QUINTAIS IMORTAIS

Lund University. "Plant substance inhibits cancer stem cells." ScienceDaily. ScienceDaily, 27 September 2017. <www.sciencedaily.com/releases/2017/09/170927093304.htm>.

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Compounds found in green tea and red wine may block formation of toxic metabolites

Discovery may pave the way for therapies to treat inborn congenital metabolic disorders

Date: July 2, 2018 Source: American Friends of Tel Aviv University Summary: A new study suggests there is hope of treating certain inborn congenital metabolic diseases -- a hope found in green tea and in red wine.

Green tea.

Credit: © Kittiphan / Fotolia

A new Tel Aviv University study suggests there is hope of treating certain inborn congenital metabolic diseases -- a hope found in green tea and in red wine.

Most people with inherited metabolic disorders are born with a defective gene that results in a critical enzyme deficiency. In the absence of a cure, many patients with inborn congenital metabolic disorders must adhere to a strict and demanding diet their entire lives. This new research finds that certain compounds found naturally in green tea and red wine may block the formation of toxic metabolites.

The research was led by Prof. Ehud Gazit of TAU's Faculty of Life Sciences and his doctoral student Shira Shaham-Niv. It was published in the Nature group journal Communications Chemistry.

The researchers considered two compounds: (1) epigallocatechin gallate, known as EGCG, found naturally in green tea, which has attracted attention within the medical community for its potential health benefits; and (2) tannic acid, found in red wine, which is known to prevent the formation of toxic amyloid structures that cause neurodegenerative disorders such as Alzheimer's and Parkinson's disease.

"In the case of inborn congenital metabolic diseases, the body does not produce a vital metabolic enzyme," Shaham-Niv said. "As a result, metabolites -- substances that are, among other things, the building blocks of DNA and proteins -- accumulate in the body. Such uncontrolled accumulation is toxic and can cause severe developmental and mental disorders.

"Our new study demonstrates once again the ability of nature to produce the best candidate of drugs to treat some of the worst human maladies."

Collectively, this group of disorders constitutes a significant portion of pediatric genetic diseases. The disease phenylketonuria (PKU), which produces the aggregation of the metabolite phenylalanine, is one common inborn metabolic disease. Infants with PKU must adhere to a strict diet free of phenylalanine for the rest of their lives. If they don't, they may face severe debilitating developmental problems.

"But this is an incredibly difficult task, since phenylalanine is found in most of the food products that we consume," Shaham-Niv said. "The avoidance of certain substances is the only way to prevent the debilitating long-term effects of inborn congenital metabolic disorders. We hope that our new approach will facilitate the development of new drugs to treat these disorders."

The new research is based on two previous studies conducted at Prof. Gazit's TAU laboratory. In the first study, phenylalanine was shown to be capable of self-assembly and of forming amyloid structures like those seen in Alzheimer's, Parkinson's and other neurodegenerative diseases. In the second study, by Shaham-Niv, other metabolites that accumulate in other inborn congenital metabolic diseases were also shown to undergo self-assembly processes and form toxic amyloid aggregates.

"Both studies led to an overhaul in the research community's understanding of metabolic diseases," Shaham-Niv said. "In our new study, we examined whether the molecules identified in past studies on Alzheimer's disease and other amyloid diseases, which are known to inhibit the formation of amyloid aggregates, could also help counteract the amyloid formation process of metabolites in metabolic diseases."

The new research focused on EGCG and tannic acid using test tubes and culture cell systems. The two substances were tested on three metabolites related to three innate metabolic diseases: adenine, cumulative tyrosine and phenylalanine. The results were promising. Both tannic acid and EGCG were effective in blocking the formation of toxic amyloid structures. The researchers also used computer simulations to verify the mechanism driving the compounds.

"We are entering a new era of understanding the role and the importance of metabolites in various diseases, including metabolic diseases, neurodegenerative diseases and even cancer," Shaham-Niv concluded. "The tools we have developed are ground-breaking and have tremendous potential to help a wide range of patients in the future."

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Materials provided by American Friends of Tel Aviv University. Note: Content may be edited for style and length.

