Planta Med 2015; 81 - PM_40
DOI: 10.1055/s-0035-1565417

New pyrrolizidine alkaloid from Heliotropium digynum

M Aboelmagd 1, 2, A Said 2, EG Haggag 3, MA Zaki 4, SA Ross 1, 5
  • 1National Center for Natural Products Research, School of Pharmacy, University of Mississippi, MS 38677, USA., University, United States
  • 2Pharmacognosy Department, National Research Center, 12622, Dokki, Giza, Egypt
  • 3Pharmacognosy Department, Faculty of Pharmacy, Helwan University, 11795, Helwan, Cairo, Egypt
  • 4Pharmacognosy Department, Faculty of Pharmacy, Beni-Suef University, Benisuef, Egypt
  • 5Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, MS 38677, USA., University, United States

The phytochemical study of the ethanol extract of aerial parts of Heliotropium digynum Forssk family Boraginaceae growing in Egypt resulted in the isolation and identification of seven pyrrolizidine alkaloids: heliotrine (1), heliotrine N-oxide (2), 7-angeloyl heliotrine (3), 7-angeloyl heliotrine N-oxide (4), lasiocarpine (5), europine (6) and europine N-oxide (7). Compound 4 was isolated for the first time from natural source and its structure was determined using 1D and 2D NMR spectroscopic analysis. Although compounds 2 and 7 are known alkaloids but were isolated for the first time from this species. The ethanol extract at concentration 25 µg/mL showed a very comparable inhibition of nitric oxide generation (40%) to reference drug dexamethasone at concentration 0.05 µg/mL (46%). It is also notable that the ethanol extract inhibits tumor necrosis factor alpha (TNFα) secretion by 66% in comparison to positive control lipopolysaccharide (LPS), in LPS stimulated RAW 264.7 murine macrophage.

R1

R2

1

H

OH

2

N-Oxide of

1

3

H

angeloyl

4

N-Oxide of

3

5

OH

angeloyl

6

OH

OH

7

N-Oxide of

6