The synthesis of macrolide and ionophore antibiotics continues to be regarded as a very active area of synthetic organic research. The attractiveness of these target molecules is related to their broad range of biological and medicinal activity together with their complex structure and array of stereogenic centers. The development of an enantioselective methodology for the synthesis of the ansamycin antibiotics rifamycin S and streptovaricin D, and the hygrolide antibiotics bafilomycin A1 and elaiophylin is the main goal of this proposal. The selection of these target molecules is based on their extensive biological activity and the challenge that represents the elaboration of the different carbon configurations found in their polypropionate units. In recent years a great interest in their study and utilization (and that of some semisynthetic derivatives) as therapeutic agents has been evidenced by the extensive and increasing scientific literature being generated in this area. The reported synthetic approaches to these targets, as for many other polypropionate systems, have been usually based on aldol and related chemistry. We would like to demonstrate that epoxides are a viable alternative and that their use can be incorporated into a general, flexible and stereoselective route to these very important target compounds. Our approach is a simple and reiterative one, and is based on the stereoselective epoxidation of homoallylic alcohols followed by their cleavage via organoalane chemistry. With this methodology we can control the configuration of the methyl and hydroxyl groups which characterize each distinct polypropionate unit. Not only the desired chemical transformations proposed in this study will be accomplished. The scope, limitations, stereoselectivity and mechanistic implications of the key reactions will be examined. Although our methodology will be applied to these specific targets, in principle, its should be applicable to many other polypropionate systems and will open the door for the synthesis of analogues which can presents opportunities for increased or modified biological activity and therapeutic potential. Since this is a reiterative approach, in the long term, it may be suitable for automation and combinatorial application.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Minority Biomedical Research Support - MBRS (S06)
Project #
Application #
Study Section
Special Emphasis Panel (ZGM1)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Puerto Rico Rio Piedras
San Juan
United States
Zip Code
Ramírez-Camejo, Luis A; Maldonado-Morales, Génesis; Bayman, Paul (2017) Differential Microbial Diversity in Drosophila melanogaster: Are Fruit Flies Potential Vectors of Opportunistic Pathogens? Int J Microbiol 2017:8526385
Morales-Rivera, Keyla F; Piñero Cruz, Dalice M; Prieto, Jose A (2017) Crystal structure of (-)-(S)-4-[(2S,3S,4S,Z)-3-hydroxy-4-methyl-hept-5-en-2-yl]-1,3-dioxolan-2-one. Acta Crystallogr E Crystallogr Commun 73:1070-1072
García-Arriaga, Marilyn; Acosta-Santiago, Maxier; Cruz, Antony et al. (2017) Probing the Limits of Supramolecular G-Quadruplexes Using Atomistic Molecular Dynamics Simulations. Inorganica Chim Acta 468:209-222
Huang, Qing; Quiñones, Edwin (2016) A spectroscopic method to determine the activity of the restriction endonuclease EcoRV that involves a single reaction. Anal Biochem 497:103-5
Mège, Pascal; Schizas, Nikolaos V; Reyes, Joselyd García et al. (2015) Genetic seascape of the threatened Caribbean elkhorn coral, Acropora palmata, on the Puerto Rico Shelf. Mar Ecol (Berl) 36:195-209
Morales-Rivera, Amarilys; Hernández-Burgos, Mayté M; Martínez-Rivera, Arlene et al. (2014) Anxiolytic effects of oxytocin in cue-induced cocaine seeking behavior in rats. Psychopharmacology (Berl) 231:4145-55
Ramírez-Camejo, Luis A; Torres-Ocampo, Ana P; Agosto-Rivera, José L et al. (2014) An opportunistic human pathogen on the fly: strains of Aspergillus flavus vary in virulence in Drosophila melanogaster. Med Mycol 52:211-9
Galindo-Cardona, Alberto; Acevedo-Gonzalez, Jenny P; Rivera-Marchand, Bert et al. (2013) Genetic structure of the gentle Africanized honey bee population (gAHB) in Puerto Rico. BMC Genet 14:65
Santiago-Rodriguez, Tasha M; Rivera, Jessica I; Coradin, Mariel et al. (2013) Antibiotic-resistance and virulence genes in Enterococcus isolated from tropical recreational waters. J Water Health 11:387-96
Pantoja-Feliciano, Ida Gisela; Clemente, Jose C; Costello, Elizabeth K et al. (2013) Biphasic assembly of the murine intestinal microbiota during early development. ISME J 7:1112-5

Showing the most recent 10 out of 194 publications