Search Results (6,668)

The spectral composition and duration of light exposure can influence plant growth, secondary metabolism, and essential oil composition in medicinal and aromatic plants. Here, we evaluated the effects of lighting regime and exposure duration on the biochemical traits and essential oil composition of rosemary (Salvia rosmarinus Spenn.) under controlled conditions. Plants were exposed to white, blue, red, red/blue LED, or natural sunlight for 2, 3, or 4 weeks. The artificial light treatments were maintained at 200 ± 10 μmol m⁻² s⁻¹ PPFD, whereas the sunlight treatment was not PPFD-matched and therefore served as a greenhouse reference rather than a spectrum-matched control. Four biological replicates were used for each treatment. Chlorophyll, carotenoids, soluble sugars, total phenolics and flavonoids, DPPH radical scavenging activity, and essential oil composition were assessed. Essential oils were analyzed by gas chromatography–mass spectrometry (GC-MS). Lighting regime and exposure duration significantly affected several biochemical traits, whereas total phenolic content was not significantly affected by lighting regime. Red/blue LED treatment was associated with the highest mean values of total chlorophyll, carotenoids, total flavonoids, soluble sugars, and DPPH radical scavenging activity, although statistical significance varied among traits. Approximately 37 volatile compounds were identified across the treatments. The major constituents included α-pinene, 1,8-cineole, camphor, verbenone, borneol, bornyl acetate, and camphene and their relative abundances varied among lighting regimes and exposure durations. Principal component analysis (PCA) described differences in multivariate essential oil profiles among treatment combinations, while correlation analysis revealed associations among the relative abundances of volatile constituents. The highest essential oil yield was obtained under blue light at week 2 (1.53 ± 0.02% dry weight), whereas red/blue lighting at week 3 was associated with favorable responses in several biochemical traits. Thus, no single lighting regime and exposure duration was optimal for all measured traits. These findings indicate that lighting regime and exposure duration may be useful factors for modulating specific biochemical and essential oil characteristics of rosemary under controlled environment conditions. Full article

Waste paper is a promising secondary cellulose resource for nanocellulose production, but residual constituents originating from its previous manufacturing and recycling history may affect the chemical quality of the final material. This study evaluated purification strategies for regenerated nanocellulose (RNC) produced from waste office paper using X-ray diffraction (XRD), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), and pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS), with commercial cellulose nanocrystals (CNCs) as a reference. Direct dissolution–regeneration retained substantial concentrations of residual non-cellulosic organic compounds (542.2 mg·kg⁻¹). It generated a membrane-associated fraction representing 18% of the recovered dry mass but containing 53% of the quantified residual organic load. Post-regeneration hexane–ethanol purification reduced the organic residuum to 11.9 mg·kg⁻¹, whereas acetic acid pretreatment followed by dissolution–regeneration resulted in 20.0 mg·kg⁻¹ and prevented formation of the membrane-associated fraction. Both values were substantially below that of commercial CNCs (229.1 mg·kg⁻¹). The results demonstrate that the purification strategy controls both residual chemical composition and fractionation behaviour during processing, supporting an application-oriented purification concept in which purification intensity is matched to the requirements of the intended nanocellulose application. Full article

Aim of the Study: The aim of this study was to characterize the volatile phytochemical composition of Cannabis sativa L. essential oil (CSEO) and evaluate its in vitro inhibitory activity against selected digestive enzymes and its antiglycation activity. Molecular docking and ADMET analyses were additionally performed to explore the possible interactions and predicted pharmacokinetic properties of the major identified constituents. Materials and Methods: The chemical composition of CSEO was characterized by Gas Chromatography–Mass Spectrometry (GC-MS). Its in vitro inhibitory activity was evaluated against α-amylase, α-glucosidase, and pancreatic lipase, while its antiglycation activity was assessed by monitoring the formation of glycation products at different stages of the glycation process. Molecular docking simulations were performed to investigate the potential interactions of major identified terpenes with the active sites of the investigated enzymes. In addition, ADME analysis was conducted to predict selected pharmacokinetic and drug-likeness properties of the major constituents. Results: gc-ms analysis revealed a complex terpenoid profile, with β-caryophyllene as the major constituent, followed by selina-3,7(11)-diene (8.00%), cubenol (6.62%), γ-eudesmol (6.57%), epiglobulol (6.04%), and valencene (5.80%). CSEO showed significant in vitro inhibitory activity against α-amylase, α-glucosidase, and pancreatic lipase. The essential oil also exhibited antiglycation activity, with inhibition observed at different stages of glycation-product formation. Molecular docking analysis indicated that several major sesquiterpenes could interact with the investigated enzyme targets through different binding interactions. ADME analysis provided predicted pharmacokinetic and drug-likeness profiles for the major constituents. Conclusions: The findings demonstrate that Cannabis sativa L. essential oil possesses in vitro digestive-enzyme inhibitory and antiglycation activities. The docking results provide molecular-level insights into possible interactions between major essential-oil constituents and the investigated enzyme targets. These findings support further investigation of CSEO and its major constituents using appropriate in vivo and mechanistic studies to determine their biological relevance and potential applications. Full article

