SOUTHWESTRETORT
SEVENTY-SEVENTH YEAR
September 2024
Published for the advancement of Chemists, Chemical Engineers and Chemistry in this area published by
The Dallas-Fort Worth Section, with the cooperation of five other local sections of the American Chemical Society in the Southwest Region.
Vol. 77 (1) September 2024
Editorial and Business Offices: Contact the Editor for subscription and advertisement information.
Editor: Connie Hendrickson: retort@acsdfw.org
Copy and Layout Editor: Lance Hughes: hugla64@gmail.com
Business Manager: Martha Gilchrist: Martha.Gilchrist@tccd.edu
The Southwest Retort is published monthly, September through May, by the Dallas-Ft. Worth Section of the American Chemical Society, Inc., for the ACS Sections of the Southwest Region.
2023 DFW Section Officers
Chair: Rajani Srinivasan
Chair-elect: Denise Lynn Merkle
Past Chair: Michaela C. Stefan
Treasurer: Martha Gilchrist
Secretary: Trey Putnam
Councilors:
MaryAnderson
Kirby Drake
Linda SchultzR
Rebecca Weber
Alternate Councilors:
Michael Bigwood
Daniela Hutanu
Danny Tran
Separating viruses from saliva with sound waves for therapeutic studies From the ACS Press Room
“Acoustofluidic Virus Isolation via Bessel Beam Excitation Separation Technology”
ACS Nano
Developing antiviral therapeutics and vaccines requires close study of the viruses that cause disease. But how can these small germs be isolated from complex biological samples like saliva? Researchers in ACS Nano describe a platform that uses sound waves as acoustic tweezers to sort viruses from other compounds in a liquid. In demonstrations, the method quickly and accurately separates viruses from large and small particles in human saliva samples.
Researchers use acoustic tweezers to pluck out coronaviruses from saliva samples in a new lab-on-a-chip device that could help scientists study viral diseases. abu_zena/ Shutterstock.com
Isolating, identifying and genetically sequencing a virus provides important information to scientists about how it causes disease and how to develop effective therapeutics. Current methods for separating viruses from other particles in biological samples
include time-consuming ultracentrifugation and cell culture procedures. To speed up and simplify the process, Luke Lee and Tony Jun Huang looked to acoustofluidics: a technology that uses sound waves to sort particles by size in a liquid. They chose a specific type of sound wave, called a Bessel beam, because it can be tuned to sort specific nanosized particles, and multiple waves remain tightly focused over long distances like a pair of tweezers.
The Bessel beam excitation separation technology (BEST) platform that Lee, Huang and colleagues developed consists of a rectangular chip with a sample-loading inlet at one end and separate virus and waste outlets at the other end. Two acoustic Bessel beams were applied across the chip, perpendicular to the sample flow. By tuning the beams’ wavelengths, the system sorted particles of different sizes:
• Large particles larger than 150 nanometers (nm) in diameter were trapped on the chip.
• Small particles smaller than 50 nm left through the waste outlet.
• Viruses of intermediate sizes (50 to 150 nm) were collected via the virus outlet.
The team tested the BEST platform on human saliva samples loaded with SARS-CoV2. Liquid collected from the chip’s virus outlet contained 90% of viral genetic material, while liquid from the waste outlet contained no viral genetic material, showing that the platform successfully isolated the virus. The
Continued on Page 13
From the ACS Press Room
How fish guts might play a role in future skin care products
“Collagenase and Tyrosinase Inhibitory Compounds from Fish Gut Bacteria Ruegeria lantca and Pseudoalteromonas neustonica”
ACS Omega
There are some pretty strange ingredients in cosmetics and skin care products. One example is snail mucin also known as snail slime which is used for its moisturizing and antioxidant properties. But researchers reporting in ACS Omega might have found something even weirder to put on your face: molecules made by fish gut bacteria. In cultured cells, the compounds had skinbrightening and anti-wrinkle properties, making them potential ingredients for your future skin care routine.
