Lincosamides of general formula I, where R1 is selected from C2-C8 alkyl or C2-C8 alkenyl; R3 is selected from OH, O(C1-C4 alkyl), SH, S(C1-C4 alkyl) or halogen; R4 is H or C1-C3 alkyl; each of R21, R22, R23, R24, R25 is independently selected from the group consisting of H, OH, C1-C4 alkyl, C1-C4 alkenyl, C1-C4 alkynyl, halogen, O(C1-C4 alkyl), O(C1-C4 alkenyl), O(C1-C4 alkynyl), NH2, N(C1-C4 alkyl)2, N(C1-C4 alkenyl)2, N(C1-C4 alkynyl)2; and pharmaceutically acceptable salts thereof. A method of preparation thereof, in particular a biosynthetic method using newly discovered functions of celesticetin biosynthetic proteins Ccb1 and/or Ccb2. Lincosamides of general formula I are suitable for use as antibacterial and antiprotozoal substances.