Transamination definition

S-(Pentachlorophenyl)-2-thioacetic acid and S-(PCP)Thio-Lactate were thought to be produced from S-(PCP)Cys by a transamination reaction. S-(Pentachlorophenyl)-2-thioacetic acid accounted for 7.3J of the in peanut roots treated with S-(PCP)Cys. S-(Pentachlorophenyl)-2-hydroxy-3-thiol-propionic acid and S-(PCP)ThioAcetate were minor metabolites and their presence was not definitively established in tissues other than peanut root. 

Returning to the question in the title of this section, capsaicin does not fall into any of the three classic types of nitrogen-bearing plant natural products, being neither a true alkaloid, a protoalkaloid, or a pseudoalkaloid. Capsaicin is oflimited distribution in Nature and shows pharmacological activity, but is non-basic, structurally unsophisticated, and not directly derived from an amino acidic precursor. On the other hand, the lack of attributes such as basicity, complexity, and an amino acidic pedigree can also be found in compounds commonly perceived as alkaloids. Thus, colchicine is neutral, ephedrine is structurally unsophisticated, and the nitrogen atom of the potato alkaloid solanine is not derived from an amino acid, but rather incorporated into as non-amino acidic framework by a transamination reaction. For the sake of clarity and consistency, it seems therefore convenient to adopt the modern definition of alkaloids, and consider capsaicin, as well as alkylamides such as piperine (18) and pellitorine (19), as such. 

In certain organs the onset of transamination is definitely coincident with critical stages of functional differentiation, e.g., in muscle — with the time of appearance and accumulation of phosphocreatine and establishment of rapid contraction (Koshtoyants and Ryabinovskaya, 103), in heart — with acquisition of definitive heart rate, in kidney — with the beginning of active excretory function. In the early period of postnatal life transamination values gradually increase, and only at the age of one month do they approach the levels characteristic of adult rabbits. 

No definite relationship has yet been established between aph actiidly and the rates of protein qrnthesis in groiving or stationary tissues. Transamination is slow in many secretory, incretoiy and proliferative organs capable of rapid protein syntheos (24). Cohen (61,63) regards the low aph... 

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