The Current Status and Perspectives of Delivery Strategy for Boronbased Drugs.

Boron-containing compounds are essential micronutrients for animals and plants despite their low-level natural occurrence. They can strengthen the cell walls of the plants and they play important role in supporting bone health. However, surprisingly, boron-containing compounds are seldom found in pharmaceutical drugs. In fact, there are no inherent disadvantages reported so far in terms of the incorporation of boron into medicines. Indeed, drugs based on boron-containing compounds, such as tavaborole (marked name Kerydin) and bortezomib (trade name Velcade) have been investigated and they are used in clinical treatment. In addition, following the advanced development of boron neutron capture therapy and a new emerging proton boron fusion therapy, more boron-containing medicinals are to be expected. This review discusses the current status and perspectives of delivery strategy for boron-containing drugs.

Study on Purification of Liquiritin by Using Ammonia Extraction and Ceramic Membrane Ultrafiltration Technology / 中国中医药信息杂志

Objective To establish a suitable extraction and purification process line for industrial production of liquiritin. Methods With the extraction rate of liquiritin as index, orthogonal test was used to determine the optimum conditions; with the retention rate of liquiritin and impurity removal rate as the indexes, orthogonal test was used to optimize the best ultrafiltration process parameters. Results The optimum extraction conditions were: 24 times 0.75%ammonia water, extracted three times, each time under 60 min. The liquiritin average extraction rate was 72.3%. The best ultrafiltration process parameters were: 10 nm inorganic ceramic membrane, pressure of 0.12 MPa, temperature of 25 ℃. The liquiritin average retention rate was 98.9%, and the average removal rate of impurity was 23.3%. Conclusion This process has low production cost and good safety, and is suitable for industrial application.

Cross-coupling reaction between arylboronic acids and carboranyl iodides catalyzed by graphene oxide (GO)-supported Pd(0) recyclable nanoparticles for the synthesis of carboranylaryl ketones.

Well-dispersed palladium(0) nanoparticles with small and narrow size distributions were synthesized conveniently on a graphene oxide (GO) surface. The GO-supported nano-Pd(0) was found to be a highly efficient and recyclable catalyst for the carbonylative cross-coupling reaction between arylboronic acids and aryl and carboranyl iodides, respectively. Benzophenone and a series of carboranylaryl ketones, 1-R-2-[C(=O)Ar]-1,2-C2B10H10 (R = H, Me, Ph; Ar = C6H5, C6H4-4-OMe and C6H4-4-F), were synthesized and fully characterized. The catalyst was recyclable at least three times with sustained activity.

Applications and perspectives of boron-enriched nanocomposites in cancer therapy.

Recently, boron compounds have attracted increasing attention both in academic laboratories and in the pharmaceutical industry. Boron, in particular the (10)B isotope, has the unique capability of absorbing a slow neutron to initiate a nuclear reaction with release of energetic particles such as α- and Li-particles, which is not observed in its carbon analogues. The nuclear capture reaction concept has been adopted in radiation therapy and used in boron neutron capture therapy (BNCT). BNCT is a potentially promising treatment for malignant brain tumors as well as other cancers, despite the limitation of a scarcity of neutron sources. There is the need in advanced research centers to construct high boron-containing composites as BNCT agents and develop more efficient drug carriers. This review discusses recent works on the development of boron-based therapeutic nanomaterials as BNCT agents.

Catalytic phenylborylation reaction by iridium(0) nanoparticles produced from hydridoiridium carborane.

Well-dispersed iridium(0) nanoparticles stabilized with the ionic liquid, trihexyltetradecylphosphonium methylsulfonate, [THTdP][MS], have been successfully prepared by reduction of the precursor hydridoiridium carborane, (Ph 3P) 2Ir(H)(7,8- nido-C 2B 9H 11). The iridium nanoparticles were found to be active catalysts for arylborylation, forming boric acids. The activity of the catalyst has been investigated as a function of the activating base, and reaction conditions. The highest yield of 91% was achieved in a microwave reactor using the base, tetra-2-pyridinylpyrazine, in the presence of [THTdP][MS]. The catalytic system could be recycled at least six times with less than a 0.5% loss of activity.

Ruthenium(0) nanoparticle-catalyzed isotope exchange between 10B and 11B nuclei in decaborane(14).

Well dispersed ruthenium(0) nanoparticles, stabilized in the ionic liquid agent, trihexyltetradecylphosphonium dodecylbenzenesulfonate, have been successfully prepared via a reduction reaction of the precursor [CpRuCp*RuCp*]PF6 (Cp* = C5Me5). The ruthenium(0) nanoparticles were shown to catalyze the isotope exchange reaction between 10B enriched diborane and natural abundant B10H14 to produce highly 10B enriched (approximately 90%) decaborane(14) products. The ruthenium(0) nanoparticles were characterized by TEM, XRD, and XPS. The 10B enriched decaborane(14) has been analyzed by Raman spectroscopy, NMR, and high-resolution MS.

Substituted carborane-appended water-soluble single-wall carbon nanotubes: new approach to boron neutron capture therapy drug delivery.

Substituted C(2)B(10) carborane cages have been successfully attached to the side walls of single-wall carbon nanotubes (SWCNTs) via nitrene cycloaddition. The decapitations of these C(2)B(10) carborane cages, with the appended SWCNTs intact, were accomplished by the reaction with sodium hydroxide in refluxing ethanol. During base reflux, the three-membered ring formed by the nitrene and SWCNT was opened to produce water-soluble SWCNTs in which the side walls are functionalized by both substituted nido-C(2)B(9) carborane units and ethoxide moieties. All new compounds are characterized by EA, SEM, TEM, UV, NMR, and IR spectra and chemical analyses. Selected tissue distribution studies on one of these nanotubes, {([Na(+)][1-Me-2-((CH(2))(4)NH-)-1,2-C(2)B(9)H(10)][OEt])(n)(SWCNT)} (Va), show that the boron atoms are concentrated more in tumors cells than in blood and other organs, making it an attractive nanovehicle for the delivery of boron to tumor cells for an effective boron neutron capture therapy in the treatment of cancer.