Boronialatenolide: a Novel Pentanortriterpene From the Aerial Parts of Boronia alata (Rutaceae)

Abstract

From the aerial parts of Boronia alata a known protolimonoid niloticin and a novel pentanortriterpene boronialatenolide have been isolated. The structure of the novel limonoid was established by extensive n.m.r. studies.

Tetranortriterpenoids from Walsura yunnanensis

“…This was corroborated by the 13 C NMR spectrum, which showed a hemiacetal carbon at δ C 98.3 (C-23) and an α,β-unsaturated-γ-lactone [δ C 136.5 (s, C-20), 171.9 (s, C-21), and 148.6 (d, C-22)]. These signals required the presence of a 23-hydroxy-20(22)-ene-21,23-γ-lactone in walsuranolide ( 3 ), by comparison with reference 13 C and 1 H NMR spectral data in the literature. , …”

“…This was corroborated by the 13 3), by comparison with reference 13 C and 1 H NMR spectral data in the literature. 13,14 The molecular formula of compound 4 was determined as C 28 H 32 O 9 by EIMS, 13 C NMR, and DEPT NMR spectral data and confirmed by HRFABMS. The EIMS exhibited a fragment ion peak at m/z 452, which was attributed to the loss of acetic acid [M -60] + from the molecular ion peak at m/z 512.…”

Constituents of Boronia pinnata

“…(Rutaceae) is a shrub found only in New South Wales, Australia . Terpenes, , acetophenones, flavanones, chalcones, quinolone alkaloids, acridone alkaloids, and furoquinoline alkaloids 7 have been reported as constituents of the plant genus Boronia . In our search for cancer chemopreventive agents (antitumor-promoters) from medicinal plants, an extract of the roots of B. pinnata was found to have an inhibitory activity for tumor-promotion.…”

“…Dried roots of B. pinnata were extracted with acetone at room temperature. The acetone extract was fractionated by a combination of Si gel column chromatography and preparative TLC to give nine new compounds (1)(2)(3)(4)(5)(6)(7)(8)(9) along with several known compounds.…”

“…In boropinal C (7), a strong band at λ max 335 nm with a shoulder at λ max 302 nm was observed. Red shifts of the UV bands of boropinals (5-7) compared with those of boropinols (2)(3)(4) suggested the presence of an additional conjugated system in those molecules. The common structure [(E)-CHdCH-CHO] in these compounds was indicated by 1 H NMR signals of a lower-field doublet at δ 9.66-9.61 (J ) 7.7 Hz) coupled with olefinic protons [δ 6.68- 6.61 (dd, J ) 15.8, 7.7 Hz) and 7.57-7.41 (d, J ) 15.8 Hz)], the same as compounds 2-4, together with a conjugated carbonyl band at υ max 1670-1672 cm -1 in the IR spectra.…”