Though fish guts might seem like the absolute last place to look for cosmetic compounds, it’s not a completely far-fetched idea. Many important drugs have been found in bizarre places famously, penicillin’s antibiotic properties were discovered after a failed experiment got moldy. More recently, the brain cancer drug candidate Marizomib was derived from microbes unearthed in marine sediments at the bottom of the ocean. Two potentially untapped sources of new compounds could be the gut microbes of the red seabream and the blackhead seabream, fish found in the western Pacific Ocean. Although these microbes were first identified in 1992 and 2016, respectively, no studies have been performed on the compounds they make. So, Hyo-Jong Lee and Chung Sub
Kim wanted to see if these bacteria produce any metabolite compounds that could have cosmetic benefits.
Compounds identified in the gut microbes of the red seabream could be useful in future skin care products. Irina Kvyatkovskaya/ Shutterstock.com
The team identified 22 molecules made by the gut bacteria of the red seabream and blackhead seabream. They then evaluated each compound’s ability to inhibit tyrosinase and collagenase enzymes in lab-grown mouse cells. (Tyrosinase is involved in melanin production, which causes hyperpigmentation in aging skin. Collagenase breaks down the structural protein collagen, causing wrinkles.) Three molecules from the red seabream bacteria inhibited both enzymes the best without damaging the cells, making them promising anti-wrinkle and skin-brightening agents for future cosmetic products.
The authors acknowledge funding from the Marine Biotechnology Program of the Ministry of Oceans and Fisheries, the National Research Foundation of Korea, the Technology Development Program of the Ministry of Small and Medium Enterprises and Startups, Sungkyunkwan University and the BK21 FOUR program of the Ministry of Education of Korea.
From the ACS Press Room
Levels of one ‘forever chemical’ are increasing in groundwater, study finds
“A 60-Year Increase in the UltrashortChain PFAS Trifluoroacetate and Its Suitability as a Tracer for Groundwater Age”
Environmental Science & Technology Letters
Rain and water in ponds and lakes slowly seeps into the soil, moving through minute cracks to refill underground aquifers. Perand polyfluoroalkyl substances (PFAS), often described as forever chemicals, can tag along into groundwater that’s later removed for drinking. Researchers in ACS’ Environmental Science & Technology Letters analyzed water from over 100 wells in Denmark for one particularly persistent PFAS: trifluoroacetate. They report steadily increasing levels of the forever chemical in recent decades.
Groundwater in Denmark has had increasing trifluoroacetate levels since the 1960s, with greater rates of deposition since 2000.
Andrii Salomatin/Shutterstock.com
Trifluoroacetate forms when fluorinated gases, such as refrigerants, and fluorinated pesti-
cides partially degrade in the environment. Water passing through air and soil picks up trifluoroacetate, transporting the persistent and mobile compound into groundwater aquifers. However, potable groundwater sources haven’t been widely tested for trifluoroacetate because there isn’t a regulatory limit for it beyond the European Environment Agency’s (EEA) limit on total PFAS in drinking water of 0.5 parts per billion (ppb). So, Christian Albers and Jürgen Sültenfuss wanted to thoroughly assess groundwater in Denmark for this contaminant, looking for potential changes in the past 60 years.
The researchers collected samples from 113 groundwater monitoring wells around Denmark. They analyzed the samples for trifluoroacetate and, using an established tritium-helium isotope method, calculated how long ago the water entered the underground aquifers. Overall, their data showed a trend of increasing trifluoroacetate concentrations since the 1960s. Specifically, groundwater from:
• Before 1960 had unmeasurable levels.
• 1960 to 1980 contained 0.06 ppb on average.
• 1980 to 2000 contained 0.24 ppb on average.
• 2000 to the 2020s contained 0.6 ppb on average, which exceeds the EEA’s total PFAS limit in drinking water.
