Sesquiterpene lactones contain £\,£]-unsaturated-£^-lactone as a major structural feature, which in recent studies have been shown to be associ-
ated with anti-tumor, cytotoxic, anti-microbial and phytotoxic activities. Previous researchers isolated sesquiterpene lactones from Eupatorium formosanum Hay. Thus, we studied Eupatorium hualienense, a unique speces in Taiwan that grows near the eastern coast. Five new sesquiter-
pene lactones of the germacranolide type, eupahualins A-E (1-5) along with the known lactone, eupasimplicin B (6). Their structures were determined by 1D-NMR(1H-NMR,13C-NMR) and 2D-NMR(COSY¡BNOESY¡BHMQC¡BHMBC).
Eupahualin A (1) exhibits an aldehyde at C-10 and an a,b-unsatura
ted acyl group at C-8. Eupahualin B (2) also has an aldehyde at C-10. The Z-form of C-4, C-5 double bond in eupahualin B (2) is the main difference from the trans-form C-4, C-5 double bond in eupahualin A (1). The difference of eupahualin C (3) and eupahualin A (1) lies in structure of a ester group at C-8. The methyl at C-4' in eupahualin A (1) was changed into hydroxy methyl while the hydroxy methyl of eupahualin A (1) was changed to methyl in eupahualin C (3). Eupahualin D (4) shows exocyclic double bond at C-10, OH at C-1 and OAc at C-3. An carboxylic group (COOH) at C-10 in eupahualin E (5) is the only difference from which in eupahualin A (1).
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0728104-152606 |
| Date | 28 July 2004 |
| Creators | Jang, Jiun-yang |
| Contributors | Hong-nong Zhou, Ya-ching Shen, Zhong-nan Lin |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0728104-152606 |
| Rights | unrestricted, Copyright information available at source archive |
Page generated in 0.0021 seconds