The African boxthorn (Lycium ferocissimum) is a medicinal plant belonging to the Solanaceae family that is used in traditional pharmacopeia. Here, its biological potential was assessed by analyzing the essential oil from its leaves (EOLF), extracted by hydro-distillation and major terpenes characterized by gas chromatography coupled to mass spectrometry (GC-MS). GC-MS analysis of EOLF identified fourteen compounds representing 99.95% of the total mass, which was dominated by carvacrol (35.96%) and sabinene (17.06%). EOLF exhibited antioxidant activity as characterized by several assays, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), Total Antioxidant Capacity (TAC) and the β-carotene/linoleic acid test. According to the results obtained, EOLF exhibited antioxidant activity, as measured by the DPPH assay, with a mean IC₅₀ of 96 µg/mL, which is relatively close to that of quercetin (74 µg/mL) and BHT (49.16 µg/mL). Furthermore, the activity assessed using the FRAP method showed an EC₅₀ of 282 µg/mL, comparable to that of BHT (292 µg/mL). Based on the results of the TAC method, the antioxidant activity was 880 ± 4 µg AAE/mg, while the efficacy for inhibition of β-carotene was 80%. Effective antimicrobial activity against several bacterial and fungal strains was assessed by measuring inhibition zones and Minimum Inhibitory Concentrations (MICs). EOLF exhibited significant antimicrobial activity, particularly against Klebsiella pneumoniae, with an inhibition zone of 25.08 ± 0.93 mm and an MIC of 15.68 ± 0.83 µg/mL. For Staphylococcus aureus, an inhibition zone of 23.84 ± 0.88 mm and an MIC of 11.03 ± 0.27 µg/mL were recorded. Strong antifungal activity was also observed against Candida albicans, with an inhibition zone of 22.55 ± 0.87 mm and an MIC of 10.51 ± 0.47 µg/mL. The conducted in-silico analysis confirmed the affinity of the main compounds with key biological targets, suggesting their likely roles in the observed antimicrobial effects. The ADEM-Tox properties demonstrated that the analyzed compounds would only be lethal at very great concentrations, indicating low acute toxicity, and would not be expected to elicit toxic effects at therapeutic doses. Full article

The increasing incidence of herbicide-resistant weeds and concerns over synthetic herbicides are driving the search for natural alternatives. This study evaluated the post-emergence bioherbicidal activity and mode of action of Santolina chamaecyparissus L. essential oil against Bidens pilosa L. seedlings. Gas chromatography–mass spectrometry revealed a chemically complex oil dominated by oxygenated monoterpenes, including cuminic alcohol, cis-carveol, cis-pinocarveol, α-phellandrene, and limonene. A preliminary dose–response assay identified an ED₅₀ of 0.82% (v/v). At this concentration, visible injury reached 75.9% at 72 h, while leaf relative water content declined to 40.0%. Electrolyte leakage reached 77.6% at 24 h, accompanied by a threefold increase in malondialdehyde, indicating severe membrane damage and lipid peroxidation. Chlorophyll fluorescence imaging showed impaired photosystem II function, reduced electron transport, altered energy dissipation, and loss of photosynthetic vitality. Photosynthetic pigments declined after 24 h, with chlorophyll a reduced by approximately 32.5%. Untargeted metabolomics revealed time-dependent depletion of soluble sugars, organic acids, ascorbate, and shikimate, together with accumulation of proline, γ-aminobutyric acid, trehalose, and branched-chain amino acids. Network analysis indicated loss of metabolic coordination. Overall, under the controlled experimental conditions used here, S. chamaecyparissus essential oil exhibited a rapid contact-type phytotoxic action characterised by membrane disruption, oxidative damage, dehydration, photosynthetic impairment, and extensive metabolic perturbation. Full article