The researchers attribute concentration differences within time periods to changing atmospheric deposition, plant uptake and local
Continued on page 13
From the ACS Press Room
Scientists use magnetic nanotech to safely rewarm frozen tissues for transplant
“Magnetic-Nanorod-Mediated Nanowarming with Uniform and Rate-Regulated Heating”
Nano Letters
Every day, people die waiting for an organ transplant. Time is at a premium, not just for those awaiting organs, but also for the organs themselves, which can deteriorate rapidly during transportation. Looking to extend the viability of human tissues, researchers report in ACS’ Nano Letters their efforts to facilitate completely freezing, rather than cooling and then thawing, potentially life-saving organs. They demonstrate a magnetic nanoparticle’s successful rewarming of animal tissues.
As of August 2024, more than 114,000 people are on the U.S. national transplant waiting list, according to the Organ Procurement and Transplantation Network, and about 6,000 annually will die before receiving an organ transplant. One reason is the loss of organs in cold storage during transportation when delays cause them to warm prematurely. Methods have been developed to quickly freeze organs for longer-term storage without risking damage from ice crystal formation, but ice crystals can also form during warming. To address this problem, Yadong Yin and colleagues advanced a technique known as nanowarming, pioneered by collaborator John Bischof, to employ magnetic nanoparticles and magnetic fields to thaw frozen tissues rapidly, evenly and safely. Recently, Yin and a team developed magnetic nanoparticles effectively extremely tiny
bar magnets that, when exposed to alternating magnetic fields, generated heat. And that heat rapidly thawed animal tissues stored at -238 degrees Fahrenheit (-150 degrees Celsius) in a solution of the nanoparticles
A new method to freeze and safely rewarm organs and tissues could extend the time frame around potentially life-saving transplants.
Maxx-Studio/ Shutterstock.com
and a cryoprotective agent. The researchers worried, however, that uneven distribution of the nanoparticles within the tissues might trigger overheating where the particles congregated, which could lead to tissue damage and toxicity from the cryoprotective agent at elevated temperatures.
To reduce these risks, the researchers have continued their investigation, working on a two-stage approach that more finely controls nanowarming rates. They describe this process in the new Nano Letters study:
• Cultured cells or animal tissues were immersed in a solution containing mag
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From the ACS Press Room
Videos
Don't drink raw milk. But what about raw milk cheese? (video)
A lot of people on the internet have been saying to drink raw milk. This is a bad idea a particularly bad one actually. Why is it such a bad idea to consume raw milk and can you eat raw milk without even knowing it via cheese. That’s when things get complicated.
https://youtu.be/SYou3cHzmvc
How a retracted paper affected the course ofAlzheimer’s research (video)
In June 2024, a landmark Alzheimer's research paper was retracted due to fraud allegations. Did we waste billions of dollars and thousands of hours of scientists’ time? Maybe not. There are now two potentially helpful drugs on the market targeting the subject of the paper: amyloid beta. This video breaks down the amyloid-beta hypothesis, the fraud itself and where we go from here.
https://www.youtube.com/watch?v=blQY0RQ2vC8
From the ACS Press Room
Why dinosaur collagen might have staying power
“Pauli Exclusion by n→π* Interactions: Implications for Paleobiology”
ACS Central Science
Dinosaurs continue to fascinate people, but that’s not their only enduring quality: Collagen in their skeletons remains intact for millions of years, despite containing chemical bonds that should only persist for about 500 years. Now, scientists report in ACS Central Science that the unique tenacity of this protein may result from a molecular structure that shields these vulnerable bonds from attack by water that’s present in the environment.
Ton Bangkeaw/Shuttestock.com
Uncovering the secret behind the long life of collagen in dinosaur bones could help in designing other durable compounds.
Collagen is the most abundant protein in animals. It’s found in skin and connective tissues, such as cartilage and bones. Fragments of collagen have been extracted from the bones of 68-million-year-old fossils of Tyrannosaurus rex and may have even
been detected in the skeleton of a 195million-year-old Lufengosaurus. Collagen consists of protein strands chains of amino acids that form triple helices. Much like a rope, the helices in turn weave together to form a strong fibrous material. When exposed to water, the peptide bonds that connect amino acids normally break down in a process known as hydrolysis. But when peptides are incorporated in collagen, that destructive process doesn’t take place. Various explanations have been proposed, but Ron Raines and colleagues felt those theories were missing a physical and chemical basis for the resistance of peptide bonds in collagen like that preserved in ancient dinosaur bones. The team set out to fill in the missing links.
