The study, published open access in Discover Chemistry, set out to close a conspicuous knowledge gap. While close relatives such as Isodon rubescens have been extensively characterized—yielding celebrated diterpenoids like oridonin that have attracted attention for anti-inflammatory and cytoprotective effects—I. coesta has remained comparatively obscure despite its wide distribution across Bangladesh, Nepal, India, China, Myanmar, the Philippines, Indonesia, Sri Lanka, and Thailand. The researchers harvested whole plants, excluding roots, in September 2023, air-dried them for two to four days, ground them into a fine powder, and extracted the material separately with methanol and hexane over ten to fifteen days of soaking. The polar solvent proved far more generous: the methanolic extract yielded 4.02 percent by weight, while the nonpolar hexane extract yielded only 1.10 percent, a difference that foreshadowed the chemistry to come.

Gas chromatography–mass spectrometry, performed at the Advanced Instrumentation Research Facility at Jawaharlal Nehru University in New Delhi on a Shimadzu GCMS-QP2010 Plus system with a DB-5 capillary column, identified 24 compounds in each extract. In the methanolic extract, these accounted for 81.93 percent of total composition, with the acyclic diterpene alcohol phytol dominating at 12.22 percent, followed by the steroid precursor pregnenolone acetate at 7.54 percent, squalene at 6.83 percent, and methyl linolenate at 6.51 percent. The hexane extract told a different story: squalene, a triterpene hydrocarbon famous for its antioxidant and skin-protective properties, led at 11.79 percent, with the long-chain hydrocarbon 2-methylhexacosane close behind at 9.68 percent, and hexatriacontane, propylene glycol monooleate, and palmitic acid rounding out the major peaks. Seven compounds appeared in both extracts, including phytol, squalene, neophytadiene, and vitamin E, suggesting overlapping biochemical pathways that persist regardless of solvent polarity.

The identity of the dominant molecules matters because several of them carry well-documented biological credentials. Phytol serves as a biosynthetic precursor to vitamins E and K1 and has reported antioxidant, anti-inflammatory, and anticancer activities. Pregnenolone acetate sits upstream in the biosynthesis of steroid hormones and has been studied for neuroprotective and anti-inflammatory effects, making it a molecule of interest in neuropharmacology and endocrinology. Squalene, meanwhile, is an intermediate in sterol biosynthesis and a widely used emollient in cosmetics and pharmaceuticals. The presence of gamma-sitosterol, tocopherol, and linoleic acid derivatives in the methanolic extract further enriches the profile of a plant whose chemical inventory had previously been little more than a footnote in the Isodon literature.

Quantitative colorimetric assays confirmed that polarity drives the phytochemical harvest. The methanolic extract registered a total phenolic content of 31.37 milligrams of gallic acid equivalents per gram, a total flavonoid content of 313.28 milligrams of quercetin equivalents per gram, and a total antioxidant capacity of 8.61 milligrams of ascorbic acid equivalents per gram. The hexane extract trailed on every measure, with 17.19 milligrams GAE per gram of phenolics, 117.57 milligrams QE per gram of flavonoids, and 2.07 milligrams AAE per gram of antioxidant capacity. The pattern is chemically intuitive: methanol, being polar, efficiently pulls phenols and flavonoids out of plant tissue, whereas hexane preferentially dissolves lipids, waxes, and terpenoid hydrocarbons. Flavonoids, in particular, are major contributors to plant antioxidant activity, so their concentration in the methanolic fraction is consistent with the rest of the data.

The radical-scavenging results, however, temper any temptation to crown the plant a super-antioxidant. In the DPPH assay, which tracks the reduction of a stable violet free radical by measuring absorbance at 517 nanometers, the methanolic extract posted an IC50 of 748.38 micrograms per milliliter and the hexane extract 794.13 micrograms per milliliter. Those figures indicate moderate to weak activity compared with ascorbic acid, the reference standard, which achieved an IC50 of just 74.72 micrograms per milliliter. Two-way ANOVA showed that concentration strongly influenced scavenging activity, with a highly significant effect, while the difference between the two extract types alone did not reach statistical significance, though a significant interaction between extract type and concentration revealed concentration-dependent divergence in their responses. The authors caution that direct comparison with the standard should be interpreted carefully because different concentration ranges were used for the plant extracts and the reference compound.

