title: Selected metabolites profiling of Orthosiphon stamineus Benth leaves extracts combined with chemometrics analysis and correlation with biological activities.
abstract: BACKGROUND
  Studies on selected metabolites profiling of Orthosiphon stamineus extracts using chromatographic and spectroscopic techniques combined with chemometric tools have not been fully elucidated. Thus present study was performed to profile selected metabolites in O. stamineus leaves extracts using HPLC and FTIR combined with chemometric tools and correlated with biological activities.
  
  
  METHODS
  Five different extracts were prepared using three methods; maceration, soxhlet and reflux. The extracts were analyzed using UV-Vis, HPLC and FTIR techniques. Analysis of selected primary and secondary metabolites was also evaluated. The antioxidant and cytotoxic activities of the extracts were evaluated. Chemometric tools were employed to classify the extracts based on HPLC analysis and FTIR fingerprints.
  
  
  RESULTS
  The ethanolic extract using maceration characterized high content of phenolics and flavonoids, (rosmarinic acid and eupatorin) with high antioxidant activity. Ethanolic (50%) and methanolic extracts using soxhlet showed high proteins and glycosaponins. Water extracts using reflux and maceration showed high polysaccharides. Methanolic extract (50%) using soxhlet and methanolic extract using maceration showed strong cytotoxic effect against MCF7 and HCT116 cell lines, respectively. Antioxidant and cytotoxic activities showed significant correlation with selected primary and secondary metabolites. HPLC fingerprints combined with chemometrics showed the extracts have been clustered based on selected major peaks profile. FTIR fingerprints combined with chemometrics showed that the extracts have been clustered based on protein and polysaccharide contents.
  
  
  CONCLUSIONS
  Ten different extracts of O. stamineus have showed significant differences in the content of selected primary and secondary metabolites as well as the biological activities. Chemometric tools were able to classify and discriminate the distinctive features of extracts thus can be correlated with the biological activities.
authors.affiliation: Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, 11800, Pulau Pinang, Malaysia. hafizohsaidan@yahoo.com.
authors.forename: Noor Hafizoh
authors.initials: NH
authors.lastname: Saidan
authors.affiliation: Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, 11800, Pulau Pinang, Malaysia. shahrul.ridzuan18@gmail.com.
authors.forename: Mohd Shahrul Ridzuan
authors.initials: MS
authors.lastname: Hamil
authors.affiliation: Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, 11800, Pulau Pinang, Malaysia. memon_h79@yahoo.com.
authors.forename: Abdul Hakeem
authors.initials: AH
authors.lastname: Memon
authors.affiliation: Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, 11800, Pulau Pinang, Malaysia. mahamansor69@gmail.com.
authors.forename: Maha Mansour
authors.initials: MM
authors.lastname: Abdelbari
authors.affiliation: Centre of Drug Research, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, 11800, Pulau Pinang, Malaysia. ikraqlah@gmail.com.
authors.forename: Mohammad Razak
authors.initials: MR
authors.lastname: Hamdan
authors.affiliation: School of Agriculture and Biotechnology, Faculty of Bioresources and Food Industry, Universiti Sultan Zainal Abidin, Tembila Campus, 22200, Besut, Terengganu, Malaysia. khamsahsuryati@unisza.edu.my.
authors.forename: Khamsah Suryati
authors.initials: KS
authors.lastname: Mohd
authors.affiliation: Department of Pharmacology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, 11800, Pulau Pinang, Malaysia. aminmalikshah@usm.my.
authors.forename: Amin Malik Shah Abdul
authors.initials: AM
authors.lastname: Majid
authors.affiliation: Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, 11800, Pulau Pinang, Malaysia. zhari@usm.my.
authors.forename: Zhari
authors.initials: Z
authors.lastname: Ismail
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D031342:Orthosiphon / Q000737:chemistry* / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry* / Q000378:metabolism; D064210:Secondary Metabolism; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000975:Antioxidants; D010936:Plant Extracts