GC-MS Analysis of the Volatile Constituents in the Leaves of 14 Compositae Plants

Insights into Metabolites Profiling and Pharmacological Investigation of Aconitum heterophyllum wall ex. Royle Stem through Experimental and Bioinformatics Techniques

The Aconitum genus is a leading source of a wide range of structurally diverse metabolites with significant pharmacological implications. The present study investigated metabolite profiling, pharmacological investigation, anticancer potential, and molecular docking analysis of the stem part of Aconitum heterophyllum (AHS). The metabolite profiling of the AHS extract was experimentally examined using LC-MS/MS-orbitrap in both modes (ESI+/ESI-) and GC-MS in EI mode. The in vitro MTT model was used to study the anticancer potential, while the in vivo animal model was used to study the anti-inflammatory and antinociceptive activities. The MOE software was used for the molecular docking study. A total of 118 novel and previously known metabolites, among 44 metabolites (26 in ESI+ positive mode and 18 in ESI- negative mode) in the MeOH extract, while 74 metabolites (46 in ESI+ and 28 in ESI- mode) were identified in the n-hexane extract via LCMS/MS. The identified metabolites include 24 phenolic compounds, 18 alkaloids, 10 flavonoids, 24 terpenoids, 2 coumarins, 2 lignans, and 38 other fatty acids and organic compounds. The major bioactive metabolites identified were hordenine, hernagine, formononetin, chrysin, N-methylhernagine, guineesine, shogaol, kauralexin, colneleate, zerumbone, medicarpin, boldine, miraxinthin-v, and lariciresinol-4-O-glucoside. Furthermore, the GC-MS study helped in the identification of volatile and nonvolatile chemical constituents based on the mass spectrum and retention indices. The methanol extract significantly inhibited tumor progression in H9c2 and MDCK cancer cells with IC50 values of 186.39 and 199.63 μg/mL. In comparison, the positive control aconitine exhibited potent IC50 values (132.32 and 141.58 μg/mL) against H9c2 and MDCK cell lines. The anti-inflammatory (carrageenan-induced hind paw edema) and antinociceptive (acetic acid-induced writhing) effects were significantly dose-dependent, (p < 0.001) and (p < 0.05), respectively. In addition, a molecular docking study was conducted on identified ligands against the anti-inflammatory enzyme (COX-2) (PDB ID: 5JVZ) and the cancer enzyme ADAM10 (PDB ID: 6BDZ) which confirmed the anti-inflammatory and anticancer effects in an in silico model. Among all ligands, L2, L3, and L7 exhibit the most potent potential for inhibiting COX-2 inflammation with binding energies of -7.3424, -7.0427, and -8.3562 kcal/mol. Conversely, against ADAM10 cancer protein, ligands L1, L4, L6, and L7, with binding energies of -8.0650, -7.7276, -7.0454, and -7.2080 kcal/mol, demonstrated notable effectiveness. Overall, the identified metabolites revealed in this AHS research study hold promise for discovering novel possibilities in the disciplines of chemotaxonomy and pharmacology.

Comparative chemical profiling of leaf essential oils from Cinnamomum kanehirae and related species using steam distillation and solvent extraction: Implications for plant-based classification

Cinnamomum kanehirae Hayata, belonging to Lauraceae family, is an indigenous and endangered species of considerable economic importance in Taiwan. It plays a crucial role as the host for the economically valuable saprotrophic fungus, Taiwanofungus camphorates. However, accurate species identification poses a challenge due to the similarity in morphological features and frequent natural hybridization with closely related species. Acquiring high-quality and pure leaf oils becomes imperative for precise species identification and producing superior goods. In this study, our objective was to establish methodologies for analyzing the chemical composition of leaf essential oils and subsequently apply this knowledge to differentiate among three Cinnamomum species. Gas chromatography-mass spectrometry (GC/MS) was employed to scrutinize the chemical makeup of leaf essential oils from three closely related species: C. kanehirae, C. micranthum, and C. camphora. We utilized Steam Distillation (SD) and steam distillation-solvent extraction (SDSE) methods, with the SDSE-Hexane approach chosen for optimization, enhancing extraction efficiency and ensuring essential oil purity. Through the SDSE-Hexane method, we identified seventy-four compounds distributed across three major classes: monoterpenes hydrocarbons (0.0-7.0 %), oxygenated monoterpenes (3.8-90.9 %), sesquiterpenes hydrocarbons (0.0-28.3 %), and oxygenated sesquiterpenes (1.6-88.1 %). Our findings indicated the presence of more than one chemotype in both C. kanehirae and C. camphora, whereas no specific chemotype could be discerned in C. micranthum. Furthermore, clustering based on chemotypes allowed for the differentiation of samples from the three species. Notably, we demonstrated that the chemical compositions of grafted C. kanehirae remained largely unaffected by the rootstock. Conversely, natural hybrids between C. kanehirae and C. camphora exhibited profiles more closely aligned with C. kanehirae. The optimized extraction method and the chemotype-based classification system established in this study present valuable tools for essential oil preparation, species identification, and further exploration into the genetic variation of Cinnamomum.