To probe how the major constituents might behave at the molecular level, the team turned to computational docking against two enzymes that sit at opposite ends of the oxidative-stress balance. Human peroxiredoxin-5, resolved by X-ray crystallography at 1.50 angstrom resolution, is a thioredoxin-family antioxidant enzyme that detoxifies hydrogen peroxide and peroxynitrite, defending cells against oxidative injury. NADPH oxidase, resolved at 1.80 angstroms, is the enzymatic engine of reactive oxygen species generation, and its overactivation drives inflammatory damage. Using PyRx 0.8 with AutoDock Vina, the researchers docked phytol, pregnenolone acetate, squalene, and 2-methylhexacosane into both binding pockets. Pregnenolone emerged as the clear frontrunner, binding peroxiredoxin-5 at minus 6.1 kilocalories per mole and NADPH oxidase at minus 8.4 kilocalories per mole through a mix of hydrogen bonds, pi-anion, and pi-alkyl contacts. Phytol followed with moderate affinities, while 2-methylhexacosane performed worst, managing only minus 3.0 and minus 5.7 kilocalories per mole through weak van der Waals and alkyl interactions.

The ADMET analysis added a sobering pharmacokinetic dimension. All four compounds passed the molecular-weight criterion of Lipinski’s rule of five, but squalene, phytol, and 2-methylhexacosane showed MLOGP values far above the acceptable ceiling of 4.15, signaling extreme lipophilicity that predicts poor aqueous solubility and low gastrointestinal absorption. Pregnenolone was the only compound predicted to have high GI absorption, the only one expected to cross the blood–brain barrier, and the only one that is not a P-glycoprotein substrate, making it the most drug-like molecule in the set. Toxicity predictions from ProTox 3.0 were reassuring across the board: none of the compounds showed hepatotoxicity, carcinogenicity, or AMES mutagenicity, and squalene and phytol carried LD50 values of 5,000 milligrams per kilogram, indicating generous safety margins. The authors suggest that nanoemulsions, liposomes, solid lipid nanoparticles, or phospholipid-based delivery systems could rescue the bioavailability of the lipophilic constituents.

The researchers are careful to frame the docking results as hypothesis-generating rather than proof of pharmacological activity, and they recommend in vivo validation, molecular dynamics simulations, and quantitative phytochemical confirmation by HPLC or LC–MS as the necessary next steps. Even with those caveats, the study positions Isodon coesta as a flavonoid-rich reservoir of bioactive metabolites from one of the world’s great biodiversity hotspots—the Indian Himalayan region harbors roughly half of India’s flowering plant species with nearly 30 percent endemism, and Uttarakhand alone supports more than 5,000 vascular plant species. As computational screening increasingly complements fieldwork in natural-product drug discovery, this aromatic undershrub of the Himalayan slopes may yet translate its ethnobotanical reputation into molecules worthy of the laboratory bench and, eventually, the clinic.

Subject of Research: Phytochemical profiling and computational antioxidant evaluation of Isodon coesta from the Uttarakhand Himalaya

Article Title: Comprehensive phytochemical profiling, molecular interaction studies, and ADMET analysis of hexane and methanol extracts of Isodon coesta from Uttarakhand’s Himalayan Region

Article References: Mawri, D., Pujari, R., Bahuguna, A., Rawat, D. S., Prakash, O., Kumar, R., & Dubey, S. K. (2026). Comprehensive phytochemical profiling, molecular interaction studies, and ADMET analysis of hexane and methanol extracts of Isodon coesta from Uttarakhand’s Himalayan Region. Discover Chemistry, 3(1), Article 558. https://doi.org/10.1007/s44371-026-01003-x