Using experimental and computational methods, the researchers examined the behavior of small-molecule mimics of collagen peptides. In particular, they studied the interactions between the molecules’ acyl groups, which each contain a carbon atom double bonded to an oxygen atom. They found that each acyl group partially shares its electrons with a neighboring acyl group. These results suggest that such interactions protect every peptide bond in a collagen triple helix from hydrolysis, and therefore the structure is able to stay intact. The researchers say lessons from the stability conferred by these interactions could help guide the design of other exceptionally long-lived materials.
The authors acknowledge funding from the National Institutes of Health.
From the ACS Press Room
Getting the stink out of smoke-tainted wine
“Amelioration of Smoke Taint in Wine via Addition of Molecularly Imprinted Polymers During or After Fermentation”
Journal of Agricultural and Food Chemistry
Wildfires can damage crops, even if flames come nowhere near the plants. One outcome can be an unpleasant flavor and smell of wine that is made from grapes exposed to smoke. But researchers report in ACS’ Journal of Agricultural and Food Chemistry that they have developed a way to lessen this smoke taint to improve the palatability of the wine.
Volatile compounds are responsible for many of the appealing aromas and flavors of food and beverages, including wine. These compounds come from the grapes themselves, as well as during the fermentation and aging processes. But not all volatile compounds present in wine are desirable: Some, produced by bacteria or yeast, smell like nail polish remover, rotten eggs, burnt rubber or onions. And if grapes absorb volatile com-
pounds from wildfires, the resulting wine can take on a disagreeable smoky, ashy or medicinal character that compromises quality and reduces value. Producers use a variety of adsorbents to remove these unpleasant compounds from wine. However, these techniques can also remove desirable constituents that contribute to the beverage’s color, bouquet and flavor. So Kerry Wilkinson and colleagues decided to investigate whether the volatile compounds responsible for smoke taint could be selectively removed with the aid of molecularly imprinted polymers (MIPs).
MIPs are synthetic materials that can bind to one or more target compound. The researchers hoped to use the polymers to fish the smoky substances out of wine, while leaving the tasty and visually appealing components in place. The team added beads made of MIPS either contained in muslin or mesh bags or floating freely in the liquid and then used chemical analysis, as well as tastetesting panels of experts, members of the public, students and staff to evaluate the results. In some cases, the MIPs were regenerated by rinsing them after extraction to remove the smoke compounds, enabling them to be reused.
In terms of improving the wines’ sensory characteristics and removing unpleasant volatile phenols, the researchers found that adding MIPs to wine after fermentation was more effective than adding MIPs during fermentation. In addition, regenerating the MIPs generally enhanced removal of smoke vola-
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Elkins Eye Visuals/Shutterstock.com
Around the Area
UT-Dallas
The Department of Chemistry and Biochemistry welcomes Assistant Professor Alistair Sterling to the faculty. Dr. Sterling earned his MChem and DPhil degrees in Organic Chemistry from Oxford University followed by postdoctoral studies at Lawrence Berkeley National Lab.
Assistant Professor Hedieh Torabifard (left), and Assistant Professor and CPRIT Scholar Fillipo Romiti (right), both were granted individualy ~$2M NIH MIRAR35 awards for Early Stage Investigators.
Robert A. Welch Distinguished Chair in Chemistry and CPRIT Scholar Rudi Fasan was awarded a $150K SRA from Janssen Pharmaceutica.
Dr. Christina Thompson won the President’s Teaching Excellence Award in Undergraduate Instruction.
Uma Nair won the Undergraduate Teaching Assistant of the Year Award from the School of Natural Sciences & Mathematics.