Comparative Analysis of Chemical Profile and Biological Activity of Juniperus communis L. Berry Extracts

Researchers are looking for the most effective ways to extract the bioactive substances of Juniperus communis L. berries, which are capable of displaying the greatest range of biological activity, namely antimicrobial potential "against phytopathogens", antioxidant activity and nematocidal activity. This study provides detailed information on the chemical activity, group composition and biological activity of the extracts of juniper berries of 1- and 2-year maturity (JB1 and JB2), which were obtained by using different solvents (pentane, chloroform, acetone, methanol and 70% ethanol) under various extraction conditions (maceration and ultrasound-assisted maceration (US)). Seventy percent ethanol and acetone extracts of juniper berries were analyzed via gas chromatography-mass spectrometry, and they contained monoterpenes, sesquiterpenes, polysaccharides, steroids, fatty acid esters and bicyclic monoterpenes. The antimicrobial activity was higher in the berries of 1-year maturity, while the acetone extract obtained via ultrasound-assisted maceration was the most bioactive in relation to the phytopathogens. Depending on the extraction method and the choice of solvent, the antioxidant activity with the use of US decreased by 1.5-1.9 times compared to the extracts obtained via maceration. An analysis of the nematocidal activity showed that the sensitivity to the action of extracts in Caenorhabditis elegans was significantly higher than in Caenorhabditis briggsae, particularly for the acetone extract obtained from the juniper berries of 1-year maturity.

Distinguishing features of Lycium L. species (family Solanaceae) distributed in Egypt based on their anatomical, metabolic, molecular, and ecological characteristics

Among the 70-80 species of the genus Lycium (family Solanaceae) disjunctly distributed around the world, only three are frequently distributed in different locations in Egypt. Due to the morphological similarities between these three species, there is a need for alternative tools to distinguish them. Thus, the objective of this study was to revise the taxonomic features of Lycium europaeum L., Lycium shawii Roem. & Schult., and Lycium schweinfurthii var. aschersonii (Dammer) Feinbrun in consideration of their anatomical, metabolic, molecular, and ecological characteristics. In addition to analysis of their anatomical and ecological features, DNA barcoding was performed for molecular characterization through internal transcribed spacer (ITS) sequencing and start codon targeted (SCoT) markers. Furthermore, metabolic profiling of the studied species was conducted based on gas chromatography-mass spectrometry (GC-MS). The observed anatomical features of the adaxial and abaxial epidermal layers, type of mesophyll, crystals, number of palisade and spongy layers, and the vascular system showed variations between the studied species. Beyond this, the anatomy of the leaves showed an isobilateral structure in the studied species, without distinct differences. Species were molecularly identified in terms of ITS sequences and SCoT markers. The ITS sequences were deposited in GenBank with accession numbers ON149839.1, OP597546.1, and ON521125.1 for L. europaeum L., L. shawii, and L. schweinfurthii var. aschersonii, respectively. The sequences showed variations in GC content between the studied species; this was 63.6% in L. europaeum, 61.53% in L. shawii, and 63.55% in L. schweinfurthii var. aschersonii. A total of 62 amplified fragments, including 44 polymorphic fragments with a ratio of 70.97%, were obtained in the SCoT analysis, as well as unique amplicons in L. europaeum L., shawii, and L. schweinfurthii var. aschersonii of 5, 11, and 4 fragments, respectively. Through GC-MS profiling, 38 compounds were identified with clear fluctuations in the extracts of each species. Of these, 23 were distinguishing chemicals that could help in chemical identification of the extracts of the studied species. The present study succeeds in identifying alternative clear and diverse characteristics that can be used to distinguish between L. europaeum, L. shawii, and L. schweinfurthii var. aschersonii.

Phytochemistry and Biological Activities of Essential Oils from Six Aromatic Medicinal Plants with Cosmetic Properties

In this work, the chemical composition and antioxidant and antimicrobial activities of the essential oils (EOs) of six species-Laurus nobilis, Chamaemelum nobile, Citrus aurantium, Pistacia lentiscus, Cedrus atlantica, and Rosa damascena-have been studied. Phytochemical screening of these plants revealed the presence of primary metabolites, namely, lipids, proteins, reducing sugars, and polysaccharides, and also secondary metabolites such as tannins, flavonoids, and mucilages. The essential oils were extracted by hydrodistillation in a Clevenger-type apparatus. The yields are between 0.06 and 4.78% (mL/100 g). The analysis of the chemical composition carried out by GC-MS showed the presence of 30 to 35 compounds and represent between 99.97% and 100% of the total composition of EOs, with a variation in the chemical composition detected at the level of the majority compounds between these species. Indeed, in the EO of Laurus nobilis, 1,8-cineole (36.58%) is the major component. In Chamaemelum nobile EO, the most abundant compound is angelylangelate (41.79%). The EO of Citrus aurantium is rich in linalool (29.01%). The EO of Pistacia lentiscus is dominated by 3-methylpentylangelate (27.83%). The main compound of Cedrus atlantica is β-himachalene (40.19%), while the EO of Rosa damascenaa flowers is rich in n-nonadecane (44.89%). The analysis of the similarity between the EOs of the plants studied by ACH and ACP showed that the chemical composition of the EOs makes it possible to separate these plants into three groups: the first represented by Chamaemelum nobile, because it is rich in oxygenated monoterpenes, the second defined Cedrus atlantica and Rosa damascena, which are rich in sesquiterpenes, and the third gathers Pistacia lentiscus, Laurus nobilis and Citrus aurantium, which are composed of oxygenated sesquiterpenes and monoterpenes (these three species are very close). The study of the antioxidant activity showed that all the EOs tested have a high capacity for scavenging free radicals from DPPH. The EOs of Laurus nobilis and Pistacia lentiscus showed the highest activity, 76.84% and 71.53%, respectively, followed by Cedrus atlantica EO (62.38%) and Chamaemelum nobile (47.98%) then Citrus aurantium EO (14.70%). Antimicrobial activity EO was tested against eight bacterial strains and eight fungal strains; the results showed that EOs exhibit significant bactericidal and fungicidal activities against all the microorganisms tested, of which the MICs of the bacterial strains start with 5 mg/mL, while the MICs of the fungal strains are between 0.60 mg/mL and 5 mg/mL. Thus, these EOs rich in antimicrobial and antioxidant components can serve as a natural alternative; this confirms their use as additives in cosmetics.

