title: Chemical composition of hexane extract of Citrus aurantifolia and anti-Mycobacterium tuberculosis activity of some of its constituents.
abstract: The main aim of this study was to isolate and characterize the active compounds from the hexane extract of the fruit peels of Citrus aurantiifolia, which showed activity against one sensitive and three monoresistant (isoniazid, streptomycin or ethambutol) strains of Mycobacterium tuberculosis H37Rv. The active extract was fractionated by column chromatography, yielding the following major compounds: 5-geranyloxypsoralen (1); 5-geranyloxy-7-methoxycoumarin (2); 5,7-dimethoxycoumarin (3); 5-methoxypsoralen (4); and 5,8-dimethoxypsoralen (5). The structures of these compounds were elucidated by 1D and 2D NMR spectroscopy. In addition, GC-MS analysis of the hexane extract allowed the identification of 44 volatile compounds, being 5,7-dimethoxycoumarin (15.79%), 3-methyl-1,2-cyclopentanedione (8.27%), 1-methoxy-ciclohexene (8.0%), corylone (6.93%), palmitic acid (6.89%), 5,8-dimethoxypsoralen (6.08%), a-terpineol (5.97%), and umbelliferone (4.36%), the major constituents. Four isolated coumarins and 16 commercial compounds identified by GC-MS were tested against M. tuberculosis H37Rv and three multidrug-resistant M. tuberculosis strains using the Microplate Alamar Blue Assay. The constituents that showed activity against all strains were 5 (MICs = 25-50 mg/mL), 1 (MICs = 50-100 mg/mL), palmitic acid (MICs = 25-50 mg/mL), linoleic acid (MICs = 50-100 mg/mL), oleic acid (MICs = 100 mg/mL), 4-hexen-3-one (MICs = 50-100 mg/mL), and citral (MICs = 50-100 mg/mL). Compound 5 and palmitic acid were the most active ones. The antimycobacterial activity of the hexane extract of C. aurantifolia could be attributed to these compounds.
authors.affiliation: Facultad de Ciencias Químicas, Universidad Autónoma de Nuevo León, Nuevo León, Mexico.
authors.forename: Nallely E
authors.initials: NE
authors.lastname: Sandoval-Montemayor
authors.forename: Abraham
authors.initials: A
authors.lastname: García
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Elizondo-Treviño
authors.forename: Elvira
authors.initials: E
authors.lastname: Garza-González
authors.forename: Laura
authors.initials: L
authors.lastname: Alvarez
authors.forename: María
authors.initials: M
authors.lastname: del Rayo Camacho-Corona
mesh_terms: D000080462:Acyclic Monoterpenes; D000995:Antitubercular Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D032082:Citrus aurantiifolia / Q000737:chemistry*; D003374:Coumarins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D004977:Ethambutol / Q000494:pharmacology; D011564:Furocoumarins / Q000494:pharmacology; D007538:Isoniazid / Q000494:pharmacology; D019787:Linoleic Acid / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D039821:Monoterpenes / Q000494:pharmacology; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D019301:Oleic Acid / Q000494:pharmacology; D019308:Palmitic Acid / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D013307:Streptomycin / Q000494:pharmacology
chemical_list: D000080462:Acyclic Monoterpenes; D000995:Antitubercular Agents; D003374:Coumarins; D011564:Furocoumarins; D039821:Monoterpenes; D010936:Plant Extracts; C015304:isopimpinellin; D019301:Oleic Acid; D019308:Palmitic Acid; D004977:Ethambutol; D019787:Linoleic Acid; C068337:bergamottin; C007076:citral; D007538:Isoniazid; D013307:Streptomycin