Journal Reference:

Shira Shaham-Niv, Pavel Rehak, Dor Zaguri, Aviad Levin, Lihi Adler-Abramovich, Lela Vuković, Petr Král, Ehud Gazit. Differential inhibition of metabolite amyloid formation by generic fibrillation-modifying polyphenols. Communications Chemistry, 2018; 1 (1) DOI: 10.1038/s42004-018-0025-z

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American Friends of Tel Aviv University. "Compounds found in green tea and red wine may block formation of toxic metabolites: Discovery may pave the way for therapies to treat inborn congenital metabolic disorders." ScienceDaily. ScienceDaily, 2 July 2018. <www.sciencedaily.com/releases/2018/07/180702094043.htm>.

quinta-feira, 5 de julho de 2018

Panorama | TVE - Boletim - Plantas Medicinais - 2/7/18

Preparação do Oleoleo de Camomila e Alecrim - Estágio em Fitoterapia - ...

quarta-feira, 4 de julho de 2018

Segurelha: condimento e medicinal

Texto:

Marcos Roberto Furlan - Engenheiro Agrônomo - Professor - Faculdade Cantareira e Universidade de Taubaté - UNITAU.
Letícia Fonseca do Pinhal - Ciências Biológicas - bacharelado UNIP - Universidade Paulista.

Ainda pouco conhecida no Brasil, mas famosa em alguns molhos franceses como uns dos "bouquet garni", a segurelha (foto) pertence ao Gênero Satureja e à família Lamiaceae. Por ser tão desconhecida aqui pela maioria da população, pode ser classificada como planta alimentícia não convencional.

Nativa do Mediterrâneo, na Europa é usada desde a antiguidade na culinária, onde faz parte, por exemplo, em tempero para carnes devido ao seu aroma, proveniente de seu óleo essencial. É uma planta interessante para ser cultivada em vasos ou jardineiras devido à sua altura, que alcança no máximo 40 cm. Cada "galhinho" pode gerar muda. Mas exige incidência de luz direta.

Também se destaca como medicinal. Popularmente, a segurelha é consumida na forma de infuso para problemas digestivos, como expectorante, cicatrizante e contra cólicas.

Quanto às pesquisas, Millezi et al. (2014) citam que seu óleo essencial possui carvacrol, cimeno e timol, os quais são responsáveis por sua ação antibacteriana contra a Staphylococcus aureus e Escherichia coli, bactérias relacionadas à diarreias e náuseas. Leandro (2015) observaram que os flavonoides encontrados na segurelha, possuem ação antioxidante testada em patas de ratos, e anti-inflamatório testado na úlcera dos ratos.

Referências

LEANDRO, Raquel. Avaliação do potencial anti-inflamatório, antioxidante e antimicrobiano de extratos de segurelha, salsa e coentros. Faculdade de Ciências e tecnologia, Universidade Nova de Lisboa. Setembro de 2015. https://run.unl.pt/bitstream/10362/16083/1/Leandro_2015.pdf acesso em: 03 Jul. 2018.

MILLEZI, A.f. et al. Caracterização química e atividade antibacteriana de óleos essenciais de plantas condimentares e medicinais contra Staphylococcus aureus e Escherichia coli. Revista Brasileira de Plantas Medicinais, [s.l.], v. 16, n. 1, p.18-24, mar. 2014. FapUNIFESP (SciELO). http://dx.doi.org/10.1590/s1516-05722014000100003.

segunda-feira, 2 de julho de 2018

Coconut Water and Depression

A new target for marijuana

Date: October 16, 2017 Source: Society for Neuroscience Summary: Cellular-level changes to a part of the brain's reward system induced by chronic exposure to the psychoactive component of marijuana may contribute to the drug's pleasurable and potentially addictive qualities, suggests a study in young mice.

Cellular-level changes to a part of the brain's reward system induced by chronic exposure to the psychoactive component of marijuana may contribute to the drug's pleasurable and potentially addictive qualities, suggests a study in young mice published in JNeurosci. The results could advance our understanding of marijuana's effects on the developing brain as the drug's rapidly changing legal status increases its recreational and medical use in the United States.