Chemical composition and healing potential of essential oil of Dennettia tripetala on methicillin-resistant Staphylococcus aureus: infected wound model

Background

Dennettia tripetala (Pepperfruit) is an important medicinal plant in some West African communities. This study was designed to examine the antibacterial properties and wound-healing abilities of D. tripetala essential oil on mice with methicillin-resistant Staphylococcus aureus (MRSA) infections. Gas chromatography-mass spectrometry (GC–MS) was used to analyse the essential oil (EO) extracted by hydro-distillation from the dried fruits of D. tripetala. MRSA was identified using 30 µg cefoxitin disk, CHROMagar, and Polymerase Chain Reaction. Congo red agar and tube technique were used to assess the production of biofilms. The antimicrobial susceptibility for both antibiotics and essential oil was determined by Kirby Bauer and broth dilution methods. Eleven male mice were used in the invivo study, and each animal had wound infection on the dorsal inter-scapular skin region created with a 6 mm biopsy punch and 50 μl (adjusted to 0.5 McFarland standard) of MRSA. The size of the wound and its histological characteristics were used to estimate healing rate.

Results

The GC–MS investigation of the essential oil revealed six compounds, with benzene (2-nitroethyl) being the most prominent. Out of the eighteen (18) isolates examined, 12 MRSA strains were identified using the three methods for methicillin resistance determination, with about 80% of them being classified as biofilm producers. More than 60% of the MRSA isolates were resistant to erythromycin, fusidic acid, gentamicin and trimethoprim/sulfamethoxazole. The essential oil had greater antibacterial activity than the reference antibiotic, vancomycin. The essential oil had a minimum inhibitory concentration of 80 l/ml and a minimum bactericidal concentration of 160 l/ml (v/v). Haematoxylin and eosin staining revealed that the skin tissue that had been exposed to D. tripetala essential oil had a thicker epithelial layer, numerous fibroblasts, a build-up of collagen, and many blood cells.

Conclusions

The results showed that D. tripetala essential oil has powerful anti-staphylococcal properties as well as the capacity to expedite wound healing. This suggests that D. tripetala essential oil could be a successful candidate for developing a topical agent for wound management.

Hydrosols of Veronica Species-Natural Source of Free Volatile Compounds with Potential Pharmacological Interest

In this study, free volatile compounds (FVCs) were isolated from the water fractions (hydrosols) of 10 Croatian Veronica species obtained by hydrodistillation (HD) and microwave-assisted extraction (MAE). The use of different isolation techniques is important for the analysis of the influence of extraction conditions on the qualitative and quantitative composition of the isolated constituents. The composition of the hydrosols was analyzed using gas chromatography and mass spectrometry. The compounds β-ionone and benzene acetaldehyde were detected in all 10 Veronica hydrosols studied. E-caryophyllene was also identified in all isolates except the MAE isolate of V. arvensis L. Caryophyllene oxide was isolated in all isolates apart from the HD isolate of V. catenata Pennell. (E)-β-Damascenone is significantly present in all isolates except the MAE isolates of V. catanata and V. cymbalaria Bodard. In these two species, α-muurolol was identified in a high percentage. The same basic phytochemical constituents and compounds characteristic of a given Veronica species suggest the importance of further research. Antioxidant activity was tested for all extracts using two methods, ORAC and DPPH. Therefore, it is crucial to identify as many specialized metabolites from Veronica species as possible, especially hydrosols, which are natural products of potential pharmacological interest.

In-vitro determination of antimicrobial activities of Eruca sativa seed oil against antibiotic-resistant gram-negative clinical isolates from neonates: a future prospect

Background

The aim of this study is investigate the antimicrobial effect of plant oils against bacterial strains isolated from neonatal asymptomatic bacteriuria (ABU) and to evaluate the antiseptic effect of the most potent one.

Methods

The antimicrobial effect of 17 plant oils were tested against 15- gram-negative bacterial strains recovered from cases of neonatal ABU (11 Escherichia. coli, 3 Klebsiella pneumonia, and 1 Pseudomonas aeruginosa) using the agar well diffusion method. The micro-dilution method was performed to investigate the minimum inhibitory concentrations (MIC) and the minimum bactericidal concentrations (MBC) in concentrations ranging from 1.95 μg/ml to 500 μg/ml. The evaluation of the antiseptic activity of the Eruca sativa (arugula) seed oil was investigated using time-kill assay in concentrations ranging from 50 μg/ml to 0.195 μg/ml.

Results

All tested oils showed variable antimicrobial activities against the tested strains. Arugula, wheat germ, cinnamon, parsley, dill, and onion oils were the most active oils. Among them, arugula oil was the most active oil with MIC₅₀ and MIC₉₀ were 3.9 μg/ml and 31.3 μg/ml respectively. MBC₅₀ and MBC₉₀ of arugula oil were 15.6 μg/ml and 125μg/ml respectively. The time-kill assay of arugula oil indicated that a concentration of 100 μg/ml completely killed nine of the tested strains after 10 min and reduced the CFU/ml of the rest of the strains by 3 log¹⁰ at the same time interval.

