Delafloxacin (CAS registry number 189279-58-1) was described as WQ-3034 by Wakunaga Pharmaceutical Co., Ltd., Osaka & Hiroshima, Japan. It was first licensed in 1999 to Abbott Park, IL, and further developed as ABT-492. Delafloxacin (Baxdela), a fluoroquinolone antibiotic, is currently being developed by Melinta Therapeutics. It is a novel investigational fluoroquinolone in development for the treatment of uncomplicated gonorrhea, and acute bacterial skin and skin structure infections. Delafloxacin shows MICs remarkably low against Gram-positive organisms and anaerobes and similar to those of ciprofloxacin against Gram-negative bacteria. It remains active against most fluoroquinolone-resistant strains, except enterococci. Its potency is further increased in acidic environments (found in many infection sites). Delafloxacin is active on staphylococci growing intracellularly or in biofilms. Delafloxacin is a dual-targeting fluoroquinolone, capable of forming cleavable complexes with DNA and topoisomerase IV or DNA gyrase and of inhibiting the activity of these enzymes in both Gram-positive and Gram-negative bacteria. On Oct 24, 2016, Melinta Therapeutics Submitted Baxdela New Drug Application for hospital-treated skin infections.

Oritavancin is an glycopeptide antibiotic with bactericidal activity effective in treating infections caused by Gram-positive organisms. It treats complicated skin and skin structure infections. This drug demonstrates similar activity to vancomycin, but it has stronger activity against Staphylococcus and Enterococcus. The pharmacokinetics and pharmacodynamics of oritavancin appear to be favourable and once-daily dosing is likely. The incidence of multi-drug resistant bacteria is increasing and explorations into additional treatment options are essential. Oritavancin is marketed under the brand name Orbactiv. Orbactiv is indicated for the treatment of adult patients with acute bacterial skin and skin structure infections caused or suspected to be caused by susceptible isolates of designated Gram-positive microorganisms. Oritavancin has the following mechanism of action: 1) Inhibition of the transglycosylation (polymerisation) step of cell wall biosynthesis by binding to the stem peptide of peptidoglycan precursors 2) Inhibition of the transpeptidation (crosslinking) step of cell wall biosynthesis by binding to the peptide bridging segments of the cell wall 3) Disruption of bacterial membrane integrity, leading to depolarisation, increased permeability and rapid cell death.

Daptomycin is a lipopeptide antibiotic used in the treatment of systemic and life-threatening infections caused by Gram-positive organisms. Daptomycin has a distinct mechanism of action, disrupting multiple aspects of bacterial cell membrane function. It inserts into the cell membrane in a phosphatidylglycerol-dependent fashion, where it then aggregates. The aggregation of daptomycin alters the curvature of the membrane, which creates holes that leak ions. This causes rapid depolarization, resulting in a loss of membrane potential leading to inhibition of protein, DNA, and RNA synthesis, which results in bacterial cell death. Daptomycin is bactericidal against Gram-positive bacteria only. It has proven in vitro activity against enterococci (including glycopeptide-resistant enterococci (GRE)), staphylococci (including methicillin-resistant Staphylococcus aureus), streptococci, corynebacteria and stationary-phase Borrelia burgdorferi persisters.

Tizoxanide, the primary active metabolite of the FDA approved drug nitazoxanide, an anti-infective that has been approved for the treatment of diarrhea caused by Giardia lamblia. Tizoxanide, an active metabolite of nitazoxanide in humans, is also an antiparasitic drug of the thiazolide class. It has broad-spectrum antiparasitic and broad-spectrum antiviral properties. Besides, it has being found that Tizoxanide exhibits appreciable antagonist activity for both mGluR1 and mGluR5 (IC50 = 1.8 uM and 1.2 uM, respectively).

Oxacillin is a penicillin beta-lactam antibiotic used in the treatment of bacterial infections caused by susceptible, usually gram-positive, organisms. The name "penicillin" can either refer to several variants of penicillin available, or to the group of antibiotics derived from the penicillins. Oxacillin has in vitro activity against gram-positive and gram-negative aerobic and anaerobic bacteria. The bactericidal activity of Oxacillin results from the inhibition of cell wall synthesis and is mediated through Oxacillin binding to penicillin binding proteins (PBPs). Oxacillin is stable against hydrolysis by a variety of beta-lactamases, including penicillinases, and cephalosporinases and extended spectrum beta-lactamases. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, Oxacillin inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins; it is possible that Oxacillin interferes with an autolysin inhibitor. Oxacillin is used in the treatment of resistant staphylococci infections. Oxacillin sodium was marketed under the trade name Bactocill.