Drugs of abuse impact the ventral tegmental area (VTA) of the brain, which is rich in dopamine neurons. Using juvenile and adolescent mice, Jeffrey Edwards and colleagues investigated the effects of tetrahydrocannabinol (THC), the chemical in marijuana responsible for its effects on cognition and behavior, on VTA GABA cells, an understudied inhibitory cell type in the reward system that regulates dopamine levels.

The authors found that a week of daily THC injections, but not a single injection, blocked the recovery of synapses onto VTA GABA cells in the mice. This finding suggests that persistent THC may alter the inhibitory function of these cells, increasing dopamine levels and the rewarding features of marijuana. These GABA neurons may represent a promising new target for treatment of cannabis use disorder, a common condition on the rise in the United States.

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Materials provided by Society for Neuroscience. Note: Content may be edited for style and length.

Journal Reference:

Lindsey Friend, Jared Weed, Philip Sandoval, Teresa Nufer, Isaac Ostlund, Jeffrey G. Edwardsa. CB1-Dependent Long-Term Depression in Ventral Tegmental Area GABA Neurons: a Novel Target for Marijuana. The Journal of Neuroscience, 2017; 0190-17 DOI: 10.1523/JNEUROSCI.0190-17.2017

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Society for Neuroscience. "A new target for marijuana." ScienceDaily. ScienceDaily, 16 October 2017. <www.sciencedaily.com/releases/2017/10/171016132754.htm>.

Marijuana use associated with cognitive dysfunction in people with HIV who have substance abuse disorder, study finds

Date: November 1, 2017 Source: Boston University School of Medicine Summary: Marijuana use is associated with cognitive dysfunction in people with HIV infection who have an alcohol or other drug use disorder, according to a new study.

Marijuana use is associated with cognitive dysfunction in people with HIV infection who have an alcohol or other drug use disorder, according to a new study from researchers at Boston University School of Public Health (BUSPH), Boston University School of Medicine (BUSM), and Boston Medical Center (BMC).

While researchers did not detect effects of lifetime cumulative exposure, the study, published in Substance Abuse, showed that more frequent current marijuana use was associated with a measure of cognitive dysfunction on the Medical Outcomes Study HIV Health Survey cognitive function scale.

"People with HIV infection have many reasons to have cognitive dysfunction, from the virus itself to medications for HIV infection and related conditions, particularly as they age," said co-author Richard Saitz, professor and chair of community health sciences at BUSPH, who served as principal investigator on the study. "They also have symptoms like chronic pain and mental health symptoms, and use of marijuana, medically or recreationally, may seem like an option to consider. But at least among people with substance use disorders, it appears to have detrimental effects on cognitive function."

Substance use and substance use disorder are disproportionally common among people living with HIV (PLWH) -- estimated at 40 percent to 74 percent. As PLWH are successfully treated for their infections and are now getting older, information about how alcohol and marijuana might affect their symptoms and physical function is critical to their continued health. Aging with HIV infection is associated with many of the same comorbid health conditions that occur in people without HIV infection. These include cardiovascular diseases and dementia, both of which can be affected by substance use.

"Few, if any, studies have examined the combined effects that alcohol use and marijuana use may have on cognition in PLWH," the authors wrote. "Such an understanding could contribute to efforts to reduce harmful substance use and prevent clinical consequences, particularly in an era in which 'moderate' drinking is at times discussed in terms of possible beneficial effects, and in which marijuana is discussed as a relatively safe and even therapeutic substance."

The researchers conducted cross-sectional regression analyses on 215 HIV-infected adults diagnosed with substance disorder, based on the current Diagnostic and Statistical Manual of Mental Disorders (fourth edition). Participants were part of the Boston Alcohol Research Collaboration on HIV/AIDS cohort, 18 years or older, and had current alcohol or other drug dependence. The study included measures of both current and lifetime alcohol and marijuana use.

