title: D-ring-opened phragmalin-type limonoid orthoesters from the twigs of Swietenia macrophylla.
abstract: Sixteen new D-ring-opened phragmalin limonoid orthoesters, swietenitins A-M (1-6, 8, 10, 12-16), 2-acetoxyswietenialide D (7), 2,11-diacetoxyswietenialide D (9), and 11-deoxyswietenialide D (11), and four known compounds were isolated from the twigs of Swietenia macrophylla. The structures of 1-16 were established on the basis of spectroscopic methods, and 1 and 2 were confirmed by single-crystal X-ray diffraction. The (1)H NMR-based conformational analysis on the epimeric compounds 1 and 2 provided a general approach to determine the absolute configuration of the 2,3-epoxy-2-methylbutyryloxy unit at C-3 borne by a large group of the known phragmalin-type limonoid orthoesters.
authors: Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, People's Republic of China.
authors: Bing-Dong
authors: BD
authors: Lin
authors: Chuan-Rui
authors: CR
authors: Zhang
authors: Sheng-Ping
authors: SP
authors: Yang
authors: Sheng
authors: S
authors: Zhang
authors: Yan
authors: Y
authors: Wu
authors: Jian-Min
authors: JM
authors: Yue
mesh_terms: D018360:Crystallography, X-Ray; D036701:Limonins / Q000737:chemistry / Q000302:isolation & purification*; D029582:Meliaceae / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018547:Plant Stems / Q000737:chemistry
chemical_list: D036701:Limonins