Heterobasidion annosum is a destructive root- and butt-rot pathogen of coniferous forests, and its detection before the development of visible disease symptoms remains challenging. In this study, volatile organic compounds (VOCs) in the headspace of H. annosum-colonized Scots pine wood and fungal cultures were characterized by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC–MS) and compared with uncolonized pine wood and uninoculated culture medium. A total of 101 VOC signals were detected, and 98 received putative or tentative assignments. The colonized wood profile was the most diverse and comprised 64 signals, compared with 24 in uncolonized wood, 27 in the fungal culture, and 25 in the culture medium. Principal component analysis and hierarchical clustering of centered log-ratio-transformed replicate-level profiles revealed distinct compositional patterns among the four sample types. Global false-discovery-rate-adjusted q-values were below 0.05 for methyl 2-furoate, iso-longifolene, and 2-(2-furanyl)-1-propanol in the exploratory wood-profile contrast; the corresponding values for 2-methylfuran and $\beta$-barbatene were 0.0885 and 0.320. The study provides a preliminary multicomponent relative VOC profile for broader experimental and field validation. Full article

Persistent aldehydic off-notes in fish products are influenced not only by lipid oxidation but also by protein-associated retention of odor-active aldehydes. A remaining question is how gingerol side-chain length and aldehyde structure jointly alter this apparent retention. Mackerel myofibrillar protein (MP) was therefore combined with (E)-2-decenal (T2D), (E,E)-2,4-decadienal (DDE), or trans-4,5-epoxy-(E)-2-decenal (E2D), with or without 6-, 8-, or 10-gingerol. Headspace solid-phase microextraction–gas chromatography–mass spectrometry, interaction disruptors, spectroscopy, molecular docking, and 100 ns molecular dynamics simulations were integrated. All three gingerols decreased the apparent aldehyde-binding ratio of MP. At 125 µmol/g protein, 10-gingerol reduced T2D, DDE, and E2D binding from approximately 81%, 72%, and 85% to 68%, 65%, and 68%, respectively. Spectroscopic responses were consistent with changes in the optical and conformational environment; fluorescence was interpreted as apparent quenching without numerical inner-filter correction, and CD band changes provided evidence of a treatment-related conformational response without assigning exact secondary-structure fractions. Docking ranked 8-gingerol most favorably, whereas the selected binary MYH7-10-gingerol trajectory showed greater pocket residence and a more favorable MM/GBSA estimate than the corresponding MYH7-DDE trajectory. The combined evidence supports a three-layer working model involving matrix partitioning, protein-level site accessibility, and pocket-level competition. These findings provide a mechanistic basis for sensory validation rather than direct proof of deodorization. Full article

Objective: Ablative fractional laser (AFL) therapy impairs epidermal barrier integrity through the disruption of stratum corneum lipids and keratinocyte differentiation, resulting in increased transepidermal water loss (TEWL) and delayed functional recovery. This study aims to develop a more effective barrier repair strategy and evaluate the efficacy of topical safflower seed oil (SSO) in promoting post-AFL barrier restoration. Methods: An optimized murine AFL model (20 W, 0.5 ms pulse delay, and 0.7 mm spot spacing) was established to investigate skin repair mechanisms. SSO composition was characterized by gas chromatography–mass spectrometry (GC-MS). Epidermal repair was assessed using confocal laser scanning microscopy, while Oil Red O staining and immunofluorescence were employed to evaluate lipid formation and the expression of lipid synthesis-related genes, respectively. Results: GC-MS analysis identified SSO as a rich natural source of linoleic acid (69.1%) and oleic acid (18.7%). Over the 7-day period of AFL exposure alone, TEWL rose by 4–6 fold in mouse skin, accompanied by a near-complete loss of epidermal lipid synthesis. However, upon SSO administration, a marked reduction in TEWL was observed from day 1, and epidermal lipid synthesis recovered by day 7. Moreover, SSO treatment significantly upregulated epidermal PPARγ expression in AFL-injured skin. Pharmacological inhibition of PPARγ (T0070907) largely abrogated the lipid synthesis and barrier repair effects of SSO, while PPARα antagonism (GW6471) showed no obvious interference with SSO’s therapeutic efficacy, suggesting a potential association between PPARγ signaling modulation and SSO-mediated skin barrier restoration. Conclusions: These findings suggest that SSO is a promising natural agent for post-AFL skin care, which improves AFL-impaired skin barrier function by remodeling lipid metabolism, at least in part through PPARγ signaling, and warrants further preclinical and clinical investigation. Full article

