Biomedical subjects
Publications and source records attributed to Quan-Bin Han.
Five new ent-kaurane diterpenoids xindongnins H-L (1-5), together with five known ones, xindongnins A and B (6, 7), melissoidesins G (8), dawoensin A (9), and glabcensin V (10) were isolated from Isodon rubescens var. rubescens. Their structures were elucidated by spectroscopic methods including extensive 2D NMR techniques.
[structure: see text] A novel nortriterpene, micrandilactone A, was isolated from the medicinal plant Schisandra micrantha. This is the first example of an unusual, natural, highly oxidized cycloartane skeleton with a biosynthetically modified eight-membered ring D isolated from the family Schisandraceae.
A new ent-kaurane diterpenoid maoyecrystal F (1) and its acetonide derivative (2), together with seven known compounds, lasiodonin, maoyerabdosin, odonicin, enmenin, oridonin, beta-sitosterol and daucosterol, were isolated from the leaves of Isodon japonica.
Five new ent-kaurane diterpenoids, ludongnins F-J (1-5), along with 10 known compounds, guidongnins A-C (6-8), angustifolin (9), 6-epiangustifolin (10), sculponeatin J (11), gardenin D, 5,3',4'-trihydroxy-6,7,8-trimethoxyflavone, pedalitin, and quercetin, were isolated from the leaves of Isodon rubescens var. lushiensis. The structures of 1-5 were determined by spectroscopic analysis, as well as X-ray crystallographic analysis of 1. Compounds 1-11 were evaluated against K562 leukemia cells for their cytotoxic effects.
Two novel octanortriterpenoids, micranoic acids A (1) and B (2), along with three known compounds, kadsuric acid (3), 3beta-hydroxy-lanost-9(11),24(25)-dien-26-oic acid (4) and schizandronic acid (5), were isolated from the leaves and stems of Schisandra micrantha. The structures of 1 and 2 were determined by 1D and 2D NMR spectroscopic analysis. Micranoic acids A and B represent a new group of triterpenes in which the entire C-17 side chain has lost. This is the first report of octanortriterpenoids isolated from the family Schisandraceae.
Four new ent-kaurane diterpenoids lushanrubescensins F-I (1-4), together with 11 known ones, lasiodonin (5), oridonin (6), ponicidin (7), isodonoiol (8), isodonal (9), rabdosin B (10), rabdoternins A and B (11 and 12), enmenol (13), epinodosin (14), and inflexusin (15), were isolated from Isodon rubescens var. lushanensis, and the structures were elucidated by spectroscopic analysis. The inhibitory effect against the K562, Bcap37, BGC823, BIU87, CA, CNE, and Hela cell lines of compounds 3 and 5-10 were evaluated.
Three new 11beta,16beta-epoxy-ent-kauranoids melissoidesins I-K (1-3) and one new ent-abietanoid melissoidesin L (4) were obtained from the aerial parts of Isodon melissoides (BENTHAM) H. HARA, their structures were established on the basis of the spectral methods, especially two dimensional (2D) NMR spectroscopy.
Eleven new diterpenoids, adenanthins B-L (1-11), together with five known analogues, calcicolin B (12), adenanthin (13), weisiensin A (14), nervosanin (15), and forrestin C (16), were isolated from the aerial parts of Isodon adenantha. The structures of 1-11 were elucidated on the basis of spectral methods, as well as the X-ray crystallographic analysis of 11. Compounds 2, 5, and 14 showed significant inhibitory activities against K562 cells, with IC(50) values less than 4.0 microg/mL, respectively.
Four new ent-kaurane diterpenoids, sculponeatins F-I (1-4), together with six known compounds, sculponeatin E (5), epi-nodosin (6), epi-nodosinol (7), enmein (8), and macrocalyxoformins A and B (9 and 10), were isolated from the leaves of Isodon sculponeata. Also obtained were ursolic acid, 2alpha,3beta-dihydroxy-urs-12-en-28-oic acid, 2alpha,3beta,19alpha-trihydroxy-urs-12-en-28-oic acid, beta-sitosterol, daucosterol, quercetin, pedalitin, rosmarinic acid, caffeic acid and ethyl caffeic acid. Their structures were determined by spectral methods (1D-, 2D-NMR and MS). Some diterpenoids were tested for their cytotoxicity to inhibit three kinds of human tumor cells K562, A549 and T24. Compounds 3, 4, 6, 8, and 10 showed significant inhibitory effect toward K562 with IC(50) values ranging from 3.2 microg/ml to 8.2 microg/ml, while 3 and 6 exhibited potent antitumor activity against T24, but none exhibited cytotoxicity toward the cells of A549.