Conclusion

Arugula seed oil could be a potentially used as an antiseptic especially for neonates.

Dynamic regulation of volatile terpenoid production and emission from Chrysanthemum morifolium capitula

Flower-associated communities consist of both mutualistic and antagonistic organisms. We have limited knowledge on how flowers regulate volatiles to balance their defense against antagonists and the attraction of beneficial organisms necessary for reproductive success. Asteraceae is the largest family among flowering plants. Its representatives are characterized by unique inflorescence called capitulum, which has been reduced to a reproduction unit resembling a single flower. Here, we chose Chrysanthemum morifolium, a model species of Asteraceae, to investigate how the capitulum balances the accumulation and emission of floral terpenoid volatiles that are implicated in defense and pollinator attraction, respectively. Our results showed that the capitula of C. morifolium produce and emit complex mixtures of monoterpenoids and sesquiterpenoids. The highest concentrations of terpenoids were detected in the bud stage of the capitula. In contrast, the capitulum reached the highest emission level prior to full blooming. The disc florets were the dominant organs of terpenoid accumulation and emission in the full-openness stage. To understand the molecular basis of volatile terpenoid biosynthesis in C. morifolium, experiments were designed to study terpene synthase (TPS) genes, which are pivotal for terpene biosynthesis. Eight CmCJTPS genes were identified in the transcriptomes of C. morifolium, and the proteins encoded by five genes were found to be biochemically functional. CmCJTPS5 and CmCJTPS8 were the multi-product enzymes catalyzing the monoterpenoid and sesquiterpenoid formation, which closely matched the major terpenoids produced in the flower heads. The five functional terpene synthase genes exhibited similar temporal expression patterns but diverse spatial expression levels, suggesting tissue-specific functions. Altogether, our results illustrate the dynamic patterns of accumulation and emission of floral volatile terpenoids implicated in defense and attracting pollinators in C. morifolium, for which both the regulation of TPS gene expression and the regulation of release may play critical roles.

Exploring the Relationship between Trichome and Terpene Chemistry in Chrysanthemum

Chrysanthemum is a popular ornamental plant with a long history of cultivation. Both the leaf and flowerhead of Chrysanthemum are known to produce diverse secondary metabolites, particularly terpenoids. Here we aimed to determine the relationship between terpene chemistry and the trichome traits in Chrysanthemum. In our examination of three cultivars of C. morifilium and three accessions of C. indicum, all plants contained T-shaped trichomes and biseriate peltate glandular trichomes. The biseriate peltate glandular trichome contained two basal cells, two stalk cells, six secondary cells and a subcuticular space, while the non-glandular T-shaped trichome was only composed of stalk cells and elongated cells. Histochemical staining analysis indicated that the biseriate peltate glandular trichome contained terpenoids and lipid oil droplets but not the T-shaped trichome. Next, experiments were performed to determine the relationship between the accumulation and emission of the volatile terpenoids and the density of trichomes on the leaves and flowerheads in all six Chrysanthemum cultivars\accessions. A significant correlation was identified between the monoterpenoid and sesquiterpenoid content and the density of glandular trichomes on the leaves, with the correlation coefficients being 0.88, 0.86 and 0.90, respectively. In contrast, there was no significant correlation between the volatile terpenoid content and the density of T-shaped trichomes on the leaves. In flowerheads, a significant correlation was identified between the emission rate of terpenoids and the number of glandular trichomes on the disc florets, with a correlation coefficient of 0.95. Interestingly, the correlation between the density of glandular trichomes and concentrations of terpenoids was insignificant. In summary, the relationship between trichomes and terpenoid chemistry in Chrysanthemum is clearly established. Such knowledge may be helpful for breeding aromatic Chrysanthemum cultivars by modulating the trichome trait.

Hydrodistillation and Microwave Extraction of Volatile Compounds: Comparing Data for Twenty-One Veronica Species from Different Habitats

Free volatile compounds were isolated from 21 Croatian Veronica species studied by hydrodistillation (HD) and microwave extraction (ME) and analyzed by gas chromatography coupled with mass spectrometry. Principal Component Analysis (PCA) distinguished some clusters based on the relative proportion of major compounds, such as hexadecanoic acid, hexahydrofarnesyl acetone, phytol, E-caryophyllene, and caryophyllene oxide, which were identified in all species studied by both isolation methods. In addition to these compounds, germacrene D, δ-selinene, and eicosane were also identified in five samples from dry habitats isolated using ME. Allo-aromadendrene and β-ionone are particularly abundant in five species from wet habitats isolated by both methods. The peculiarities of Veronica species from moderate habitats isolated with HD are benzene acetaldehyde, n-nonanal, and the identification of significant compounds from the hydrocarbon class, while the peculiarity of ME is (E)-β-damascenone. In this article, we present new results on the phytochemical characterization of Veronica species from different habitats. The biological potential of these compounds should be further investigated for a better understanding and utilization of the specialized plant metabolites.

Specific sub fractions from Terminalia mantaly (H. Perrier) extracts potently inhibit Plasmodium falciparum rings, merozoite egress and invasion

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia mantaly (H. Perrier) and Terminalia superba (Engl. & Diels) are sources of treatment for various diseases, including malaria and/or related symptoms in parts of Southwestern Cameroon. However, there is limited information on the extent of the antiplasmodial potential of their extracts.

