Abstract
In continuation of our search for bioactive natural products from Thai medicinal plants as potential anti-inflammatory, anticancer and antioxidant agents [1],
Gynura pseudochina
(L.)
var. hispida
Thv. (GPH) (Asteraceae) was studied for potential NF-kB inhibitory compounds. Traditionally the fresh leaves and rhizomes have been used externally to treat inflammations of the skin as well as for viral infections and has been investigated as a potential AIDS remedy [2–4]. Extraction of the leaves was carried out by cold extraction using petroleum ether, ethyl acetate and methanol. Separation and isolation were achieved using Sephadex LH-20 column chromatography, TLC and HPLC. For the structure elucidation, 1D and 2D NMR and ESI-MS experiments were used. Quercetin-rutinoside, 3, 5- dicaffeoyl quinic acid, 4, 5 dicaffeoyl quinic acid and 3-, or 5- caffeoyl quinic acid were isolated and found to possess NF-kB inhibitory properties with the IC50 values ranging from 25 to 83µg/ml. All are reported from this species for the first time.
Gynura spp.
is a member of the Senecioneae, and
G. segetum
and
G. divaricata
were reported to contain hepatotoxic pyrrolizidine alkaloids (PAs) [5]. Consequently, the presence of PAs in the methanol extract of GPH was assessed. TLC with spray reagents were used and the results were compared with the PAs fraction separated from Comfrey (
Symphytum officinale
L.). No hepatotoxic PAs were found to present in the methanol extract of GPH.
References:
1. Siriwatanametanon, N. et al. (2010). J. Ethnopharmacol.
in press
.
2. Saralamp, P. et al. (2000). Medicinal plants in Thailand. Amarin printing & publishing. Bangkok, Thailand.
3. Lemmens, R.H., Bunyapraphatsara, N. (2003). Plant Resources of South-East Asia 12(3). Backhuys Publishers. Leiden, the Netherlands.
4. Woradulayapinij, W. et al. (2005). J. Ethnopharmacol. 101(1–3): 84–89.
5. Jiang, Y. et al. (2006). Asian J. Pharmacodynamics & Pharmacokinetics. 6(3): 187–192.