Unspecific peroxygenases, or UPOs, are heme-thiolate enzymes that use hydrogen peroxide to insert oxygen atoms into carbon-hydrogen bonds and double bonds under remarkably mild conditions. That ability makes them attractive alternatives to metal-based oxidation catalysts, which often require harsh reagents, elevated temperatures, and elaborate protecting-group strategies. Yet industrial adoption has lagged because most UPOs are difficult to produce, poorly stable, or hard to engineer. CglUPO, the enzyme from Chaetomium globosum discovered in 2017, exemplified all three problems. It oxidizes an unusually broad range of substrates, including steroids, resveratrol analogs, isophorone, fatty acids, and short-chain olefins, but the wild-type enzyme, when produced in its native fungus, loses significant activity within days even at 4 degrees Celsius.

The first hurdle was expression. When the CglUPO gene was previously expressed in Saccharomyces cerevisiae, secretion levels of roughly 0.6 milligrams per liter were far too low to support laboratory evolution, which requires screening thousands of variants, each producing measurable enzyme. The team, led by Miguel Alcalde’s group, tested signal peptides from several peroxygenase-producing fungi to drive secretion, finding that CglUPO’s own native leader sequence performed best, yielding about 3 units per liter of activity in 96-well microfermentations. That modest baseline was enough to launch a directed evolution campaign combining rounds of error-prone PCR, saturation mutagenesis, and in vivo DNA recombination, all screened with a high-throughput assay based on oxidation of 2,6-dimethoxyphenol.

An unexpected bonus appeared immediately: simply switching the expression host from the native fungus to yeast raised the enzyme’s kinetic thermostability, measured as the T50 value at which half the activity survives a 10-minute incubation, by 4 degrees, from 52 to 56 degrees Celsius. The researchers attribute this likely to yeast glycosylation, which can stabilize the secreted protein. Subsequent evolution rounds delivered mutants 9G3 and 11G4 bearing substitutions at position 210, a saturation library at that position produced variant 4B10 with a 16-fold total activity improvement thanks to an M210R mutation, and recombination of the best parents yielded the AckBar mutant, carrying F154L and M210V, with roughly 10-fold improved functional expression and secretion levels of about 6 milligrams per liter in yeast.

To move from laboratory evolution to industrial relevance, the team exploited a tandem-yeast strategy: Saccharomyces cerevisiae for building and screening mutant libraries, and Pichia pastoris, recently renamed Komagataella phaffii, for large-scale production. In a 30-liter fed-batch bioreactor, AckBar reached approximately 90 milligrams per liter, tripling the yield of the parental enzyme in the same host without any process optimization. The purified enzymes, roughly 37 kilodaltons with about 24 percent glycosylation, showed T50 values near 60 degrees Celsius, placing them among the most stable recombinant UPOs reported to date. Crucially, while the wild-type enzyme died within days at refrigeration, AckBar retained nearly full activity for months in storage. Both variants were active across a broad pH range from 5.0 to 9.0.

Then came the surprises. Screening the evolved variants against model substrates revealed that AckBar dramatically inverted the enantioselectivity of tetrahydronaphthalene oxidation, producing the S-enantiomer of the benzylic alcohol with 86 percent enantiomeric excess, whereas the parental enzyme favored the R-enantiomer. Even more striking, both the parental and evolved enzymes catalyzed the anti-Markovnikov Wacker-Tsuji oxidation of styrene to phenylacetaldehyde, a long-pursued synthetic transformation that had only very recently been reported in other peroxygenases and in engineered cytochrome P450 monooxygenases, but never before for CglUPO. In such oxidations, the oxygen lands on the terminal carbon of the alkene to yield an aldehyde rather than the more conventional epoxide, giving direct access to aldehyde building blocks under mild aqueous conditions.

Control experiments confirmed that the aldehyde forms directly from the alkene and not through rearrangement of a preformed epoxide: when styrene oxide was offered as a substrate, no phenylacetaldehyde appeared whether or not hydrogen peroxide was present. With 4-chlorostyrene, the aldehyde-to-epoxide ratio climbed as high as 0.79 for AckBar, and total turnover numbers exceeded 5,000 for epoxidation with low enzyme loadings of 0.1 micromolar. To enable future optimization of this reactivity, the team developed a high-throughput screening assay using Purpald, an aldehyde-specific colorimetric reagent previously applied to evolving anti-Markovnikov P450s. In microfermentations of yeast secreting AckBar, the assay gave a stable, quantifiable response, opening the door to dedicated evolution campaigns aimed at pushing the moderate chemoselectivity toward the levels industry demands.

