title: Antimycobacterial, docking and molecular dynamic studies of pentacyclic triterpenes from Buddleja saligna leaves.
abstract: Buddleja saligna (family Buddlejaceae) is a medicinal plant endemic to South Africa. Two isomeric pentacyclic triterpenes, oleanolic acid and ursolic acid, were isolated from the leaves of B. saligna using silica gel column chromatography. Compounds oleanolic acid and ursolic acid were subjected to derivatization with acetic anhydride in the presence of pyridine to obtain oleanolic acid-3-acetate and ursolic acid-3-acetate, respectively. The structures of these compounds were fully characterized by detailed nuclear magnetic resonance (NMR) investigations, which included1H and13C NMR. Molecular docking studies predicted the free binding energy of the four triterpenes inside the steroid binding pocket of Mycobacterium tuberculosis fadA5 thiolase compared to a reported inhibitor. Thus, their ability to inhibit the growth of M. tuberculosis was predicted and was confirmed to possess significant antimycobacterial activity when tested against Mycobacterium smegmatis, M. tuberculosis H37Rv (ATCC 25177), clinical isolates of multi-drug-resistant M. tuberculosis (MDR-TB) and extensively drug-resistant M. tuberculosis (XDR-TB) using the Micro Alamar Blue Assay. Ursolic acid was isolated from this plant for the first time.
authors.affiliation: a Department of Biotechnology and Food Technology , Durban University of Technology , Durban 4001 , South Africa.
authors.forename: Alveera
authors.initials: A
authors.lastname: Singh
authors.affiliation: a Department of Biotechnology and Food Technology , Durban University of Technology , Durban 4001 , South Africa.|b Department of Pharmaceutical Sciences , College of Clinical Pharmacy, King Faisal University , Al-Ahsa 31982 , Saudi Arabia.
authors.forename: Katharigatta N
authors.initials: KN
authors.lastname: Venugopala
authors.affiliation: b Department of Pharmaceutical Sciences , College of Clinical Pharmacy, King Faisal University , Al-Ahsa 31982 , Saudi Arabia.|c Faculty of Pharmacy, Department of Pharmaceutical Chemistry , Helwan University , Ein Helwan, Cairo 11795 , Egypt.
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Khedr
authors.affiliation: d Department of Microbiology, NHLS , Inkosi Albert Luthuli Hospital , Durban , South Africa.
authors.forename: Mellendran
authors.initials: M
authors.lastname: Pillay
authors.affiliation: e Faculty of Pharmacy, Department of Pharmaceutical Chemistry , University of Lagos , Lagos 100213 , Nigeria.
authors.forename: Kenneth U
authors.initials: KU
authors.lastname: Nwaeze
authors.affiliation: d Department of Microbiology, NHLS , Inkosi Albert Luthuli Hospital , Durban , South Africa.
authors.forename: Yacoob
authors.initials: Y
authors.lastname: Coovadia
authors.affiliation: a Department of Biotechnology and Food Technology , Durban University of Technology , Durban 4001 , South Africa.
authors.forename: Francis
authors.initials: F
authors.lastname: Shode
authors.affiliation: a Department of Biotechnology and Food Technology , Durban University of Technology , Durban 4001 , South Africa.
authors.forename: Bharti
authors.initials: B
authors.lastname: Odhav
mesh_terms: D000995:Antitubercular Agents / Q000302:isolation & purification / Q000494:pharmacology*; D032861:Buddleja / Q000737:chemistry*; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D009161:Mycobacterium / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D009828:Oleanolic Acid / Q000737:chemistry; D053978:Pentacyclic Triterpenes / Q000737:chemistry / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D014315:Triterpenes / Q000737:chemistry; D014376:Tuberculosis / Q000188:drug therapy / Q000382:microbiology; D000097245:Ursolic Acid
chemical_list: D000995:Antitubercular Agents; D009828:Oleanolic Acid; D053978:Pentacyclic Triterpenes; D010936:Plant Extracts; D014315:Triterpenes; D000097245:Ursolic Acid
keywords: Buddleja saligna; antimycobacterial activity; docking; fadA5 thiolase; oleanolic acid; pentacyclic triterpenes; ursolic acid