Bioactive cembrane-type diterpenoids from the gum-resin of Boswellia carterii

Sacraoxides A–G, Bioactive Cembranoids from Gum Resin of Boswellia sacra

“…Compound 1 showed superimposable 1 H and 13 C NMR resonances as the known compound 9, but lacked resonances for an acetyl moiety. In the 13 C NMR spectrum of 1, two oxygenated tertiary carbons resonances at δ C 88.5 (C-1) and 84.1 (C-12) were assignable to a tetrahydrofuran structure formed by cyclization between C-1 and C-12 through an ether bond, which was indicated by the HMBC correlations between H-15/C-14, H-15/C-1, H 3 -20/C-12 and H 3 -20/C-13 (Figure 2) Wang Y. G. et al, 2019;Wang et al, 2020). Further functionalities were suggested to be two tri substituted olefins [δ H 5.27 (H-3), δ C 121.9 (C-3), 130.7 (C-4); δ H 5.34 (H-9), δ C 121.9 (C-9), 140.7 (C-8)] and two oxygenated methines [δ H 4.63 (H-7), δ C 68.3 (C-7); δ H 3.45 (H-11), δ C 76.9 (C-11)].…”

“…A 95% EtOH extract of the gum resin of B. sacra was separated by multiple column chromatography (CC) including silica gel, Sephadex LH-20 and ODS CC, as well as preparative HPLC to afford nine cembranoids (1-9, Figure 1). The known compounds were identified as boscartin AD (2) and boscartin L (9) by detailed spectroscopic and physicochemical analyses and comparison of literature data Wang Y. G. et al, 2019). The new compounds were named as sacraoxides A-G (1, 3-8), and their structures were elucidated as follows.…”

Cembrane-type diterpenoids from the gum resin of Boswellia carterii and their biological activities

“…The partitioned PE part was eluted rapidly by silica gel chromatography with PE and CH 2 Cl 2 . The eluted PE part was subjected to multiple column chromatography (CC) to afford eight newly described cembrane-type diterpenes (1)(2)(3)(4)(5)(6)(7)(8) and two known cembranes (9)(10). The NMR spectra analysis of these isolated compounds also revealed the characteristic structure category of cembrane-type diterpenoids, with elucidated as preliminary common cembranoid featured by one fourteen-member ring incorporated with one isopropyl.…”

“…1 Previous studies have led to the identication of the active compounds from the gum resin of Boswellia carterii mainly as mono-, sesqui-, di-and tri-terpenoids, which have been discovered to show anti-inammatory, cytotoxic, hepatoprotective, antibacterial, and antifungal activities. [2][3][4][5][6][7][8][9][10] Among these different kinds of metabolites, diterpenoids and triterpenoids have been identied as the main bioactive ones, which have been mainly classied into the cembrane-type and prenylaromandendrane-type diterpenoids and the oleananetype and ursane-type triterpenoids. In particular, cembranetype diterpenoids bearing a 14-membered oxygenated macrocycle have received more and more interest in the laboratory studies of structural modication and natural product research, however, which are mainly contained in so corals.…”

“…Nowadays, more and more pharmacological studies have been carried out to research the chemical diversity of cembrane-type diterpenoids reported from the gum resin of Boswellia carterii, the acquisition of which is in great demand from the viewpoints of structural and pharmacological properties. 2,3,16,17 As part of an ongoing research for cembrane-type diterpenoids with diverse structures and signicant activities from the gum resin of Boswellia carterii, a phytochemical investigation of the petroleum ether extract was conducted on the basis of the cytotoxic activity against HCT 116 cell, anti-inammatory activity against nitric oxide (NO) production, and hepatoprotective activity in vitro. During this study, eight new cembrane-type diterpenoids (1)(2)(3)(4)(5)(6)(7)(8) and two known ones (9-10) Fig.…”