156-57-0Relevant articles and documents
Method for preparing cysteamine hydrochloride
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Paragraph 0032; 0035-0038, (2020/03/09)
The invention relates to a method for preparing cysteamine hydrochloride. The method comprises the following steps: 1, reacting carbon disulfide with sodium sulfide in alcohol to obtain sodium thiocarbonate; 2, fully reacting 2-aminoethyl sulfate sodium salt or 2-chloroethylamine hydrochloride with the sodium thiocarbonate prepared in the step 1; 3, continuing to add hydrochloric acid for a reaction to obtain first-stage cysteamine hydrochloride mother liquor; 4, cooling and crystallizing the cysteamine hydrochloride mother liquor obtained in the step 3 to crystallize sodium sulfate and/or sodium chloride generated in the reaction in the step 2, and carrying out filtering after crystallization to obtain a filtrate which is second-stage cysteamine hydrochloride mother liquor; 5, carrying out reduced-pressure distillation on the second-stage cysteamine hydrochloride mother liquor obtained in the step 4, and carrying out cooling and crystallizing to obtain a cysteamine hydrochloride solid, wherein a ratio of the 2-aminoethyl sulfate sodium salt to the 2-chloroethylamine hydrochloride is 1: 1. Through further optimization, yield is further increased, and the mass yield can reach 95% interms of sodium sulfide.
Synthesis and antiproliferative activities of conjugates of paclitaxel and camptothecin with a cyclic cell-penetrating peptide
El-Sayed, Naglaa Salem,Shirazi, Amir Nasrolahi,Sajid, Muhammad Imran,Park, Shang Eun,Parang, Keykavous,Tiwari, Rakesh Kumar
, (2019/04/30)
Cell-penetrating peptide [WR]5 has been previously shown to be an efficient molecular transporter for various hydrophilic and hydrophobic molecules. The peptide was synthesized using Fmoc/tBu solid-phase chemistry, and one arginine was replaced with one lysine to enable the conjugation with the anticancer drugs. Paclitaxel (PTX) was functionalized with an esterification reaction at the C20 hydroxyl group of PTX with glutaric anhydride and conjugated with the cyclic peptide [W(WR)4K(βAla)] in DMF to obtain the peptide-drug conjugate PTX1. Furthermore, camptothecin (CPT) was modified at the C(20)-hydroxyl group through the reaction with triphosgene. Then, it was conjugated with two functionalized cyclic peptides through a formyl linker affording two different conjugates, namely CPT1 and CPT2. All the conjugates showed better water solubility as compared to the parent drug. The cytotoxicity assay of the drugs and their conjugates with the peptides were evaluated in the human breast cancer MCF-7 cell line. PTX inhibited cell proliferation by 39% while the PTX-peptide conjugate inhibited the proliferation by ~18% after 72 h incubation. On the other hand, CPT, CPT1, and CPT2 reduced the cell proliferation by 68%, 39%, and 62%, respectively, in the MCF-7 cell lines at 5 μM concentration after 72 h incubation.
Synthesis of mercaptoethylammonium chloride in alkaline medium
Xiao, Feng,Tan, Shiyu,Zou, Xiaobing
experimental part, p. 3247 - 3248 (2012/08/29)
A new way synthesis of mercaptoethylammonium chloride is reported. Using NaOH replace HCl, the results present that the target product can be made in alkaline medium and the velocity of new way is much faster than the tradition one, which is hydrolyzed at high pressure. 1H NMR and IR characterized the structure of the product.
