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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Lignans, Molecular Conformation, Molecular Structure, Pinus, Plant Leaves, Plants, Medicinal, Umbelliferones.
user
Do [ Isolation and structure identification of the chemical constituents from pine needles of Pinus massoniana Lamb ]? Context: To study the chemical constituents of the water-extracts of the pine needles of Pinus massoniana Lamb.. Pine needles were collected in Xixia country and extracted with boiling water for two times and the water-extracts were concentrated. The crude extract of pine needles was fractionated into four fractions by Et2O, EtOAc and n-BuOH. Various column chromatography with D-101 macroreticular resin, Toyopearl HW-40 and silica gel were employed for the isolation and purification of compounds from the n-BuOH fraction of pine needles. The structures of the compounds were identified by physiochemical properties and spectral analysis (UV, IR, MS, 1HNMR, 13CNMR, DEPT, HMQC, HMBC, etc.). Four compounds were isolated from the n-BuOH fraction of water-extracts, and their structures were identified as 3-methoxyl-9'-O-alpha-L-rhamnopyranosyl-4':7,5':8-diepoxyneoligan-4,9-diol (massonianoside E, I), 4,4',8,8',9-pentahydroxyl-3,3'-dimethoxyl-7,9'-monoepoxylignan (II), umbelliferon (III), 4-(4'-hydroxyl-3'-methoxylbenzyl)-2-butanone (IV).
assistant
Compound I is a new compound, and compounds II, III and IV were isolated from this plant for the first time. Final Decision: yes