There were no effects detected of alcohol or past marijuana exposure on cognitive function, nor did there appear to be any evidence for synergistic effects on cognition. Furthermore, neither alcohol nor marijuana appeared to affect simple tests of memory or attention. The authors postulated that such effects were not detected, even though they are expected at the least with heavy alcohol use, because of multiple other exposures and comorbid health conditions that participants had.

The study was led by Sara Lorkiewicz, who earned her Master of Medical Science at BUSM and is currently a doctoral student at Palo Alto University. The other authors were: Alicia Ventura, director of operations and special projects at BMC; Timothy Heeren, professor of biostatistics at BUSPH; Michael R. Winter, associate director of the Data Coordinating Center at BUSPH; Alexander Y. Walley, associate professor of medicine at Boston University; Meg Sullivan, clinical director of HIV services at Boston Medical Center; and Jeffrey Samet, professor of community health sciences at BUSPH.

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Materials provided by Boston University School of Medicine. Note: Content may be edited for style and length.

Journal Reference:

Sara A. Lorkiewicz, Alicia S. Ventura, Timothy C. Heeren, Michael R. Winter, Alexander Y. Walley, Meg Sullivan, Jeffrey H. Samet, Richard Saitz. Lifetime Marijuana and Alcohol Use, and Cognitive Dysfunction in People with Human Immunodeficiency Virus Infection. Substance Abuse, 2017; DOI: 10.1080/08897077.2017.1391925

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Boston University School of Medicine. "Marijuana use associated with cognitive dysfunction in people with HIV who have substance abuse disorder, study finds." ScienceDaily. ScienceDaily, 1 November 2017. <www.sciencedaily.com/releases/2017/11/171101151215.htm>.

Canola oil linked to worsened memory and learning ability in Alzheimer's

Date: December 7, 2017 Source: Temple University Health System Summary: Canola oil is one of the most widely consumed vegetable oils, yet little is known about its health effects. Now, a study links canola oil consumption in the diet with worsened memory, worsened learning ability and weight gain in mice which model Alzheimer's disease. It's the first study to suggest that canola oil is more harmful than healthful for the brain.

Canola oil is one of the most widely consumed vegetable oils in the world, yet surprisingly little is known about its effects on health. Now, a new study published online December 7 in the journal Scientific Reports by researchers at the Lewis Katz School of Medicine at Temple University (LKSOM) associates the consumption of canola oil in the diet with worsened memory, worsened learning ability and weight gain in mice which model Alzheimer's disease. The study is the first to suggest that canola oil is more harmful than healthful for the brain.

"Canola oil is appealing because it is less expensive than other vegetable oils, and it is advertised as being healthy," explained Domenico Praticò, MD, Professor in the Departments of Pharmacology and Microbiology and Director of the Alzheimer's Center at LKSOM, as well as senior investigator on the study. "Very few studies, however, have examined that claim, especially in terms of the brain."

Curious about how canola oil affects brain function, Dr. Praticò and Elisabetta Lauretti, a graduate student in Dr. Pratico's laboratory at LKSOM and co-author on the new study, focused their work on memory impairment and the formation of amyloid plaques and neurofibrillary tangles in an Alzheimer's disease mouse model. Amyloid plaques and phosphorylated tau, which is responsible for the formation of tau neurofibrillary tangles, contribute to neuronal dysfunction and degeneration and memory loss in Alzheimer's disease. The animal model was designed to recapitulate Alzheimer's in humans, progressing from an asymptomatic phase in early life to full-blown disease in aged animals.

Dr. Praticò and Lauretti had previously used the same mouse model in an investigation of olive oil, the results of which were published earlier in 2017. In that study, they found that Alzheimer mice fed a diet enriched with extra-virgin olive oil had reduced levels of amyloid plaques and phosphorylated tau and experienced memory improvement. For their latest work, they wanted to determine whether canola oil is similarly beneficial for the brain.

The researchers started by dividing the mice into two groups at six months of age, before the animals developed signs of Alzheimer's disease. One group was fed a normal diet, while the other was fed a diet supplemented with the equivalent of about two tablespoons of canola oil daily.

