0000000000343182
AUTHOR
Kenneth F. Bastow
Cytotoxic activity of some natural and syntetic sesquiterpene lactones
Several natural and synthetic sesquiterpene lactones with different skeletons were tested and found to be active against nine cancer cell lines. Elemane (4), heliangolane (5) and their hydroxy analogues 9 and 10, all containing an α,β-unsaturated aldehyde substituent, were the most potent compounds.
Cytotoxic geranylflavonoids from Bonannia graeca
The analysis of the aerial parts of Bonannia graeca led to the isolation and characterization of two new polar geranylated flavonoids (6 and 7). The structure elucidation was performed by extensive spectroscopic methods (1D and 2D NMR) and comparison with literature data. All natural flavonoids isolated from B. graeca (1–7) and some synthetic derivatives (8–11) were tested for cytotoxic activity against four human tumor cell lines. Preliminary structure-activity relationship correlations are discussed.
Cytotoxic Activity of Some Natural and Synthetic ent-Kauranes
Atractyligenin (1) and several synthetic derivatives were tested and found to be active against tumor cell replication. Compound 1 was readily converted to the 2,15-diketo (3) or 15-keto (4) derivatives, which contain an alpha,beta-unsaturated ketone. Compounds 3 and 4 showed significant cytotoxic activity against all six tested cancer cell lines and were most potent against 1A9 ovarian cancer cells with EC50 values of 0.2 and 0.3 microM, respectively. These two 1-analogues are promising lead compounds for further investigation.
The Cytotoxic Properties of Natural Coumarins Isolated from Roots ofFerulago campestris(Apiaceae) and of Synthetic Ester Derivatives of Aegelinol
Grandivittin (1), agasyllin (2), aegelinol benzoate (3) and felamidin (20), four natural coumarins isolated from Ferulago campestris, and several synthetic ester derivatives of aegelinol (4) were tested against four tumor cell lines. Some of them were shown to be marginally cytotoxic against the A549 lung cancer cell line.
Cytotoxic activity of some natural and synthetic guaianolides
Several natural guaianolides and synthetic derivatives of repin (1) were tested and found to be active against tumor cell replication. Repin (1) and both mono- and di-halohydrin analogues (2, 7-9, 11, 12) showed significant antitumor potency. A more effective compound (17) was obtained by esterificating repin with the paclitaxel side chain.
Acid Rearrangment of Epoxy-germacranolides and Absolute Configuration of 1β,10α-Epoxy-salonitenolide
The acid-catalyzed cyclization of mono epoxides of cnicin acetonide (3) was investigated. Several 6,12-eudesmanolides were obtained, and their stereochemistry established by extensive spectroscopic analyses. Chemical correlations also led to the assignment of the absolute configuration of 1β,10α-epoxy-salonitenolide (13), a previously isolated natural product. The cytotoxic activities of some compounds were determined against A549 and MCF-7 tumor cell lines. The esterified germacranolides 2–6 were selectively cytotoxic against the MCF-7 breast cancer cell line.