Functionalized pyrrolotriazine 1b is a key heterocyclic building block in the synthesis of BMS-690514, a potent anticancer agent. Described herein are our development activities that led to the ...efficient preparation of 1b on a large scale. The key transformations include a selective C-alkylation of an oxalacetate salt with a hydrazonyl bromide to form a 2-hydrazonoethyl-3-oxosuccinate, followed by cyclodehydration to an aminopyrrole. Subsequent deprotection and condensation with formamidine afforded the pyrrolotriazine scaffold. Further elaboration of this core provided the desired pyrrolotriazinyl amine.
Dietary iron and folate are nutrients of great importance during pregnancy because of the role they play to ensure optimal birth outcomes. Dietary intake has been found to decline during the third ...trimester. This study sought to assess the dietary iron and folate intake in the third trimester and pregnancy outcomes of women in their third trimester attending antenatal clinics at Korle-Bu Teaching Hospital. Eighty-one participants at a gestational age of 32 weeks were recruited and monitored until delivery-from May 4, 2020 to July 1 2020-using a consecutive sampling method at the Department of Obstetrics and Gynecology, Korle-Bu Teaching Hospital. Dietary intake information was obtained based on a 52-item quantitative food frequency questionnaire. Daily supplement doses of participants were recorded. Serum concentrations of iron (ferritin) and folate were determined using ELISA microwells. The mean dietary intake of iron and folate was 13.5 ± 8.30 mg and 331.0 ± 114.0 μg, respectively. The mean intake of iron and folic acid supplements was 42.7 ± 48.8 mg and 5.5 ± 11.1 mg, respectively. Most of the participants had serum ferritin and folate levels in the normal range (82.7% and 87.7%, respectively). Almost all the participants had positive birth outcomes, and total dietary iron was a significant predictor of birth outcome (P = 0.041). The majority of pregnant women did not meet the daily recommendation for iron and folate, but adherence to daily supplement intake was good and could have accounted for the positive birth outcomes.
Chronic skin wounds are characterized by poor re-epithelialization, angiogenesis and granulation. Previous work has demonstrated that topical stromal cell-derived growth factor-1 (SDF1) promotes ...neovascularization, resulting in faster re-epithelialization of skin wounds in diabetic mice. However, the clinical usefulness of such bioactive peptides is limited because they are rapidly degraded in the wound environment due to high levels of proteases. Here, we describe the development of a recombinant fusion protein comprised of SDF1 and an elastin-like peptide that confers the ability to self-assemble into nanoparticles. The fusion protein and recombinant human SDF1 showed similar binding characteristics, as indicated by the measured equilibrium dissociation constant (Kd) for the binding of free SDF1 or the fusion protein to the CXCR4 receptor. The biological activity of SDF1-ELP, as measured by intracellular calcium release in HL60 cells was dose dependent, and also very similar to that of free SDF1. In contrast, the biological activity of SDF1-ELP in vivo was significantly superior to that of free SDF1. When applied to full thickness skin wounds in diabetic mice, wounds treated with SDF1-ELP nanoparticles were 95% closed by day 21, and fully closed by day 28, while wounds treated with free SDF1, ELP alone, or vehicle were only 80% closed by day 21, and took 42days to fully close. In addition, the SDF1-ELP nanoparticles significantly increased the epidermal and dermal layer of the healed wound, as compared to the other groups. These results indicate that SDF1-ELP fusion protein nanoparticles are promising agents for the treatment of chronic skin wounds.