The researchers then assessed the animals at 12 months. One of the first differences observed was in body weight -- animals on the canola oil-enriched diet weighed significantly more than mice on the regular diet. Maze tests to assess working memory, short-term memory, and learning ability uncovered additional differences. Most significantly, mice that had consumed canola oil over a period of six months suffered impairments in working memory.

Examination of brain tissue from the two groups of mice revealed that canola oil-treated animals had greatly reduced levels of amyloid beta 1-40. Amyloid beta 1-40 is the more soluble form of the amyloid beta proteins. It generally is considered to serve a beneficial role in the brain and acts as a buffer for the more harmful insoluble form, amyloid beta 1-42.

As a result of decreased amyloid beta 1-40, animals on the canola oil diet further showed increased formation of amyloid plaques in the brain, with neurons engulfed in amyloid beta 1-42. The damage was accompanied by a significant decrease in the number of contacts between neurons, indicative of extensive synapse injury. Synapses, the areas where neurons come into contact with one another, play a central role in memory formation and retrieval.

"Amyloid beta 1-40 neutralizes the actions of amyloid 1-42, which means that a decrease in 1-40, like the one observed in our study, leaves 1-42 unchecked," Dr. Praticò explained. "In our model, this change in ratio resulted in considerable neuronal damage, decreased neural contacts, and memory impairment."

The findings suggest that long-term consumption of canola oil is not beneficial to brain health. "Even though canola oil is a vegetable oil, we need to be careful before we say that it is healthy," Dr. Praticò said. "Based on the evidence from this study, canola oil should not be thought of as being equivalent to oils with proven health benefits."

The next step is to carry out a study of shorter duration to determine the minimum extent of exposure necessary to produce observable changes in the ratio of amyloid beta 1-42 to 1-40 in the brain and alter synapse connections. A longer study may be warranted in order to determine whether canola oil also eventually impacts tau phosphorylation, since no effects on tau were observed over the six-month exposure period.

"We also want to know whether the negative effects of canola oil are specific for Alzheimer's disease," Dr. Praticò added. "There is a chance that the consumption of canola oil could also affect the onset and course of other neurodegenerative diseases or other forms of dementia."

The research was funded in part by a grant from the Wanda Simone Endowment for Neuroscience.

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Materials provided by Temple University Health System. Note: Content may be edited for style and length.

Journal Reference:

Elisabetta Lauretti, Domenico Pratic&#2013265922;. Effect of canola oil consumption on memory, synapse and neuropathology in the triple transgenic mouse model of Alzheimer’s disease. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-17373-3

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Temple University Health System. "Canola oil linked to worsened memory and learning ability in Alzheimer's." ScienceDaily. ScienceDaily, 7 December 2017. <www.sciencedaily.com/releases/2017/12/171207141624.htm>.

Medical marijuana for children with cancer? What providers think

Date: December 12, 2017 Source: Ann & Robert H. Lurie Children's Hospital of Chicago Summary: Most providers willing to consider medical marijuana use in children with cancer, but those with legal eligibility to certify are less likely to approve.

A study published in Pediatrics examined interdisciplinary provider perspectives on legal medical marijuana use in children with cancer. It found that 92 percent of providers were willing to help children with cancer access medical marijuana. However, providers who are legally eligible to certify for medical marijuana were less open to endorsing its use.

While nearly a third of providers received one or more requests for medical marijuana, the lack of standards on formulations, dosing and potency was identified as the greatest barrier to recommending it. These findings reflect survey responses from 288 providers in Illinois, Massachusetts and Washington.

"It is not surprising that providers who are eligible to certify for medical marijuana were more cautious about recommending it, given that their licensure could be jeopardized due to federal prohibition," said co-author Kelly Michelson, MD, Critical Care physician at Ann & Robert H. Lurie Children's Hospital of Chicago, Associate Professor of Pediatrics and Director of the Center for Bioethics and Medical Humanities at Northwestern University Feinberg School of Medicine. "Institutional policies also may have influenced their attitudes. Lurie Children's, for example, prohibits pediatric providers from facilitating medical marijuana access in accordance with the federal law, even though it is legal in Illinois."

