Insecticidal pyrido[1,2-a]azepine alkaloids and related derivatives from Stemona species

Alkaloids from the roots of Stemona javanica (Kunth) Engl. (Stemonaceae) and their anti-malarial, acetylcholinesterase inhibitory and cytotoxic activities

“…Successive purification of the crude MeOH extract (35.2 g) by column chromatography gave pure samples of 13-demethoxy-11(S*),12(R*)-dihydroprotostemonine (1) (Tang et al, 2008), protostemonine (Kaltenegger et al, 2003), isoprotostemonine (2) (Ye et al, 1994), isomaistemonine (Guo et al, 2008), and two new Stemona alkaloids, javastemonine A (3) and javastemonine B (4) (Figure 1 .9, 4.9) and H-18 (δ 4.14, ddd, J = 11.2, 7.9, 5.3)}] (Kaltenegger, 2003;Tang et al, 2008). …”

“…More than 190 unique Stemona alkaloids have been isolated, some of these have significant antitussive activity (Chung et al, 2003;Lin et al, 2008aLin et al, , 2008bLin et al, , 2006Xu et al, 2010Xu et al, , 2006Yang et al, 2009;Zhou et al, 2009;), as well as insect toxicity, antifeedant, and repellent activities (Brem et al, 2002;Jiwajinda et al, 2001;Kaltenegger et al, 2003;Kongkiatpaiboon et al, 2013Kongkiatpaiboon et al, , 2012Mungkornasawakul et al, 2009Mungkornasawakul et al, , 2004aPhattharaphan et al, 2010;Sanguanpong and Hummel, 2008;Sakata et al, 1978;Tang et al, 2008). These latter properties are most likely associated with the ability of these alkaloids to inhibit insect acetylcholinesterase (AChE) (Brem et al, 2002;Jiwajinda et al, 2001;Kaltenegger et al, 2003;Kongkiatpaiboon et al, 2013Kongkiatpaiboon et al, , 2012Mungkornasawakul et al, 2009Mungkornasawakul et al, , 2004Phattharaphan et al, 2010;Sanguanpong and Hummel 2008;Sakata et al, 1978;Tang et al, 2008). While other alkaloids have shown oxytocin antagonism (Phuwapraisirisan et al, 2006), nitric oxide inhibition (Hosoya et al, 2011) and the ability to inhibit P-glycoprotein in multi-drug-resistant cancer cell lines (Chanmahasathien et al, 2011a(Chanmahasathien et al, , 2011bLimtrakul et al, 2007;…”

Chromosome Numbers and Other Karyological Data of Four Stemona Species (Stemonaceae) from Thailand

“…The new data support the assumption of Oginuma et al (2001), that x = 7 is the basic number for the whole genus. The uniformity in chromosome numbers is in contrast to differences observed in other character states within the genus, like morphology (Duyfjes, 1993;Tsi & Duyfjes, 2000), chemistry (Brem et al, 2002;Kaltenegger et al, 2003) and DNA-sequence analysis (Pfosser, unpubl.). These differences seem to support a classification of the genus into subgroups.…”

Studies on the Synthesis of Croomine: Synthesis of the Tricyclic B,C,D-Ring Core Structure

“…2 Later in that year Hofer and Greger reported the isolation of four other Stemona alkaloids with the pyrido[1,2-a]azepine A,B-ring system plus stemocurtisine. 3 These alkaloids represent a new and sixth structural group for Stemona alkaloids. Extracts of the roots of Stemona species have been used in traditional Chinese medicine for the treatment of various respiratory diseases and as anthelmintic agents for domestic animals.…”

“…This was dissolved in EtOAc (30 mL) and stirred with activated charcoal for 20 min to remove residual ruthenium, then filtered through celite. 3 (0.5 mL), then MeOH (4.0 mL) and conc HCl (1.0 mL, 38 % w/w) were added. The mixture was heated in a sealed tube at 90 o C for 3d then cooled.…”