Image Credits: AI Generated

DOI: 10.1007/s44371-026-01003-x

Keywords: Isodon coesta, phytochemistry, GC-MS, antioxidant, molecular docking, ADMET, Uttarakhand, Himalayan medicinal plants, phytol, pregnenolone, squalene, Lamiaceae

The research, led by Patricia Rodríguez-Castillo and colleagues at Tecnológico de Monterrey, tackles a fundamental problem in food chemistry. In cereal and pseudocereal grains, many phenolic compounds are not freely floating in the cell interior. Instead, they are esterified or otherwise bound to cell-wall polymers and other macromolecular structures. This bound fraction can represent a large share of the total phenolic pool, and unless the matrix is physically disrupted, standard solvent extraction simply cannot reach it. Hydroxycinnamic acid derivatives of genuine nutritional significance may remain locked inside structural fractions, leading analysts to underestimate the true antioxidant wealth of the seed.

DIC offers a strikingly elegant solution. The process works like a controlled steam explosion: amaranth grains are loaded into a reactor, a preliminary vacuum is drawn, and dry saturated steam is injected until a target pressure is reached. After a precisely timed hold, the pressure is dropped almost instantaneously toward a deep vacuum, at rates exceeding 0.5 megapascals per second. This sudden decompression forces the moisture inside the grain to flash-evaporate, cooling the material instantly while simultaneously causing it to expand and develop a sponge-like network of microstructural alveoli. The resulting porous architecture makes it far easier for solvents to penetrate the matrix and leach out compounds that were previously physically entrapped within the cell-wall network.

To test how these thermomechanical forces translate into chemical changes, the team worked with two Mexican subvarieties of A. hypochondriacus, Laura and Criollo, from the 2023 harvest in Puebla. They designed a rigorous central composite experiment spanning thirteen treatment combinations, with steam pressure ranging from 0.10 to 0.40 megapascals and processing times from 10 to 90 seconds. Treated and untreated grains were then ground, extracted with ethanol, and analyzed by high-performance liquid chromatography to quantify individual phenolic compounds, while the lipid fraction was characterized by gas chromatography-mass spectrometry.

The results for the Criollo variety were remarkable. Total quantified phenolics ranged from a low of 346.14 micrograms per gram under mild conditions to a striking 3035.2 micrograms per gram at moderate settings of 0.25 megapascals and 50 seconds, a condition that more than tripled the untreated control’s 828.38 micrograms per gram. Catechin emerged as the dominant compound in every sample, soaring from 679 micrograms per gram in the control to as much as 2704 micrograms per gram after treatment. Rutin, quercetin, gallic acid, and trans-4-hydroxycinnamic acid all showed statistically significant increases across most treatments, and the most favorable conditions also produced the widest diversity of detected compounds, with seven of eight identified peaks appearing in the chromatograms.

The Laura variety told a more nuanced story, one that underscores how sensitive these responses are to both genetics and processing intensity. Here, the same moderate condition of 0.25 megapascals for 50 seconds again delivered the highest phenolic concentration at 2074.15 micrograms per gram, though this did not differ significantly from the untreated grain. More revealing was what happened under harsher treatment: at 0.36 megapascals for 78 seconds, total phenolics collapsed to just 281.51 micrograms per gram and only three of ten peaks remained detectable. The contrast between this sample and DIC 6, which shared the same pressure but ran for only 22 seconds and displayed nine peaks, suggests that prolonged exposure to high-pressure steam can actively degrade delicate bioactive compounds rather than merely failing to release them.

