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Did you know that not all types of bacteria in this world are harmful to humans? Some bacteria can be used in the production of cheese, and can even be used to manufacture antibiotics for human use. Dr. Jason Hedges and Dr. Katherine Ryan of the University of British Columbia took a look into finding new ways to produce antibiotics from bacteria. 

Their recent publication in 2019 showed how they were able to convert an amino acid (a building block of proteins) into a modern day antibiotic.

Antibiotics are used to cure bacterial infections by killing bacteria. For example,  an antibiotic called penicillin was used extensively in the 19th century to save thousands of lives.

As Amazing as they Sound, Antibiotics are not a Permanent Solution

The over-usage of antibiotics results in bacteria that can build resistance to them and cause the medication to be ineffective. 

The World Health Organization announced: “A serious threat is no longer a prediction for the future, it is happening right now in every region of the world and has the potential to affect anyone” on development of drug resistant bacteria.

Once a type of bacteria develops a resistance to a specific antibiotic, other antibiotics must be used in its place to treat the infection. 

Nitroimidazoles are a group of antibiotics which have been used for decades. Due to its low resistance by bacteria, it has been used extensively to treat bacteria that have developed a resistance to certain antibiotics.

This is the chemical structure of azomycin. Azomycin is a type of antibiotic that falls under the family of antibiotics labelled nitroimidazoles. It is used to treat drug resistant bacteria.

Diving into the Research

The researchers used bioinformatics, a data analysis tool, to find all previous work that has been done on this topic. Bioinformatic searches are performed on databases such as the NCBI.

They found that back in 1953, azomycin (a type of nitroimidazole) was produced by a strain of bacteria that is found in the soil. The researchers adapted this old method by applying modern techniques to it, in an attempt to produce azomycin in a different strain of soil bacteria called Streptomyces cattleya.

The two researchers aimed to find new ways to synthesize azomycin, and proposed that it could be done by using an amino acid called arginine. Once a pathway connecting arginine to azomycin had been developed, their end goal was to synthesize and extract azomycin in Streptomyces cattleya.

Hedges and Ryan were able to develop a multi-step pathway for the conversion of arginine to azomycin through experimentation. However, they were unable to detect any azomycin in the bacteria itself.

They noted that the bacteria of interest was unable to synthesize azomycin, and a separate drug or antibiotic may have produced in its place.

A simplified overview of converting an amino acid (Arginine) into an antibiotic drug (Azomycin).

A Bright Future

The significance of this research transcends the synthesis of azomycin. Although they failed to detect azomycin in Streptomyces cattleya, their work provides a stepping stone for further research to be conducted. 

This study provides insight on new biosynthetic pathways which is important to those currently in the field of life sciences and pharmacology. 

Furthermore, this study expands people’s knowledge of bacteria engineering and how antibiotics are created.

In the near future, researchers could test their synthetic pathway on other bacteria such as E. coli to determine if azomycin could be produced. This will allow for the production of more antibiotics, or even the discovery of new antibiotics.

Reference:

Hedges, J. B.; Ryan, K. S. In Vitro Reconstitution of the Biosynthetic Pathway to the Nitroimidazole Antibiotic Azomycin. Angewandte Chemie International Edition 2019, 58 (34), 11647–11651.

– Adrian Emata, Vicky Gu, Jackson Kuan, Yicheng Zhu

Cancer is a disease that killed 8.9 million people by 2016, and it is very hard to detect. For someone suffering cancer, they may want to detect it as early as possible so they can be treated. In the past, doctors have to take a patient’s tissue. With naked eyes, the doctor has to search for tiny cancer monsters in this tissue under a microscope, which is like searching a needle in an ocean. Even for highly-experienced doctors, this process is time-consuming and has a high chance of miss-detecting.

