Structural relations among cytotoxic and antitumor benzophenanthridine alkaloid derivatives

DNA Topoisomerase I Inhibitory Alkaloids from Corydalis saxicola

“…So far, seven quaternary alkaloids (i.e., dehydrocavidine (1), chelerythrine (10), berberine (2), palmatine (3), coptisine, dehydroapocavidine, and tetradehydroscoulerine) [1] [3] and ten tertiary alkaloids (i.e., cavidine (12), thalictrifoline, 13b-hydroxystilopine, scoulerine (11), tetrahydropalmatine (13), tetrahydrocolumbamine, protopine, oxyacanthine, allocryptopine, and 1-nitroapocavidine) were isolated from C. saxicola [1] [3] [4]. Furthermore, seven non-alkaloid compounds (i.e., oleanolic acid, daucosterol, b-sitosterol, betulin, cycloeucalenol, betulinic acid, and bamyrin acetate) were also isolated from this plant [3].…”

“…Pharmacological studies of the alkaloids established that scoulerine (11), tetrahydropalmatine (13), and palmatine (3) showed significant cytotoxic activities against P-388, KB16, A549, and HT-29 cell lines [8]. Tetrahydropalmatine (13) and cheilanthifoline (14) displayed inhibitory effects on EBV-EA (Epstein-Barr virus early antigen) activation induced by 12-O-tetradecanoylphorbol-13-acetate in Raji cells [9].…”

Synthesis of Enantioenriched 5,6‐Dihydrophenanthridine Derivatives through retro‐Carbopalladation of Chiral o‐Bromobenzylamines

“…(1), Scheme 2]. [3a] Based on these interesting observations and our previous work on the Catellani reaction, [4] in which formation of Pd IV intermediate and retro-carbopalladation of norbornene are two of the key steps, [5] we anticipated that 5,6-dihydrophenanthridine derivatives 7, which are prevalent structural units in natural products and biologically active molecules, [6,7] might be accessible if obromobenzylamines 6 undergo a similar Pd-catalyzed homocoupling reaction as that of o-bromobenzyl alcohols 1 [Eq. (2), Scheme 2].…”

“…b-Carbon elimination of intermediate I then furnishes the aryl palladium species J with concomitant formation of the imine byproduct K and its decomposition product L. Buchwald-Hartwig amination of intermediate J produces the final product and regenerates the catalytically active Pd 0 species. In conclusion, we have developed a novel synthetic approach for the rapid generation of biologically important 5,6-dihydrophenanthridine skeletons, [6] in which an unprecedented retro-carbopalladation of aldimines was observed. By taking advantage of Rh and Pd catalysis, a highly enantioselective synthesis of 6-aryl-substituted 5,6-dihydrophenanthridine derivatives was achieved in a one-pot manner.…”

Simple and one-pot synthesis of new heterocyclic compounds in three-component reactions between isoquinoline or phenanthridine and acetylenic esters in the presence of N-heterocycles or 1,3-dicarbonyl compounds

“…1 Phenanthridines are important core structures found in a variety of natural products and other biologically important molecules with a wide range of biological activities and applications, [2][3][4][5][6][7][8][9][10] including antibacterial, antiprotozoal, anticancer, antimicrobial, anti-inflammatory, antivirial, antioxidant [11][12][13][14][15][16][17][18][19][20][21] and also with applications as drugs, 8 DNA targeting agents, 22 dyes, 23 and probes. 24 Isoquinoline is also present in various natural products such as cryptaustoline and cryptowoline.…”