The study, conducted with the DMol3 module of BIOVIA Materials Studio 2023, employed the generalized gradient approximation with the Perdew–Burke–Ernzerhof exchange–correlation functional and a double numerical basis set with polarization functions. The researchers, Eman H. Salem, Abbas M. Abbas and Adel S. Orabi, optimized the geometries of ketoprofen and its ten molecular partners—tryptophan, uric acid, glutathione, asparagine, glycine, proline, glucose, valine, cysteine and glutamic acid—selected to span amino acids, antioxidants, aromatic metabolites and carbohydrates. Convergence criteria were strict, with energy changes limited to 1.0 × 10−5 Hartree, maximum forces to 2.0 × 10−3 Hartree per Ångström and maximum displacements to 5.0 × 10−3 Ångströms. All calculations were performed in the gas phase, a deliberate simplification the authors acknowledge as a limitation, since the aqueous environment of living cells would modulate but not necessarily eliminate the electronic effects they observed.

The heart of the analysis lies in frontier molecular orbital theory, the quantum chemical framework that treats the highest occupied molecular orbital, or HOMO, as the electron-donating frontier of a molecule and the lowest unoccupied molecular orbital, or LUMO, as its electron-accepting frontier. The gap between these two orbital energies serves as a proxy for chemical reactivity: small gaps imply soft, polarizable, highly reactive species, while large gaps indicate hard, kinetically stable ones. Among the biomolecules examined, glutamic acid emerged as the most reactive, with the smallest energy gap of just 0.009 Hartree, while tryptophan proved the most stable, with a gap of 0.227 Hartree. Uric acid displayed the highest HOMO energy at −0.079 Hartree, marking it as the best electron donor in the set, whereas DL-proline possessed the lowest LUMO energy at −0.113 Hartree, making it the most eager electron acceptor. Ketoprofen itself carried the lowest HOMO energy of all compounds studied, a signature of its inclination to act as an electrophile in encounters with biological partners.

From these orbital energies the team derived a battery of global reactivity descriptors grounded in Koopmans’ theorem: ionization potential, electron affinity, chemical hardness, softness, chemical potential, electronegativity and the electrophilicity index. Glutathione, the cell’s principal low-molecular-weight antioxidant, showed the lowest chemical hardness at 0.005 Hartree and a softness value of 96.34, confirming its exceptional reactivity. Glutamic acid and glutathione also registered the highest electrophilicity indices, 1.296 and 1.091 respectively, indicating strong appetites for electrons, whereas glycine, uric acid and tryptophan sat at the opposite end of the scale. When the researchers asked which molecule would be most likely to interact with ketoprofen—an electrophile with an electronegativity of 0.105 Hartree and moderate hardness—uric acid stood out clearly. With the lowest electronegativity, 0.031 Hartree, the lowest electrophilicity index, 0.010, and high softness, uric acid behaves as the strongest nucleophile in the panel, making it the theoretically best-matched partner for the drug.

To move from global tendencies to atom-by-atom predictions, the team computed Fukui functions, local reactivity descriptors derived from Mulliken atomic charges in neutral, anionic and cationic states. These functions pinpoint where a molecule’s electron density is most inclined to shift upon accepting or donating electrons. For ketoprofen, the carboxyl oxygen designated O8 proved to be the star of the show. It exhibited the highest values for all three Fukui functions—0.150 for electrophilic attack, 0.307 for nucleophilic attack and 0.229 for radical attack—revealing a remarkable dual character in which the atom can both donate and accept electrons, a property the authors attribute to its lone pairs and self-electronegativity. The C7 atom of the benzoyl group followed closely as a second electrophilic hotspot. In tryptophan, the C9 site showed the highest nucleophilic Fukui value of the entire dataset at 0.660, while cysteine’s sulfur atom S5 registered a strong 0.420, flagging the thiol sulfur as a potent electron donor poised to engage the drug’s electrophilic centres.

One of the most striking findings concerns cysteine, whose electronic personality changes dramatically upon binding to ketoprofen. Before interaction, cysteine’s HOMO sat at −0.207 Hartree with an energy gap of 0.157 Hartree; after complexation, the gap swelled to 0.318 Hartree, with the LUMO localized largely on the ketoprofen moiety. This widening indicates that ketoprofen accepts electron density from cysteine while simultaneously dampening the amino acid’s chemical reactivity and electron-transfer capability. Because cysteine’s thiol group underpins redox balance, disulfide-bridge formation in proteins and detoxification pathways, the authors suggest that ketoprofen’s electronic grip on the molecule could, in principle, interfere with oxidative stress defences and enzymatic functions that depend on free thiol chemistry. The effect is predicted to be weak and reversible, but its direction is chemically unambiguous.

