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Background: Plant essential oils have long been regarded as repositories of antimicrobial agents. In recent years, they have emerged as potential alternatives or supplements to antimicrobial drugs. Although literature reviews and previous studies have indicated that cinnamon essential oil (CIEO) and its major component, cinnamaldehyde (CID), possess potent antibacterial activities, their antibacterial mechanisms, especially the in vivo antibacterial mechanisms, remain elusive.Methods: In this study, we utilized the in vivo assessment system of Caenorhabditis elegans (C. elegans) to investigate the effects and mechanisms of high dose (100 mg/L) and low dose (10 mg/L) CIEO and CID in inhibiting Pseudomonas aeruginosa (P. aeruginosa). In addition, we also examined the in vitro antibacterial abilities of CIEO and CID against other common pathogens including P. aeruginosa and 4 other strains.Results: Our research revealed that both high (100 mg/L) and low doses (10 mg/L) of CIEO and CID treatment significantly alleviated the reduction in locomotion behavior, lifespan, and accumulation of P. aeruginosa in C. elegans infected with the bacteria. During P. aeruginosa infection, the transcriptional expression of antimicrobial peptide-related genes (lys-1 and lys-8) in C. elegans was upregulated with low-dose CIEO and CID treatment, while this trend was suppressed at high doses. Further investigation suggested that the PMK-1 mediated p38 signaling pathway may be involved in the regulation of CIEO and CID during nematode defense against P. aeruginosa infection. Furthermore, in vitro experimental results also revealed that CIEO and CID exhibit good antibacterial effects, which may be associated with their antioxidant properties.Conclusion: Our results indicated that low-dose CIEO and CID treatment could activate the p38 signaling pathway in C. elegans, thereby regulating antimicrobial peptides, and achieving antimicrobial effects. Meanwhile, high doses of CIEO and CID might directly participate in the internal antimicrobial processes of C. elegans. Our study provides research basis for the antibacterial properties of CIEO and CID both in vivo and in vitro.

Nanocapsule preparation technology, as an emerging technology with great development prospects, has uniqueness and superiority in various industries. In this paper, the preparation technology of nanocapsules was systematically divided into three categories: physical methods, chemical methods, and physicochemical methods. The technological innovation of different methods in recent years was reviewed, and the mechanisms of nanocapsules prepared via emulsion polymerization, interface polymerization, layer-by-layer self-assembly technology, nanoprecipitation, supercritical fluid, and nano spray drying was summarized in detail. Different from previous reviews, the renewal iteration of core–shell structural materials was highlighted, and relevant illustrations of their representative and latest research results were reviewed. With the continuous progress of nanocapsule technology, especially the continuous development of new wall materials and catalysts, new preparation technology, and new production equipment, nanocapsule technology will be used more widely in medicine, food, cosmetics, pesticides, petroleum products, and many other fields.

Litsea cubeba (Lour.) Pers. is an important woody spice tree in southern China, and its fruit is a rich source of valuable essential oil. We surveyed and sampled L. cubeba germplasm resources from 36 provenances in nine Chinese provinces, and detected rich phenotypic diversity. The survey results showed that plants of SC-KJ, SC-HJ, and SC-LS provenance presented higher leaf area (LA); YN-SM and YN-XC plants had larger thousand-grain fresh weight (TFW); and HN-DX plants had the highest essential oil content (EOC). To explain the large differences in the phenotypes of L. cubeba among different habitats, we used Pearson’s correlation analysis, multiple stepwise regression path analysis, and redundancy analysis to evaluate the phenotypic diversity of L. cubeba. It was found that compared to other traits, leaf and fruit traits had more significant geographical distributions, and that leaf phenotypes were correlated to fruit phenotypes. The results showed that elevation, latitude, longitude, total soil porosity (SP), soil bulk density (SBD), and average annual rainfall (AAR, mm) contributed significantly to the phenotypic diversity of L. cubeba. Geographical factors explained a higher percentage of variation in phenotypic diversity than did soil factors and climate factors. Plants of SC-KJ and HN-DX provenances could be important resources for domestication and breeding to develop new high-yielding varieties of this woody aromatic plant. This study describes significant phenotypic differences in L. cubeba related to adaptation to different environments, and provides a theoretical basis for the development of a breeding strategy and for optimizing L. cubeba cultivation.

