L. J. Chen

Bio: L. J. Chen is an academic researcher from Fooyin University. The author has contributed to research in topics: Michelia. The author has an hindex of 1, co-authored 1 publications receiving 60 citations.

Chemical constituents from the leaves of Michelia alba

Abstract: The genus Michelia (Magnoliaceae) consists of about 30 species. Michelia alba is an evergreen tree, especially distributed in Taiwan and China. Michelia species have been used by indigenous peoples for the treatment of cancer. For example, Michelia champaca has been used in India for the treatment of abdominal tumors and M. hypoleuca and M. officinalis for carcinomatous sores and leukemia, respectively, in China [1]. Previous phytochemical studies on this species isolated, from the roots and flowers of M. alba, ushinsunine, oxoushinsunine, salicifoline, michelalbine, limonene, benzyl acetate, linalool, nerol, hydroxycitronellal, benzaldehyde, benzyl benzoate, and methyl eugenol [2, 3]. To further understand the chemotaxonomy and to continue searching for novel agents from Magnoliaceous plants, the leaves of M. albawere chosen for the first time for phytochemical investigation. In this paper, we report the isolation of 21 pure substances. The compounds included four aporphines, (-)-anonaine ( 1) [4], (-)-norushinsunine ( 2) [5], (-)-ushinsunine ( 3) [5], and (-)-N-acetylanonaine ( 4) [6]; two oxoaporphines, liriodenine ( 5) [5] and oxoxylopine ( 6) [7]; three sesquiterpene lactones, michelenolide ( 7) [8], costunolide ( 8) [8], and 11,13-dehydrolanuginolide ( 9) [9]; one amide, N-trans-feruloyltyramine ( 10) [10]; one lignan, (+)-syringaresinol ( 11) [11]; three benzenoids, 4-hydroxybenzaldehyde ( 12) [12], 4-hydroxybenzoic acid ( 13) [12], and methylparaben ( 14) [12]; two steroids, β-sitosterol and stigmasterol [13]; three aliphatic compounds, palmitic acid [14], stearic acid [15], and linoleic acid [16]; and two chlorophylls, pheophorbide a [17] and aristophyll-C [18]. In addition to 3 and 5, all of these compounds were isolated for the first time from this source.

Bioconstituents from stems of Synsepalum dulcificum Daniell (Sapotaceae) inhibit human melanoma proliferation, reduce mushroom tyrosinase activity and have antioxidant properties

Abstract: A new amide, dihydro-feruloyl-5-methoxytyramine ( 1 ), along with 13 known compounds, including (+)-syringaresinol ( 2 ), (+)- epi -syringaresinol ( 3 ), 4-acetonyl-3,5-dimethoxy- p -quinol ( 4 ), cis - p -coumaric acid ( 5 ), trans - p -coumaric acid ( 6 ), p -hydroxybenzoic acid ( 7 ), syringic acid ( 8 ), vanillic acid ( 9 ), veratric acid ( 10 ), N - cis -feruloyltyramine ( 11 ), N - trans -feruloyltyramine ( 12 ) and N - cis -caffeoyltyramine ( 13 ), were isolated from the stems of Synsepalum dulcificum Daniell (Sapotaceae). The structures of these compounds were established on the basis of spectroscopic analysis. One of the purposes of this study was to survey the antioxidant properties of 13 pure constituents. The radical scavenging and antioxidant activities were investigated by: scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals; metal chelating power was completed by ferrous ions; and reducing power was demonstrated by iron ions reduction reaction. In addition, all compounds were evaluated for their cell proliferation inhibition activities on human skin melanoma cells and tyrosinase inhibitions. The anti-tyrosinase effects were to calculate the hydroxylation of l -tyrosine to l -dopa according to in vitro mushroom tyrosinase assay. In sum, the inhibition effects of compounds ( 2 – 3 ) on human melanoma cells were significant. Besides, DPPH, ABTS radical scavenging, metal chelating and reducing power were found to be moderate compared with the positive controls.

The pharmacological activities of (-)-anonaine.

Abstract: Several species of Magnoliaceae and Annonaceae are used in Traditional Chinese Medicine. (−)-Anonaine, isolated from several species of Magnoliaceae and Annonaceae, presents antiplasmodial, antibacterial, antifungal, antioxidation, anticancer, antidepression, and vasorelaxant activity. This article provides an overview of the pharmacological functions of (−)-anonaine.