Response surface modeling and Pareto analysis confirmed these patterns statistically, showing that moderate to high pressure combined with moderate time frames consistently maximized phenolic recovery, while quadratic terms in the fitted equations captured the penalty for pushing conditions too far. The findings align with earlier work by the same group showing improved antioxidant capacity in DIC-treated amaranth, as well as studies on green lentils, grape pomace, and oleaster flour, all of which reported enhanced polyphenol extractability following thermomechanical texturing. Together they paint a coherent picture: the sweet spot lies in enough mechanical disruption to fracture cell walls, but not so much thermal load that phenolics break down.

Crucially, the team also asked whether this violent process damages the lipid fraction, a legitimate concern given that unsaturated fatty acids and minor lipids like squalene are notoriously vulnerable to oxidation and heat. The answer was reassuring. Gas chromatography-mass spectrometry confirmed that amaranth oil remained dominated by nutritionally favorable components: in Criollo, oleic acid accounted for roughly 27 percent, linoleic acid 21 percent, palmitic acid 11 percent, and squalene an impressive 26 percent of the oil. Laura showed a similar pattern with 24 percent oleic, 25 percent linoleic, 20 percent palmitic, and 19 percent squalene. Saturated fatty acids made up only 22 to 30 percent of the total, preserving the grain’s balanced lipid signature.

Squalene deserves particular attention here. This triterpenoid, found in significant quantities in amaranth oil, exhibits documented antioxidant, anti-inflammatory, hepatoprotective, and cardioprotective activities, and it is one of the main reasons amaranth oil commands interest beyond basic nutrition. The study found that processing parameters did influence the relative proportions of specific fatty acids, with lower pressures and longer times favoring higher linoleic acid percentages in Criollo, and lower pressures boosting squalene in Laura, while oleic acid remained largely indifferent to the treatments. Some minor saturated fatty acids, including stearic and arachidic acid, disappeared from certain treatments, echoing similar observations in DIC-processed cardamom seeds and hinting at selective effects on less abundant lipid species.

The broader implications are compelling for the functional food industry. Amaranth’s phytochemical profile, spanning hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids related to quercetin and kaempferol, varies considerably with species, genotype, and growing conditions, which has long complicated its use as a standardized ingredient. This study demonstrates that DIC is not merely a passive processing step but a tunable dial: by adjusting steam pressure and exposure time, manufacturers can deliberately modulate which compounds become extractable and in what quantities, all within processing windows measured in seconds rather than minutes. The fact that catechin remained dominant across all treatments indicates that DIC primarily shifts availability and relative distribution rather than eliminating key constituents. As demand grows for nutrient-dense, plant-based ingredients with verified bioactive content, the image of amaranth grains exploding into porous, antioxidant-rich flour inside a steel reactor may become a familiar sight, bridging five centuries of agricultural heritage with some of the most sophisticated food engineering available today.

Subject of Research: Effect of Instant Controlled Pressure Drop processing on phenolic compounds and fatty acids in amaranth grain

Article Title: Instant Controlled Pressure Drop Processing Modulates Phenolic Composition and Fatty Acid Profile in Amaranthus hypochondriacus Grain.

Article References: Rodríguez-Castillo, P., Teresa-Martínez, G., Alonzo-Macías, M., Téllez-Pérez, C., & Cardador-Martínez, A. (2026). Instant Controlled Pressure Drop Processing Modulates Phenolic Composition and Fatty Acid Profile in Amaranthus hypochondriacus Grain.. Current Research in Food Science, Article 101576. https://doi.org/10.1016/j.crfs.2026.101576

Image Credits: AI Generated

DOI: 10.1016/j.crfs.2026.101576

Keywords: amaranth, Instant Controlled Pressure Drop, phenolic compounds, fatty acids, squalene, catechin, functional foods, HPLC, GC-MS, pseudocereal, antioxidants, food processing

The research team, led by Danhong Ge, YangYang Luo, Ruyu Zhang, Xuechao Hu, and Lujing Ren, set out to answer a deceptively simple question: what happens when you expose a microbe that normally grows in the dark to sustained light stress? Schizochytrium sp. HX-308, the strain used in the study, was isolated from seawater and deposited in the China Center for Type Culture Collection. In industrial settings it is typically fermented in large, dark vessels where it converts glucose into a lipid-rich biomass. Light, in this context, is usually treated as an irrelevance or even a nuisance. The new study suggests that assumption deserves a second look, because light turns out to be a powerful abiotic stress factor that reprograms the cell’s entire metabolic priorities.

