title: Expedient preparative isolation and tandem mass spectrometric characterization of C-seco triterpenoids from Neem oil.
abstract: C-seco triterpenoids are widely bioactive class of natural products with high structural complexity and diversity. The preparative isolation of these molecules with high purity is greatly desirable, although restricted due to the complexity of natural extracts. In this article we have demonstrated a Medium Pressure Liquid Chromatography (MPLC) based protocol for the isolation of eight major C-seco triterpenoids of salannin skeleton from Neem (Azadirachta indica) oil. Successive application of normal phase pre-packed silica-gel columns for the fractionation followed by reverse phase in automated MPLC system expedited the process and furnished highly pure metabolites. Furthermore, eight isolated triterpenoids along with five semi-synthesized derivatives were characterized using ultra performance liquid chromatography-electrospray ionization-quadrupole/orbitrap-MS/MS spectrometry as a rapid and sensitive identification technique. The structure-fragment relationships were established on the basis of plausible mechanistic pathway for the generation of daughter ions. The MS/MS spectral information of the triterpenoids was further utilized for the identification of studied molecules in the complex extract of stem and bark tissues from Neem.
authors.affiliation: Chemical Biology Unit, Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
authors.forename: Saikat
authors.initials: S
authors.lastname: Haldar
authors.affiliation: Chemical Biology Unit, Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
authors.forename: Fayaj A
authors.initials: FA
authors.lastname: Mulani
authors.affiliation: Chemical Biology Unit, Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
authors.forename: Thiagarayaselvam
authors.initials: T
authors.lastname: Aarthy
authors.affiliation: Chemical Biology Unit, Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
authors.forename: Devdutta S
authors.initials: DS
authors.lastname: Dandekar
authors.affiliation: Chemical Biology Unit, Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India; CSIR-Institute of Genomics and Integrative Biology, Mall Road, New Delhi 110007, India. Electronic address: hv.thulasiram@ncl.res.in.
authors.forename: Hirekodathakallu V
authors.initials: HV
authors.lastname: Thulasiram
mesh_terms: D005989:Glycerides / Q000737:chemistry*; D000077222:Limonene; D053719:Tandem Mass Spectrometry; D013729:Terpenes / Q000737:chemistry* / Q000302:isolation & purification*; D014315:Triterpenes
chemical_list: D005989:Glycerides; D013729:Terpenes; D014315:Triterpenes; C002443:neem oil; C105836:salannin; D000077222:Limonene
keywords: ESI(+)-quadrupole/orbitrap-MS/MS; MPLC; Neem oil; Preparative isolation; Salannin; Triterpenoids