The reactivity profile extended well beyond styrenes. AckBar oxidized ethylbenzene with 79 percent enantiomeric excess toward the R-alcohol, compared with 31 percent for the parental enzyme, and overoxidized alcohols to ketones to a much greater degree, a property that is useful in cases like isophorone, where the overoxidized product 4-ketoisophorone normally requires cumbersome multi-enzyme cascades. With the bicyclic terpene pinene, AckBar performed notably higher levels of direct carbon-hydrogen oxidation to verbenol and verbenone, exceeding 800 total turnover numbers, whereas limonene yielded exclusively epoxide products, with the cis-to-trans ratio flipping depending on which limonene enantiomer was supplied. This preference for epoxidation over allylic hydroxylation with limonene matches the behavior of other UPOs and underscores how substrate structure governs the reaction channel.

To explain these altered selectivities, the researchers turned to long molecular dynamics simulations, since no crystal structure of CglUPO exists. They built a structural model with AlphaFold2, aligned it to the crystal structure of a related peroxygenase from Hypoxylon sp. EC38, and docked the heme cofactor and substrates before running multiple 0.5-microsecond trajectories for each enzyme-substrate pair. For tetrahydronaphthalene, the simulations showed that the F154L and M210V mutations, both located in the heme access channel, enlarge and reshape the active-site cavity, allowing the substrate to penetrate deeper and lock into catalytically competent poses stabilized by interactions with residues His88 and Glu158. In the parental enzyme, the substrate samples non-reactive positions; in AckBar, the hydrogen atom that yields the S-alcohol sits preferentially close to the iron-oxo of Compound I, reproducing the experimentally observed inversion of enantioselectivity. For styrene, the simulations linked chemo- and enantioselectivity to the geometry of the oxo attack on the terminal versus internal carbon of the double bond, predicting predominant epoxidation with a slight S-preference consistent with the experimental data.

The authors are candid about the study’s limits: all biotransformations were analytical-scale, some products could not be resolved on chiral columns, and every structural interpretation rests on a model whose C-terminal region was predicted with low confidence and equilibrated separately. Even so, the achievement is substantial. A promiscuous but fragile enzyme from a fungus that grows on wallpaper has been re-engineered into a secretable, evolvable, bioreactor-ready catalyst that already performs one of synthetic chemistry’s most coveted reactions. With ongoing evolution of AckBar’s anti-Markovnikov activity, deliberate engineering of the signal peptide, and complementary strategies such as ancestral sequence reconstruction, the team believes the full breadth of this enzyme’s capabilities is now within reach, offering a sustainable enzymatic answer to selective oxygen insertion that chemical catalysis has struggled to provide.

Subject of Research: Directed evolution of the fungal unspecific peroxygenase CglUPO for improved expression, stability, and selective oxyfunctionalization chemistry

Article Title: Promiscuous fungal peroxygenase from Chaetomium globosum by directed evolution

Article References: Upp, D. M., Mateljak, I., Mendez-Sanchez, D., Gomez de Santos, P., Sanchez-Moreno, I., Valles, M., Świderek, K., Moliner, V., Scheibner, K., Hofrichter, M., Gonzalez-Perez, D., & Alcalde, M. (2026). Promiscuous fungal peroxygenase from Chaetomium globosum by directed evolution. iScience, 29(10), Article 117534. https://doi.org/10.1016/j.isci.2026.117534

Image Credits: AI Generated

DOI: 10.1016/j.isci.2026.117534

Keywords: directed evolution, unspecific peroxygenase, Chaetomium globosum, biocatalysis, anti-Markovnikov oxidation, enzyme engineering, Saccharomyces cerevisiae, Pichia pastoris, molecular dynamics, oxyfunctionalization, thermostability, heme-thiolate enzyme

The significance of sustainability in pharmaceuticals cannot be overstated. While the sector is responsible for developing life-saving medications, it also contributes significantly to pollution and resource depletion. Notably, the production and distribution of pharmaceuticals, accompanied by their packaging, generate considerable waste. The analysis sheds light on the urgent need for pharmaceutical companies to adopt more environmentally friendly practices. By incorporating green chemistry principles into their processes, firms can minimize hazardous waste and reduce their carbon emissions.

Chandra and Subashini’s bibliometric analysis utilized an extensive dataset to map out trends, gaps, and the evolution of sustainable practices within the pharmaceutical industry. By analyzing thousands of academic papers, the authors identified key themes and areas of growth. This data-driven approach not only reveals the current state of sustainability in pharmaceuticals but also highlights the potential for innovation. The increasing presence of sustainability-focused literature indicates a shift within the industry toward integrating environmental considerations into drug development processes.

One of the most striking findings of the study is the rise in collaborative research efforts. The authors emphasize that sustainable development in the pharmaceutical industry requires a collective effort involving academia, regulatory bodies, and the private sector. Collaborative projects are emerging as crucial avenues for advancing sustainability practices. Such partnerships foster knowledge sharing, stimulate innovation, and lead to the co-creation of solutions that address both health and environmental concerns.

