27 research outputs found
The efficient synthesis of d-xylulose and formal synthesis of Syringolide 1
Wittig reaction and asymmetric dihydroxylation were used as the key steps in the synthesis of D-xylulose, a commercially available but costly carbohydrate. The effects of protecting groups and reactions conditions on asymmetric dihydroxylation are demonstrated. Optically pure D-xylulose was obtained after 4-6 steps from readily available hydroxyacetone and ethylene glycol. The method also involves some other valuable intermediates along the synthesis. Those intermediates were applied in the formal synthesis of Syringolides. A key precursor butenolide to Syringolide 1, the first non-proteinaceous specific elicitors of plant hypersensitive response, was obtained after 3 steps from the intermediate (8–10 steps from hydroxyacetone and ethylene glycol).
Wittig reaction and asymmetric dihydroxylation were used as the key steps in the synthesis of D-xylulose, a commercially available but costly carbohydrate. The effects of protecting groups and reactions conditions on asymmetric dihydroxylation are demonstrated. Optically pure D-xylulose was obtained after 4-6 steps from readily available hydroxyacetone and ethylene glycol. The method also involves some other valuable intermediates along the synthesis. Those intermediates were applied in the formal synthesis of Syringolides. A key precursor butenolide to Syringolide 1, the first non-proteinaceous specific elicitors of plant hypersensitive response, was obtained after 3 steps from the intermediate (8–10 steps from hydroxyacetone and ethylene glycol)
Characterization of Anti-Cancer properties of Fungal Metabolite Ophiobolin A
Background: Ophiobolin A (Oph A) is a secondary metabolite and a phytotoxin produced by the pathogenic fungi Cochliobolus heterostrophus that causes “southern corn leaf blight” disease in maize via modulation of the calcium binding protein calmodulin. Numerous studies have found antiproliferative effects of Ophiobolin A against a variety of cells including bacteria and various cancers including melanoma, glioma and leukemia. Recent studies have shown that OphA induces paraptosis-like cell death in glioblastoma multiforme (GBM) cells via vacuolization of the cytoplasm and enlargement of the mitochondria and endoplasmic reticulum. Notably, unlike apoptosis, paraptosis cell death lacks DNA fragmentation and activation of caspases, creating a possible mechanism for targeted treatment of malignant brain tissue of GBM patients who have GBM cells that are highly resistant to pro-apoptotic treatments. This study aimed to further characterize the effects of this promising anti-cancer agent on glioblastoma (U118 and U87), breast cancer (MCF7 and T47D), neuroblastoma cells (SH-SY5Y) and rat pheochromocytoma cells (PC12). SH-SY5Y and rat PC12 commonly serve as two popular neuron models to test drug toxicity and viability.
Methods: The effects of Ophiobolin A were studied in six cancer cell lines from various tissue types including glioblastoma, breast cancer and rat pheochromocytoma cells: U87, MCF-7, T47D, U118, SH-SY5Y and PC12. Over 4 weeks, cell lines were recovered and cultured until adequate confluence was reached with subculturing and medium refreshing. Once adequate growth and attachment was confirmed with microscopy, cells were seeded in 6-well plates from 100k to 600k and treated with either DMSO or 1 µM of Ophiobolin A. Cell morphology was monitored using inverted microscope at 1 hour, 3 hours, and 6 hours following Ophiobolin A application. Cell survivability was measured using Countess at 6 hours post drug treatment.
Results: Similar to previous studies, OphA was found to induce cell apoptosis and decrease cell numbers in glioblastoma cell lines, U87 and U118. As expected, similar results were observed in the breast cancer line MCF7. The impact of Oph A on cell morphology changes demonstrated a time-dependent manner in both glioblastoma cell lines, showing elongated neuronal bodies and cell processes. In MCF7 cells, we observed increased vacuolization after drug treatment at 1 hour, 3 hours, and 6 hours. Cell survival rates were significantly reduced in all tested cancer cells in compared to the control groups.
Conclusions: Ophiobolin A has been shown to induce cell apoptosis in glioblastoma cells and breast cancer cells. The effect of OphA on healthy cells and the mechanisms underlying the OphA-induced cell apoptosis will be studied
Triterpenoid CDDO-EA Protects from Obesity and Insulin Resistance in an Animal Model of Type 2 Diabetes
Background: Type 2 diabetes (T2D) is characterized by insulin resistance, an impaired response to insulin by cells. Although several medications target insulin sensitivity, they fail to prevent progression to T2D in most high-risk individuals. Oleanolic acid (OA) is a pentacyclic triterpenoid found in plants with unique cardioprotective and anti-diabetic properties. OA can serve as a scaffold to produce synthetic molecules, known as synthetic oleanane triterpenoids (SOs), with enhanced biological activity. Our published findings show that the SO CDDO-EA (2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid-ethyl amide) facilitates translocation of the glucose transporter protein, GLUT4, as a new mechanism of CDDO-EA in regulating glucose metabolism. Thus, we hypothesize that CDDO-EA prevents glucose intolerance to protect from the development of T2D.
