  A nearly 11-day delayed very-high-energy(VHE) activity compared to the
Fermi-LAT flare from quasar 3C 279 was reported by H.E.S.S. on 28 January 2018.
3C 279 has long been considered a candidate site for particle acceleration;
hence such events may embed information about the high-energy phenomena. We
propose the production channel being leptonic for the multi-wavelength flare,
UV-Optical-Xrays-$\gamma$-rays, whereas the delayed VHE activity originated
from the proton synchrotron. Our model requires the magnetic field to be 2.3 G
and the proton luminosity (L$_{p}$) $1.56
  \times 10^{46}$ erg/sec, whereas the lepton luminosity (L$_e$) $3.9
  \times 10^{43}$ erg/sec.