The bibliometric study also brings to light the importance of regulatory frameworks in promoting sustainable practices in the industry. As governments worldwide implement stricter environmental regulations, pharmaceutical companies must adapt to this shifting landscape. This regulatory pressure could serve as a catalyst for change, compelling companies to invest in sustainable technologies and processes. Chandra and Subashini argue that regulatory compliance should not be viewed merely as another hurdle but rather as an opportunity for companies to differentiate themselves in the marketplace.

Moreover, the study underscores the role of consumer awareness and demand in shaping sustainable practices within the pharmaceutical sector. Today’s consumers are increasingly inclined to support companies that prioritize environmental stewardship. As the public becomes more educated about the environmental impacts of pharmaceuticals, firms that disregard sustainability may find themselves at a competitive disadvantage. This shift in consumer behavior places additional pressure on companies to adopt and showcase their sustainable practices.

Another pivotal aspect discussed in the analysis is the integration of sustainability metrics into corporate strategies. The authors highlight that organizations must move beyond mere compliance with regulations and start measuring their sustainability performance. By establishing Key Performance Indicators (KPIs) related to environmental impact, pharmaceutical companies can gain valuable insights into their practices and identify areas for improvement. This holistic approach to sustainability management can drive efficiency and innovation, ultimately benefiting both the company and the environment.

The research also stresses the potential for emerging technologies to revolutionize sustainability in the pharmaceutical industry. Innovations such as artificial intelligence, machine learning, and big data analytics have the potential to transform supply chain management, reduce waste, and optimize resource allocation. As companies increasingly harness these technologies, they can streamline their operations and substantially lower their environmental impact. The intersection of technology and sustainability is a powerful arena for the pharmaceutical industry to explore.

In addition, the study raises important questions about the role of pharmaceutical waste in environmental sustainability. The disposal of expired and unused medications presents a significant challenge, contributing to environmental pollution. The authors advocate for the implementation of take-back programs and responsible disposal options, positioning pharmaceutical companies as responsible stewards of the environment. By ensuring that medications are disposed of safely, firms can protect ecosystems and public health while enhancing their sustainability credentials.

Chandra and Subashini’s comprehensive analysis also emphasizes the need for education and training related to sustainability within the pharmaceutical workforce. As the industry evolves, professionals must be equipped with the knowledge and skills necessary to implement sustainable practices effectively. Educational institutions and companies must collaborate to develop curricula that address the unique needs of sustainable pharmaceutical development. This investment in human capital will be crucial to driving the industry forward.

Equally noteworthy is the issue of sustainability reporting. The authors assert that transparency in sustainability practices is essential for building trust with stakeholders. By regularly publishing sustainability reports that disclose environmental impacts and progress toward goals, pharmaceutical companies can enhance their reputations and demonstrate accountability. Such transparency also aligns with a broader trend of corporate social responsibility, which is becoming increasingly expected by investors, consumers, and regulatory bodies alike.

As the landscape of sustainable development within the pharmaceutical industry continues to evolve, companies must navigate a complex web of challenges and opportunities. Chandra and Subashini’s bibliometric analysis serves as a guiding light, illuminating the path forward. The implications of their findings extend beyond academic circles; they resonate with industry leaders, policymakers, and consumers alike. By embracing sustainability, the pharmaceutical sector has the potential to not only enhance its operational efficiency but also contribute positively to global environmental goals.

In conclusion, the urgent call for sustainability within the pharmaceutical industry cannot be ignored. Chandra and Subashini’s study encapsulates the current state of research and trends while stimulating critical discussions about the future. As stakeholders across the board recognize the importance of sustainable development, there is hope that the pharmaceutical industry will adapt its practices to meet the needs of a changing world. Embracing sustainability is not merely a choice but an imperative for creating a healthier planet for generations to come.

Subject of Research: Sustainable Development in the Pharmaceutical Industry

Article Title: Mapping the landscape of sustainable development in the pharmaceutical industry a bibliometric analysis

Article References: Chandra, N.P., Subashini, R. Mapping the landscape of sustainable development in the pharmaceutical industry a bibliometric analysis. Discov Sustain 6, 1218 (2025). https://doi.org/10.1007/s43621-025-02010-1

Image Credits: AI Generated

DOI: https://doi.org/10.1007/s43621-025-02010-1

Keywords: sustainable development, pharmaceutical industry, bibliometric analysis, environmental stewardship, corporate responsibility, regulatory frameworks, emerging technologies, consumer awareness, sustainability metrics.