Litsea cubeba (Lour.) Pers. is an important economic tree. We aimed to explore the phenotypic diversity of wild L. cubeba provenances from Jiangxi province and identify the germplasms with desirable characteristics. Nest variance analysis, multiple comparisons, correlation analysis, path analysis, redundancy analysis, and cluster analysis were conducted to compare the phenotypes of 526 wild L. cubeba trees from 27 provenances. We detected significant differences in the growth traits, fruit traits, and essential oil (EO) content of L. cubeba provenances, as well as significant differences in tree height, thousand seed dry weight, and the proportion of five essential oil components (citral, neral, geranial, D-limonene, and citronellal) within the provenances. The fresh fruit yield (FFY) was mainly determined by the ground diameter and the annual average minimum temperature. The EO content was mainly affected by the water content, annual average temperature, longitude, and latitude. The proportion of citral (CitrP) was negatively affected by extreme low temperatures. Four individual L. cubeba trees had a high FFY of over 10.00 kg·tree−1. Two trees had a high EO content exceeding 5%, with their CitrP over 80%. The provenances with high FFY were Guixi and Yushan (2.65 kg·tree−1; 2.89 kg·tree−1). The provenances with a high EO content of about 4.00% were Dayu, Yudu, Ji’an, Xinfeng, and Yushan. The provenance with the highest CitrP level (80.61%) was Ningdu.

Litsea cubeba is an important woody oil plant. The essential oils (EOs) can be extracted from its flowers, leaves and peels and, by volume, it is the most exported natural EOs from China. Thus, L. cubeba has important economic and medicinal value. Although there is demand for the rapid expansion of L. cubeba production, there has been a sharp reduction in natural resources. Therefore, determining the potentially suitable area for L. cubeba and expanding its cultivation will help meet the growing demand for volatile oil. Based on 453 distribution records of L. cubeba in China and 16 major environmental factors, we simulated the distribution pattern of the potentially suitable area of L. cubeba under three different climate change scenarios (SSP126, SSP370 and SSP585) in three time periods: the current period, 2050 s, and 2070 s. The analysis was implemented using the MaxEnt model, optimized using the ENMeval package. The jackknife test, percent contribution and response curve were used to determine the most important environmental factors and response intervals affecting the distribution of L. cubeba. We found that the parameter settings of the optimal model were RM = 2.5 and FC = LQH. The results of the MaxEnt model exhibited a high prediction accuracy and a low degree of overfitting. Precipitation of the driest quarter, annual precipitation, temperature annual range and minimum temperature of the coldest month were the dominant factors affecting the distribution of L. cubeba, and their thresholds were ≥ 36.21 mm, ≥905.95 mm, ≤32.44 °C and ≥ -3.73 °C, respectively. The results showed that the total potentially suitable area of L. cubeba in China was 208.19 × 104 km2 under current climate conditions. The predicted potentially suitable area was mainly concentrated in the 19 provinces and cities in the Yangtze River Basin and its southern area. Under future climate change conditions, the predicted potentially suitable area of L. cubeba increased with time, and the centroid of the predicted potentially suitable area of each grade moved northward. The results of this study can be used to guide the selection of future introductions, as well as the development, artificial cultivation and resource conservation of L. cubeba.

To provide data support for the development of green, efficient and safe sustained-release bacteriostatic agent of citral, the stability of the two kinds of sustained-release preparation of citral liposome (CL) and citral liposome-chitosan (CL-CS) and the bacteriostatic effect and mechanism of Aspergillus flavus were investigated. Under the condition of different temperature and pH, the appearance, particle size, Zeta potential and retention rate were studied to explore the storage stability. The instantaneous bacteriostasis rate and long-term bacteriostasis rate of citral sustained-release were determined by spore counting method. The bacteriostatic mechanism of citral sustained-release preparations was revealed according to the changes of cell permeability. The results showed that the two citral sustained-release preparations had uniform nano-sized particle sizes. After chitosan modification, the Zeta potential of the system changed from −16.63±1.67 to 35.72±3.29. After 28 days of storage at 4 ℃, the change of particle size and Zeta potential was small, and the retention rate was higher, CL-CS was more stable than CL. At pH4~6, the two sustained-release preparations were more stable, and the particle sizes of CL and CL-CS were about 150 and 200 nm. The instantaneous inhibitory EC50 of CL and CL-CS against Aspergillus flavus within 48 h were 77.88 and 68.20 mg·L−1, respectively. After 48 h of culture, the inhibitory rates of CL and CL-CS were 67.69% and 82.89%, respectively, while citral was only 30.26%. The results showed that CL-CS had good bacteriostatic effect and long-term bacteriostatic effect. The extracellular conductivity and nucleic acid content of Aspergillus flavus both increased after treatment with the two kinds of sustained release preparations, indicating that the permeability of cell membrane increased and the action time was shorter than that of free citral. In conclusion, the two kinds of sustained-release preparations have good stability. They inhibited the growth of Aspergillus flavus by the change of cell permeability and the leak of insoluble substance. The properties of CL-CS was better than CL, and it would have the potential to be developed as plant source mildew inhibitor.

