Chemical transformation of protoberberines. XV. A novel and efficient method for the introduction of alkyl groups on the C-13 position in the protoberberine skeleton.
Several 13-alkyl substituted analogs of berberine and palmatine were found to be highly active against two types of Staphylococcus aureus (S1 and S2) of different origin. The most active 13-hexylberberine was 8 times more active (against S1) and the same order active (against S2) as kanamycin sulfate. 13-Hexylpalmatine displayed an activity against S. aureus (S1) 4 times greater than that of kanamycin sulfate. The activities of 13-hexylberberine against two types of S. aureus were 64 and 128 times greater than those of the clinically used alkaloid berberine. Additionally two hexyl derivatives possessed antifungal activity.
Berberine Analogues as a Novel Class of the Low-Density-Lipoprotein Receptor Up-Regulators: Synthesis, Structure−Activity Relationships, and Cholesterol-Lowering Efficacy
Twenty-nine derivatives of berberine (1) or pseudoberberine (2) were designed, semisynthesized, and evaluated for their up-regulatory activity on the low-density-lipoprotein receptor (LDLR) expression. SAR analysis revealed that (i) the methylenedioxy group at the 2- and 3-position is an essential element to keep the activity, (ii) the 7-position quaternary ammonium and planar structure of the compound are activity-required, and (iii) addition of electron-donating groups at the 7- or 13-position reduced the activity. Of the compound I analogues, compound 2 exhibited an increased activity on LDLR expression compared to 1. In the hyperlipidemic rats, compound 2 (100 (mg/kg)/day) reduced blood CHO and LDL-c by 42.6% and 49.4%, respectively, more efficient than I did (p < 0.01 for both). The results were confirmed in the hyperlipidemic mice. LD50 of 2 in mice was over 5000 mg/kg (oral). We consider compound 2 a promising cholesterol-lowering drug candidate.
HANAOKA, MIYOJI;YOSHIDA, SHUJI;MUKAI, CHISATO, CHEM. AND PHARM. BULL., 37,(1989) N2, C. 3264-3267
作者:HANAOKA, MIYOJI、YOSHIDA, SHUJI、MUKAI, CHISATO
DOI:——
日期:——
A novel and efficient synthesis of 13-methylprotoberberine alkaloids
作者:Miyoji Hanaoka、Shuji Yoshida、Chisato Mukai
DOI:10.1039/c39850001257
日期:——
13-Methylberberine (6a), dehydrocorydaline (6b), and corysamine (6c, and their tetrahydro derivatives (9a–c) were efficiently synthesised from the corresponding protoberberines (1) through photochemical electrocyclic reaction of 13-methylene-8, 14-cycloberbines (3).
Chemical transformation of protoberberines. XV. A novel and efficient method for the introduction of alkyl groups on the C-13 position in the protoberberine skeleton.
作者:Miyoji HANAOKA、Shuji YOSHIDA、Chisato MUKAI
DOI:10.1248/cpb.37.3264
日期:——
The Wittig reaction of 8, 14-cycloberbin-13-ones (4), derived from the corresponding protoberberine alkaloids (2), with methylenetriphenylphosphorane afforded 13-methylene-8, 14-cycloberbines (5). Irradiation of 5 with a 100 W high pressure mercury lamp effected photochemically-induced electrocyclic fission of the aziridine ring to yield 13-methylberberine (1a), dehydrocorydaline (1b), and corysamine (1c) in high yield. Introduction of ethyl and propyl groups on the C-13 position in 2 was also conveniently achieved via photochemical reaction of the corresponding alkylidene derivatives (8 and 9, respectively).