The researchers divided the fermentation process into three distinct phases: a cell growth stage from zero to forty-eight hours, a lipid accumulation stage from forty-eight to ninety-six hours, and a lipid turnover stage from ninety-six to one hundred forty-four hours, when the cells begin consuming their own stored fat reserves. Under normal dark conditions, the culture reached a maximum cell dry weight of 50.5 grams per liter at seventy-two hours. When the flasks were illuminated with an array of LED strips delivering a total luminous flux of 18,311.4 lumens, growth slowed noticeably. Glucose consumption was delayed, the fermentation cycle stretched from seventy-two to ninety-six hours, and the peak biomass fell to 41.3 grams per liter, a reduction of 18.21 percent compared with the dark-grown control.

Microscopy revealed that the light-exposed cells were visibly different from their dark-grown counterparts. They grew larger in diameter, became more dispersed and independent in their morphology, and accumulated more prominent lipid droplets as the fermentation progressed. Using propidium iodide staining under a confocal fluorescence microscope, the team showed that cell membrane damage was consistently higher under light stress, peaking at ninety-six hours, precisely when the lipid turnover phase begins. The researchers hypothesize that the enlarged cell diameter is an adaptive response, allowing the organism to meet the elevated energy and material demands imposed by the stressful environment. Similar light-induced changes in cell size have been documented in diatoms such as Ditylum brightwellii, suggesting this may be a widespread strategy among marine microbes.

The real surprise came when the team measured what the cells were actually producing. Although the light-stressed cultures grew more slowly, their final lipid yield reached 8.45 grams per liter, a striking 39.67 percent higher than the 6.05 grams per liter measured in the control after the turnover phase had run its course. The delayed glucose consumption appears to slow the onset of lipid turnover, effectively extending the window during which the cells hold onto their oil. In other words, the stress that cost the microbe some of its growth paid off handsomely in the currency that industry actually cares about: stored lipid that survives to the end of the fermentation.

The composition of that lipid changed too, and in commercially interesting directions. Saturated fatty acids, particularly myristic acid (C14:0) and palmitic acid (C16:0), were 1.49 times more abundant in the light-treated group, reaching 4.97 percent and 15.86 percent of the total fatty acid pool respectively. Saturated fats of this kind are the raw material for neutral lipid formation and have their own market in oleochemical applications. Meanwhile, the polyunsaturated fatty acids docosapentaenoic acid and DHA declined modestly, from 24.74 percent and 59.14 percent in the control to 20.59 percent and 56.28 percent under light. But eicosapentaenoic acid, or EPA, an omega-3 fatty acid with anti-inflammatory applications and a notoriously difficult production process, jumped from 2.14 percent to 8.30 percent of total fatty acids, a 3.88-fold increase that caught the researchers’ attention.

Beyond the fatty acids, light stress proved to be a potent trigger for two of the microbe’s most valuable secondary metabolites. Squalene, a terpenoid used in cosmetics, vaccines, and pharmaceutical formulations, peaked at 67.46 milligrams per liter at seventy-two hours under light stress, compared with 55.67 milligrams per liter at forty-eight hours in the dark, and the light-stressed cultures sustained higher squalene levels through the later stages of fermentation, ending 21.17 percent above the control. Beta-carotene followed a similar pattern, peaking at roughly 7,184 micrograms per liter at ninety-six hours under light versus 5,368 micrograms per liter at seventy-two hours in the dark. By the end of fermentation, the light-stressed cultures contained 5,675 micrograms per liter of beta-carotene, 4.75 times the control level. Astaxanthin, a premium carotenoid synthesized downstream of beta-carotene, rose continuously throughout the light-stressed fermentation, finishing nearly 2,081 micrograms per liter, 11.39 percent above the control, and its accumulation only accelerated after beta-carotene had peaked, consistent with beta-carotene serving as a metabolic precursor.