In order to develop a new type of antioxidants with high efficiency, a series of β-ionone thiazolylhydrazone derivatives were designed and synthesized from β-ionone, and their structures were characterized by 1H-NMR, 13C-NMR, FT-IR, and HR-MS. The antioxidant test in vitro indicated that most of the target compounds had high biological activity. Among them, compound 1k exhibited very strong DPPH (1,1-diphenyl-2-picrylhydrazyl radical)-scavenging activity with a half-maximal effective concentration (IC50) of 86.525 μM. Furthermore, in the ABTS (2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt)-scavenging experiment, compound 1m exhibited excellent activity with an IC50 of 65.408 μM. Their biological activities were significantly better than those of the positive control Trolox. These two compounds, which have good free-radical-scavenging activity in vitro, were used as representative compounds in the anti-browning experiment of fresh-cut potatoes. The results showed that 1k and 1m had the same anti-browning ability as kojic acid, and they were effective browning inhibitors. In addition, it is well known that microbial infection is one of the reasons for food oxidation. Therefore, we investigated the antifungal activity of 25 target compounds against eight plant fungi at a concentration of 125 mg/L. The results indicated that these compounds all have some antifungal activity and may become new potential fungicides. Notably, compound 1u showed the best inhibitory effect against Poria vaporaria, with an inhibition rate as high as 77.71%; it is expected to become the dominant structure for the development of new antifungal agents.

Pyranoquinolinones synthesized from citral were used for Cu-catalyzed N-arylation with a wide range of arylboric acids. The reaction proceeded well with a broad substrate scope, providing a direct way to access highly functional pyranoquinolinone core structure derivatives in yields of up to 80%. Compared to citral, the compounds we obtained have a much better inhibitory effect on HeLa cervical cancer cells, and compound 3p has an IC50 value of 4.6 μM, lower than cisplatin’s 5.9 μM.

Acetaminophen (AC) is one of the most common over-the-counter drugs, and its pollutant in groundwater has attracted more attention due to its serious risk to human health. Currently, the research on AC is mainly focused on its detection, but few are concerned about its removal. In this work, for the first time, nitrogen-doped Soulangeana sepals derived biochar/β-cyclodextrin-Metal-organic frameworks (N-SC/β-CD-MOFs) composite was proposed for the simultaneous efficient removal and detection of AC. N-SC/β-CD-MOFs combined the properties of host-guest recognition of β-CD-MOFs and porous structure, high porosity, and large surface area of N-SC. Their synergies endowed N-SC/β-CD-MOFs with a high adsorption capacity toward AC, which was up to 66.43 mg/g. The adsorption type of AC on the surface of N-SC/β-CD-MOFs conformed to the Langmuir adsorption model, and the study of the adsorption mechanism showed that AC adsorption on N-SC was mainly achieved through hydrogen bonding. In addition, the high conductivity, large specific surface area and abundant active sites of N-SC/β-CD-MOFs were of great significance to the high-performance detection of AC. Accordingly, the sensor prepared with N-SC/β-CD-MOFs presented a wide linear range (1.0–30.0 μM) and a low limit of detection of 0.3 nM (S/N = 3). These excellent performances demonstrate that N-SC/β-CD-MOFs could act as an efficient dual-functional material for the detection and removal of AC.

At present, the technology used for the extraction and purification of Camellia oleifera saponins generally has the problems of high cost and low purity, and the quantitative detection of Camellia oleifera saponins also has the problems of low sensitivity and easy interference from impurities. To solve these problems, this paper aimed to use liquid chromatography for the quantitative detection of Camellia oleifera saponins, and to adjust and optimize the related conditions. In our study, the average recovery of Camellia oleifera saponins obtained was 100.42%. The RSD of precision test was 0.41%. The RSD of the repeatability test was 0.22%. The detection limit of the liquid chromatography was 0.06 mg/L, and the quantification limit was 0.2 mg/L. In order to improve the yield and purity, the Camellia oleifera saponins were extracted from Camellia oleifera Abel. seed meal by methanol extraction. Then, the extracted Camellia oleifera saponins were extracted with an ammonium sulfate/propanol aqueous two-phase system. We optimized the purification process of formaldehyde extraction and aqueous two-phase extraction. Under the optimal purification process, the purity of Camellia oleifera saponins extracted by methanol was 36.15%, and the yield was 25.24%. The purity of Camellia oleifera saponins obtained by aqueous two-phase extraction was 83.72%. Thus, this study can provide a reference standard for rapid and efficient detection and analysis of Camellia oleifera saponins for industrial extraction and purification.