Methods: CDDO-EA was synthesized in powder form from OA via CDDO-methyl ester. The final product, CDDO-EA, was analyzed by high performance liquid chromatography (HPLC) and atmospheric pressure ionization/mass spectrometry (APCI-MS) to determine the purity and confirm the exact molecular formula. C57BL/6J mice (6 – 8 weeks old, male) were fed a low- fat diet (LFD, 10% of total calories from fat) or a high-fat diet (HFD, 60% of total calories from fat) with or without CDDO-EA (diet containing 0.04% CDDO-EA) for six weeks. Mice were unrestrained and awake throughout the collection of blood samples, oral glucose tolerance tests (OGTTs), and measurements of body weight. Blood samples were collected via tail snip before the start of experimental feeding and then every two weeks. Glucose levels were measured using a glucometer, and insulin concentrations were measured using an ELISA. Mice were weighed once a week. OGTTs were performed after the six-week experimental feeding.
Results: HPLC showed high purity (\u3e99%) and APCI-MS showed the correct mass and fragmentation pattern of the synthesized CDDO-EA. Mice fed a HFD weighed significantly more than the LFD fed animals by week two, and this was consistent throughout the six-week study. The incorporation of CDDO-EA in the HFD prevented excess weight gain in mice fed a HFD. Further, CDDO-EA decreased energy intake in mice fed a HFD. Serum glucose levels were significantly increased in mice fed only a HFD at 2 weeks and remained significantly increased throughout the rest of the feeding. Serum glucose levels in mice fed a HFD with CDDO-EA did not increase throughout the six-week feeding. In addition, serum insulin levels were significantly higher at 2 weeks and remained significantly higher in mice fed only a HFD compared to mice fed a HFD with CDDO-EA. OGTTs showed that CDDO-EA prevented increased serum glucose and insulin concentrations in mice fed a HFD. The HFD + CDDO-EA group’s glucose levels overlap with the HFD up to the 45 min. timepoint and then significantly decrease to glucose levels before experimental feeding. The HFD+CDDO-EA group insulin levels did not increase significantly and did overlap with the insulin levels before experimental feeding.
Conclusions: CDDO-EA prevents obesity due to decreased food intake and protects from hyperglycemia, hyperinsulinemia, and glucose intolerance. Our findings show for the first time that CDDO-EA has the potential to prevent insulin resistance and T2D
Commentary on Metabolic Health Disparities Affecting the Rio Grande Valley Mexican American Population: Seeking Answers Using Animal Models
Mexican Americans living in the Rio Grande Valley (RGV) have a high prevalence of type 2 diabetes (T2D). The US–Mexico border frontier has a unique blended culture of American lifestyle and Mexican traditions. Some examples of the cultural traditions are the food and the use of herbal medicine, but these traditions are in danger of disappearing after a very short number of generations living in the United States. This article describes the use of animal models under experimental conditions to solve practical questions (etiology or treatment). We performed studies with murine (ie, mouse and rat) models to elucidate the characteristics of medicinal plants that modulate glucose metabolism and inflammation and protect from bone loss, complications related to T2D. The University of Texas Rio Grande Valley researchers also have collaborated with the University of Texas Health Science Center at San Antonio researchers in performing studies in nonhuman primates (NHP) (ie, baboon) to understand the effect of T2D and diets on organs and tissues. With the new knowledge gained from the use of animal models (murine and NHP), new therapies are discovered for the prevention and treatment of T2D and its related complications, such as bone loss and nonalcoholic fatty liver disease, all of which the Mexican American and other human populations are at high risk of developing
SAR Study of Niclosamide Derivatives for Neuroprotective Function in SH-SY5Y Neuroblastoma
Background: Neurodegenerative disease is a debilitating and incurable condition that affects millions of people around the world. The loss of functions or malfunctions of neural cells causes mortality. A proteasome inhibitor, MG132, is well known to cause neurodegeneration in vitro when model neuronal-derived cell lines are exposed to it. Niclosamide, an anthelmintic drug, which has been used for more than 50 years, has recently attracted renewed attention in drug repurposing because it has been found as a good candidate against various diseases in screenings. We recently found that all markers of MG132-induced neuronal cell toxicity, including the accumulation of ubiquitinated proteins, were prevented by niclosamide. In addition, niclosamide was shown to enhance autophagy induced by MG132. Therefore, our results suggest that niclosamide could be a potential neuroprotective agent. In the present study, niclosamide derivatives were synthesized by changing substituents, and their structure-activity relationship (SAR) of the protein ubiquitination induced by MG132 and cell survival signaling pathways for neuroprotective function were studied.