AIM OF THE STUDY

The present study was designed to investigate the antiplasmodial potential of chromatographic sub fractions (SFs) from promising fractions of Terminalia mantaly (Tm) [Tmsb^wChl, the chloroform fraction from water extract of Tm, IC₅₀ (μg/mL) PfINDO: 0.56, Pf3D7: 1.12; SI > 357 (HEK/PfINDO) & 178 (HEK/Pf3D7)] and Terminalia superba (Ts) [Tsr^mEA, the ethyl acetate fraction from methanolic extract of Ts, IC₅₀ (μg/mL) PfINDO: 1.82, Pf3D7: 1.65; SI > 109 (HEK/PfINDO) & 121 (HEK/Pf3D7)] obtained from previous studies. The SFs were tested against Plasmodium falciparum 3D7 (Pf3D7-chloroquine sensitive) and INDO (PfINDO-chloroquine resistant) strains in culture. Also, the phytochemical profile of potent SFs was determined and finally, the inhibition of the asexual blood stages of Plasmodium falciparum by the SFs with the highest promise was assessed.

MATERIAL AND METHODS

Selected SFs were submitted to a second bio-guided fractionation using silica gel column chromatography. The partial phytochemical composition of potent antiplasmodial SFs was determined using gas chromatography coupled to mass spectrometry (GC-MS). The SYBR Green I-based fluorescence microtiter plate assay was used to monitor the growth of Plasmodium falciparum parasites in culture in the presence or absence of extracts. Microscopy and flow cytometry counting was used to assess the Plasmodium falciparum stage-specific inhibition and post-drug exposure growth suppression by highly potent extracts.

RESULTS

Twenty-one of the 39 SFs afforded from Tmsb^wChl showed activity (IC₅₀: 0.29-4.74 μg/mL) against both Pf3D7 and PfINDO strains. Of note, eight SFs namely, Tm25, Tm28-30, Tm34-36 and Tm38, exerted highly potent antiplasmodial activity (IC₅₀ < 1 μg/mL) with IC₅₀PfINDO: 0.41-0.84 μg/mL and IC₅₀Pf3D7: 0.29-0.68 μg/mL. They also displayed very high selectivity (50 < SI_PfINDO, SI_Pf3D7 > 344) on the two Plasmodial strains. On the other hand, 7 SFs (SFs Ts03, Ts04, Ts06, Ts09, Ts10, Ts12 and Ts13) from Tsr^mEA showed promising inhibitory potential against both parasite strains (IC₅₀: 2.01-5.14 μg/mL). Sub fraction Tm36 (IC₅₀PfINDO: 0.41 μg/mL, SI_PfINDO > 243; IC₅₀Pf3D7: 0.29 μg/mL, SI_Pf3D7 > 344) showed the highest promise. The GC-MS analysis of the 8 selected SFs led to the identification of 99 phytometabolites, with D-limonene (2), benzaldehyde (12), carvone (13), caryophyllene (35), hexadecanoic acid, methyl ester (74) and 9-octadecenoic acid, methyl ester (82) being the main constituents. Sub fractions Tm28, Tm29, Tm30, Tm36 and Tm38 inhibited all the three intraerythrocytic stages of P. falciparum, with strong potency against ring stage development, merozoite egress and invasion processes.

CONCLUSIONS

This study has identified highly potent antiplasmodial SFs from Terminalia mantaly with significant activity on the intraerythrocytic development of Plasmodium falciparum. These SFs qualify as promising sources of novel antiplasmodial lead compounds. Further purification and characterization studies are expected to unravel molecular targets in rings and merozoites.

Metabolic Perturbation and Synthetic Biology Strategies for Plant Terpenoid Production-An Updated Overview

Terpenoids represent one of the high-value groups of specialized metabolites with vast structural diversity. They exhibit versatile human benefits and have been successfully exploited in several sectors of day-to-day life applications, including cosmetics, foods, and pharmaceuticals. Historically, the potential use of terpenoids is challenging, and highly hampered by their bioavailability in their natural sources. Significant progress has been made in recent years to overcome such challenges by advancing the heterologous production platforms of hosts and metabolic engineering technologies. Herein, we summarize the latest developments associated with analytical platforms, metabolic engineering, and synthetic biology, with a focus on two terpenoid classes: monoterpenoids and sesquiterpenoids. Accumulated data showed that subcellular localization of both the precursor pool and the introduced enzymes were the crucial factors for increasing the production of targeted terpenoids in plants. We believe this timely review provides a glimpse of current state-of-the-art techniques/methodologies related to terpenoid engineering that would facilitate further improvements in terpenoids research.

Concentration-dependent emission of floral scent terpenoids from diverse cultivars of Chrysanthemum morifolium and their wild relatives

Floral scent is an important trait that has a significant influence on the reproduction of many flowering plants and the market value of several ornamental crops. The family of Asteraceae is well known for its unique floral structure (capitulum) that consists of many florets. Although the constituents of either floral essential oils or emitted floral volatiles have been reported in many species of Asteraceae, little information is available on the mechanisms that determine floral volatile emission. In the present study, a total of 44 species/varieties of Chrysanthemum were analyzed to determine the relationship between the internal accumulation of floral terpenoids and their release as volatiles. By performing both headspace collection and organic extraction, it has been found that the emission rates of floral terpenoids are largely correlated to their internal concentrations. Particularly, the flowers of cultivated C. morifolium, when compared to their wild relatives, were found to exhibit lower emission rates that contain lowered concentrations of floral terpenoids. The differences were largely determined by six monoterpenes and five sesquiterpenes that were revealed by principal component analysis. Besides, the relationship between concentrations and emission rates of floral terpenoids as well as the sizes of capitulum was studied in detail. Separated into three different parts, disc florets were found to have a larger contribution to floral volatile emission than ray florets, whereas the phyllaries and receptacles are the main parts of volatiles accumulation. Finally, the potential biosynthetic pathway of the floral terpenoids produced in capitula of Chrysanthemum was proposed. In summary, our findings on the diversity and variations of floral terpenoids in Chrysanthemum reveal correlations between their production and emission. These findings can be useful to develop different plant breeding methods to create novel aromatic cultivars of Chrysanthemum.