Pediatric oncology providers received frequent requests for medical marijuana for relief of nausea and vomiting, lack of appetite, pain, depression and anxiety. Most providers considered medical marijuana more permissible for use in children with advanced cancer or near the end of life than in earlier stages of cancer treatment. This is consistent with the current American Academy of Pediatrics (AAP) position that sanctions medical marijuana use for "children with life-limiting or seriously debilitating conditions." Only 2 percent of providers reported that medical marijuana was never appropriate for a child with cancer.

The majority of providers (63 percent) were not concerned about substance abuse in children who receive medical marijuana. Their greatest concern was absence of standards around prescribing medical marijuana to children with cancer.

"In addition to unclear dosage guidelines, the lack of high quality scientific data that medical marijuana benefits outweigh possible harm is a huge concern for providers accustomed to evidence-based practice," said Michelson. "We need rigorously designed clinical trials on the use of medical marijuana in children with cancer."

Story Source:

Materials provided by Ann & Robert H. Lurie Children's Hospital of Chicago. Note: Content may be edited for style and length.

Journal Reference:

Prasanna Ananth, Clement Ma, Hasan Al-Sayegh, Leah Kroon, Victoria Klein, Claire Wharton, Elise Hallez, Ilana Braun, Kelly Michelson, Abby R. Rosenberg, Wendy London, Joanne Wolfe. Provider Perspectives on Use of Medical Marijuana in Children With Cancer. Pediatrics, 2017; e20170559 DOI: 10.1542/peds.2017-0559

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Ann & Robert H. Lurie Children's Hospital of Chicago. "Medical marijuana for children with cancer? What providers think: Most providers willing to consider medical marijuana use in children with cancer." ScienceDaily. ScienceDaily, 12 December 2017. <www.sciencedaily.com/releases/2017/12/171212091039.htm>.

Marijuana may help HIV patients keep mental stamina longer

Date: December 12, 2017 Source: Michigan State University Summary: A chemical found in marijuana, known as tetrahydrocannabinol, or THC, has been found to potentially slow the process in which mental decline can occur in up to 50 percent of HIV patients, says a new study.

A chemical found in marijuana, known as tetrahydrocannabinol, or THC, has been found to potentially slow the process in which mental decline can occur in up to 50 percent of HIV patients, says a new Michigan State University study.

"It's believed that cognitive function decreases in many of those with HIV partly due to chronic inflammation that occurs in the brain," said Norbert Kaminski, lead author of the study, now published in the journal AIDS. "This happens because the immune system is constantly being stimulated to fight off disease."

Kaminski and his co-author, Mike Rizzo, a graduate student in toxicology, discovered that the compounds in marijuana were able to act as anti-inflammatory agents, reducing the number of inflammatory white blood cells, called monocytes, and decreasing the proteins they release in the body.

"This decrease of cells could slow down, or maybe even stop, the inflammatory process, potentially helping patients maintain their cognitive function longer," Rizzo said.

The two researchers took blood samples from 40 HIV patients who reported whether or not they used marijuana. Then, they isolated the white blood cells from each donor and studied inflammatory cell levels and the effect marijuana had on the cells.

"The patients who didn't smoke marijuana had a very high level of inflammatory cells compared to those who did use," Kaminski said. "In fact, those who used marijuana had levels pretty close to a healthy person not infected with HIV."

Kaminski, director of MSU's Institute for Integrative Toxicology, has studied the effects of marijuana on the immune system since 1990. His lab was the first to identify the proteins that can bind marijuana compounds on the surface of immune cells. Up until then, it was unclear how these compounds, also known as cannabinoids, affected the immune system.

HIV, which stands for human immunodeficiency virus, infects and can destroy or change the functions of immune cells that defend the body. With antiretroviral therapy -- a standard form of treatment that includes a cocktail of drugs to ward off the virus -- these cells have a better chance of staying intact.

Yet, even with this therapy, certain white blood cells can still be overly stimulated and eventually become inflammatory.

"We'll continue investigating these cells and how they interact and cause inflammation specifically in the brain," Rizzo said. "What we learn from this could also have implications to other brain-related diseases like Alzheimer's and Parkinson's since the same inflammatory cells have been found to be involved."

