Bioactive Azafluorenone Alkaloids from Polyalthia debilis (Pierre) Finet & Gagnep.

Abstract

This study investigated bioactive extracts of Polyalthia debilis (Annonaceae) with antimicrobial, antimalarial and cytotoxic activities. Extensive chromatographic isolations provided azafluorenone alkaloids; onychine (1) and 7-methoxyonychine (2) together with a mixture of β–sitosterol and stigmasterol. The two alkaloids were isolated from the P. debilis for the first time. Isolated fractions containing a mixture of triterpenoids (C7, C8 and C9) exhibited the most potent antimicrobial activity against many bacterial strains with minimum inhibitory concentration of 64 μg/mL. Fractions with antimalarial and cytotoxic activities were also observed. The findings suggest the potential use of P. debilis in medicinal applications.

Effect of Crude Leaf Extract of Bauhinia strychnifolia in BALB/c Mice Infected with Plasmodium berghei

“…This increased percent suppression of parasitemia with increased dose was observed by other studies on different plant species [15][16][17][18]. Alkaloids, polyphenolic compounds, terpenoids, flavonoids and quercetin in this extract could be responsible for its antimalarial activity [19][20][21][22][23]. Moreover, it has been reported that quercetin and terpenoids showed strong antimalarial, anti-microbials and anti-cancer activities [23].…”

Efficient two-step access to azafluorenones and related compounds

“…The structure is closely related to the dimers of (TMP) 2 Cu(CN)Li 2 ·THF 9 and (TMP) 2 Cu(I)Li 2 ·THF, 10 with Cu maintaining a near linear geometry (N(1)-Cu(1)-N(2) 174.45(11)°) and the amides acting as inter-metal bridges (Cu(1)-N(1)-Li(1) 92.1(2), Cu(1)-N(2)-Li(2) 84.77(19)°). However, in contrast to the cyanide-and iodide-based dimers, in which the THF-solvated Li + ions reside within 0.14 and 0.15 Å, respectively, of planes defined by the (LiX) 2 (X = N, I) metallocyclic cores of the structures, in 1 2 they are significantly displaced (by 0.49 Å) from the analogous (LiCl) 2 core plane. Lastly, we can empirically view formation of the higher-order dimer as resulting from the formal insertion of two units of in situ-generated LiCl·THF 11 into a lower-order dimer based on a (NCuNLi) 2 ring.…”

“…Using Cy 3 P in DMF at 130 °C, different transition metal-ligand ratios were tested. The best result was observed using 5 mol% of Pd(OAc) 2 and 10 mol% of phosphine; using 20 mol% of Pd(OAc) 2 and 10 mol% of phosphine, a lower yield was observed due to recovered starting material (Scheme 1). (9) 25 were formed from the ketones 2 and 3b respectively, and isolated in 63-69% yield (Scheme 2).…”

“…Azafluorenones represent the heterocyclic cores of many molecules of biological interest; derivatives have, for example, been described for their antifungal, 1 antibacterial, 2 and antimalarial 3 properties. In the course of the development of lithium-metal amido-based heterometallic bases, synergic reagents with which to functionalize aromatic compounds unsuitable for reaction with traditional organolithium bases have been identified and developed.…”

Potent anti-proliferative effects against oral and cervical cancers of Thai medicinal plants selected from the Thai/Lanna medicinal plant recipe database “MANOSROI III”

“…(Rhamnaceae) stems gave the highest and lowest yields of 43.88 and 4.97% w/w, respectively. Several traditional uses including cancer treatment of the medicinal plants have been reported (Coe & Anderson, 2005;Houghton et al, 2007;Manaharan et al, 2011;Manosroi et al, 2009;Prachayasittikul et al, 2009;Siriwatanametanon et al, 2010;Su et al, 2008;Trakulsomboon et al, 2006;Ueda et al, 2002).…”