Euphorbia Research Articles

Palynotaxonomical study of honeybees (Apis mellifera var. adansonii) forage and/or preference plants in South-Western Nigeria

The disputed issues of higher plant taxonomy and phylogeny are greatly impacted by pollen morphology because pollen grains have clear distinctive characteristics that are typically labeled. Palynotaxonomical study of Honeybees preference plants in South-Western Nigeria were conducted between the months of May, 2019 and June 2021 using fresh polleniferous materials which were extracted through acetolysis methods. Results showed that ninety-two (92) plant species belonging to thirty-six (36) plant families of apicultural importance most visited by honeybees (Apis mellifera var. adansonii) were documented. At x100 magnification, thorough morphological studies were performed, and the results showed that pollen grains from plant species in the family Asteraceae were spinolous and spherical in shape; those from the Fabaceae sub-families Caesalpinoideae, Mimosoideae, and Papilionoideae, on the other hand, had a great deal of morphological diversity with variations in symmetry, position and distribution. Those of the families Malvaceae was echinate and Myrtaceae were colporate; syncolpate and prolate respectively. However, the variations above were generally reduced within species in the same genera. Tricolpate aperture type was observed in the genus Euphorbia; giving reason for their classification in the same genera. The genus Combretum was all heterocolpate, circular in shape and heteroporate. Sculpturing was psilate or scabrate and pollen shape class were sub-prolate, oblate-spheroidal or prolate spheroidal. Similar form and symmetry observed in all the species studied were reason for their classification into the same family. The study revealed that the flowering period for most of these honeybees’ forage plants were between the months of October to March. Identification, propagation, cultivation, conservation, and sustainable exploitation of these honeybee (Apis mellifera var. adansonii) forage and preference plants would be beneficial in potentially increasing the efficiency of apiculture and commercial cultivation in South-Western Nigeria.

Phytochemical Constituents and Antimicrobial Activity of Euphorbia serrata L. Extracts for Borago officinalis L. Crop Protection

The Euphorbia genus is the third-largest group of blooming plants, features a rich morphological variability, has a near-cosmopolitan distribution, and diverse medicinal uses. Nonetheless, phytochemical information about Euphorbia serrata L. extracts is not available. The objective of this research was to examine the constituents of the hydromethanolic extract of its aerial parts and propose valorization pathways. The results of gas chromatography-mass spectroscopy (GC−MS) demonstrated that 3-methylbutyl formate, quinic acid, N1-(4-hydroxybutyl)-N3-methylguanidine acetate, and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one were the main phytocompounds, which have antimicrobial activity. Such activity was assayed against Pseudomonas cichorii, Botrytis cinerea, Fusarium oxysporum, and Sclerotinia sclerotiorum, four of the most destructive diseases of borage (Borago officinalis L.) crops, obtaining minimum inhibitory concentrations (MICs) of 750 and 1000 μg·mL−1 against the bacterium and the three fungal taxa, respectively, in in vitro tests. Conjugation of the extract with chitosan oligomers (COS) enhanced this activity, leading to MIC values of 187.5, 750, 500, and 500 μg·mL−1 for P. cichorii, B. cinerea, F. oxysporum, and S. sclerotiorum, respectively. Additional in vivo assays against two of the pathogens confirmed the protective action of the COS–E. serrata extract conjugate complexes on artificially inoculated plants at a dose of 375 and 1000 μg·mL−1 for P. cichorii and F. oxysporum, respectively. These findings suggest that this plant species can be a rich source of biorationals for prospective use in crop protection.

A deep learning-based approach for the identification of selected species of genus Euphorbia L.

A deep learning-based approach for the identification of selected species of genus Euphorbia L.