Cinnamomum camphora is a traditional aromatic plant used to produce linalool and borneol flavors in southern China; however, its leaves also contain many other unutilized essential oils. Herein, we report geographic relationships for the yield and compositional diversity of C. camphora essential oils. The essential oils of 974 individual trees from 35 populations in 13 provinces were extracted by hydrodistillation and analyzed qualitatively and quantitatively by gas chromatography-mass spectrometry and gas chromatography-flame ionization detection, respectively. Oil yields ranged from 0.01% to 3.46%, with a significantly positive correlation with latitude and a significantly negative correlation with longitude. In total, 41 compounds were identified, including 15 monoterpenoids, 24 sesquiterpenoids, and two phenylpropanoids. Essential oil compositions varied significantly among individuals and could be categorized into various chemotypes. The six main chemotypes were eucalyptol, nerolidol, camphor, linalool, selina, and mixed types. The other 17 individual plants were chemotypically rare and exhibited high levels of methyl isoeugenol, methyl eugenol, δ-selinene, or borneol. Eucalyptol-type plants had the highest average oil yield of 1.64%, followed in decreasing order by linalool-, camphor-, mixed-, selina-, and nerolidol-type plants. In addition, the five main compounds exhibited a clear geographic gradient. Eucalyptol and linalool showed a significantly positive correlation with latitude, while selina-6-en-4-ol was significantly and negatively correlated with latitude. trans-Nerolidol and selina-6-en-4-ol showed significantly positive correlations with longitude, whereas camphor was significantly and negatively correlated with longitude. Canonical correspondence analysis indicated that environmental factors could strong effect the oil yield and essential oil profile of C. camphora.

We synthesized a series of quinazolinone derivates as tyrosinase inhibitors and evaluated their inhibition constants. We synthesized 2-(2,6-dimethylhepta-1,5-dien-1-yl)quinazolin-4(3H)-one (Q1) from the natural citral. The concentration, which led to 50% activity loss of Q1, was 103 ± 2 μM (IC50 = 103 ± 2 μM). Furthermore, we considered Q1 to be a mixed-type and reversible tyrosinase inhibitor, and determined the KI and KIS inhibition constants to be 117.07 μM and 423.63 μM, respectively. Our fluorescence experiment revealed that Q1 could interact with the substrates of tyrosine and L-DOPA in addition to tyrosinase. Molecular docking studies showed that the binding of Q1 to tyrosinase was driven by hydrogen bonding and hydrophobicity. Briefly, the current study confirmed a new tyrosinase inhibitor, which is expected to be developed into a novel pigmentation drug.

Control of fungal phytopathogens affecting crops and woodlands is an important goal in environmental management and the maintenance of food security. This work describes the synthesis of 37 camphor derivatives, of which 27 were new compounds. Their antifungal effects on six fungi were evaluated in vitro. Compounds 3a, 4a and 5k showed strong antifungal activity against Trametes versicolor, with EC50 values of 0.43, 6.80 and 4.86 mg/L, respectively, which were better than that of tricyclazole (EC50 118.20 mg/L) and close to or better than that of carbendazim (EC50 1.20 mg/L). The most potent compound, 3a, exhibited broad-spectrum antifungal activity towards six fungi with EC50 values within the range of 0.43–40.18 mg/L. Scanning electron microscopy demonstrated that compounds 3a, 4a and 5k gave irregular growth and shriveling of the mycelia. In vitro cytotoxicity evaluation revealed that the tested camphor derivatives had mild or no cytotoxicity for LO2 and HEK293T cell lines. Quantitative structure−activity relationship (QSAR) analysis revealed that the number of F atoms, relative molecular weight, the atomic orbital electronic population and total charge on the positively charged surfaces of the molecules of camphor derivatives have effects on antifungal activity. The present study may provide a theoretical basis for a high-value use of camphor and could be helpful for the development of novel potential antifungals.