The significance of this research cannot be overstated, as the antimicrobial resistance crisis looms larger in the medical community. Antibiotic-resistant strains of bacteria have cultivated a pressing need for researchers to identify and develop new classes of antimicrobial agents. By exploring alternative methods of synthesis, this research paves the way for environmentally sustainable practices that also deliver potent biological activity.

Choline hydroxide, the key component in their synthesis, is a quaternary ammonium compound known for its excellent solubility and low toxicity. Its application in organic synthesis is relatively novel, setting this research apart from traditional methods that often rely on hazardous reagents or solvents. This environmentally friendly approach aligns well with the current scientific ethos that promotes sustainability and green chemistry, helping to diminish the ecological footprint of chemical manufacturing.

Upon employing choline hydroxide in their synthesis process, the researchers succeeded in producing the target compound with remarkable efficiency. The structural characterization and the purity of the synthesized 5-arylidene thiazol-4(5H)-one were rigorously validated through various spectroscopic techniques. Techniques such as Nuclear Magnetic Resonance (NMR) and Infrared (IR) spectroscopy were utilized to confirm the molecular structure, providing a robust framework that supports the reliability of their findings.

Further expanding the impact of their successful synthesis, the research team conducted a thorough antimicrobial evaluation of the newly synthesized compound. In vitro tests were performed against a wide spectrum of microbial strains, including both Gram-positive and Gram-negative bacteria. The results were promising, revealing significant antimicrobial activity that opens avenues for the development of new therapeutic agents. This aspect of the research highlights the urgency and relevance of discovering alternatives to existing antibiotics amid growing resistance.

Additionally, the research incorporated in silico studies to elucidate the potential mechanisms of action of the synthesized compound. Molecular docking simulations were employed to predict how the compound interacts with specific bacterial enzymes and receptors. These computational methods provided deeper insights into its bioactivity, thus fortifying the experimental findings with theoretical validation. The synergy of experimental and computational approaches enhances the overall credibility of the claims made in the study.

What is particularly fascinating about this research is its dual focus on both sustainability and efficacy. By choosing choline hydroxide—an eco-friendly reagent—the researchers have set a precedent for others in the pharmaceutical field to follow. In an era where environmental concerns are increasingly taking center stage in scientific discourse, such innovative approaches not only to synthesize but also to evaluate new antimicrobial agents are crucial.

The collaborative nature of this research is also worthy of note, as it brings together experts from diverse fields, allowing for a comprehensive exploration of the compound’s properties and potential applications. This interdisciplinary approach is essential when tackling complex issues such as antimicrobial resistance, making it a model for future studies aiming to bridge multiple areas of expertise.

In conclusion, the study’s findings mark a significant advancement in the ongoing effort to develop new antimicrobial compounds through eco-friendly methods. By harnessing the properties of choline hydroxide in the synthesis of 5-arylidene thiazol-4(5H)-one, the researchers have not only created a promising candidate for future medications but also demonstrated the larger potential for green chemistry in drug discovery. As the scientific community continues to respond to the challenges posed by resistant bacteria, such innovative research will undoubtedly play a pivotal role in shaping the future of antimicrobial therapy.

The implications of this study extend far beyond its immediate findings. It acts as a clarion call for researchers to pursue sustainable practices while maintaining scientific rigor. The path that Al-Saleem and co-researchers have embarked upon is one that encourages the exploration of not just what can be synthesized, but how it can be done responsibly. Thus, the ripple effects of this research will likely inspire a new wave of methodologies in organic synthesis that prioritize both efficiency and environmental stewardship.

As these developments unfold, it will be essential for stakeholders in the pharmaceutical and environmental sectors to examine and support such research initiatives. By investing in sustainable approaches, we can ensure a healthier future not only for our societies but also for the planet we inhabit.

As we look forward to further advancements stemming from this study, one can only hope that the antimicrobial landscape will soon be populated by new, effective agents, heralding a new chapter in the fight against infectious diseases.

Subject of Research: Eco-friendly synthesis of antimicrobial agents

Article Title: Choline hydroxide mediated eco-friendly synthesis of 5-arylidene thiazol-4(5H)-one clubbed coumarin: antimicrobial evaluation and in silico studies.

Article References:

Al-Saleem, M.S.M., Al-Humaidi, J.Y., Elhenawy, A.A. et al. Choline hydroxide mediated eco-friendly synthesis of 5-arylidene thiazol-4(5H)-one clubbed coumarin: antimicrobial evaluation and in silico studies.
Sci Nat 112, 74 (2025). https://doi.org/10.1007/s00114-025-02026-7

Image Credits: AI Generated

DOI: https://doi.org/10.1007/s00114-025-02026-7

Keywords: antimicrobial synthesis, eco-friendly chemistry, choline hydroxide, thiazole derivatives, green chemistry, drug discovery.