Sulfur-containing antibiotics isolated from Streptomyces lincolnensis Most active and medically useful of compounds obtained from fermentation Resemble macrolides in antibacterial spectrum and MOA Clindamycin: 7-chloro-7 deoxy Active against GRAM POSITIVE COCCI, non-spore forming anaerobic bacteria, actinomycetes, mycoplasma, Plasmodium Inhibit 50s ribosomal subunit May be bacteriostatic/ bactericidal