[ Eq(Derivative(x1, t), ((-1)*k2*x16*x1*k19 + (-1)*k6*x1*k19 + 1*k7*x2*k19)/k19),
  Eq(Derivative(x2, t), (1*k6*x1*k19 + (-1)*k7*x2*k19)/k19),
  Eq(Derivative(x3, t), (1*k2*x16*x1*k19 + (-1)*k3*x3*x7*k19)/k19),
  Eq(Derivative(x4, t), (1*k3*x3*x7*k19 + (-1)*k4*x4*k19)/k19),
  Eq(Derivative(x5, t), (1*k4*x4*k19 + (-1)*k5*x5*k19)/k19),
  Eq(Derivative(x6, t), ((-1)*k8*x3*x6/(1 + k14*x14)*k19 + (-1)*k8*x4*x6/(1 + k14*x14)*k19 + 1*k9*x7*x8*k19)/k19),
  Eq(Derivative(x7, t), (1*k8*x3*x6/(1 + k14*x14)*k19 + 1*k8*x4*x6/(1 + k14*x14)*k19 + (-1)*k9*x7*x8*k19)/k19),
  Eq(Derivative(x8, t), 0/k19),
  Eq(Derivative(x9, t), ((-1)*k10*x9*x7*k19 + 1*k11*x10*x8*k19)/k19),
  Eq(Derivative(x10, t), (1*k10*x9*x7*k19 + (-1)*k11*x10*x8*k19)/k19),
  Eq(Derivative(x11, t), 1*x10*k12*k19/k19),
  Eq(Derivative(x12, t), (-1)*k13*x16*x12*k19/k19),
  Eq(Derivative(x13, t), 1*k13*x16*x12*k19/k19),
  Eq(Derivative(x14, t), (1*x11*k15/(k16 + x11)*k19 + (-1)*k17*x14*k19)/k19),
  Eq(Derivative(x15, t), 1*x10*k18*k19/k19) ]