement and ring contraction can be considered as homologous variations in the cyclic series (mentioned in Chapter 14). 

Variation of substituents Variation of homology Variation of position Variation of chain length... 

Homology variation. Variation within a series of specific structures which are homologues to one another. The series may be finite or infinite and is defined by a set of one or more structural properties common to all specifics contained in the series, e.g., alkyl 1-4C, halogen. 

Synthetics. The lack of spice products to satisfy demand and the wide variation in price and availabihty have caused the manufacture of selected synthetics, chemically identical to the component in the natural spice, to replace the vital components of some spices. However, synthetic organic chemistry is not yet able to manufacture economically the many homologous piperine [94-62-2] components in black pepper or those capsaicin [404-86-4] amides in... 

The ring-contracted analog of alphaprodine is prepared by a variation of the scheme above. Alkylation of 109 with ethyl bromoacetate affords the lower homolog diester (115). Dieckmann cyclization followed by saponification-decarboxylation yields the pyrrolidine (116). Reaction with phenylmagnesium bromide leads to the condensation product (117) acylation with propionic anhydride gives the analgesic agent prolidine (118)... 

The two isozymes are both homodimers, composed of approximately 600 amino acids and possess approximately 60% homology. The three-dimensional structures of COX-1 and COX-2 are very similar. Each one consists of three independent units an epidermal growth factor-like domain, a membrane-binding section and an enzymic domain. The catalytic sites and the residues immediately adjacent are identical but for two small but crucial variations that result in an increase in the volume of the COX-2-active site, enabling it to accept inhibitor-molecules larger than those that could be accommodated in the COX-1 molecule. 

The lUPAC name of cannabidiol is 2-[(lS, 6iI)-3-methyl-6-prop-l-en-2-yl-l-cyclohex-2-enyl]-5-pentyl-benzene-1,3-diol. Cannabidiol (CBD, 2.9) in its acidic form cannabidiolic acid (CBDA, 2.10) is the second major cannabinoid in C. sativa besides A9-THC. As already mentioned for A9-THC, variations in the length of the side chain are also possible for CBD. Important in this context are the propyl side chain-substituted CBD, named cannabidivarin (CBDV, 2.11), and CBD-C4 (2.12), the homologous compound with a butyl side chain. Related to the synthesis starting from CBD to A9-THC as described in Sect. 3.1, it was accepted that CBDA serves as a precursor for THCA in the biosynthesis. Recent publications indicate that CBDA and THCA are formed from the same precursor, cannabigerolic acid (CBGA), and that it is unlikely that the biosynthesis of THCA from CBDA takes place in C. sativa. 

De Bono, M. and Bargmann, C.I. (1998) Natural variation in a neuropeptide Y receptor homolog modifies social behaviour and food response in C. elegans. Cell94, 679-689. 

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