Yamasachi, an original red wine grape in Hokkaido, is a hybrid variety between ‘Seibel 13053’ and an indigenous wild grape. This study aimed to elucidate the aromatic compounds characterizing Yamasachi wine. Two methods, instrumental analysis using gas chromatography combined with time-of-flight mass spectrometry (GC–TOFMS) and sensory perception, were employed. Seven unique key aroma compounds, linalool ethyl ether, vitispirane, Bois de Rose oxide, trans-2-hexen-1-ol, cis-3-hexen-1-ol, 4-ethylguaiacol, and 4-ethylphenol, were identified. Additionally, principal component analysis revealed strong perceptions of green pepper, horseradish, earthy, mushroom, black fruits, herbs, and spices in the Yamasachi wine aroma profile. Surprisingly, sensory analysis of Yamasachi wine did not detect any negative phenolic off-flavors; nevertheless, the higher 4-ethylguaiacol and 4-ethylphenol concentrations were detected. Spike experiments with these compounds repressed the unpleasant phenolic aroma in Yamasachi wine. These results suggest that Yamasachi wine has a masking effect on phenolic off-flavors. Full article

Pelargonium graveolens and Pelargonium zonale are promising sources of natural antioxidants and other bioactive compounds that may find future use in topical cosmetic preparations. The aim of our study was to investigate the antioxidant properties and chemical composition of extracts obtained from various aerial parts of both plant species using ultrasound-assisted extraction (UAE) and Soxhlet extraction. Their suitability as active ingredients in cosmetic emulsions and hydrogel patches was also evaluated. The plant material was extracted with aqueous ethanol solutions of various concentrations under various extraction conditions. The antioxidant activity of the extracts was tested using the DPPH, ABTS, and Folin–Ciocalteu methods, whereas their chemical composition was characterized by gas chromatography–mass spectrometry (GC–MS). Selected extracts were incorporated into cosmetic formulations, which were then assessed for antioxidant activity, cytocompatibility, and antimicrobial properties. The antioxidant activity of the extracts depended on the Pelargonium species, plant organ, extraction method, and the composition of the aqueous ethanol solutions used for extraction. Among the extracts obtained by UAE, those prepared from dried P. graveolens leaves in 40% (v/v) EtOH after 30 min, fresh P. zonale leaves in 96% (v/v) EtOH for 60 min and fresh P. zonale flowers in 96% (v/v) EtOH for 60 min exhibited the highest antioxidant potential. GC–MS analysis revealed the presence of a large number of compounds with antioxidant properties reported in the scientific literature, including geraniol, citronellol, linalool, phytol, ethyl gallate, and 1,2,3-benzenetriol. These findings confirm that both plant species are rich in biologically active compounds. The developed cosmetic emulsions retained considerable antioxidant activity and showed high in vitro cytocompatibility toward human fibroblasts, although a modest concentration-dependent reduction in metabolic activity was observed at the highest concentration tested. Selected hydrogel discs containing Pelargonium extracts produced measurable control-corrected antibacterial responses against Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922. Among the four Soxhlet extracts evaluated, measurable minimum inhibitory concentration (MIC) values ranged from 5% to 28%. The lowest MIC value against S. aureus (5 ± 2%) was observed for the fresh-flower extract of P. zonale, whereas no MIC endpoint was observed for the dried-leaf extract of P. graveolens against E. coli within the tested concentration range. No measurable inhibition zone was observed for the cream formulations under the applied paper-disc diffusion conditions. The obtained results indicate that P. graveolens and P. zonale are valuable natural sources of bioactive compounds with antioxidant potential and that selected hydrogel formulations show preliminary antibacterial activity under the tested in vitro conditions. Full article

