Identification of Datura innoxia as a potential source of antimycobacterial components

Muhammad Sheeraz Ahmad^1*Sajjad Ahmed Khan¹Wayne Thomas Shier^2*Anthony Baughn^3*Muzafar Ahmad Rather³Ziyi Jia³Sabira Tahseen⁴Sajid Iqbal⁵Peter William Villalta⁶Syed Mehmood Qadir⁷Dr. Muhammad Umer Khan⁸

• ¹Institute of Biochemistry and Biotechnology, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan
• ²Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota, United States
• ³Department of Microbiology and Immunology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
• ⁴National TB Control Program, National Reference Laboratory for Tuberculosis, Islamabad, Pakistan
• ⁵Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Islamabad, Pakistan
• ⁶Masonic Cancer Center, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
• ⁷National TB Control Program, National TB Reference Laboratory, Islamabad, Islamabad, Pakistan
• ⁸Institute of Molecular Biology and Biotechnology, University of Lahore, Lahore, Punjab, Pakistan

Datura innoxia is a medicinal plant from the Solanaceae family having medicinal properties and some toxic effects. It is widely distributed in Asia, Africa, Europe, America, and other subtropical and tropical regions for use by the local pharmaceutical industries. In this study, bioassay-guided fractionation and LC-MS/MS were used for identification of secondary metabolites with anti-tuberculosis activity in methanolic leaf extracts of D. innoxia. Bioassayguided fractionation was conducted using normal and reverse phase column chromatography, and the fractions were assayed for antituberculosis activity in vitro by serial dilution in Mycobacterium tuberculosis H37Ra cultures. The structures of known secondary metabolites in the purified extracts were identified using LC-ESI-MS/MS mass spectroscopy. A purified fraction of the methanolic extract of D. innoxia leaves inhibited M. tuberculosis growth at concentrations as low as 25 μg/mL. Metabolic profiling with LC-ESI-MS/MS enabled the identification of the purified extract of 16 known metabolites, including loliolide, scopolamine, kuromanin, isoquercitrin, moupinamide, methyl isoquinoline-3-carboxylate, trans-3-Indoleacrylic acid, tyramine, (3β,5ξ,9ξ)-3,6,19-Trihydroxyurs-12-en-28-oic acid, milbemycin A3 oxime, methyl jasmonate, nicotinamide, methyl ferulate, trifolin, 2-[(1S,2S,4aR,8aS)-1hydroxy-4a-methyl-8-methylidene-decahydronaphthalen-2-yl]prop-2-enoic acid, and methyl 4-hydroxycinnamate. These results indicate that D. innoxia is a rich natural source of potential antitubercular secondary metabolites.