PROFILING SCREENING OF 55 SPECIES OF THE GENUS EUPHORBIA L. (EUPHORBIACEAE) AS POTENTIAL SOURCES OF ELLAGIC ACID

Methanol extracts from the leaves of 55 species, belonging to 4 subgenera and 16 subsection of genus Euphorbia (Euphorbiaceae) have been screened for presence of ellagic acid (EA). EA was quantified by gas chromatography-mass spectrometry (GC-MS) in fresh plant material Euphorbia sp. growing in Russia and Kyrgyzstan in the wild and in indoor and outdoor collections of the Peter the Great Botanical Garden of the Komarov Botanical Institute of the Russian Academy of Sciences (Saint-Petersburg). EA was detected in the extracts of 17 species of tree subgenera. In subgenus Althymalus Neck. Ex Rchb. EA was detected in E. hamata (Haw.) Sweet (section Anthacanthae Lem.), in subgenus Chamaesyce Raf. – E. maculata L. (section Anisophyllum Roep.); in subgenus Esula Pers. This compound was found in representatives of sections Esula (Pers.) Dumort. (E. virgata Waldst. Et Kit.), Helioscopia Dumort. (E. alpina Ledeb., E. aristata Schmalh., E. condylocarpa M. Bieb., E. lucorum Rupr. ex Maxim., E. palustris L., E. procera M. Bieb., E. semivillosa (Prokh.) Kryl., E. squamosa Willd., E. stricta L.), Holophyllum (Prokh.) Prokh. (E. griffithii Hook. f., E. komaroviana Prokh., E. rupestris Ledeb.), Paralias Dumort. (E. taurinensis All.) and Pithyusa (Raf.) Lázaro (E. glareosa Pall. Ex M. Bieb.). In 38 EA was not detected, including all studies species of subgenus Euphorbia. For 10 species (E. alpina, E. glareosa, E. griffithii, E. hamata, E. lucorum, E. procera, E. rupestris, E. semivillosa, E. stricta and E. taurinensis) EA was detected for the first time. Highest EA amount was found in leaves of E. hamata (4100 ppm) and E. squamosa (4300 ppm).

Metabolomics as a Potential Chemotaxonomical Tool: Application on the Selected Euphorbia Species Growing Wild in Serbia.

Chemotaxonomy presents various challenges that need to be overcome in order to obtain valid and reliable results. Individual genetic and environmental variations can give a false picture and lead to wrong conclusions. Applying a holistic approach, based on multivariate data analysis, these challenges can be overcome. Thus, a metabolomics approach has to be optimized depending on the subject of research. We used 1H NMR-based metabolomics as a potential chemotaxonomic tool on the selected Euphorbia species growing wild in Serbia. Principal components analysis (PCA), soft independent modeling by class analogy (SIMCA) and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) were used to analyze obtained NMR data in order to reveal chemotaxonomic biomarkers. The standard protocol for plant metabolomics was optimized aiming to extract more specific metabolites, which are characteristic for the Euphorbia genus. The obtained models were validated, which revealed that variables unique for each species were associated with certain classes of molecules according to literature data. In E. salicifolia, acacetin-7-O-glycoside (not found before in the species) was detected, and the structure of the aglycone part was solved based on 2D NMR data. In the presented paper, we have shown that metabolomics can be successfully used in Euphorbia chemotaxonomy.

An alternative key for identifying three prostrate species of the genus Euphorbia

Plants are a valuable source of different folk and modern medicines. Therefore, correctly identifying the plant species is a prerequisite for using them in the health care system. Euphorbia species are of great medicinal importance but are difficult to distinguish due to the occurrence of ecotypes and a high degree of polymorphism within the species. Therefore, the present study was planned to explore the extent of variations in morphological characters among three Euphorbia species, namely, Euphorbia prostrata Aiton, Euphorbia serpens Kunth and Euphorbia thymifolia L. The edaphic ecotypes red and green forms of Euphorbia prostrata growing separately or adjacent to each other were reported during field surveys. To ensure identification accuracy, illustrated online key was prepared as a supportive tool for the traditional key.

Seed Morphology of some taxa of the genus Euphorbia L. (Euphorbiaceae) in Turkey and its taxonomic significance

Seed Morphology of some taxa of the genus Euphorbia L. (Euphorbiaceae) in Turkey and its taxonomic significance

Phytochemical Study of Euphorbia turcomanica Boiss.

