Chemical and chemotaxonomical studies of ferns. LIV. Pterosin derivatives of the genus Microlepia (Pteridaceae).

Isolation and characterisation of 13 pterosins and pterosides from bracken (Pteridium aquilinum (L.) Kuhn) rhizome

“…The remaining 1 H NMR signals were in agreement with a pterosin-type structure (Fukuoka et al, 1978;Kovganko et al, 2004;Kuraishi et al, 1985;Tanaka et al, 1982). The 13 C NMR data of 5 (Table 4) shows fourteen distinct carbon environments, confirming the presence of a pentasubstituted aromatic ring, including a low-field signal at C 208.9 ppm (C=O) assigned as the C-1 of a pterosin-type sesquiterpene skeleton.…”

“…More than twenty sesquiterpenoid constituents have been identified with UV absorption spectra profiles in the 340 to 205 nm region characteristic of 1-indanone derivatives (Fukuoka et al, 1978;Kuraishi et al, 1985;Murakami et al, 1980;Yoshihira et al, 1971). The chloroform extract was repeatedly subjected to thin-layer, normalphase column, and automated reversed phase flash chromatography to afford thirty five compounds (1-35).…”

“…One-and two-dimensional NMR experiments combined with mass spectrometry were used to identify thirteen novel natural products (1-13) (Supplementary Information 1) belonging to the sesquiterpenoid family. The structures of twenty two previously reported pterosins and pterosides 14, 27, 29 (Lee et al, 2012), 15-18, 30-33, 35 (Kuroyanagi et al, 1979), 19-25 (Fukuoka et al, 1978), 26 (Kuraishi et al, 1985;Tanaka et al, 1982), 28 (Murakami et al, 1980), 34 (Castillo et al, 2003) were determined by the comparison of their spectroscopic data with those reported in the literature . The structures of compound 1-13 are shown in Figs.…”

“…Other pterosins have been isolated from different subsp. of Pteridium aquilinum (Fukuoka et al, 1978;Kuraishi et al, 1985;Murakami et al, 1980;Sengupta et al, 1976;Tanaka et al, 1982;Yoshihira et al, 1971). Pterosins are sesquiterpenoids and their structures are derivatives of 1-indanone.…”

New Benzoyl Glucosides and Cytotoxic Pterosin Sesquiterpenes from Pteris ensiformis Burm.

“…The IR spectrum indicated the presence of a carbonyl group (1689 cm -1 ). Characteristic 1 H-NMR signals, including one methyl group at δ 1.21 (3H, s, C-10), two aromatic methyl groups attaching to C-5 and C-7 at δ 2.48 (3H, s) and 2.66 (3H, s), two coupled methylenes of a hydroxyethyl group at δ 3.01 (2H, t, J = 8.4 Hz) and 3.61 (2H, t, J = 8.4 Hz ), one hydroxymethyl group at δ 3.37 (2H, AB q, J = 12.1 Hz), one allylic oxygenated methylene at δ 4.97 (1H, s), and one aromatic proton at δ 7.53 (1H, s), indicated the presence of a pterosin-sesquiterpene skeleton [13]. Furthermore, the configuration of the anomeric position was judged to be β from a large 3 J H1′,H2′ coupling constant ( J = 7.6 Hz) [14].…”