1. [Chemical constituents of Cassia siamea]
Shan-Shan Wang, Wen-Zhong Huang, Guang-Zhi Zeng, Hong Zhu, Zai Zhang, Gan-Peng Li, Meng-Yuan Jiang, Xue-Mei Gao Zhongguo Zhong Yao Za Zhi. 2019 Feb;44(4):712-716. doi: 10.19540/j.cnki.cjcmm.20181121.007.
A total of ten compounds were isolated from the 90% Et OH extract of Cassia siamea by using various chormatographic techniques,and their structures were established as( 2' S)-2-( propan-2'-ol)-5,7-dihydroxy-benzopyran-4-one( 1),chrobisiamone( 2), 2-( 2'-hydroxypropyl)-5-methyl-7-hydroxychromone( 3), 2,5-dimethyl-7-hydroxychromone( 4), 2-methyl-5-acetonyl-7-hydroxychromone( 5),3-O-methylquercetin( 6),3,5,7,3',4'-pentahydroxyflavonone( 7),luteolin-5,3'-dimethylether( 8),4-( trans)-acetul-3,6,8-trihydroxy-3-methyl-dihydronapht halenone( 9) and 6-hydroxymellein( 10) based on the spectroscopic data.Compound 1 was a new compound,and 3,4,6,8 were isolated from this plant for the first time.
2. [N-containing compounds from seeds of Paganum harmala]
Xin Fang, Hai-Yang Yu, Li-Feng Han, Xu Pang Zhongguo Zhong Yao Za Zhi. 2019 Apr;44(8):1601-1606. doi: 10.19540/j.cnki.cjcmm.20190118.009.
To investigate the N-containing compounds in the seeds of Paganum harmala,fourteen compounds were finally isolated from the 95% Et OH extract of P. harmala seeds by using various chromatographic techniques including silica gel,MCI resin,and ODS column chromatography as well as the semi-preparative HPLC. Depending on spectroscopic techniques and comparison with the reported data in the literatures,the structures of all compounds were identified as N-[3-(2-amino-4-methoxyphenyl)-3-oxopropyl]acetamide(1),dehydroharmalacidine(2),harmalacidine(3),harmine N-oxide(4),harmine(5),tetrahydroharmine(6),demethylharmalacidine(7),harmol(8),tetrahydroharmol(9),harmindol β-D-glucopyranoside(10),tryptophyl β-D-glucopyranoside(11),pegamineβ-D-glucopyranoside(12),vasicol(13) and vasicinone(14). Among them,1 was a new compound,and 2 and 10 were obtained as natural products for the first time.
3. Development and Characterization of Unmodified and Modified Natural Rubber Composites Filled with Modified Clay
Adisak Keereerak, Nusara Sukkhata, Nussana Lehman, Yeampon Nakaramontri, Karnda Sengloyluan, Jobish Johns, Ekwipoo Kalkornsurapranee Polymers (Basel). 2022 Aug 27;14(17):3515. doi: 10.3390/polym14173515.
Novel composite based on rubber and modified bentonite clay (Clay) was investigated. The modified bentonite clay was developed by dispersing in ethanol solutions (Et-OH) using ultrasonic method. The effect of Et-OH on the dispersion of bentonite clay at various mixing temperatures in case of different type of rubber matrix, i.e., natural rubber (NR), epoxidized natural rubber (ENR25, ENR50) on dynamic mechanical rheology, Payne effect, XRD and mechanical properties of rubber composites were studied in detail. The bentonite clay dispersion in Et-OH at a mixing temperature of 80 °C improves the intercalation and exfoliation in rubber chains. Bentonite clay is highly intercalated in ENR 50-Clay composite, which can be confirmed from its superior mechanical properties. The results indicated that sonication of bentonite clay in Et-OH improves the interlayer spacing of bentonite clay by partial intercalation of rubber matrix.