Heterologous Biosynthesis of Artemisinin in Chrysanthemum morifolium Ramat

Artemisinin-based drugs are the most effective medicine against multidrug-resistant Plasmodium spp., the parasite that causes malaria. To this day, wormwood A. annua L. is the sole commercial source of artemisinin, where it is produced in minor amounts. The artemisinin yield depends on numerous poorly regulated agricultural factors and the genetic variability of this non-domesticated plant. This has aroused significant interest in the development of heterologous expression platforms for artemisinin production. Previously, we obtained lines of Chrysanthemum morifolium Ramat. (C. morifolium Ramat.), cvs. White Snowdon and Egyptianka, transformed with artemisinin biosynthesis genes. Here, we report the results of an analysis of artemisinin production in transgenic chrysanthemums. Transcription of heterologous amorpha-4,11-diene monooxygenase and cytochrome P450 reductase genes in transgenic lines was confirmed using high-resolution melting analysis. Artemisinin accumulation was detected using GC-MS in White Snowdon plants, but not in Egyptianka ones, thereby demonstrating the possibility of transplanting active artemisinin biosynthetic pathway into chrysanthemum. Ways of increasing its content in producer plants are discussed.

Authentication, phytochemical characterization and anti-bacterial activity of twoArtemisiaspecies

Artemisia species are aromatic herbs used as food and/or ethnomedicine worldwide; however, the use of these plants is often impeded by misidentification. Here, molecular and chemotaxonomic approaches were combined to assist in the morphology-based authentication of Artemisia species, and Artemisia indica and Artemisia argyi were identified. The plant extracts and compounds obtained from these species, 1,8-cineole, carveol, α-elemene, α-farnesene, methyl linolenate, diisooctyl phthalate inhibited the growth of food-borne harmful bacteria. Mechanistic studies showed that the extract and active compounds of A. indica killed Gram-negative and -positive bacteria via destruction of the bacterial membrane. Finally, in vivo data demonstrated that A. indica protected against bacterial infection in mice as evidenced by survival rate, bacterial load in organs, gut pathology, diarrhea, body weight, food consumption, stool weight, and pathology score. A. indica and its active compounds have potential for use as food supplements for food-borne bacterial diseases and thus improve human health.

Effects of light, sucrose concentration and repetitive subculture on callus growth and medically important production in Justicia gendarussa Burm.f

Objective

This research aimed at the discovering the effects of light, sucrose concentration and repetitive subculture on the growth of Justicia gendarussa Burm.f. calluses based on biomass, morphological characters and metabolic profiles.

Methods

The second and third leaves of young J. gendarussa Burm.f. were isolated and cultured in solid Murashige and Skoog (MS) medium with the addition of 1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/L benzyl amino purine (BAP). Different sucrose concentrations, varying from 0 to 5%, were included in the medium. The cultures were incubated under light and dark conditions for 6 weeks. Repetitive subculture was carried out every 2 weeks for a total of four times, and 3% sucrose gave the best callus growth. Dry calluses were extracted with methanol, and their metabolic profiles were analyzed using gas chromatography/mass spectrometry (GC/MS). Compound identification was performed by comparing the mass spectra to references from the WILEY version 7n.1 library.

Results

Among the 12 conditions tested for the prolonged 6-week culture, the 2-5 % sucrose treatments under light and 3-5 % sucrose treatments under dark exhibited the highest dry weight. For repetitive subculture, the highest wet and dry weights were identically detected under both light and dark conditions after the second repetitive subculture. A total of 19 metabolites was identified by GC/MS, with major compounds being taraxasterol, monoplex D, 2-methoxy-4-vinylphenol, and palmitic acid.

Conclusion

Light, sucrose concentration, and repetitive subculture all significantly impacted the growth and metabolic profiles of J. gendarussa Burm.f. calluses. A concentration of 3% sucrose demonstrated the best growth of callus and could be further applied for mass production.

Agrobacterium-Mediated Transformation of Chrysanthemum with Artemisinin Biosynthesis Pathway Genes

Artemisinin-based drugs are the most effective medicine for the malaria treatment. To date, the main method of artemisinin production is its extraction from wormwood plants Artemisia annua L. Due to the limitation of this source, considerable efforts are now directed to the development of methods for artemisinin production using heterologous expression systems. Artemisinin is a sesquiterpene lactone, synthesized through the cyclization of farnesyl diphosphate involved in other sesquiterpene biosynthetic systems. Chrysanthemum species as well as A. annua, belong to Asteraceae family, and had been characterized by containing highly content of sesquiterpenes and their precursors. This makes chrysanthemum a promising target for the production of artemisinin in heterologous host plants. Chrysanthemum (C. morifolium Ramat.) was transformed by Agrobacterium tumefaciens carrying with the binary vectors p1240 and p1250, bearing artemisinin biosynthesis genes coding: amorpha-4,11-diene synthase, artemisinic aldehyde Δ11(13) reductase, amorpha-4,11-diene monooxygenase (p1240 was targeted to the mitochondria and p1250 was targeted to the cytosol), cytochrome P450 reductase from A. annua, as well as yeast truncated 3-hydroxy-3-methylglutarylcoenzyme A reductase. This study obtained 8 kanamycin-resistant lines after transformation with the p1240 and 2 lines from p1250. All target genes were detected in 2 and 1 transgenic lines of the 2 vectors. The transformation frequency of all target genes were 0.33% and 0.17% for p1240 and p1250, relative to the total transformed explant numbers. RT-PCR analysis revealed the transcription of all transferred genes in two lines obtained after transformation with the p1240 vector, confirming the possibility of transferring genetic modules encoding entire biochemical pathways into the chrysanthemum genome. This holds promise for the development of a chrysanthemum-based expression system to produce non-protein substances, such as artemisinin.