Cancer Deaths
(Source: Our World Data)

Now there are radioactive chemicals that can efficiently detect cancer cells. It works like this. There is a blue-colored chew-chew train in these chemicals called a positron, which collides with the red chew-chew train in your body called an electron. When they collide, they annihilate each other and make huge lightning like in a nuclear bomb. These lights are so strong that they can penetrate through your body and be captured by our detecting machine. So you might wonder, how do we know if there are cancer monsters then? Well, the cancer monsters can eat away light, so when the detecting machine receive light from areas of the patient’s body where cancer cell is present, the picture coming out would be much, much darker.

chew-chew trains colliding (source: google)

But here is another problem–––the radioactive chemicals are so dangerous that they can destroy your body, which is also why we make nuclear bombs out of them. Therefore scientists have found types of these chemicals that only explode for a few hours, on top of them is something called Germanium, it is not made in Germany, but you could memorize it that way. It’s not just normal Germanium, but a thin, thin Germanium that is a little lighter than the normal Germanium.
But the problem has not been solved. What if the Germanium jumps around your body and destroys everything? We need a claw that clamps onto this Germanium to transfer it into the patient’s body and hold it in the spot. There used to be many candidates, but they can only function at small ranges of pH outside your body. Now you must be confused; what exactly is pH? Well, think of a pool of sticky bubble gums. These gums are called H. When the pH is low, there are a lot of gums in the pool, so when the claw enters the pool, the gum will stick onto the claw, now the claw surface becomes soft, and the Germanium just slips away. Unfortunately, the human body is such a low pH pool. No claw has been able to hold the playful Germanium under every condition. Surprisingly, Dr. Ovrig just made this new big claw in his lab that would hold onto the Germanium. When they tested it in different pools, even one similar to the human body, the Germanium stayed happily inside the claw. If you are curious about the name of this claw, it’s called Ga(hox).

The researchers then brought this claw into practice. They used the claw and germanium combination on a mouse, and it easily detected cancer monsters in the heart within a short 1 minute. The monsters in the liver and bladder are also exposed after 1 hour. Now, patients no longer have to worry about the long period of cancer examination. Besides, this technique can detect even tiny amounts of cancer monsters. Therefore, even in the very early stage of cancer, the claw-germanium combo can detect cancer and allow treatment before the cancer monster goes rampart.

Reference

Wang, X.; De Guadalupe Jaraquemada-Peláez, M.; Cao, Y.; Pan, J.; Lin, K. S.; Patrick, B. O.; Orvig, C. H2hox: Dual-Channel Oxine-Derived Acyclic Chelating Ligand for 68Ga Radiopharmaceuticals. Inorg. Chem. [Online] 2019, 58, 2275-2285. (Accessed: March 23, 2020).

Responding to a need for scientific literacy in the public, researchers at the Samuel Neaman Institute examine ways to promote chemical literacy among different stakeholders.

The public increasingly encounters with real-life scientific and technological contexts, and scientific professional and chemical educators have realized the need for chemical literacy among the public to understand, and critically evaluate the scientific information they absorb. The University of British Columbia even offers a course, called CHEM 300, which teaches how to communicate scientific knowledge.

Broggan Textbook
(source: thriftbooks)

In an attempt to narrow the gap between the scientific and the non-scientific communities, researchers led by Zehavit Kohen conducted a comprehensive analysis of chemistry education methods most valued by different stakeholders.

The researchers identified four groups, K-12 students, teachers, scientists, and the educated public, from a sample population of 347. The survey divides into two sections, scientific literacy construction, and communication channel types.

According to the study, K-12 students valued cognitive and affective components twice more than scientists or educated adults. Besides, all stakeholders favored open discussions as their communication channel. Mass media dominates the scientific community besides open discussions. Whereas, students use mass media, be available to the public, and share of scientific materials indistinguishably.

Mass Media
(Source: flickr)

Investigating question posts on an ask-a-scientist-type website, the research further discovered that the public’s questions usually concern symbols over processes or systems. The type of information involved in these questions is mostly explanatory.

Data from Zehavit’s article

The results encourage students to gain chemical literacy in real-world contexts through analogies and symbols. The researchers also suggest that scientists should attempt other communication channels since interactive and affective activities on mass media are often challenging.

