Phytochemical study of the trunk bark of Citharexylum spinosum L. growing in Tunisia: Isolation and structure elucidation of iridoid glycosides

• Published in: Phytochemistry (Oxford) Vol. 146; pp. 47 - 55
• Main Authors: Saidi, Ilyes, Waffo-Téguo, Pierre, Ayeb-Zakhama, Asma E.L., Harzallah-Skhiri, Fethia, Marchal, Axel, Ben Jannet, Hichem
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 01.02.2018; Elsevier
• Subjects: 8,3′-neolignan glycosides; Biochemistry & Molecular Biology; Chemical and Process Engineering; Citharexylum spinosum L; Engineering Sciences; ESI-HRMS; Food engineering; HPLC; Iridoid glycosides; Life Sciences; Life Sciences & Biomedicine; NMR; Phenylethanoid glycosides; Phytochemical investigation; Plant Sciences; Science & Technology; Tunispinosides A-D; Verbenaceae; NMR; Tunispinosides A-D; Verbenaceae; ESI-HRMS; 8,3′-neolignan glycosides; Citharexylum spinosum L; Phytochemical investigation; Iridoid glycosides; HPLC; Phenylethanoid glycosides; LIGNAN GLYCOSIDES; METABOLITES; LABIATAE; 8,3'-neolignan glycosides; STEMS; BIOSYNTHESIS; VERBASCOSIDE; GLUCOSIDES; FLOWERS; phenylethanoid glycosides; phytochemical investigation; citharexylum spinosum L; verbenaceae; tunispinosides A-D; iridoid glycosides
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2017.11.012

A phytochemical investigation of the trunk bark ethyl acetate extract of Citharexylum spinosum L. has led to the isolation of four previously undescribed iridoid glycosides, tunispinosides A-D, and five known phenylethanoid glycosides, verbascoside, leucosceptoside A, martynoside, isoverbascoside and plantainoside C, together with 4-hydroxy-2,6-dimethoxyphenyl 6′-O-vanilloyl-β-D-glucopyranoside, two 8,3′-neolignan glycosides, plucheosides D1-D2, coniferyl aldehyde, vanillic acid, syringic acid, ferulic acid and tyrosol. All compounds were isolated for the first time from C. spinosum. Their isolation was carried out using silica gel column and high performance liquid chromatography (HPLC). Structures were established by spectroscopic means including 1D and 2D NMR experiments, and spectrometric ESI-HRMS analysis. A phytochemical study of the ethyl acetate extract of Citharexylum spinosum L. trunk bark allowed the identification of four previously undescribed iridoid glycosides, Tunispinosides A-D (1–4), together with thirteen known compounds not previously isolated from this plant. [Display omitted] •The trunk bark of Citharexylum spinosum L. was studied phytochemically.•The chromatographic separation of the EtOAc extract yielded four previously undescribed iridoids.•Their structures were established by spectroscopic means, named Tunispinosides A-D.•Thirteen other known compounds were identified for the first time in this plant.