To understand why light produces these effects, the team measured intracellular reactive oxygen species and performed a full transcriptomic analysis using Illumina RNA sequencing. Light stress elevated oxidative pressure inside the cells, but the light-stressed cultures actually showed lower peak ROS levels than the controls, indicating that the organism mounts a robust antioxidant defense. The transcriptome told the molecular story. A core set of 226 differentially expressed genes was shared across all light-versus-dark comparisons, while the 144-hour comparison alone revealed 788 unique light-responsive genes. At seventy-two hours, light stress predominantly suppressed metabolic genes, an acute stress response; by 144 hours, the pattern flipped to widespread upregulation, signaling a transition to long-term metabolic reprogramming. Gene ontology analysis showed marked enrichment of genes involved in stimulus response, antioxidant activity, and transporter activity under light, while genes for lipid biosynthesis and antioxidant processes became dominant at the later time point.

The pathway-level details are particularly revealing. In the mevalonate pathway, which supplies the building blocks for isoprenoids such as squalene, the enzyme isopentenyl diphosphate isomerase was significantly upregulated under light, especially at 144 hours, along with farnesyl diphosphate synthase and squalene synthase, the enzymes that assemble farnesyl diphosphate into squalene itself. Fatty acid metabolism showed a dual pattern: acetyl-CoA carboxylase and fatty acid synthase were upregulated, driving carbon toward palmitic acid, while a key beta-oxidation gene was downregulated, meaning the cells burned less of the fat they stored. Intriguingly, glycolysis genes were suppressed, suggesting the microbe rerouted carbon flux away from rapid energy production and toward lipid and terpenoid biosynthesis, a strategy that mirrors engineered lipid-boosting interventions in other microalgae. The upregulated polyketide synthase genes hint at the channeling of resources toward EPA production, which supports membrane fluidity under stress.

For the biotechnology industry, the implications are considerable. Light is an inexpensive, non-invasive, and precisely controllable stimulus compared with chemical additives or genetic engineering, and this study demonstrates that it can simultaneously raise lipid yield, enrich EPA, and boost squalene and carotenoid production in a single fermentation run. The trade-off, a longer fermentation cycle and lower biomass, is a real cost, but the researchers argue that the metabolic insights gained here, particularly the coordinated upregulation of the mevalonate pathway and the suppression of fatty acid degradation, could guide further optimization, whether through tuned light regimens, light combined with other stressors, or targeted engineering of the genes identified in the transcriptome. As demand for omega-3 oils and natural antioxidants continues to climb, the idea that a well-placed bank of LED strips could coax more value out of every liter of fermentation broth is an appealingly simple proposition, and one that this marine microbe appears ready to deliver on.

Subject of Research: Effect of light stress on lipid, fatty acid, squalene, and carotenoid biosynthesis in the marine protist Schizochytrium sp.

Article Title: Effect of light stress on the production of lipid compounds by Schizochytrium sp. and its underlying mechanism

Article References: Ge, D., Luo, Y., Zhang, R., Hu, X., & Ren, L. (2025). Effect of light stress on the production of lipid compounds by Schizochytrium sp. and its underlying mechanism. Blue Biotechnology, 2(1), Article 8. https://doi.org/10.1186/s44315-025-00029-7

Image Credits: AI Generated

DOI: 10.1186/s44315-025-00029-7

Keywords: Schizochytrium, light stress, lipid biosynthesis, EPA, DHA, squalene, beta-carotene, astaxanthin, reactive oxygen species, transcriptomics, mevalonate pathway, marine biotechnology