EAS activators

The objective of this research was to examine the effect of crystallinity, additives and data analysis technique on isothermally pyrolyzed cellulose. The Ea, activation enthalpy (AH+) and activation entropy (AS+) were determined from the mass loss rates. This data was used to develop an understanding of how cellulose pyrolysis is affected by crystallinity and additives and how the results obtained are dependent on the data analysis technique. 

In 2004, Fumkawa and co-workers reported the isolation of glybomine B (60) and glybomine C (61), along with glybomine A (42) (see Scheme 2.9), from the stem of G. arborea (68). This group of carbazole alkaloids showed antitumor-promoting activity against (12-0-tetradecanoylphorbol-13-acetate) TPA-induced EBV-EA activation. 

EBV Inhibition of Epstein-Barr virus early antigen (EBV-EA) activation induced by TPA [22-27]... 

The in vitro EBV-EA activation inhibition assay uses EBV genome-carrying lymphoblastoid cells (Raji cells derived from Burkitt s lymphoma). Many compounds which inhibit EBV-EA induction by tumor promoters have been demonstrated to act as inhibitors of tumor promotion in vivo [16,22,42,66-68]. This assay has an advantage since it obtaines the information on die cytotoxicity from the viability of Raji cells. High viability of these cells is an important factor in developing a compound for the chemoprevention of cancer [16]. So far, a number of triterpenoids and steroids from plants and their derivatives have been shown to possess... 

M, mM, /xM = molar, millimolar, and micromolar, respectively T = absolute temperature k,R = Boltzmann s constant and the gas constant Ea = activation energy D = diffusion coefficient... 

Fig. 10.1 Energy required (E1 and E2) to break bonds and energy released (E3 and E4) when forming bonds (EA activation energy).

Ea = Activation energy, Kcal/mole, for thermal ring opening, r = Half-life time for thermal ring opening. 

Arrhenius equation, k = Atemperature dependence of a rate constant, A = frequency factor, Ea = activation energy. 

---