The attraction to the Euphorbia genus, with its remarkable diversity in species, is due to its variety of chemical compositions. Euphorbia turcomanica is one of the species of the spurge family growing wildly in Iran. This research aims to investigate the presence of secondary metabolites, specially terpenoid compounds, in terms of structural determination. Samples of E. tucomanica were finely powdered and macerated with acetone/dichloromethane 2:1. Repeated column chromatography using silica gel, MPLC, and HPLC methods followed by the analysis of data obtained from spectroscopic means was carried out to purify and identify the terpenoid constituents. The chemical structures of nine known terpenoids were determined for the first time from E. turcomanica during this study. Loliolide (1), a monoterpene, and eight steroids and triterpenes, including simiarenol (2), isomultiflorenol (3), cycloart-25-ene-3β,24-diol (4), β-sitosterol (5), cycloart-23-ene-3β,25-diol (6), 3α, 11α-dihydroxyurs-12-ene (7), 3β, 24β, 25-trihydroxycycloartane (8), and 7α-hydroxystigmasterol (9) were isolated and identified. E. tucomanica, with a rich terpenoid profile, can be one of the valuable and economic sources providing compounds for drug development.

Euphorbia species latex: A comprehensive review on phytochemistry and biological activities.

The genus Euphorbia includes about 2,000 species commonly widespread in both temperate and tropical zones that contain poisonous milky juice fluid or latex. Many species have been used in traditional and complementary medicine for the treatment of various health issues such as dropsy, paralysis, deafness, wounds, warts on the skin, and amaurosis. The medicinal applications of these species have been attributed to the presence of various compounds, and most studies on Euphorbia species have focused on their latex. In this review, we summarize the current state of knowledge on chemical composition and biological activities of the latex from various species of the genus Euphorbia. Our aim was to explore the applications of latex extracts in the medical field and to evaluate their ethnopharmacological potential. The databases employed for data collection, are obtained through Web of Science, PubMed, Google Scholar, Science Direct and Scopus, from 1983 to 2022. The bibliographic data indicate that terpenoids are the most common secondary metabolites in the latex. Furthermore, the latex has interesting biological properties and pharmacological functions, including antibacterial, antioxidant, free radical scavenger, cytotoxic, tumor, anti-inflammatory, healing, hemostatic, anti-angiogenic, insecticidal, genotoxic, and mutagenic activities. However, the role of other components in the latex, such as phenolic compounds, alkaloids, saponins, and flavonoids, remains unknown, which limits the application of the latex. Future studies are required to optimize the therapeutic use of latex extracts.

Chemical Composition, Anti-Breast Cancer Activity and Extraction Techniques of Ent-Abietane Diterpenoids from Euphorbia fischeriana Steud.

Ent-abietane diterpenoids are the main active constituents of Euphorbia fischeriana. In the continuing search for new anti-breast cancer drugs, 11 ent-abietane diterpenoids (1–11) were isolated from E. fischeriana. The structures of these compounds were clearly elucidated on the basis of 1D and 2D NMR spectra as well as HRESIMS data. Among them, compound 1 was a novel compound, compound 10 was isolated from Euphorbia genus for the first time, compound 11 was firstly discovered from E. fischeriana. These compounds exhibited varying degrees of growth inhibition against the MCF-10A, MCF-7, ZR-75-1 and MDA-MB-231 cell lines in vitro. The experimental data obtained permit us to identify the roles of the epoxy group, hydroxyl group and acetoxyl group on their cytotoxic activities. Extraction is an important means for the isolation, identification, and application of valuable compounds from natural plants. To maximize yields of ent-abietane diterpenoids of E. fischeriana, 17-hydroxyjolkinolide B, jolkinolide B, 17-hydroxyjolkinolide A and jolkinolide A were selected as quality controls to optimize the salting-out-assisted liquid–liquid extraction (SALLE) by response surface methodology (RSM). The optimized conditions for SALLE were 0.47 g sodium dihydrogen phosphate, 5.5 mL acetonitrile and 4.5 mL water at pH 7.5. The experimental values of 17-hydroxyjolkinolide B, jolkinolide B, 17-hydroxyjolkinolide A and jolkinolide A (2.134, 0.529, 0.396, and 0.148 mg/g, respectively) were in agreement with the predicted values, thus demonstrating the appropriateness of the model.