Vancomycin is a branched tricyclic glycosylated nonribosomal peptide produced by the fermentation of the Actinobacteria species Amycolatopsis orientalis (formerly Nocardia orientalis). Vancomycin became available for clinical use >50 years ago. It is often reserved as the "drug of last resort", used only after treatment with other antibiotics had failed. Vancomycin has been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections: Listeria monocytogenes, Streptococcus pyogenes, Streptococcus pneumoniae (including penicillin-resistant strains), Streptococcus agalactiae, Actinomyces species, and Lactobacillus species. The combination of vancomycin and an aminoglycoside acts synergistically in vitro against many strains of Staphylococcus aureus, Streptococcus bovis, enterococci, and the viridans group streptococci. The bactericidal action of vancomycin results primarily from inhibition of cell-wall biosynthesis. Specifically, vancomycin prevents the incorporation of N-acetylmuramic acid (NAM)- and N-acetylglucosamine (NAG)-peptide subunits from being incorporated into the peptidoglycan matrix; which forms the major structural component of Gram-positive cell walls. The large hydrophilic molecule is able to form hydrogen bond interactions with the terminal D-alanyl-D-alanine moieties of the NAM/NAG-peptides. Normally this is a five-point interaction. This binding of vancomycin to the D-Ala-D-Ala prevents the incorporation of the NAM/NAG-peptide subunits into the peptidoglycan matrix. In addition, vancomycin alters bacterial-cell-membrane permeability and RNA synthesis. There is no cross-resistance between vancomycin and other antibiotics. Vancomycin is not active in vitro against gram-negative bacilli, mycobacteria, or fungi.

Penicillin V is a penicillin beta-lactam antibiotic used in the treatment of bacterial infections caused by susceptible, usually gram-positive, organisms. The name "penicillin" can either refer to several variants of penicillin available, or to the group of antibiotics derived from the penicillins. Penicillin V has in vitro activity against gram-positive and gram-negative aerobic and anaerobic bacteria. The bactericidal activity of Penicillin V results from the inhibition of cell wall synthesis and is mediated through Penicillin V binding to penicillin binding proteins (PBPs). Penicillin V is stable against hydrolysis by a variety of beta-lactamases, including penicillinases, and cephalosporinases and extended spectrum beta-lactamases. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, Penicillin V inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins; it is possible that Penicillin V interferes with an autolysin inhibitor. Used for the treatment of mild to moderately severe infections (e.g. dental infection, infections in the heart, middle ear infections, rheumatic fever, scarlet fever, skin infections, upper and lower respiratory tract infections) due to microorganisms.

Deoxycholic acid is a a bile acid which emulsifies and solubilizes dietary fats in the intestine, and when injected subcutaneously, it disrupts cell membranes in adipocytes and destroys fat cells in that tissue. In April 2015, deoxycholic acid was approved by the FDA for the treatment submental fat to improve aesthetic appearance and reduce facial fullness or convexity. It is marketed under the brand name Kybella by Kythera Biopharma and is the first pharmacological agent available for submental fat reduction, allowing for a safer and less invasive alternative than surgical procedures. As a bile acid, deoxycholic acid emulsifies fat in the gut. Synthetically derived deoxycholic acid, when injected, stimulates a targeted breakdown of adipose cells by disrupting the cell membrane and causing adipocytolysis. This results in an inflammatory reaction and clearing of the adipose tissue remnants by macrophages. Deoxycholic acid's actions are reduced by albumin and tissue-associated proteins, therefore its effect is limited to protein-poor subcutaneous fat tissue. Protein-rich tissues like muscle and skin are unaffected by deoxycholic acid, contributing to its safety profile. Deoxycholic acid is a cytolytic agent. The physiologic effect of deoxycholic acid is by means of decreased cell membrane integrity. Deoxycholic acid inhibits miR-21 expression in primary rat hepatocytes in a dose-dependent manner, and increases miR-21 pro-apoptotic target programmed cell death 4 (PDCD4) and apoptosis. Deoxycholic acid decreases NF-κB activity, shown to represent an upstream mechanism leading to modulation of the miR-21/PDCD4 pathway.

Pentisomicin (Sch 21420) is semisynthetic aminoglycosides with marked antibacterial activity. Like many new aminoglycosides prepared by chemical modification or mutational biosynthesis, Pentisomicin was designed either to enhance potency of the parent compound and/or resist enzymatic inactivation. The activity of Pentisomicin was comparable to gentamicin, sisomicin, netilmicin, and tobramycin but greater than amikacin or kanamycin against S. aureus and most genera of Enterobacteriaceae.

CRS-3123, also known as REP-3123, is a methionyl-tRNA synthetase inhibitor potentially for the treatment of enteric infections. CRS-3123 is in Phase 1 clinical development for the treatment of Clostridium difficile Infection (CDI). CRS-3123 is a small molecule protein synthesis inhibitor that acts on the novel target methionyl-tRNA synthetase (MetRS). REP-3123 has been shown to be active in vitro against clinical isolates of C. difficile including epidemic strains such as B1/ NAP1/027; MIC values of REP-3123 for C. difficile are typically 0.5 -- 1.0 mg/l. REP-3123 is also active against a range of clinically important aerobic Gram-positive bacteria including methicillin-susceptible and -resistant Staphylococcus aureus (MIC90 values of 0.06 and 0.25 mg/l, respectively), Streptococcus pyogenes (MIC90 0.5 mg/l) and enterococci (MIC90 32 mg/l). CRS-3123 has numerous potential advantages over current CDI therapies. In addition to being highly potent against all clinical isolates of C. difficile tested, CRS-3123 has several desirable qualities for the treatment of CDI which include: Narrow spectrum for C. difficile, which may substantially reduce the disruption of normal intestinal flora compared to current therapies; Inhibition of toxin production, potentially leading to lower morbidity and mortality; Inhibition of sporulation, potentially leading to lower rates of transmission and recurrence; A novel mechanism of action, which means that its use will not compromise the utility of systemic antibiotics while maintaining activity against pre-existing resistance mechanisms.