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Melting points were determined with a Buchi B-540 melting point apparatus. 1H, 13C-NMR (DEPT) and 2D-NMR were recorded on Bruker (DRX-500 Avance) NMR spectrometer. Silica gel (kieselgel 60, 70–230 mesh, Merck) was used for column chromatography. Spots were detected on TLC under UV or by heating after spraying with 5% phosphomolybdic acid in C2H5OH.
Aerial parts of cultivated S. khuzistanica in flowering stage from open field were prepared by Khorraman Company in industrial village of Khoramabad, Lorestan Province, Iran, November 2005 (Fig. 1). The plant was authenticated by herbal museum of the Faculty of Pharmacy, Tehran University of Medical Science, Tehran, Iran and a voucher specimen (No. 6650-THE) is deposited.
The air-dried aerial parts of cultivated S. khuzistanica (1 kg) was crushed and extracted with CH2Cl2 (3 x 3 liters) at room temperature for 6 days. The CH2Cl2 extracts were combined and concentrated in vacuo to yield a gummy extract. This residue treated with MeOH to remove waxy compounds.
The MeOH soluble portion (33.2 g) was subjected to a silica gel column chromatography (70–230 mesh, 800 g) with a gradient of hexane–EtOAc and then EtOAc–MeOH as eluent. Eight fractions were collected according to TLC analysis. The fraction of hexane–EtOAc (75:25) was subjected to another column chromatography using hexane–EtOAc (10:1) as the eluent. After recrystallization from MeOH, we obtained 75 mg of compound (1). The fraction of hexane–EtOAc (70:30) was rechromatographed over silica gel and eluted with hexane–EtOAc (9:1) to give 150 mg of compound (2). The fraction of hexane–EtOAc (60:40) was separated on another column chromatography and eluted with hexane–EtOAc (9:1) to give 270 mg of compound (3). From the fraction of EtOAc–MeOH (20:1), crude crystals were obtained, which gave after recrystallization from pyridine/MeOH 40 mg of pure compound (4).
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