From the ACS Press Room
continued
Separating viruses from saliva
Continued from page 5
researchers confirmed the results with electron microscopy, finding viruses only in liquid sampled from the virus outlet. Although BEST cannot yet separate waste particles from viruses that are smaller than 50 nm, such as parvoviruses, the researchers are working to broaden the technology’s range to enable its use in developing new therapeutic targets for numerous viral diseases.
The authors acknowledge funding from the National Institutes of Health, National Science Foundation (NSF) and NSF Graduate Research Fellowship Program.
Some authors have competing financial interests in Ascent Bio-Nano Technologies Inc., to commercialize technologies involving acoustofluidics and acoustic tweezers, and equity in Liquid Diagnostics.
Levels of one ‘forever chemical’
Continued from page 7
pesticide application. For example, pesticides that might be precursors for trifluoroacetate have been applied to agricultural areas within Denmark since the late 1960s. On the basis of those observations, the researchers say that trifluoroacetate concentrations could be used to categorize when groundwater entered aquifers, such as after 1985 or before 2000, rather than using more sophisticated and tedious dating methods that require isotopes. Additionally, Albers says some particularly high trifluoroacetate concentrations in groundwater less than 10 years old could suggest local sources have recently become more important, such as fluorinated pesticide applications.
The authors acknowledge funding from the Danish Environmental Protection Agency and the Danish Groundwater Monitoring Program.
From the ACS Press Room
continued
Scientists use magnetic nanotech
Continued from page 8
• netic nanoparticles and a cryoprotective substance and then frozen with liquid nitrogen.
• In the first stage of thawing, as before, an alternating magnetic field initiated rapid rewarming of animal tissues.
• As the samples approached the melting temperature of the cryoprotective agent, the researchers applied a horizontal static magnetic field.
• The second field realigned the nanoparticles, effectively tapping the brakes on heat production.
The heating slowed fastest in areas with more nanoparticles, which dampened concerns about problematic hotspots. Applying the method to cultured human skin fibroblasts and to pig carotid arteries, the researchers noted that cell viability remained high after rewarming over a few minutes, suggesting the thawing was both rapid and safe. The ability to finely control tissue rewarming moves us one step closer to longterm organ cryopreservation and the hope of more life-saving transplants for patients, the researchers say.
The authors acknowledge funding from the U.S. National Science Foundation.
Getting the stink out of smoke-tainted wine
Continued from page 11
tile compounds. Although the MIPs also adsorbed some desirable compounds associated with aroma, flavor and red wine color, the researchers say the project showed that the method can be used successfully to reduce the perception of smoke taint.
The authors acknowledge funding and support from the Australian Government as part of a Cooperative Research Centre Project; Wine Australia; Metabolomics South Australia, which is funded through Bioplatforms Australia Pty Ltd.; the National Collaborative Research Infrastructure Strategy; and the South Australian State Government. One author declared a potential conflict of interest as an employee of amaea.
From the Editor
Welcome back to the SOUTHWEST RETORT in its 77th year!
This month, two papers particularly caught my attention...fish guts and dinosaur collagen. What could beat that combo?!
Everyone knows there are some pretty strange ingredients in skin care products...heck, if you do any formulating, you probably have worked with some. For example, snail mucin also known as snail slime (wonder why?) is used for its moisturizing and antioxidant properties. In ACS Omega, Hyo-Jong Lee and Chung Sub Kim tested molecules made by fish gut bacteria. In cultured cells, the compounds had skinbrightening and anti-wrinkle properties, making them potential ingredients for skin care.
Collagen consists of protein strands that form triple helices which in turn weave together to form a strong fibrous material. In water, the peptide bonds that connect amino acids in protein strands normally break down by hydrolysis. However, in collagen, hydrolysis doesn’t take place. Fragments of collagen have been extracted from the bones of 68-million-year-old fossils of T. rex and in older fossils. In ACS Central Science, Ron Raines and colleagues set out to fill in the missing links; apparently, acyl groups in the chain partially share electrons with a neighboring acyl group, protecting the chain from hydrolysis.
Raw milk and raw milk products: don’t. Although states are currently listed as TBfree, why take the chance?
