Two New Cyclopentenone Derivatives and a New Cyclooctadienone Derivative from Erigeron annuus (L.) PERS., Erigeron philadelphicus L., and Erigeron sumatrensis RETZ.

Abstract

The genus Erigeron is a common group of Compositae plants, and Erigeron annuus (L.) PERS. (himejyon in Japanese), Erigeron philadelphicus L. (harujion in Japanese) and Erigeron sumatrensis RETZ. (oarechinogiku in Japanese) are now, as naturalized weeds, widely distributed throughout urban and rural areas of Japan.1) Among these, E. annuus has been used as an hypoglycemic drug in China.2) The constituents of E. annuus, E. philadelphicus, and E. sumatrensis have been previously investigated and shown to contain monoterpenoids, 3) sesquiterpenoids, 3) diterpenoid, 4) polyacetylenic compounds, 5) and g-pyrone derivatives. 1) Recently we reported the isolation and structural elucidation of norisoprenoids, 6) sesquiterpenoids, 7) diterpenoids, 7) triterpenoids, 8) and sterols 8) from the aerial parts and roots of E. annuus, E. philadelphicus, and E. sumatrensis. As part of our continuing study of the constituents of the genus Erigeron plants, we now report the isolation and structural elucidation of two new cyclopentenone derivatives, erigerenons A (1) and B (2), and a new cyclooctadienone derivative, erigerenone C (3), from the aerial parts of E. annuus, E. philadelphicus, and E. sumatrensis.Compound 1 was isolated as a colorless oil, [a] D ϩ7.3°. The molecular formula was determined to be C 12 H 16 O 4 by high-resolution (HR)-electron ionization (EI)-MS. The IR spectrum showed the presence of ester (1735 cm Ϫ1) and a,bunsaturated ketone (1691, 1596 cm Ϫ1 ) functionalities. The UV spectrum also suggested the presence of an a,b-unsaturated ketone (l max ϭ237 nm). The 1 H- (Table 1) and 13 C-NMR spectra ( H COSY spectrum of 1 implied connectivities for H 2 -2-H-3, H-3-H-7, H-7-H-8, H-8-H-9, and H-9-H 3 -10. Interpretation of the HMBC spectrum revealed correlations from H 2 -2 to C-1 and C-4; H-5 to C-3 and C-7; H-7 to C-6; CH 3 O-1 to C-1; and CH 3 O-6 to C-6. Thus the gross structure of 1 was deduced to be as shown in Fig. 1. The relative stereochemistry at C-3 and C-7 was established by comparing the proton coupling constant between H-3 and H-7 with analogous couplings observed for other cyclopentenones.9,10) In cyclopentene rings, a vicinal coupling constant of 5-6 Hz normally indicates a cis relationship, while a coupling constant of ca. 2 Hz suggests a trans relationship.11) These observations have been extended to cyclopentenone rings and a similar correlation has been observed.9,10) Thus, in the case of 1, the small coupling constant of 2.2 Hz is suggestive of a trans relationship between H-3 and H-7. The geometry of the D 8 -double bond was deduced to be Z from 1 H-1 H coupling constant (Jϭ11.0 Hz) between H-8 and H-9. On the basis of the above data, the structure of 1 was represented as shown in the formula.Compound 2 Aoba-ku, Sendai, Miyagi 981-8558, Japan. Received March 6, 2003; accepted March 30, 2003 Two new cyclopentenone derivatives, erigerenones A (1) and B (2), and a new cyclooctadienone derivative, erigerenone C (3), were isolated from the aerial parts of Erigeron philadelphicus L. Compound 2 ...

Constituents of the flowers of Erigeron annuus with inhibitory activity on the formation of advanced glycation end products (AGEs) and aldose reductase

“…Previous phytochemical investigations on this plant have resulted in the isolation of γ-pyranone derivatives (Hashidoko, 1995;Li et al, 2006;Oh et al, 2002), cyclopentenone derivatives (Iijima et al, 2003a), sesquiterpenoids (Iijima et al, 2003b;Li et al, 2005), flavonoids (Hashidoko, 1995), triterpenoids (Hashidoko, 1995), and phenolic derivatives (Li et al, 2006;Oh et al, 2002). In the present study, seven phenolic compounds (1-7) were isolated from the EtOAc-soluble partition of the flowers of Erigeron annuus.…”

Neuroprotective and anti-oxidant effects of caffeic acid isolated from Erigeron annuus leaf

“…E. annuus has been used in Chinese medicine for treating indigestion, enteritis, epidemic hepatitis and hematuria [10]. Phytochemicals from this plant have been isolated and reported such as γ-pyranone derivatives, flavonoids, triterpenoids [11], phenolic derivatives [12,13], cyclopentenone derivatives [14] and sesquiterpenenes [15]. E. annuus possesses antioxidant [16] antiglycation and rat lens aldose reductase inhibition activities [17].…”

Chemical variability of Conyza sumatrensis and Microglossa pyrifolia from Côte d'Ivoire

“…Solvent extracts of C. sumatrensis have been reported to contain sesquiterpenoids and diterpenoids 9 and cyclooctadienone derivatives. 10 A sample of leaf oil of Brazilian origin contained (Z)-lachnophyllum acid methyl ester and limonene as the major components. 11 Sesquiterpenes and diterpenes, 7 aurone glucosides, 12 and dihydrobenzofurans and triterpenoids 13 have been reported in solvent extracts of M. pyrifolia.…”