Shun Gao

The Houpoea officinalis flower (HOF) represents an underutilized sustainable bio-resource. This study systematically evaluated its potential using an ethanol-based green extraction process optimized by Response Surface Methodology, with the optimal conditions consisting of approximately 50% ethanol, a solvent-to-solid ratio of 54 mL/g, and an extraction time of 31 min. Chemical profiling across four developmental stages—S1 (Bud), S2 (Bud swelling), S3 (Initial flowering), and S4 (Full bloom)—suggested magnolol and honokiol as the major phenolic compounds, showing a trend of decline during early development followed by an increase at the S4 stage. A significant positive correlation was observed between total phenolic content and antioxidant activity, and the S1 stage extract displayed the strongest antioxidant capacity in multiple in vitro assays. Network pharmacology analysis predicted oxidative stress-related targets and pathways, with TP53, AKT1, IL6, BCL2, and CASP3 recognized as key hub genes. Molecular docking further predicted favorable binding interactions between major HOF phenolics and these target proteins. Collectively, these findings reveal the multi-target antioxidant potential of HOF and provide evidence supporting its potential role in antioxidant-related traditional applications based on predicted mechanisms. Moreover, HOF, particularly at the S1 developmental stage, shows promise as a sustainable source of natural antioxidants and functional ingredients, promoting the high-value utilization of agricultural by-products.

Carbon (C), nitrogen (N) and phosphorus (P), and non-structural carbohydrates (NSCs) are basic nutrients and energy sources for flower development. In this study, the morphological traits, C, N, P, and NSC concentrations, and C:N:P ratios in pistil, stamen, and petal of C. maxima flower at three phenophases (BBCH54, BBCH59, and BBCH61) were comparatively analyzed. Morphology diverged markedly among the three phenophases, whereas relative water contents were stable. C, N, P, and NSC showed larger variations at three phenophases and parts in C. maxima flower. Maximal C:N, C:P, and N:P occurred in pistils, pistils, and petals at BBCH61, respectively. C:N:P stoichiometry was the most responsive to ontogeny, indicating development-specific elemental storage and biomass partitioning of C. maxima flowers. NSC contents (glucose, fructose, sucrose, starch) differed significantly among organs and phenophases, and peak NSC appeared in the pistils at the three phenophases. High correlations between NSCs and C:N:P ratios suggested coordinated resource allocation. Correlation analysis showed that significant differences occurred at three phenophases for the accumulation and allocation of C, N, P, and NSCs. Principal component analysis (PCA) ordinated samples along PC-1 (44.2%) and PC-2 (24.4%), cumulatively explaining 68.6% of variance, corroborating development- and organ-dependent divergence. These data elucidated the intricate regulatory dynamics of nutrient contents among the three parts during the flower development of C. maxima, providing a robust quantitative framework for targeted nutrient management strategies.

Zanthoxylum armatum DC. (Z. armatum) is a versatile plant species valued for its aroma oil and nutritional components. However, the variability of chemical composition in Z. armatum fruits in the field remains largely unknown, and it is still unclear how harvest parameters affect the aroma and nutritional quality of the fruits. To address this gap, Z. armatum fruits from varying harvest times, tree ages, and fruiting positions were analyzed for physicochemical properties, nutrients, minerals, aroma profiles, and antioxidant activity. A quality assessment method was developed based on key Z. armatum fruit parameters. Results showed significant differences in the size, weight, total phenol, flavonoid and sanshool content of Z. armatum fruit from different harvest parameters. Z. armatum fruits contained abundant minerals, showing diverse harvest-condition variations. In vitro antioxidant assays showed higher ABTS/DPPH scavenging activity and reducing capacity (23–54 mg/g). HS-SPME-GC-MS identified 64 aroma compounds, encompassing terpenes, alcohols, etc. Linalool was the predominant constituent (46.65%). PLS-DA and Volcano plot analyses highlighted significant differences in VOCs among harvest times and tree ages, while fruit positions showed minimal impact. The Mantel test identified aroma-active compounds associated with antioxidant activity. These findings facilitate a science-based harvesting strategy to standardize Z. armatum fruit quality and marketability.

Houpoea officinalis (H. officinalis) flowers are rich in a spectrum of bioactive compounds and mineral nutrients. The availability and balance of mineral elements directly impact the morphogenesis of flower organs, which play pivotal roles in various physiological and biochemical processes that drive flower development. However, relatively little is known about the changes in mineral elements composition that occur during flower development in H. officinalis. The objective of this study is to analyze the variations of 22 mineral elements contents in pistil, stamens, and petals of H. officinalis flower at four development stages. The amount of mineral elements (Na, Mg, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Sn, Al, Ti, Ga, Cd, Ba, Tl, Pb, and Bi) in these samples was determined using atomic absorption spectroscopy and inductively coupled plasma mass spectrometry. Results showed that H. officinalis flowers are rich in macroelements such as potassium (K, 25.80–48.06 mg/g) and calcium (Ca, 17.27–31.00 mg/g), as well as microelements like zinc (Zn, 445.17–1553.16 μg/g) and iron (Fe, 324.27–622.31 μg/g). Notably, the pistil part is found to harbor a more significant concentration of mineral elements during the early developmental stages of flowers. Correlation analysis and PCA have effectively exposed a pronounced association between the accumulation patterns of mineral elements in H. officinalis flowers and their corresponding developmental stages and organs. These findings will provide more detailed information about the accumulation and distribution of mineral elements in H. officinalis flowers at different development stages and organs, which help to encourage researchers to enhance the flower quality for human consumption.

Allelopathy is an underlying and controversial mechanism for detrimental environmental effects in the management of Eucalyptus plantations. However, little attention has been paid to the dynamics of allelochemicals and phytotoxicity in soil fauna during litter decomposition. To explore the relationship between the dynamics of phytotoxicity and allelochemicals, a decomposition experiment was conducted using 4-year-old and 8-year-old Eucalyptus grandis litter (0, 10, 20, 30, and 45 days). The acute toxicity of Eisenia fetida was assessed, and a chemical analysis of the eucalyptus leaves was performed. Biochemical markers, including total protein, acetylcholinesterase (AChE) activity, and oxidative stress levels (SOD and MDA) were measured. A comet assay was used to determine DNA damage in E. fetida cells. The results showed that after 20–30 days of decomposition, E. grandis litter exhibited stronger phytotoxic effects on E. fetida in terms of growth and biochemical levels. After 20 days of decomposition, the weight and total protein content of E. fetida first decreased and then increased over time. SOD activity increased after 20 days but decreased after 30 days of decomposition before increasing again. MDA content increased after 20 days, then decreased or was stable. AChE activity was inhibited after 30 days of decomposition and then increased or stabilized with further decomposition. Soluble allelochemicals, such as betaine, chlorogenic acid, and isoquercitrin, significantly decreased or disappeared during the initial decomposition stage, but pipecolic acid significantly increased, along with newly emerging phenolic fractions that were present. More allelochemicals were released from 8-year-old litter than from 4-year-old E. grandis litter, resulting in consistently more severe phytotoxic responses and DNA damage in E. fetida. Scientific management measures, such as the appropriate removal of leaf litter in the early stages of decomposition, might help support greater biodiversity in E. grandis plantations.