Methods: The 12 niclosamide derivatives were synthesized; mostly, they were prepared from the corresponding benzoic acid and aniline derivatives in the presence of PCl3 in dry xylene under reflux conditions. Niclosamide and the 12 derivatives were dissolved in DMSO. The SH-SY5Y cells were cultured at 5% CO2 at 37 °C in EMEM: Ham’s F-12K medium (1:1), 5% horse serum with penicillin (100 units/mL), and streptomycin (100 μg/mL). The cells were sub-cultured weekly in 60 mm or 100 mm cell culture dishes and used for experiments at 85-90% confluence of the cell monolayer. SH-SY5Y cells were treated with niclosamide or derivatives and 5 μM MG132 for 24 h. The cell lysates were prepared for Western blot assays using anti-ubiquitin antibodies, including ubiquitin, PARP, p-JNK, CHOP, cyclin D, and p53.
Results: Our results indicate that when phenol OH was present, the compounds demonstrated neuroprotective activity, while the presence or absence of Cl (5- or 2’-Cl) showed almost the same neuroprotective effect. 4’-NO2 can be replaced by N3 or CF3 to have neuroprotective activity, whereas NH2 significantly decreased activity. Yet, when there is no substituent at the 4’- position, there is no significant activity. All the bioassays showed that niclosamide and certain derivatives showed a neuroprotective function. While there is no evidence for the direct bindings of niclosamide and their derivatives to any specific proteins, the results indicate that the phenol OH plays an important role, and chloride at 2’-Cl or 5-Cl, does not affect the neuroprotective activity. 4’-NO2 can be replaced with N3 or CF3. However, 4’-NH2 and 4’-H significantly decreased the neuroprotective function. This suggested the substituent at 4’ position plays some role in bindings. The inhibition of p53 expression by these compounds may have a different mechanism of action, and further investigation will be required in the future.
Conclusions: Based on the results of the present study, niclosamide, and its derivatives can be new target molecules for the prevention of Parkinson’s disease (PD) and other neurodegenerative diseases. Also, these findings provide valuable information for the development of the next generation of niclosamide analogs
Ultrasound assisted one-pot synthesis of benzo-fused indole-4, 9-dinones from 1,4-naphthoquinone and α-aminoacetals
A one-pot synthesis of benzo[f]indole-4,9-diones from 1,4-naphthoquinone with α-aminoacetals has been developed. This method provides a straightforward synthesis of benzo[f]indole-4,9-diones via intramolecular nucleophilic attack of aminoquinones to aldehydes under mild reaction conditions. The detailed mechanism was also investigated
Lifestyle Habits Adjustment for Hypertension and Discontinuation of Antihypertensive Agents
Background: Hypertension is one of lifestyle-related diseases, and prevention and effect of reduction pressure can be expected by non-pharmacological interventions. Authors have continued guidance of adjustment for lifestyle to thousands of hypertensive patients, resulting 4.6%-6.1% case could discontinue hypertensive agents. This study enrolled patients with all necessary related data.
Subjects and methods: Subjects were 50 patients with hypertension (M/F: 25/25, age 65.4 ± 8.6 vs. 53.4 ± 6.2 years, BMI 23.4 ± 2.7 vs. 22.3 ± 2.5, respectively), who could discontinued antihypertensive agents. They received consultation and intervention from registered dietitian nutritionists, exercise therapists and nurses.
Results: The comparative results on males and females are as follows: smoking habit was 76% vs. 0%, alcohol intake was 60% vs. 0%, diabetes complication was 16% vs. 8%, and hyperlipidemia was 32% vs. 52%, respectively. These cases showed rare to none incidence of cerebral vascular accident (CVA), coronary heart disease (CHD) and chronic kidney disease (CKD). Consultations in median were 4.0 vs. 4.0 times, median weight reduction was 2.2 kg vs. 1.6 kg and median period withdrawal of the drug was 2.0 years vs. 2.5 years.
Discussion and conclusion: When living adjustment is advised, blood pressure decreases due to behavior change. Our results suggest that these cases have less arteriosclerosis development, which enables withdrawal of medicine. It is necessary to carefully observe the progress whether the antihypertensive drug will be unnecessary or will be restarted. Current results obtained would become the fundamental data in the future, and the adjustment for diet and exercise would be useful for more adequate treatment for hypertension