Taslim Ersam

20(S)-Ginsenoside Rh2 as aldose reductase inhibitor from Panax ginseng.

The root of Panax ginseng C. A. Meyer (Araliaceae) is a well-known herbal medicine in East Asia. The major bioactive metabolites in this root are commonly identified as ginsenosides. A series of ginsenosides were determined for in vitro human recombinant aldose reductase. This Letter aims to clarify the structural requirement for aldose reductase inhibition. We discovered that only ginsenoside 20(S)-Rh2 showed potent against aldose reductase, with an IC50 of 147.3 μM. These results implied that the stereochemistry of the hydroxyl group at C-20 may play an important role in aldose reductase inhibition. An understanding of these requirements is considered necessary in order to develop a new type of aldose reductase inhibitor. Furthermore, P. ginseng might be an important herbal medicine in preventing diabetic complications.

The inhibitory activity of aldose reductase in vitro by constituents of Garcinia mangostana Linn

We investigated aldose reductase inhibition of Garcinia mangostana Linn. from Indonesia. Dichloromethane extract of the root bark of this tree was found to demonstrate an IC50 value of 11.98 µg/ml for human aldose reductase in vitro. From the dichloromethane fraction, prenylated xanthones were isolated as potent human aldose reductase inhibitors. We discovered 3-isomangostin to be most potent against aldose reductase, with an IC50 of 3.48 µM.

Cylindroxanthones A-C, three new xanthones and their cytotoxicity from the stem bark of Garcinia cylindrocarpa.

Three new xanthones, cylindroxanthones A-C (1-3), were isolated from the stem bark of Garcinia cylindrocarpa. The structures were established on the basis of spectroscopic analysis. The molecular structure of 1 was unequivocally confirmed by single-crystal X-ray diffraction analysis. These three xanthones were evaluated regarding their cytotoxicity against KB, HeLa S-3, HT-29, MCF-7, and Hep G2 cancer cell lines. Compound 1 exhibited good cytotoxicity against KB cell with IC50 value of 2.36 μM.

Xanthones and biphenyls from the stems of Garcinia cylindrocarpa and their cytotoxicity

Six new compounds including four new xanthones, cylindroxanthones D-G (1-4), and two new biphenyls, cylindrobiphenyls A and B (5 and 6), were isolated from the stems of Garcinia cylindrocarpa together with 28 known compounds (7-34). The structures of the new compounds were established on the basis of extensive 1D and 2D NMR and HRESIMS spectroscopic analysis. Their cytotoxicity was evaluated against five human cancer cell lines including KB, HeLa S-3, MCF-7, Hep G2, and HT-29. Compound 23 showed strong cytotoxicity against KB, HeLa S-3, MCF-7, and Hep G2 cells with IC50 values in the range of 2.20-6.00 μM. Furthermore, compound 25 selectively exhibited good cytotoxicity against MCF-7 cells with IC50 value of 8.77 μM, while 31 showed good cytotoxicity against HT-29 cells with IC50 value of 9.18 μM.

Influence of CTAB and Sonication on Nickel Hydroxide Nanoparticles Synthesis by Electrolysis at High Voltage

CTAB and Sonication has been used for preparing Ni(OH)2 nanoparticles by electrolysis at high voltage. The effect of CTAB and sonication on the morphology and size of Ni(OH)2 nanoparticles was observed. The results obtained were characterized with UV-Vis spectroscopy, X-ray Diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), and Transmission Electron Microscopy (TEM). The TEM image shows that Ni(OH)2 nanoparticles obtained with and without CTAB under sonication were nearly spherical. UV-Vis Spectrums show that with CTAB has higher concentration in comparison with without CTAB. But no significant different was found for FTIR spectrum. Thermogram shows Ni(OH)2 nanoparticles obtained with and without CTAB have different properties at 60–140 °C due to association of water and CTAB. The most stable Ni(OH)2 nanoparticles were obtained by addition CTAB under sonication.