Title: Josamycin
CAS Registry Number: 16846-24-5
CAS Name: Leucomycin V 3-acetate 4B-(3-methylbutanoate)
Additional Names: leucomycin A3
Manufacturers' Codes: EN-141
Trademarks: Iosalide (Schering); Jomybel (Sarva); Josamina (Novag)
Molecular Formula: C42H69NO15
Molecular Weight: 827.99
Percent Composition: C 60.92%, H 8.40%, N 1.69%, O 28.98%
Literature References: Macrolide antibiotic produced by Streptomyces narbonensis var. josamyceticus nov. var. Isoln and characterization: T. Osono et al., J. Antibiot. 20A, 174 (1967). Manuf process: H. Umezawa,T. Osono, JP 66 21759 (1966 to Microbiochemical Res. Found.), C.A. 66, 54258w (1967). Prepn: Y. Oka et al., JP Kokai 76 41497 (1976 to Yamanouchi), C.A. 85, 121788b (1976). Identification with leucomycin A3: S. Omura et al., J. Antibiot. 23, 511 (1970). Structure: eidem, ibid. 27, 366 (1974). Absolute configuration: A. Ducruix et al., Chem. Commun. 1976, 947. Stereospecific total synthesis: K. Tatsuta et al., Tetrahedron Lett. 1980, 2837. Retrosynthetic studies: K. C. Nicolaou et al., J. Am. Chem. Soc. 103, 1222 (1981). A 17-membered aglycone was proposed at one time, see T. Osono, H. Umezawa in Drug Action and Drug Resistance in Bacteria 1, S. Mitsuhashi, Ed. (University Park Press, Baltimore, 1971) pp 41-120; T. Osono et al., J. Antibiot. 27, 366 (1974). Pharmacology: K. Kuriaki et al., Jpn. J. Antibiot. 22, 232 (1969). Review: T. Osono, H. Umezawa, loc. cit.
Properties: Colorless needles from benzene, mp 130-133° (after drying under reduced pressure at 100° for 5 hrs). [a]D25 -70° (c = 1 in ethanol). uv max (0.001N HCl): 232 nm (E1%1cm 325). pKa 7.1 (40% aq methanol). Very sol in methanol, ethanol, acetone, chloroform, ethyl acetate, dioxane, acidic water. Sol in butanol, ether, CCl4, benzene, toluene. Practically insol in water, petr ether, ligroin, n-hexane.
Melting point: mp 130-133° (after drying under reduced pressure at 100° for 5 hrs)
pKa: pKa 7.1 (40% aq methanol)
Optical Rotation: [a]D25 -70° (c = 1 in ethanol)
Absorption maximum: uv max (0.001N HCl): 232 nm (E1%1cm 325)
Derivative Type: Propionate
CAS Registry Number: 51016-68-3
Trademarks: Josacine (Bellon); Josamy (Yamanouchi); Josaxin (Boots); Wilprafen (Mack, Illert.)
Molecular Formula: C45H73NO16
Molecular Weight: 884.06
Percent Composition: C 61.14%, H 8.32%, N 1.58%, O 28.96%
Therap-Cat: Antibacterial.
Therap-Cat-Vet: Antibacterial.
Keywords: Antibacterial (Antibiotics); Macrolides.
Juglans Juglone Julocrotine Juniper Tar Justicidins

Josamycin ball-and-stick.png
Systematic (IUPAC) name
(2S,3S,4R,6S) -6- {[(2R,3S,4R,5R,6S) -6- {[(4R,5S,6S,7R,9R,10R,11E,13E,16R) -4- (acetyloxy)-10-hydroxy-5-methoxy-9, 16-dimethyl-2-oxo-7-(2-oxoethyl)-1-oxacyclohexadeca-11, 13-dien-6-yl]oxy}-4-(dimethylamino)-5-hydroxy-2-methyloxan-3-yl]oxy}-4-hydroxy-2, 4-dimethyloxan-3-yl 3-methylbutanoate
Clinical data
AHFS/ International Drug Names
Legal status  ?
CAS number 16846-24-5 YesY
ATC code J01FA07
PubChem CID 5284579
DrugBank DB01321
ChemSpider 4447629 YesY
KEGG D01235 YesY
Chemical data
Formula C42H69NO15 
Mol. mass 827.995 g/mol
 N (what is this?)  (verify)

Josamycin is a macrolide antibiotic. It is synthesized from strains of Streptomyces narbonensis var. josamyceticus var. nova

Currently sold in various countries.

Brand examples are:

Europe: Josalid, Josacine, Iosalide, Josamina. Russia: Wilprafen (Вильпрафен). Japan: Josamy.