{ diff(x1, t) = (1*k30*k24*x2/(x2 + k28)*k29^2/(k29^2 + x3^2) + (-1)*k30*k18*x1*x8)/k30,
  diff(x2, t) = (1*k30*k23*x1/(x1 + k26 + k27*x1*x6) + 1*k30*k24*x2/(x2 + k28)*k29^2/(k29^2 + x3^2) + (-1)*k30*k10*x2)/k30,
  diff(x3, t) = (1*k30*2*k23*x1/(x1 + k26 + k27*x1*x6) + 1*k30*k22*x4/(x4 + k8)*k25/(k25 + x5) + (-1)*k30*k11*x3)/k30,
  diff(x4, t) = (1*k30*k23*x1/(x1 + k26 + k27*x1*x6) + (-1)*k30*k14*x4)/k30,
  diff(x5, t) = (1*k30*2*k24*x2/(x2 + k28)*k29^2/(k29^2 + x3^2) + (-1)*k30*k15*x5)/k30,
  diff(x6, t) = (1*k30*2*k24*x2/(x2 + k28)*k29^2/(k29^2 + x3^2) + 1*k30*k23*x1/(x1 + k26 + k27*x1*x6) + (-1)*k30*k16*x7*x6 + 1*k30*k17*x8 + (-1)*k30*k13*x6)/k30,
  diff(x7, t) = ((-1)*k30*k16*x7*x6 + 1*k30*k17*x8 + 1*k30*k23*x1/(x1 + k26 + k27*x1*x6) + 1*k30*k22*x4/(x4 + k8)*k25/(k25 + x5) + (-1)*k30*k12*x7)/k30,
  diff(x8, t) = (1*k30*k16*x7*x6 + (-1)*k30*k17*x8 + (-1)*k30*k18*x1*x8)/k30 }