Microscopic Characteristic and Chemical Composition Analysis of Three Medicinal Plants and Surface Frosts

The accumulation of chemical constituents of some medicinal plants, such as Paeonia ostii T. Hong et J. X. Zhang, Houpoëa officinalis (Rehder and E. H. Wilson) N. H. Xia and C. Y. Wu. and Atractylodes lancea (Thunb.) DC, can precipitate on the surface and form frosts after natural or artificial intervention. The characteristics of these three medicinal plants and their frosts were analyzed by light microscope, polarizing microscope, stereomicroscope, and metalloscope. The results of ordinary Raman of P. ostii and H. officinalis showed that the frosts of P. ostii matched paeonol, while that of H. officinalis matched magnolol and honokiol. In P. ostii and its frost, 19 peaks were identified by UPLC-Q/TOF-MS, and the main component was paeonol. Eleven components were identified in H. officinalis and its frosts, and the main components were magnolol and honokiol. A. lancea and its frosts were analyzed by gas chromatography-mass spectrometry (GC-MS), 21 were identified, and its main components were hinesol and β-eudesmol. These three medicinal plants accumulate compounds and precipitate frosts on the surface. The results show that the components of the frosts provide a basis for quality evaluation and research on similar medicinal plants, and reveals the scientific connotation of "taking the medicinal materials' precipitated frosts as the best" of P. ostii, H. officinalis, and A. lancea, to some extent.

Network pharmacology-based analysis on bioactive anti-diabetic compounds in Potentilla discolor bunge

ETHNOPHARMACOLOGICAL RELEVANCE

Potentilla discolor Bunge (PDB) is a commonly used herbal for alleviating diabetes mellitus and its complications. Although accumulating evidences show the anti-diabetic efficacy of PDB, the vital anti-diabetic compounds and their functional targets remain elusive.

AIM OF THE STUDY

To investigate the anti-diabetic ingredients and their functional mechanisms in PDB, gas chromatograph-mass spectrometry analysis was performed on PDB extract and 21 were testified as anti-diabetic compounds.

MATERIALS AND METHODS

Subsequently their potential protein targets were also identified. The bioinformatics analysis was implemented by network pharmacology-based approaches. STRING analysis was performed to reveal enrichment of these target proteins, protein-protein interactions, pathways and related diseases. Cytoscape was used to determine the potential protein targets for these components in PDB, indicating that 21 anti-diabetic compounds in PDB regulate 33 diabetes-related proteins in 28 signal pathways and involve 21 kinds of diabetes-related diseases. Among the 21 potential anti-diabetic components predicted by network analysis, tricetin was firstly experimentally validated at the molecular and cellular level.

RESULTS

Results indicated that this active small-molecule compound may have beneficial effects on improving glucose uptake.

CONCLUSIONS

We envisage that network analysis will be useful in screening bioactive compounds of medicinal plants.

Identification and characterization of (+)-α-bisabolol and 7-epi-silphiperfol-5-ene synthases from Artemisia abrotanum

Triquinane is a type of sesquiterpenoid with a unique structure that contains a fused tricyclopentane ring and exhibits a wide range of bioactivities. Like other sesquiterpenoids, the first committed step in triquinane-type sesquiterpenoid biosynthesis is the cyclization of farnesyl pyrophosphate (FPP), a common precursor of all sesquiterpenoids, catalyzed by sesquiterpene synthase. Artemisia abrotanum L. (Asteraceae), a common plant used in the culinary and cosmetics industries, has been reported to accumulate high levels of triquinane silphiperfol-5-en-3-one A. This compound is potentially biosynthesized from the cyclization of FPP into 7-epi-silphiperfol-5-ene followed by a multi-step oxidation to silphiperfol-5-en-3-one A. In this study, we aimed to identify the sesquiterpene synthase responsible for the synthesis of 7-epi-silphiperfol-5-ene. We performed RNA sequencing of A. abrotanum leaves and gene candidates were mined by homology searches using the triquinane α-isocomene synthase of chamomile (MrTPS2) as query. After gene cloning, we obtained five variants of putative sesquiterpene synthase showing greater than 85% amino acid identity to MrTPS2 and greater than 95% amino acid identity to each other. Heterologous expression of these variants in a FPP-high-producing yeast strain revealed the first four variants to be (+)-α-bisabolol synthases (AabrBOS1-4). However, the fifth candidate cyclized FPP into 7-epi-silphiperfol-5-ene and can therefore be defined as a 7-epi-silphiperfol-5-ene synthase (AabrSPS). These findings revealed the first committed enzyme involved in silphiperfol-5-en-3-one A and (+)-α-bisabolol biosyntheses in A. abrotanum. Furthermore, the results of this study will be useful for enhancing the production of these compounds for further applications.