Canine cancer screening has an important limitation in that organ-specific screening strategies used in human medicine cannot be directly applied across routine veterinary clinical practice. Blood-based volatile organic compound (VOC) profiling may provide a practical approach for pan-cancer screening; however, its application in multicenter and multinational settings requires evaluation that accounts for cohort heterogeneity and analytical variability. In this study, we evaluated the canine cancer screening performance of an integrated classification framework using a headspace gas chromatography–mass spectrometry (HS-GC/MS)-based targeted blood VOC panel in a retrospective multicohort dataset comprising dogs recruited in Korea and Thailand. Whole-blood samples from 590 dogs recruited in Korea and Thailand were analyzed, including 167 dogs in the malignant tumor group and 423 dogs in the non-cancer control group. The predefined targeted VOC panel consisted of aromatic compounds and straight-chain alkanes and was analyzed using HS-GC/MS. The Korea and Thailand cohorts were incorporated into a single integrated classification framework rather than being separated into country-specific models. To evaluate performance variability associated with data partitioning, cohort-aware stratified training–validation splitting was repeated 30 times within the integrated retrospective cohort, with both national cohorts represented in the training and validation sets in each repeat. Class imbalance correction was applied only to the training data, and validation performance was assessed using both threshold-dependent and threshold-independent metrics. Across the 30 repeated validations, the integrated framework achieved an AUROC of 0.926 ± 0.019 and an AUPRC of 0.894 ± 0.023. Balanced accuracy, accuracy, sensitivity, specificity, F1-score, MCC, and Cohen’s κ were 0.858 ± 0.024, 0.895 ± 0.018, 0.772 ± 0.048, 0.943 ± 0.022, 0.805 ± 0.033, 0.736 ± 0.046, and 0.734 ± 0.045, respectively. In the sample-level prediction score analysis, the median predicted cancer probabilities for cancer and non-cancer samples were 0.954 and 0.041, respectively, indicating clear probability-based separation between the two groups. In the cohort-specific analysis, the discrimination signal was maintained in both the Korea and Thailand cohorts, although threshold-dependent performance differed between the two cohorts. These findings indicate that an HS-GC/MS-based targeted blood VOC panel provided a consistent cancer-associated classification signal under repeated internal validation within the specific integrated retrospective dataset evaluated in this study. The results demonstrate the feasibility of evaluating a common classification framework across the Korea and Thailand cohorts without constructing separate country-specific models, while not establishing independent external generalizability or platform-independent robustness. Because the Korea and Thailand cohorts were completely confounded with the Agilent and Thermo Fisher analytical platforms, respectively, the independent contributions of cohort characteristics and analytical platform cannot be determined from the present data. Further independent prospective validation in newly recruited populations and institutions, together with disease-control evaluation including clinically relevant controls, cohort-specific calibration, evaluation across analytical platforms, and assessment of clinical utility within real-world workflows, is required before the external generalizability and clinical applicability of the framework can be determined. Full article

Recycled polyethylene terephthalate (rPET) intended for food-contact applications contains complex mixtures of non-intentionally added substances (NIAS) originating from polymer degradation, recycling, packaging-related inputs, and external contamination. Although non-targeted analytical techniques can characterise these complex chemical fingerprints, a standardised framework for their systematic interpretation is lacking. This study introduces a literature-informed, pattern-based framework for interpreting Py-GC/MS fingerprints of commercial PET bottles. Twenty-two commercial PET beverage bottles were analysed by pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS), and detected compounds were organised into four diagnostic profile groups: PET transformation products (C-PET), packaging-associated compounds (E-PS/PVC/FCM), mixed-origin compounds (M-MIX), and condensed aromatic structures (A-AROM). Principal component analysis and a composite Quality Index (QI) were used to evaluate chemical variability. PET transformation products formed a consistent chemical baseline across all samples, whereas chemical variability was primarily associated with packaging-associated compounds and condensed aromatic structures. Bottles containing 100% rPET spanned the full range of chemical profiles, suggesting that the observed variability may be influenced more strongly by feedstock quality, packaging-related inputs, and processing history than by declared recycled content alone. The proposed framework enables a systematic interpretation of Py-GC/MS fingerprints through diagnostic chemical patterns rather than unique source attribution of individual compounds. The proposed framework provides a scalable methodology for comparative evaluation of recycled PET. It highlights that improving chemical quality requires controlling feedstock purity, packaging-related contamination, and processing conditions rather than relying solely on recycled content. Full article

