排序方式: 共有4条查询结果,搜索用时 15 毫秒
1
1.
Cong-Luan Tran Thi-Bich-Ngoc Dao Thanh-Nha Tran Dinh-Tri Mai Thi-Minh-Dinh Tran Nguyen-Minh-An Tran Van-Son Dang Thi-Xuyen Vo Thuc-Huy Duong Jirapast Sichaem 《Molecules (Basel, Switzerland)》2021,26(8)
Bioactive-guided phytochemical investigation of Euphorbia antiquorum L. growing in Vietnam led to the isolation of five ent-atisanes, one seco-ent-atisane, and one lathyrane (ingol-type). The structures were elucidated as ent-1α,3α,16β,17-tetrahydroxyatisane (1), ethyl ent-3,4-seco-4,16β,17-trihydroxyatisane-3-carboxylate (2), ent-atisane-3-oxo-16β,17-acetonide (3), ent-3α-acetoxy-16β,17-dihydroxyatisane (4), ent-16β,17-dihydroxyatisane-3-one (5), calliterpenone (6), and ingol 12-acetate (7). Their chemical structures were unambiguously determined by analysis of one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) and high resolution mass spectrometry, as well as by comparison with literature data. Among them, 1 is a new compound while 2 is an ethylated artifact of ent-3,4-seco-4,16β,17-trihydroxyatisane-3-carboxylic acid, a new compound. Isolates were evaluated for alpha-glucosidase inhibition. Compound 3 showed the most significant inhibitory activity against alpha-glucosidase with an IC50 value of 69.62 µM. Further study on mechanism underlying yeast alpha-glucosidase inhibition indicated that 3 could retard the enzyme function by noncompetitive. 相似文献
2.
3.
Tran Thi-Minh-Dinh Duong Thuc-Huy Tran Thanh-Nha Nguyen Thi-Hang Nguyen Ngoc-Phuong Nguyen Ngoc-Hong Dinh Minh-Hiep Nguyen Thi-Anh-Tuyet 《Chemistry of Natural Compounds》2021,57(2):388-389
Chemistry of Natural Compounds - 相似文献
4.
The induction of liquid crystal orientation through mechanical stretching was investigated for polymer dispersed liquid crystals (PDLCs) by means of infrared dichroism. Using a nematic liquid crystal BL006 and polyacrylic acid as the polymer matrix, it was possible to stretch the PDLC films with BL006 in either the isotropic or the nematic phase. After cooling the films under strain to room temperature, the molecular orientation of BL006 was found to be much higher for films that contained isotropic liquid droplets of BL006 at the time of stretching than for films that had nematic droplets. Stretching PDLC films with isotropic droplets results in no molecular orientation, but the orientation is induced during the subsequent cooling when BL006 goes through the isotropic-to-nematic phase transition. Interestingly for PAA/BL006, the nematic director orients along the long axes of the elongated droplets despite liquid crystal anchoring perpendicular to the polymer interface. 相似文献
1