Aspergillus flavus (A. flavus) is a frequent harmful fungal pathogen. It can infect traditional Chinese medicine materials and release aflatoxin, to cause both economic and human health effects. By comparing the inhibitory potential of Litsea cubeba oil and its active components to A. flavus CGMCC 3.4408, citral was confirmed to be the main component that inhibits the growth of A. flavus CGMCC 3.4408, and the EC50 was 163.65 mg L−1. The inhibitory effect of citral on A. flavus CGMCC 3.4408 was studied for colony growth rate, mycelium biomass, aflatoxin production, and microstructure. Citral slowed down the growth rate of colonies and reduced mycelium biomass and toxin production. Moreover, citral altered the morphology of fungal spores and mycelium. In addition, citral also has the inhibitory effects on the isolates of A. flavus from moldy traditional Chinese medicinal materials. Thus, citral can be used as a potential agent to check the growth of A. flavus or related fungal strains.

Using a mixture of neutral primary amine dehydroabietylamine (DHAA) and long-chain cetyltrimethyl ammonium bromide (CTAB) as the template, ordered lamellar supermicroporous silicas were synthesized with NaOH as the base source and tetraethylorthosilicate (TEOS) as the silica source. The concentrations of DHAA, CTAB, and NaOH in the synthesis system had great effects on the structural properties of the samples. When the molar ratio of components was nTEOS:nCTAB:nDHAA:nNaOH:nH2O = 1:0.114:0.00457:0.5:60, the material showed a lamellar phase with the highest ordering degree. By adding only a trace amount of DHAA into the synthesis system, the structure of the samples could be transformed from cubic phase to lamellar phase, since the added DHAA solubilized in CTAB micelles to change the effective surfactant ion pair packing parameter. The dosage of CTAB should be moderate; too high or too low will decay the ordering degree of the lamellar structure.A much higher concentration of NaOH resulted in an ethanol-rich solvent in which the DHAA did not solubilize in the micelles of CTAB, but adsorbed at the hydrophilic headgroup-solvent interface. Accordingly, a structural transformation from lamellar phase to hexagonal phase occurred.

By using dehydroabietyltrimethyl ammonium bromine (DTAB), a novel rosin-derived quaternary ammonium salt, as template and peroxotitanium acid as precursor, ordered lamellar supermicroporous titania has been synthesized via a hydrothermal process. The template agent:titanium source molar ratio in the synthesis system and the hydrothermal temperature have great impact on the microstructure characteristics of the samples. The increase of DTAB:TiO2 molar ratio from 0.04:1 to 0.10:1 is favorable to the increase of regularity of pore structures, but has no significant effects on the crystalline structures. The increase of the hydrothermal temperature from 343 to 393 K can induce an increase in crystallinity of the samples. However, the exorbitant hydrothermal temperature will reduce the regularity of pore structures. When the mole ratio of DTAB:TiO2 is 0.10:1 and the hydrothermal temperature is 373 K, the as-synthesized sample possesses pore structure with the highest level of long-range order, as well as pore wall with semicrystallized anatase phase. The pore size and the pore wall thickness are about 2.0 nm and 1.0 nm, respectively.

Moso bamboo (Phyllostachys edulis) is an important source of lignocellulosic materials because of its fast growth, its vegetative propagation, and its easy harvesting. The pretreatment of bamboo with dilute sulfuric acid and the effects on its chemical components and enzymatic hydrolysis were studied, in addition to the fibrous structural properties of pretreated residues by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. The results showed that dilute sulfuric acid pretreatment primarily hydrolyzed hemicelluloses and resulted in enhanced cellulose and lignin content in the pretreated solids. The maximum yield of hemicellulose recovery was 81.42% when pretreated with 1.00% sulfuric acid at 150 °C for 30 min, and the enzymatic hydrolysis yield was 79.45% when hydrolyzed for 72 h with an enzyme loading of cellulase 40 FPU/g of cellulose. Under these conditions, the overall sugar yield was 83.36% (cellulose and hemicellulose), with a total of 67.11 g fermentable sugars from 100 g dry bamboo. The results indicated that Moso bamboo underwent considerable changes in its chemical composition and physical properties after acid pretreatment, such as the removal of hemicellulose and lignin, an increase in specific surface area and pore volume, and exposure of internal structure, which enhances the enzymatic hydrolysis of Moso bamboo.