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Chronic skin wounds are characterized by poor re-epithelialization, angiogenesis and granulation. Previous work demonstrated that topical stromal cell-derived growth factor-1 (SDF1) promotes ...neovascularization, resulting in faster re-epithelialization of skin wounds in diabetic mice. However, the clinical usefulness of such bioactive peptides is limited because they are rapidly degraded in the wound environment due to high levels of proteases. The goal of this project was to develop a novel fusion protein comprising of SDF1 and an elastin like peptide (ELP), which could be used as a therapeutic alternative to recombinant SDF1, for the treatment of chronic skin wounds. ELPs are derivatives of tropoelastin with repeats of VPGXG, where X can be any natural amino acid except Proline. The dissertation aimed to characterize the physical properties of the SDF1-ELP fusion protein, demonstrate its in vitro and in vivo bioactivity and understand its mechanism of action. We showed that SDF1-ELP conferred the ability to self-assemble into nanoparticles. The fusion protein showed binding characteristics similar to that reported for free SDF1 to the CXCR4 receptor. The biological activity of SDF1-ELP, as measured by intracellular calcium release in HL60 cells was dose dependent, and very similar to that of free SDF1. SDF1-ELP monomers promoted the migration of cells similar to SDF1, and the fusion protein promoted tube formation and capillary-like networks similar to SDF1. In contrast, SDF1-ELP was found to be more stable in elastase and in wound fluid than SDF1. Likewise, the biological activity of SDF1-ELP in vivo was significantly superior to that of free SDF1. When applied to full thickness skin wounds in diabetic mice, wounds treated with SDF1-ELP nanoparticles were 95% closed by day 21, and fully closed by day 28, while wounds treated with free SDF1 and other controls took 42 days to fully close. In addition, the SDF1-ELP nanoparticles increased the amount of vascular endothelial cells, and the epidermal and dermal layer of the healed wound, as compared to the other groups. SDF1-ELP is a promising agent for the treatment of chronic skin wounds.
Stromal cell-derived growth factor-1 (SDF1) is a chemokine that is over-expressed at sites of injury and is believed to play an important role in wound repair. At the cellular level, SDF1 regulates ...the mobilization and trafficking of endothelial progenitors that originate in the bone marrow and functionally contribute to neovascularization and angiogenesis in the wound. Consequently, SDF1 is a potentially interesting therapeutic with the potential to enhance these processes in acute and chronic injuries that otherwise tend to heal poorly, such as spinal cord injury, stroke, myocardial infarction, diabetic skin wounds and acute burns. However, the therapeutic usefulness of SDF1, as many other similar peptide-based growth factors and chemokines, is severely limited due to its short in vivo half-life, as it is rapidly degraded by proteases, which are typically very abundant at the wound site. Several studies have reported methodologies to increase SDF1 in vivo stability by mutating the protease cleavage sites of the molecule. Another approach has been to incorporate the chemokine into biomaterials that shield it from degradation. Yet another approach would be to develop a system that is inherently stable and could be combined with these aforementioned strategies. For example, self-assembled nanoparticles could shield SDF1 (or one of its forms engineered to be more resistant to proteolysis) from proteolysis and then be incorporated into suitable biomaterials. Nanotechnology-based delivery systems have however been used to a very limited extent for SDF1. This paper aims to provide a summary of the various stabilization and delivery methods available for SDF1, some of which have been already used, as well as others that have been used with other bioactive peptides, but would be potentially applicable to SDF1.
The logarithm of the octanol–water partition coefficient, log
P, is a key physicochemical property for both pharmaceutical drugs and agrochemicals. It is also required by legislation as part of the ...physicochemical properties profile for high volume production chemicals. This Letter describes a simple method for determining log
P values (over a wide range from −0.8 to 5.3) for 12 organic weak acids and bases using potentiometric titrations, with octanol or phosphatidyl choline liposomes as the partitioning medium. Such titrations take comparatively little time (about 30–45
min per titration), are easy to implement, and can be carried out with an inexpensive laboratory titrator.
Small glass laboratory reactors are commonly used to determine the kinetics of the individual reaction steps required to synthesize the active pharmaceutical ingredients contained in the typical drug ...dosage form. These reactors are typically assumed by the user to be perfectly well mixed, and have a homogeneous content at all times. In this work a factorial experimental design scheme was used to carry out semi-batch reaction experiments aimed at determining the reactors’ micromixing effectiveness as a function five independent variables, i.e., agitation speed, impeller type, number of baffles, feed location and liquid level. A parallel, competitive fast reaction scheme was used to quantify the mixing effects by experimentally determining the yield,
X
S
of one of the reaction products. In addition, computational fluid dynamics (CFD) was used to predict the flow field in the reactor as a function of the independent variables, and relate it to the reaction yield. The main effects of each of the independent variables on
X
S
, as well as the two-way interactions between the variables, were obtained. Impeller speed, impeller type, and, under specific conditions, the number of baffles were found to affect significantly the mixing effectiveness. The local value of the energy dissipation rate at the feed point was calculated with CFD and found to correlate with
X
S
. Additional experiments were conducted to investigate the effect of scale-up in laboratory units. The results indicate that mixing effectiveness decreases appreciably when the laboratory reactor scale changes from 2000 to 4000
mL. These results could be of significant importance in the evaluation of laboratory data for the organic synthesis of pharmaceuticals.
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