Knowing more about this interaction could ultimately lead to new therapeutic agents that could help HIV patients specifically maintain their mental function.

"It might not be people smoking marijuana," Kaminski said. "It might be people taking a pill that has some of the key compounds found in the marijuana plant that could help."

Story Source:

Materials provided by Michigan State University. Note: Content may be edited for style and length.

Journal Reference:

Michael D. Rizzo, Robert B. Crawford, Joseph E. Henriquez, Yasser Aldhamen, Peter Gulick, Andrea Amalfitano, Norbert E. Kaminski. HIV-infected cannabis users have lower circulating CD16 monocytes and IP-10 levels compared to non-using HIV patients. AIDS, 2017; 1 DOI: 10.1097/QAD.0000000000001704

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Michigan State University. "Marijuana may help HIV patients keep mental stamina longer." ScienceDaily. ScienceDaily, 12 December 2017. <www.sciencedaily.com/releases/2017/12/171212092100.htm>.

Synthesis of opium alkaloids using electric current

A selective electrochemical reaction enables the synthesis of thebaine and offers a solution to a long-standing synthetic challenge

Date: June 28, 2018 Source: Johannes Gutenberg Universitaet Mainz Summary: Researchers have mastered a nearly 50-year-old challenge of electrosynthetic chemistry -- the electrochemical synthesis of thebaine.

Researchers at Johannes Gutenberg University Mainz (JGU) have mastered a nearly 50-year-old challenge of electrosynthetic chemistry, namely the electrochemical synthesis of thebaine. The chemists had set themselves this difficult task within the framework of a collaboration with the University of Münster.

Thebaine is a component of the latex of the opium poppy and is named after the old designation of Luxor, i.e., the Ancient Egyptian city of Thebes. This opium alkaloid is the biosynthetic precursor of codeine and morphine and serves as the starting material for the industrial production of important pharmaceuticals, such as oxycodone or naloxone. The key step in the biosynthesis of thebaine, codeine, and morphine involves a reaction known as oxidative coupling. For decades, researchers have been trying to mimic this transformation in the laboratory. However, this oxidative coupling represents a considerable challenge because it can result in the formation of four different products, only one of which can be further converted into thebaine. Hence, in order to efficiently mimic this naturally occurring process, a highly selective reaction is mandatory.

For decades, chemists have attempted to accomplish a biomimetic synthesis of thebaine using conventional oxidants. However, large quantities of these often toxic reagents were required and undesired coupling products were obtained in most cases. Electrochemistry is a technique that involves the transfer of electrons to or from molecules on the surface of electrodes immersed in a solution. Using this method, it is possible to perform reagent-free oxidations. In fact, these environmentally benign processes only require electric current and avoid the production of chemical waste. So far, electrochemistry did not provide coupling products which could be transformed into thebaine, and its electrochemical synthesis remained a challenging task.

Alexander Lipp and Professor Till Opatz from the Institute of Organic Chemistry at JGU have now solved this long-standing problem. Their approach involved astute modification of the starting materials used in the oxidative coupling. With this, they have also paved the way for the future electrochemical synthesis of further opium alkaloids. Other participants involved in the project were Professor Siegfried R. Waldvogel, also from the Institute of Organic Chemistry at Mainz University, and Professor Hans J. Schäfer from the University of Münster. The project was undertaken under the aegis of the Advanced Lab for Electrochemistry and Electroorganic Synthesis (ELYSION), financed by the Carl Zeiss Foundation.

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Materials provided by Johannes Gutenberg Universitaet Mainz. Note: Content may be edited for style and length.

Journal Reference:

Alexander Lipp, Dorota Ferenc, Christoph Gütz, Mario Geffe, Nina Vierengel, Dieter Schollmeyer, Hans J. Schäfer, Siegfried R. Waldvogel, Till Opatz. A Regio- and Diastereoselective Anodic Aryl-Aryl Coupling in the Biomimetic Total Synthesis of (−)-Thebaine. Angewandte Chemie International Edition, 2018; DOI: 10.1002/anie.201803887

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