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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]

Abstract: In this study, we evaluated the effect of reactor type with increased surface area on the fractional precipitation process for the efficient purification of paclitaxel. The three types of reactors (spiral, round, and twisted types) all exhibited higher yields than in cases where the surface area had not been increased at the same precipitation time. It was possible to obtain a high paclitaxel yield of 70% or above after 4h of precipitation. In particular, in the case of the spiral-type reactor, high yields of 64% and 72%, respectively, were obtained 2h and 4h after precipitation, thus exhibiting the highest precipitation efficiency. In addition, it was also possible to dramatically reduce the time necessary for fractional precipitation. On the other hand, the reactor type hardly affected the purity. The size of the paclitaxel precipitate increased with precipitation time. With the spiral-, round-, and twisted-type reactors, it was possible to obtain paclitaxel precipitates with smaller sizes than cases where the surface area had not been increased. [Copyright &y& Elsevier]

Abstract: Huperzine A (HupA) and Huperzine B (HupB) are natural alkaloids existed in Lycopodium plants. They both have potential clinical application for treating Alzheimer''s Disease (AD). For the purpose of better utilizing the limited plant resources, a quick and low cost method to separate and purify HupA and HupB from Huperzia serrata (Thunb. ex Murray) was established in this paper. Low polarity macroporous resin SP850 was selected from eight kinds of resins during initial purification. Trifluoroacetic acid (TFA) was proved to be the best acid modifier reagent among all acids used in our experiment for improving separation. HupA and HupB were baseline separated on a C18 column by preparative high performance liquid chromatography (Preparative HPLC), the optimal gradient mobile phase system contained methanol increasing from 15% (v/v) to 35% (v/v) and 0.1% (v/v) TFA within the water. The purity of HupA and HupB obtained was 99.1% and 98.6%, respectively, and the total recovery for them was 83.0% and 81.8%, respectively. [Copyright &y& Elsevier]

An efficient new alkyne-acetal cyclization procedure has been developed to prepare enantiopure indolizidine building blocks from l-proline and then applied to prepare the Elaeocarpus-derived alkaloids grandisine B and grandisine D in an efficient manner. However, evidence is presented which indicates that grandisine B does not occur naturally but is formed by reaction of grandisine D with ammonia during the extraction/purification process. [ABSTRACT FROM AUTHOR]

Preparative separation of quinolone alkaloids in Evodia rutaecarpa (Juss.) Benth was conducted by high performance counter-current chromatography (HPCCC) with a pair of two solvent systems consisting of n-hexane-methanol-water-acetic acid (2:1:1:0.2, v/v) and (5:4:2:0.1, v/v). Consequently, 31.78 mg 1-methyl-2-nonyl-4 (1H)-quinolone (I), 59.25 mg 1-methyl-2-(6-undecenyl)-4 (1H)-quinolone (II), 333.27 mg evocarpine (III), 101.13 mg 1-methyl-2-(6,9-pentadecadienyl)-4(1H)-quinolone (IV), 132.17 mg dihydroevocarpine (V), and 86.99 mg 1-methyl-2-(10-pentadecenyl)-4(1H)-quinolone (VI) were obtained from 1.3 g of the crude extract. The structures of these compounds were identified by mass spectrometer (MS), nuclear magnetic resonance (1H NMR and 13C NMR). [ABSTRACT FROM AUTHOR]

Abstract: A fast and simple solvent system screening method was established based on average polarity, which was much easier to find a suitable solvent system for high-speed counter-current chromatography (HSCCC) separation. Six alkaloids were separated and purified simultaneously with n-hexane–ethyl acetate–methanol–water (2:5:2:5) on HSCCC in one step. As a result, 4.7mg palmatine, 7.1mg berberine, 0.8mg worenine, 1.5mg epiberberine, 1.9mg coptisine and 0.6mg jatrorrhizine from 20mg Rhizoma coptidis extract were obtained with the purities of 98.5%, 94.1%, 90.4%, 95.5%, 88.4% and 91.1% respectively as determined by high-performance liquid chromatography (HPLC), and they were characterized by MS and 1H NMR. [Copyright &y& Elsevier]

Results of the application of microfine ionites of different classes for sorption methods in the production of versatile drugs are systemized. Kinetic and dynamic parameters of sorption isolation and chemical purification of drugs with participation of ion-exchanger of small graining are discussed; essential advantages of their application allowing intensification of ion-exchange technological processes of drugs production are determined. The review can be useful at elaboration of new sorption methods used for the production of the wide assortment of drugs and, first of all, antibiotics, enzymes, and vitamins. [ABSTRACT FROM AUTHOR]

Dihydromorphone was prepared from morphine in high yield, excellent purity, and low residual metal content. The key steps used palladium on porous glass and a modified Oppenauer oxidation, or Wilkinson's catalyst. [ABSTRACT FROM AUTHOR]

Abstract: A facile and high-yielding route for the synthesis of solasodine from diosgenin is devised. Ring opening of steroidal spiroketal under mild conditions with trifluoroacetyl trifluoromethanesulfonate (TFAT) provides an applicable protocol to prepare key intermediates 4 or 3-Ac-solasodine, which can potentially serve as a platform for the selective functionalization of C(3)–OH and N–H of solasodine. The simple operations without purification by column chromatography make this method suitable to scale up. [Copyright &y& Elsevier]

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]