Glutamic acid tells a different and equally consequential story. The neurotransmitter and metabolic intermediate is extraordinarily reactive in its free state, with that minuscule 0.009 Hartree gap and an electrophilicity index of 1.296. When complexed with ketoprofen, however, its electrophilicity plummets to 0.231 Hartree, essentially matching that of the drug itself, while the HOMO–LUMO gap of the complex remains close to ketoprofen’s original 0.112 Hartree. Fukui mapping identified the O8 carboxyl oxygen of ketoprofen, with a nucleophilic index of 0.308 and a Mulliken charge of −0.493 elementary charges, as the dominant site of interaction. The binding energy for this pair was computed at −6.49 Hartree, by far the most negative value in the study and a strong indication of thermodynamically favourable complex formation. Critically, the authors conclude that the interaction is moderately weak and reversible, that the carboxylate groups responsible for glutamic acid’s biological activity remain intact, and that excitatory neurotransmission through NMDA and AMPA receptors should be largely preserved, with any effect limited to a temporary dip in free glutamic acid concentration.

Binding energies across the full panel revealed a heterogeneous landscape. Only four complexes proved thermodynamically favourable: ketoprofen–DL-proline at −0.0299 Hartree, ketoprofen–glucose at −0.00486 Hartree, ketoprofen–valine at −0.0028 Hartree and ketoprofen–glutamic acid. The remaining pairs, including tryptophan, uric acid, glutathione, asparagine, glycine and cysteine, yielded positive binding energies, signalling weak or unfavourable associations under the gas-phase conditions of the calculation. Notably, the researchers found no consistent linear correlation between the global electronic descriptors and the binding energies, a result they interpret as evidence that geometry, steric effects and hydrogen-bonding patterns matter as much as orbital energies in determining complex stability. Electronic descriptors, they conclude, are best treated as complementary rather than predictive tools.

The glucose interaction carries particular practical weight. Upon complexation, glucose’s energy gap widened from 0.034 to 0.111 Hartree, indicating reduced reactivity, and a calculated charge transfer of roughly 0.42 electrons flowed from glucose to ketoprofen, confirming the drug’s electron-acceptor role. The authors propose that ketoprofen may form stable hydrogen bonds or weak ester-like linkages with glucose, potentially reducing its bioavailability and perturbing normal glucose-related biochemical pathways. They flag this as a theoretical concern especially relevant to diabetic patients or individuals with impaired glucose regulation, while stressing that the finding is purely computational and awaits experimental confirmation. Prior work has, in fact, exploited glucose moieties to shuttle ketoprofen across the blood–brain barrier via glucose transporters, lending plausibility to a genuine chemical affinity between the two molecules.

Tryptophan, meanwhile, emerged as the most electronically transformed partner in the panel. Complexation dropped its energy gap from 0.227 to 0.074 Hartree, softened the molecule and raised its electrophilicity, producing a highly reactive adduct. Because tryptophan is the essential precursor of serotonin and other neuroactive compounds, the authors warn that strong electronic engagement with ketoprofen could, under chronic exposure, subtly interfere with neurotransmitter biosynthesis. A parallel concern applies to glutathione: even though its formal binding energy was unfavourable, its pronounced softness and electrophilic character suggest meaningful interactions with electron-rich regions of the drug, raising the possibility that long-term ketoprofen use could tax antioxidant capacity at a time when NSAIDs are already associated with oxidative stress. Cysteine, paradoxically, ranked as the least likely significant partner despite its reactive thiol, owing to its low softness.

The authors are careful to frame their conclusions within the limits of the method. No solvent model was applied, counterpoise correction for basis set superposition error was not performed, and the work is explicitly theoretical, intended as a molecular-level hypothesis generator rather than a clinical verdict. Their overarching message is that quantum chemical modelling of the kind demonstrated here—combining frontier orbital analysis, global reactivity descriptors, Fukui mapping and binding energy calculations—offers drug developers a fast, inexpensive screen for off-target chemistry that might otherwise surface only after years of clinical use. Ketoprofen remains, in their assessment, neither toxic nor dangerous on its own terms, but the study suggests it is an electronically promiscuous molecule capable of transiently engaging sensitive players in cellular biochemistry. Translating these predictions into certainty will require the in vitro and in vivo experiments the researchers explicitly call for, but the work stands as a demonstration that the hidden life of a familiar drug, down to its last reactive oxygen atom, can now be read directly from the mathematics of its electrons.

The significance of Thymbra spicata L. extends beyond its traditional use in gastronomy; it has been employed in folk medicine for its purported anti-inflammatory and antioxidant properties. The basis of the study revolves around the extraction and characterization of its bioactive compounds, paving the way for understanding how these compounds could be harnessed to combat inflammation and other health-related issues. By employing state-of-the-art analytical techniques such as GC–MS and LC–Orbitrap HRMS, the researchers succeeded in identifying a multitude of phytochemicals that could hold significant pharmacological promise.

