Alkaloids from Melochia chamaedrys

Abstract

Investigation of the chemical constituents from the roots of Melochia chamaedrys (Sterculiaceae) resulted in the isolation of two quinolinone alkaloids: a new alkaloid, named chamaedrone (1), and a known alkaloid, antidesmone (2). Their structures and stereochemistry were elucidated on the basis of 2D NMR and X-ray crystallographic analysis. Furthermore, alkaloids 1 and 2, and the synthetic analogues 3-6 obtained from 2, were screened for antimicrobial activities.

Plants from deer diet in the Brazilian Pantanal Wetland as potential source of antiviral and antioxidant compounds

“…The antiviral activity of M. villosa and other species from the genus was not assessed before, although the antimicrobial properties of some substances isolated from other Melochia species have already been reported (Dias et al 2007;Tripathi et al 2010).…”

4-Quinolone Alkaloids from Melochia odorata

“…St.-Hil., 8 and the leaves of Melochia odorata L.f. 9 Waltherione A was reported to possess antifungal activity against Candida albicans , Cryptococcus neoformans, and Saccharomyces cerevisiae 9 and to inhibit acetylcholinesterase. 10 4-Quinolone alkaloids that are structurally related to waltherione A include waltherione B ( 4 ), 7 vanessine, 7 antidesmone, 11 chamaedrone, 12 and melochinone. 13 Vanessine was reported to have weak antibacterial activities against Escherichia coli, Salmonella setubal, and Klebsiella pneumoniae, 7 while antidesmone was reported to have antifungal activity.…”

“…11 Chamaedrone was found to be antimicrobial against the bacteria Staphylococcus epidermidis and Escherichia coli and against the fungi Candida albicans and Sacharomyces cereviseae . 12 In Papua New Guinea, chewing of Melochia odorata roots with lime and betel nut to treat painful urination has been reported in Siwai, located in the Autonomous Region of Bougainville. 14 …”

Acetylcholinesterase Activity of Alkaloids from the Leaves ofWaltheria brachypetala

“…W. douradinha [1], and W. americana [2], M. corchorifolia [3] and M. tomentosa [4] are the most studied species. Plants belonging to this tribe are known to contain cyclic peptides, quinolinone and isatine alkaloids [5], [1]. The occurrence of quinolinone alkaloids in the Sterculiaceae was first reported from Melochia tomentosa which afforded a 4-quinolinone alkaloid, named melochinone, with a 7-membered ring fused to the quinolinone system and an open chain analogue derivative named melovinone [4].…”

“…The occurrence of quinolinone alkaloids in the Sterculiaceae was first reported from Melochia tomentosa which afforded a 4-quinolinone alkaloid, named melochinone, with a 7-membered ring fused to the quinolinone system and an open chain analogue derivative named melovinone [4]. More recently, the waltherione-A analogue of melochinone was isolated from Waltheria douradinha [1], M. chamaedrys [5] and M. odorata [6]. Waltheria brachypetala Turks grows in Brazilian semiarid regions, mainly in Bahia State (Brazil) and is known as "malva" by the local population.…”