Continuous, real-time monitoring of volatile organic compounds (VOCs) in surface water is critical for environmental protection, yet conventional laboratory Gas Chromatography–Mass Spectrometry (GC-MS) suffers from analyte loss during sample transport. This study field-validates a portable Membrane Inlet Mass Spectrometry (MIMS) system for direct, on-site monitoring of seven target VOCs (benzene, toluene, xylenes, chlorobenzene, 1,2-dichloroethane, trichloroethylene, and tetrachloroethylene). Laboratory validation established limits of detection between 4 and 8 µg/L, linearity (R² > 0.98), and acceptable precision and accuracy per AOAC guidelines, benchmarked against headspace GC-MS. In-field testing at 36 locations across the Danube–Tisa–Danube (DTD) irrigation canal demonstrated system robustness. Baseline canal samples remained below the detection limits, but real-time MIMS successfully identified localized benzene and toluene contamination near a gasoline station. On-site MIMS detected higher VOC concentrations than delayed laboratory GC-MS, demonstrating its key advantage in preventing sampling volatilization losses. Portable MIMS proves to be a powerful, rapid screening tool for continuous aquatic environmental monitoring. Full article

Colorectal cancer (CRC) remains one of the leading causes of cancer-related mortality worldwide, largely due to delayed diagnosis. Current screening approaches are limited by invasiveness, cost, and low patient adherence, underscoring the urgent need for non-invasive biomarkers that could complement the existing strategies. Cancer-associated metabolic reprogramming, together with alterations in host–microbiota interactions, is reflected in the urinary volatilome, offering a potential source of candidate biomarkers. In this exploratory, case–control pilot study, urinary volatile organic metabolites (VOMs) were profiled in patients with colorectal cancer (CRC, n = 19) and healthy controls (HCs, n = 17) using headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC–MS). Univariate and multivariate statistical modelling was applied to characterize disease-associated metabolic patterns. Sixty-seven urinary VOMs were identified, with terpenoids, ketones, phenolic compounds and norisoprenoids representing the predominant chemical classes. Following participant-level analysis and correction for multiple comparisons, 18 VOMs remained statistically significant between the two groups, consistent with metabolic perturbations previously associated with colorectal carcinogenesis, including gut microbial dysbiosis, oxidative stress, lipid peroxidation, chronic inflammation and altered energy metabolism. Orthogonal partial least squares-discriminant analysis (OPLS-DA), validated with participant-level cross-validation and 1000 permutations, revealed a separation between CRC and HC groups, supporting the existence of a disease-associated urinary volatilomic profile. Notably, one participant initially classified as an HC was subsequently diagnosed with metastatic CRC. This participant clustered with the CRC group in an unsupervised analysis performed using the original group label, without knowledge of the later diagnosis, raising the hypothesis, to be confirmed in a prospective cohort, that urinary volatilomic alterations may be detectable before clinical diagnosis. Our findings indicate that urinary volatilomic profiling captures metabolic changes associated with CRC and represents a promising, hypothesis-generating starting point for non-invasive biomarker discovery. Full article

Poecilocerus pictus and Danaus chrysippus are two common herbivorous insects that share the same host plant, Calotropis gigantea, yet they exhibit distinct feeding preferences and food utilization patterns across leaf ages. D. chrysippus larvae performed better on young leaves, which contain higher water content and suitable nutrients; before feeding, they cut leaf surfaces and inflorescence bases to interrupt latex flow and access floral sugars. P. pictus thrived on mature leaves, which offer a more balanced nutrient composition and moisture level; nymphs made serial cuts on the lower leaf surface to block latex, while adults typically fed from leaf tips. Both species performed poorly on senescent leaves, which are tough, nutrient-poor, and show altered glycoside profiles. Amino acids such as asparagine, proline, glutamine, glutamic acid, valine, alanine, and phenylalanine were more abundant in young leaves, likely explaining the strong preference of D. chrysippus, whereas mature leaves had an amino acid profile better suited to P. pictus. Gas chromatography–mass spectrometry (GC-MS) analysis revealed distinct phytochemical compositions among young, mature, and senescent leaves, as well as inflorescences. These chemical differences, particularly in water, nitrogen, and key metabolites, strongly influence the feeding behavior and growth of both the hemimetabolous grasshopper and the holometabolous butterfly. Full article