Orlistat or tetrahydrolipstatin (Xenical, Hoffmann-La Roche) is a saturated derivative of lipstatin originally isolated from Streptomyces toxytricini. Orlistat (Xenical, Hoffmann-La Roche) is a powerful inhibitor of gastrointestinal lipase and as such, reduces fat absorption. Orlistat acts by binding covalently to the serine residue of the active site of gastric and pancreatic lipases. When administered with fat-containing foods, orlistat partially inhibits hydrolysis of triglycerides, thus reducing the subsequent absorption of monoaclglycerides and free fatty acids. Unlike other weight-reducing drugs it is minimally absorbed and has no effects in the CNS. Xenical is indicated for obesity management including weight loss and weight maintenance when used in conjunction witha reduced-calorie diet. XENICAL is also indicated to reduce the risk for weight regain after prior weight loss. XENICAL is indicated for obese patients with an initial body mass index (BMI) ≥ 30 kg/m2 or ≥ 27 kg/m2 in the presence of other risk factors (eg, hypertension, diabetes, dyslipidemia). In addition to its well established efficacy in achieving modest weight loss, orlistat has been shown to improve glycaemic parameters in obese adults with type 2 diabetes mellitus as well as some features of the metabolic syndrome.

Pyrazinamide is indicated for the initial treatment of active tuberculosis in adults and children when combined with other antituberculous agents. (The current recommendation of the CDC for drug-susceptible disease is to use a six-month regimen for initial treatment of active tuberculosis, consisting of isoniazid, rifampin and pyrazinamide given for 2 months, followed by isoniazid and rifampin for 4 months. Pyrazinamide should only be used in conjunction with other effective antituberculous agents. Pyrazinamide diffuses into M. tuberculosis, where the enzyme pyrazinamidase converts pyrazinamide to the active form pyrazinoic acid. Under acidic conditions, the pyrazinoic acid that slowly leaks out converts to the protonated conjugate acid, which is thought to diffuse easily back into the bacilli and accumulate. The net effect is that more pyrazinoic acid accumulates inside the bacillus at acid pH than at neutral pH. Pyrazinoic acid was thought to inhibit the enzyme fatty acid synthase (FAS) I, which is required by the bacterium to synthesise fatty acids. However, this theory was thought to have been discounted. However, further studies reproduced the results of FAS I inhibition as the putative mechanism first in whole cell assay of replicating M. tuberculosis bacilli which have shown that pyrazinoic acid and its ester inhibit the synthesis of fatty acids . This study was followed by in vitro assay of tuberculous FAS I enzyme that tested the activity with pyrazinamide, pyrazinoic acid and several classes of pyrazinamide analogs. Pyrazinamide and its analogs inhibited the activity of purified FAS I. It has also been suggested that the accumulation of pyrazinoic acid disrupts membrane potential and interferes with energy production, necessary for survival of M. tuberculosis at an acidic site of infection. Pyrazinoic acid has also been shown to bind to the ribosomal protein S1 (RpsA) and inhibit trans-translation. This may explain the ability of the drug to kill dormant mycobacteria

Tetrahydro-4-Methylene-2-octyl-5-oxo-3-furancarboxylic acid or C75 is an inhibitor of fatty acid synthase. Additionally, C75 increased fatty acid oxidation and ATP levels by increasing carnitine palmitoyltransferase I (CPT I) activity. Unlike the activation produced by C75, the CoA derivative is a potent competitive inhibitor that binds tightly but reversibly to CPT I. C75 exerts antitumor and anti-obese potential. C75 has two enantiomers: (-)-C75 inhibits FAS activity in vitro and has a cytotoxic effect on tumor cell lines, without affecting food consumption, (+)-C75 inhibits CPT1 and its administration produces anorexia, suggesting that central inhibition of CPT1 is essential for the anorectic effect of C75.

Cerulenin ((2R,3S)-2,3-epoxy-4-oxo-7,10-trans, trans-dodecadienoylamide) is an antifungal antibiotic isolated from Cephalosporium caerulens, that inhibits eukaryotic lipid and sterol synthesis and blocks lipid modification of proteins. Cerulenin is a potent inhibitor of fatty acid synthase (FAS). It inhibits all known types of FASs: both multifunctional enzyme complexes (Type I) (from yeast, rat liver, mammalian cells, and certain bacteria) and unassociated enzymes (Type II) (from most bacteria, and higher plants). Cerulenin blocks the synthesis of polyketides in a wide variety of organisms, including actinomycetes, fungi, and higher plants. In addition, cerulenin is suggested to inhibit the condensation step in polyketide synthesis as well as fatty acid synthesis. Cerulenin has a wide range of antimicrobial activity, the drug significantly inhibits the growth of yeast-like fungi, such as Candida, Saccharomyces, and Cryptococcus. Cerulenin is commercially available as a biochemical reagent for widespread use in the field of obesity, cancer biology, posttranslational protein modification system, drug discovery research and so on.

Nimbin is the active compound from the neem leaf extract which is now being tested in silico as a potential remedy against tuberculosis and dengue virus. Recent studies have shown that the drug interacts with NS2B-NS3 protease from dengue virus and fatty acid synthase of Mycobacterium tuberculosis. Nimbin can also be used as a pesticide.