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We report on the preparation of synthetically versatile N-carboxyanhydrides (NCAs) directly from amino acids and CO2 using n-propylphosphonic anhydride. Most of the NCAs were isolated with >95% purity after simple workup, avoiding the need for tedious purification procedures typically required using conventional methods. Because the reagents and conditions employed are mild, tandem reactions with moisture-sensitive NCAs were carried out to transform them into the medicinally active alkaloids tryptanthrin and phaitanthrin A in one pot. A qualitative analysis revealed that our NCA synthesis approach is more green than conventional methods, which all directly or indirectly use the highly poisonous gas phosgene. [ABSTRACT FROM AUTHOR]

The current study included the separation of three alkaloid compounds from Anastatica Hierochuntica and studied the effect of the these compounds on cancerous cells, specifically liver cancer it was found that compound number one is the most influential or inhibiting at 50 percent followed by compound number three when using concentration of 400 μg/mL. [ABSTRACT FROM AUTHOR]

The total alkaloids from Nitraria sibirica leaves have been confirmed to exhibit significant protective effects against inflammatory renal injury, hypertension and albuminuria in angiotensin II-salt hypertension. In the present study, a separation method of pH-zone-refining counter-current chromatography was established for separation of the alkaloids from N. sibirica . The separation was performed with a solvent system of MtBE- n -BuOH-H 2 O (2:2:5, v / v ) at a flow rate of 2.0 mL/min. And 15 mM triethylamine (TEA) was added to the upper organic phase, while 10 mM hydrochloric acid was added to the lower aqueous phase. As a result, a new alkaloid, schobemine (5.6 mg), and a known alkaloid, nitraramine (5.0 mg), together with fractions A and B were obtained from the total alkaloids of N. sibirica . The fractions A and B were further purified by means of pH-zone-refining counter-current chromatography with solvent systems of n -hexane- n -BuOH-H 2 O (1.5:3.5:5, v / v ) and (2:3:5, v / v ), respectively. TEA (10 mM) was added to the upper phase, and 10 mM of HCl was added to the lower phase in above two solvent systems, respectively. As a result, a known alkaloid, schoberidine (5.0 mg), and a new alkaloid, schoberimine (3.0 mg) were obtained from fractions A and B, respectively. The purities of the compounds were measured by HPLC–ELSD, and their structures were identified by ESI–MS, 1D and 2D NMR. [ABSTRACT FROM AUTHOR]

Some ionic liquids have good potential to play the role of anti-solvents in the crystallization of natural active compounds after their initial extraction. In order to prove it and explore suitable candidates, a novel separation method of berberine hydrochloride was developed based on benzothiazolium ionic liquid induced crystallization in this study. Ionic liquids [C 6 Bth]PF 6 and [HBth]BF 4 were selected to conduct the separation process. The effects of various conditions on IL performance were investigated, under which the separation efficiency could achieve above 90% just by using a small amount of these ionic liquids. Moreover, the separation process was greatly simplified due to the different solubility of ionic liquids and berberine hydrochloride, so the further purification of target compounds and recycling process of the ILs could be avoided. The whole process is very easy to be scaled up and has been practiced for actual herbal sample. • Benzothiazolium ILs were reported in the crystallization for the first time. • A new separation method of IL-induced crystallization was developed. • High separation efficiency could be achieved through simple steps. • Conditions were investigated detailedly and practiced for herbal sample. [ABSTRACT FROM AUTHOR]