Chemical Constituents Of Mitrella Kentii ( Annonaceae ) Ainnul Hamidah
Abstract: Mitrella kentii which belongs to the Annonaceae family is a tree-climbing liana found in the Malaysian Peninsula, Islands of Sumatra, Borneo, and New Guinea. This species was studied in 1972 for their alkaloids, 1997 and 2012 for their non-alkaloid constituents. In this study, chalcones, Desmosdumotin C (1) and their tautomer, 2-cinnamoyl3-hydroxy-5-methoxy-4,6,6-trimethylcyclohexa-2,4-dienone (2), flavanone, 7-hydroxy-5,6-dimethoxy-2-phenylchroman4-one (3), oxoaporphine alkaloids, Liriodenine (4) and Atherospermidine (5) and also terpenoid, -Sitostenone (6) have been isolated from this species. All these compounds were isolated for the first time from Mitrella kentii except Liriodenine (4). The isolated compounds were elucidated using spectroscopic techniques such as UV, IR,1D and 2D NMR and mass spectroscopy and by comparison their spectral data with those previously reported in the literatures. Desmosdumotin C (1) showed the anti-ulcer activity.
New Terpenylated Dihydrochalcone Derivatives Isolated from Mitrella kentii
From the EtOH extract of the stem bark of Mitrella kentii (Annonaceae), two new terpenylated dihydrochalcones were isolated, namely (−)-neolinderatin (1) and (−)-linderatin (2), together with known compounds 2‘,6‘-dihydroxy-4‘-methoxydihydrochalcone and (+)-catechin. Their structures were elucidated by means of combined analytical methods including HREIMS, DC, 1D, and 2D NMR spectroscopies.
Extractives of Dalea species (Leguminosae)
Abstract Coumarin(4), 5-methoxycoumarin(5) and two deep red pigments have been isolated from the extracts of Dalea emoryi. The two pigments, dalrubone and methoxydalrubone differ by a single OMe group and are assigned structures 9 and 10 respectively on the basis of an X-ray crystallographic structure determination as well as their chemical and spectroscopic properties. These pigments appear to be biogenetically derived from a C6C3C6 flavonoid system. Extracts of D. polyadenia were shown to contain coumarin(4), 5-methoxycoumarin(5), dalrubone(9) and 2S-demethoxymatteucinol(17). Dalrubone undergoes a photochemical oxidation leading to a B-ring contracted product (15) having an α-hydroxymethyl ketone group.