A simplified methodology for the activation of organic charcoal.

One in three people globally are challenged to live on hazardous, unsanitary water, and this relates to higher risks of death and development of diseases. According to scientific research, activated charcoal can be used to clean water contaminants to help make water safer.•Carbonization: this study demonstrates an inexpensive method of producing activated charcoal that can be performed in any setting using locally available biomass materials.•Activation: thermal air oxidation between moderate temperatures of 450-550 °C. Our data indicate that this technique produces charcoal with an adsorptive capacity near to that of commercial-grade charcoal as demonstrated by spectrophotometric analysis. This simple approach to charcoal activation may benefit rural communities where sources of sanitary water are low or nonexistent.

Synthesis and Microbiological Evaluation of Novel Tetracyclic Fluoroquinolones.

Conformationally constrained tetracyclic fluoroquinolones (FQs) were synthesized and profiled for their microbiological spectrum. The installation of a seven-membered ring between the pyrrolidine substituents and the C8 position on the FQ core scaffold resulted in a remarkable enhancement of microbiological potency toward both Gram-positive and Gram-negative bacteria. Focused optimization of seven-membered ring composition, stereochemistry, and amine placement led to the discovery of the two lead compounds that were selected for further progression.

Advances in the discovery of novel antibacterial agents during the year 2002.

The development of bacterial resistance is a significant problem in the treatment of infection, and the importance of research directed toward the discovery of novel agents to treat infections cannot be underestimated. In the past, discovery programs have focused on modification of natural products or existing classes of marketed antibacterial agents. A significant period of time lapsed between the introduction of the nalidixic acid-based quinolones and the next novel antibacterial agent (Zyvox). However, the advent of the "genomics era" has provided a wealth of new targets that afford the opportunity to discover novel antibacterial agents. This review reports on the state of antibacterial research directed toward the development of novel antibacterial agents with novel mechanisms of action for the calendar year, 2002. While variations on existing drug classes continue to appear, we have chosen to limit our discussion to novel classes of antibacterial agents which have not yet been marketed.

Probing the SAR of dEpoB via chemical synthesis: a total synthesis evaluation of C26-(1,3-dioxolanyl)-12,13-desoxyepothilone B.

A practical total synthesis of 26-(1,3-dioxolanyl)-12,13-desoxyepothilone B (26-dioxolanyl dEpoB) was accomplished in a highly convergent manner. A novel sequence was developed to produce the vinyl iodide segment 17 in high enantiomeric excess, which was used in a key B-alkyl Suzuki merger. Subsequently, a Yamaguchi macrocyclization formed the core lactone, while a selective oxidation and a late stage Noyori acetalization incorporated the dioxolane functionality. Sufficient amounts of synthetic 26-dioxolane dEpoB were produced using this sequence for an in vivo analysis in mice containing xenograft CCRF-CEM tumors.

Sequential Ketyl-Olefin Coupling/beta-Elimination Reactions Mediated by Samarium(II) Iodide.

Samarium(II) iodide (SmI(2)) has been employed in an intramolecular sequential ketyl-olefin coupling/beta-elimination reaction. The overall process results in the net addition of an alkenyl species to a ketone carbonyl. This novel protocol for the intramolecular delivery of an alkenyl moiety avoids the basic reaction conditions typical of nucleophilic additions that are mediated by alkenylmagnesium halides and alkenyllithium reagents. A high degree of stereocontrol is imparted in the SmI(2)-mediated process as a result of the excellent facial selectivity conveyed in the initial ketyl-olefin coupling reaction. The relative asymmetric induction engendered in these addition reactions is complementary to more traditional nucleophilic addition reactions in that the alkenyl group is directed to the carbonyl center by an attached tether.

Sequenced Reactions with Samarium(II) Iodide. Sequential Nucleophilic Acyl Substitution/Ketyl Olefin Coupling Reactions for the Preparation of Oxygen Heterocycles.

Samarium(II) iodide has been employed to promote a sequential intramolecular nucleophilic acyl substitution/intramolecular ketyl olefin coupling cyclization sequence to provide bicyclic, tricyclic, and spiro-fused oxygen heterocycles in excellent yield and with high diastereoselectivity.

Conjugate Addition Reactions Mediated by Samarium(II) Iodide.

Samarium(II) iodide in conjunction with a catalytic low-valent transition metal species has been employed to promote the conjugate addition reaction of primary and secondary alkyl halides onto alpha,beta-unsaturated esters and amides. The method has been determined to be quite general and hence has been extended to the cyclization reactions of alkyl halides onto alpha,beta-unsaturated lactones, lactams, and nitriles. The cyclization reactions described herein provide a very general approach to the synthesis of functionalized carbocycles from simple acyclic precursors with excellent diastereoselectivity and under very mild reaction conditions.