Seven herbs against the stored product insect: Toxicity evidence and the active sesquiterpenes from Atractylodes lancea

In this work, the essential oils (EO) were extracted from seven typical Chinese herbs, and their repellent and contact toxicities against Tribolium castaneum adults (red flour beetles) were evaluated. The experimental results showed that the above EOs presented the various levels of repellent and contact toxicities. The EOs extracted from A. lancea and A argyi of the Compositae (Asteraceae) family presented obvious repellent effects (Repellency Percentage > 90% at 3.15 nL/cm² after 4 h exposure) and strong contact toxicity with LD₅₀ values of 5.78 and 3.09 μg/adult respectively. Based on literature researches and screening results, the EO from A. lancea was analyzed by GC-MS and chosen for further identification of bioactive components. Altogether 59 chemical components were identified and 17 of them were recognized as sesquiterpene compounds, accounting for 57.8% of the total weight of the EO. From the identified sesquiterpenes, three individual compounds (β-eudesmol, hinesol, valencene) were selected for the laboratory bioassays of the toxicity against red flour beetles. It was found that all the three compounds expressed some repellent effects. Although β-eudesmol (31.2%) and hinesol (5.1%) were identified as main constituents and had been considered to be symbolic characteristics of high medicinal value, valencene (0.3%) showed strong repellent property which could be comparable to that of DEET (N, N‑diethyl‑3‑methylbenzamide), a powerful commercial pesticides, and it had best toxicity with LD₅₀ values of 3.25 (μg/adult) in the contact test. This work may provide toxicity evidence of seven common herbs against red flour beetles, add the information for the development and comprehensive utilization of A. lancea, and will contribute to the application of grain preservation.

Egg yolk immunoglobulin interactions with Porphyromonas gingivalis to impact periodontal inflammation and halitosis

Porphyromonas gingivalis is a pathogenic Gram-negative anaerobic bacterium that colonizes the subgingival region of gums. These bacteria can invade periodontal tissues, form plaques, and produce volatile sulfur compounds (VSC) and volatile organic compounds (VOC). Egg yolk immunoglobulin (IgY) that was specifically produced in egg yolks after chickens were challenged with P. gingivalis could control and prevent oral diseases caused by P. gingivalis. The releases of P. gingivalis offensive metabolic odors in vitro and in vivo were determined using a Halimeter and GCMS. With IgY bacterial growth was inhibited, and the relative amounts of VOC and VSC were decreased. The scores for the oral health index and the levels of IL-6 and TNF-α are also decreased. All treatment groups showed significant anti-inflammatory effects, which strongly suggests that specifically IgY against P. gingivalis may be an effective treatment for the prevention and protection of periodontal inflammation and halitosis.

The Chemical Composition and Functional Properties of Essential Oils from Four Species of Schisandra Growing Wild in the Qinling Mountains, China

The aim of this study was to investigate the chemical composition and functional properties of the essential oils from the plants Schisandra grandiflora (Wall.) Hook. f. et Thoms, Schisandra rubriflora (Franch). Rehd. et Wils., Schisandra sphenanthera Rehd. et Wils., and Schisandra propinqua (Wall.) Baill var. sinensis Oliv. collected in the Qinling Mountains. Under the optimum conditions of the ultrasonic-assisted extraction method, the extraction yields were 7.51% (S. grandiflora), 6.91% (S. rubriflora), 6.11% (S. sphenanthera), and 5.88% (S. propinqua). A total of 86 components were identified from four species of Schisandra and 16 components were shared among the essential oils of all samples with different contents. However, some components were identified only in a certain plant, for example, β-caryophyllen (S. grandiflora), α-bulnesene (S. rubriflora), and α-Chamigrene (S. propinqua). Terpenoids (sesquiterpenes and oxygenated sesquiterpenes), accounting for 73.87–82.08% of the total compounds, were the main components. Meanwhile, the antioxidant activities of the essential oils were evaluated through three free radical scavenging assays and a reducing power assay, which were related to the contents of the individual bioactive composition. These results provide a phytochemical foundation for the use of four species, and for the further study of the identification of Schisandra species.

Efficacy of Compounds Isolated from the Essential Oil of Artemisia lavandulaefolia in Control of the Cigarette Beetle, Lasioderma serricorne

To develop natural product resources to control cigarette beetles (Lasioderma serricorne), the essential oil from Artemisia lavandulaefolia (Compositae) was investigated. Oil was extracted by hydrodistillation of the above-ground portion of A. lavandulaefolia and analyzed using gas chromatography-mass spectrometer (GC-MS). Extracted essential oil and three compounds isolated from the oil were then evaluated in laboratory assays to determine the fumigant, contact, and repellent efficacy against the stored-products’ pest, L. serricorne. The bioactive constituents from the oil extracts were identified as chamazulene (40.4%), 1,8-cineole (16.0%), and β-caryophyllene (11.5%). In the insecticidal activity assay, the adults of L. serricorne were susceptible to fumigant action of the essential oil and 1,8-cineole, with LC₅₀ values of 31.81 and 5.18 mg/L air. The essential oil, 1,8-cineole, chamazulene, and β-caryophyllene exhibited contact toxicity with LD₅₀ values of 13.51, 15.58, 15.18 and 35.52 μg/adult, respectively. During the repellency test, the essential oil and chamazulene had repellency approximating the positive control. The results indicated that chamazulene was abundant in A. lavandulaefolia essential oil and was toxic to cigarette beetles.