With the assistance of a rosin-based surfactant, dehydroabietyltrimethyl ammonium bromine (DTAB), well-dispersed hollow cube-like zirconia particles were firstly synthesized by the hydrothermal treatment of ZrOCl2 aqueous solutions. The introduction of DTAB is crucial for improving the dispersion and regularity of the as-synthesized sample. After calcination, the crystal size of the calcined samples increased, and the edge angle of the cube-like particles became round accordingly. Finally, a hollow spherical morphology was formed for the sample calcined at 923 K. The as-synthesized sample showed big surface area of 146.78 m2/g and large pore volume of 0.23 cm3/g. With the increase of calcination temperature, the surface area and pore volume of the samples decreased significantly, and the pore size increased accordingly.

Background: The development of new antifungal agents has always been a hot research topic in pesticide development. In this study, a series of derivatives of natural compound β-pinene were prepared, and the antifungal activities of these derivatives were evaluated. The purpose of this work is to develop some novel molecules as promising new fungicides. Methods: Through a variety of chemical reactions, β-pinene was transformed into a series of β-pinene-based derivatives containing amide moieties and acylthiourea moieties. The antifungal activities of these derivatives against five plant pathogens including Colletotrichum gloeosporioides, Fusarium proliferatum, Alternaria kikuchiana, Phomopsis sp. and Phytophthora capsici were tested; preliminary structure−activity relationship was discussed. Results: Some derivatives exhibited moderate or significant antifungal activity due to the fusion of the amide moiety or the acylthiourea moiety with the pinane skeleton. The structure−activity relationship analysis showed that the fluorine atom and the strong electron withdrawing nitro group, or trifluoromethyl group on the benzene ring of the derivatives had a significant effect on the improvement of the antifungal activity against Colletotrichum gloeosporioides, Fusarium proliferatum, Alternaria kikuchiana and Phomopsis sp. Meanwhile, the introduction of an ethyl group at the meta-position on the benzene ring of the derivatives could improve the antifungal activity against Phytophthora capsici. Compounds 4e, 4h, 4q, 4r exhibited broad-spectrum antifungal activity against the tested strains. Compound 4o had significant antifungal activity against Phytophthora capsici (IC50 = 0.18 μmol/L). These derivatives were expected to be used as precursor molecules for novel pesticide development in further research.

Turpentine is a renewable and resourceful forest product. The deep processing and utilization of turpentine, particularly its primary component β-pinene, has garnered widespread attention. This study aimed to synthesize 40 derivatives of β-pinene, including nopinone, 3-cyanopyridines of nopinone, myrtanyl acid, myrtanyl acylthioureas, and myrtanyl amides. We assessed the antiviral activities of these β-pinene derivatives against influenza virus A/Puerto Rico/8/34 (H1N1) using the 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The β-pinene derivatives were used before and after cellular infection with the influenza virus to evaluate their preventive and therapeutic effects against the H1N1 virus. The results showed that only compound 10o exhibited a preventive effect against the H1N1 virus with a half-maximal inhibitory concentration (IC50) value of 47.6 μmol/L. Among the compounds, 4e, 4i, and 4l demonstrated therapeutic effects against cellular infection, with compound 4e displaying the most potent therapeutic effect (IC50 = 17.5 μmol/L), comparable to the positive control ribavirin. These findings indicated that certain β-pinene derivatives exhibited in vitro antiviral activity against the H1N1 influenza A virus, warranting further investigation as potential anti-influenza agents. [ABSTRACT FROM AUTHOR]

The development of new antimicrobials has always been a research hotspot. In this study, β-pinene-based derivatives were synthesized, and their antimicrobial activity was evaluated. The purpose was to develop some novel, promising new fungicides. Three β-pinene derivatives containing bis-hydronopyl were prepared, and their antifungal and antibacterial activities were evaluated against 6 plant pathogenic fungi and 4 bacterial species; a preliminary structure-activity relationship is discussed. The results indicated that the derivatives containing the blend of alkyl group and bis-hydronopyl had potent inhibitory activities against plant fungal pathogens and bacteria. Among these molecules, bis-hydronopyl dimethyl ammonium bromide showed excellent effects on Colletotrichum acutatum with a half-maximal effective concentration of 0.538 μg/mL, which was lower than that of carbendazim. Scanning electron microscope showed that after administration of bis-hydronopyl dimethyl ammonium bromide (compound 3a), the C. acutatum mycelia were sunken and deformed in comparison with the control group. Furthermore, the inhibitory activities of the methyl derivatives against the plant pathogens were better than those of the ethyl derivatives. These results provide new insights into the inhibition of fungi and bacteria by β-pinene derivatives, which may lead them to be used as precursor molecules for novel pesticides and antimicrobials in further research. [ABSTRACT FROM AUTHOR]