Central to the study is the utilization of Density Functional Theory (DFT) and molecular docking studies, which reveal deeper insights into the interactions between identified compounds and biological targets. The researchers conducted rigorous computational analyses to predict how these bioactive molecules might interact at the cellular level, offering a glimpse into their potential efficacy as anti-inflammatory agents. This integrative approach signifies a step forward in the synergy of modern technology and traditional herbal medicine.

Through DFT calculations, the researchers investigated the electronic structure of the bioactive compounds, shedding light on their stability and reactivity. This theoretical background allowed for an informed selection of compounds for subsequent docking studies, emphasizing the significance of computational chemistry in drug discovery. Coupled with these advanced analytical techniques, the study addressed the biological activity of the compounds, assessing their therapeutic potential through established drug-like characteristics.

The ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) profiling of the bioactive molecules further underscores the comprehensive nature of the research. Understanding these pharmacokinetic and pharmacodynamic properties is pivotal for evaluating the safety and efficacy of potential therapeutic agents. The research team meticulously examined the compounds’ ADMET profiles to gauge their suitability for pharmaceutical development and real-world application.

In addressing the biological target and activity of the identified molecules, the study provides crucial insights that could inform future research directions. The significance of targeting specific biological pathways in inflammatory responses highlights the ongoing need for innovative treatments in the realm of chronic diseases. Through this lens, the findings may resonate with the broader scientific community, encouraging further investigation into natural compounds as sources of novel therapeutics.

The implications of such research extend far beyond academic interest; they speak to a growing trend towards holistic and nature-derived health solutions that resonate with contemporary wellness trends. As awareness of the potential adverse effects of synthetic drugs increases, a return to nature as a resource for healing is becoming more appealing. The investigation into Thymbra spicata L. is emblematic of this shift, showcasing how the fusion of technology and traditional knowledge can lead to groundbreaking discoveries in the field of medicine.

This study could undoubtedly serve as a catalyst for subsequent investigations into other overlooked flora, encouraging researchers to explore their pharmacological properties. Such explorations may unearth a wealth of bioactive compounds that have remained on the periphery of scientific inquiry. By broadening the horizon of research, the potential exists not only to enhance the pharmacopoeia but also to invigorate natural product chemistry as a discipline.

Moreover, the public health implications of such research are profound. As chronic inflammatory conditions like arthritis, inflammatory bowel disease, and cardiovascular diseases continue to pose significant health burdens globally, the pursuit of natural, effective treatments is paramount. The exploration of Thymbra spicata L. positions it as a potential player in the future landscape of anti-inflammatory therapeutics.

The findings inaugurated by the research team mark a pivotal point in tapping into the wealth of knowledge that traditional medicine offers. Generations have relied on herbs like Thymbra spicata L., not merely out of tradition but through centuries of experiential learning. Integrating this knowledge with modern analytical capabilities paves the way for a renaissance in herbal medicine.

As the scientific community and the public alike turn a discerning eye towards natural remedies, the study is a clarion call to stakeholders in healthcare, urging them to invest in research that validates and utilizes plant-based solutions. By doing so, we can bridge the gap between conventional and alternative medicine, fostering an environment where each can inform and elevate the other.

This multifaceted examination of Thymbra spicata L. symbolizes a synergistic approach to health and well-being—one that embraces the wisdom of the past while innovatively looking towards the future. As these types of studies continue to emerge, the horizon seems limitless in discovering natural compounds that could be transformed into the next generation of anti-inflammatory solutions.

In summary, the study by Unsal, Ercan, and Calıskan has contributed significantly to our understanding of Thymbra spicata L. and its bioactive constituents. By employing an arsenal of methodologies from chemical analysis to computational modeling, the researchers have set a precedent for future investigations into the complex interplay between traditional herbal medicine and modern scientific inquiry. The implications of such research could herald a new era in therapeutic development, urging both academia and industry to reconsider the potent possibilities that lie within nature’s bounty.

Subject of Research: Investigation of bioactive and anti-inflammatory molecules in Thymbra spicata L.

Article Title: Determination of bioactive and anti-inflammatory molecules of Thymbra spicata L. from Mardin by GC–MS and LC–Orbitrap HRMS: a DFT, molecular docking, ADMET, biological target and activity study.

Article References:

Unsal, V., Ercan, L. & Calıskan, C.G. Determination of bioactive and anti-inflammatory molecules of Thymbra spicata L. from Mardin by GC–MS and LC–Orbitrap HRMS: a DFT, molecular docking, ADMET, biological target and activity study.
BMC Complement Med Ther 25, 358 (2025). https://doi.org/10.1186/s12906-025-05054-y

Image Credits: AI Generated

DOI: 10.1186/s12906-025-05054-y

Keywords: Thymbra spicata, bioactive compounds, anti-inflammatory, GC–MS, LC–Orbitrap HRMS, DFT, molecular docking, ADMET, pharmacognosy, natural products, herbal medicine, therapeutic agents, inflammation, public health.