Reference

Zehavit, K.; Orit, H.; Yehudit J. D. How to promote chemical literacy? On-line question posing and communicating with scientists. Chem. Educ. Res. Pract., 2020, 21, 250

Cancer is complicated, there’s no doubt about that. From its onset to its invasive prevalence, preventing the progression of each stage seems like a never-ending battle. Be that as it may, with the advent of new chemical entities, this fight has become a lot easier.

In 2019, the Orvig group in the University of British Columbia were able to design and create a new molecule with a variety of applications. One of which is in cancer imaging, which is what makes their compound particularly astonishing. Further, the authors have reported that their chemical species is stable in, and is removed quite easily from the body. Though to understand the importance of their findings, it is vital to start at the very beginning.

Dr. Orvig (Top row, left) and his medicinal inorganic chemistry group

Within the realm of diagnostic medicine, imaging is a vital facet. The goal of imaging is to ultimately produce a viable image of the body. Positron emission tomography (PET) is an imaging method used to generate images of the chemical changes that happen in tissue. These scans often rely on the properties of the radiation emitted by a radioactive isotope. In this instance, the radioisotope used is Gallium-68 (⁶⁸Ga), which is a readily available and versatile tracer species. Though, to harness the tracer capabilities of ⁶⁸Ga, it would have to exist in the form of a compound. This is where the Orvig group plays an important role.

They were able to synthesize a ligand with the ability to interact with the ⁶⁸Ga. A ligand is essentially a molecule that can bind to a metal center, forming a metal complex. This leads to the generation of a stable species that can exist in solution and thus can move around the body. What the group was able to show was that this novel ligand had a high affinity for ⁶⁸Ga even at low concentrations. Their ligand is an acyclic hexadentate ligand, named H₂hox. Though the name is inherently complicated, it does make sense once it is explained in some depth.

The Orvig group’s hexadentate chelating ligand

A hexadentate ligand is a ligand that coordinates to the metal center at 6 different positions. What this means is that there are 6 different points on the one molecule that bond with the metal center. Furthermore, the ligand is said to chelate the metal center. This term is generally given to a ligand that binds to a central metal atom at two or more points. Fortunately, this ligand is advantageous in a number of different ways.

The authors have stated that this compound is easy to synthesize, removing a number of potentially challenging synthetic strategies typically associated with ⁶⁸Ga chelating species. Their initial starting materials were also inexpensive and are actually available online. To put this into perspective relative to some of the other ligand synthesis methods, it’s like baking a box cake versus baking a cake from scratch. The former is simple and quite easy to do, while the latter is a lot harder and is a lot more intensive. Ease of synthesis is an important feature, as it can affect the commercial applicability of the chelating ligand. Fortunately, their synthesis strategy is also mild.

What was also found is that their ligand is more stable than other ⁶⁸Ga chelating ligand species. One advantage reported is with respect to acids and bases, where it was found that the complex is actually stable in both. It was found that there exists a single species, [⁶⁸Ga(H₂hox)]⁺, within a pH range of 1-11. Moreover, the group assessed the conditional stability of the complex. Again, these findings reinforce the advantages of their chelating ligand, H₂hox.

Stability studies conducted in the sternum of mice and dynamic imaging PET studies also suggest that their compound is stable in the body and in a vial. This impressive aspect correlates with the enhanced stability of the H₂hox metal complex. It was also removed from the mouse relatively quickly.

As a result of their success, their chelating species surpasses any ligand currently used as a ⁶⁸Ga chelator. Not only have they managed to add to the current library of chelators, but they have also developed a convenient toolkit radiopharmaceutical compound.

Reference:

Wang, X.; De Guadalupe Jaraquemada-Peláez, M.; Cao, Y.; Pan, J.; Lin, K. S.; Patrick, B. O.; Orvig, C. H2hox: Dual-Channel Oxine-Derived Acyclic Chelating Ligand for 68Ga Radiopharmaceuticals. Inorg. Chem. [Online] 2019, 58, 2275-2285. (Accessed: March 23, 2020).

https://pubs.acs.org/doi/abs/10.1021/acs.inorgchem.8b01208

– Akash Panjabi