Traditional Uses, Pharmacological, and Phytochemical Studies of Euphorbia: A Review.

Plants of the genus Euphorbia have long been used as traditional medicine in China, Europe, America, Turkey, India, Africa, Iran, and Pakistan for their great medicinal value and health benefits. Their stems, leaves, roots, and latex are widely used to treat respiratory infections, body and skin irritations, digestive disorders, inflammatory infections, body pain, snake or scorpion bites, pregnancy, sensory disturbances, microbial and anticancer diseases. This review aims to provide updated information on the genus Euphorbia, including traditional medicinal uses, valuation and exploitation of medicinal plants, phytochemistry, botanical characterization, pharmacological and toxicological research focused on the medicinal properties of several Euphorbias in particular their antibacterial, anti-tumor, and cell manifestations, in addition to the effect of each isolated bioactive molecule from these species and their pharmacological use including preclinical evaluation of new drugs. This work was conducted using scientific databases such as: PubMed, Google Scholar, Scopus, Science Direct, etc. In addition, ChemDraw software has been used for the drawing of chemical molecules. The correct names of the plants were confirmed from plantlist.org. The results of this review research were interpreted, analyzed and documented based on the bibliographical information obtained. Among all the species of the Euphorbiaceae family, 15 species have been demonstrated to exhibit anticancer activity, 21 species have antibacterial activity, and 10 species have cytotoxic activity. The majority of the chemical constituents of this plant include triterpenoid glycosides, diterpenoids, flavonoids, and the 4α-methyl steroids. Among them, the main bioactive constituents are present in the diterpenoid fraction. The study of more than 33 steroid plants identified more than 104 compounds. Pharmacological research proved that the crude extracts and some pure compounds obtained from Euphorbia had activities for the treatment of different diseases. The objective of the present study was focused on cytotoxic, antibacterial and antitumor diseases. The study of the phytochemistry of the Euphorbia families led to the conclusion that all the plants studied had active compounds, of which 27 plants were characterized by their cytotoxic effects, 7 had antibacterial effects and 10 plants had anti-tumor activities. Therefore, the safety of Euphorbia herbal medicine should be considered a top priority in the early stages of development and clinical trials. Many previous studies have validated many traditional uses of Euphorbia species. The latex of some Euphorbia species seems to be toxic however, studies dealing with the safety and quality of these species are still incomplete. Extensive studies are needed on the Euphorbia plants before they can be fully used in clinics as a potent drug candidate, as researchers are focusing mainly on diterpenoids and triterpenoids, while there are many other types of compounds that may possess new biological activities.

Pharmacological Potential of Lathyrane-Type Diterpenoids from Phytochemical Sources.

Lathyrane diterpenoids are one of the primary types of secondary metabolites present in the genus Euphorbia and one of the largest groups of diterpenes. They are characterized by having a highly oxygenated tricyclic system of 5, 11 and 3 members. These natural products and some synthetic derivatives have shown numerous interesting biological activities with clinical potential against various diseases, such as cytotoxic activity against cancer cell lines, multi-drug resistance reversal, antiviral properties, anti-inflammatory activity and their capability to induce proliferation or differentiation into neurons of neural progenitor cells. The structure of the lathyrane skeleton could be considered privileged because its framework is able to direct functional groups in a well-defined space. The favorable arrangement of these makes interaction possible with more than one target. This review aims to highlight the evidence of lathyranes as privileged structures in medicinal chemistry. Chemical structures of bioactive compounds, the evaluation of biological properties of natural and semisynthetic derivatives, and the exploration of the mechanisms of action as well as target identification and some aspects of their targeted delivery are discussed.

In vitro and in silico studies on clinically important enzymes inhibitory activities of flavonoids isolated from Euphorbia pulcherrima

Introduction: The genus Euphorbia is known to contain diterpenoids, and several isolated compounds which exhibited biological activities including significant multidrug resistance reversal effects. This work is focused on the isolation, in vitro and in silico studies of two natural bio-active flavonoids (1 & 2) isolated from Euphorbia pulcherrima bark for the very first time. Methods: The phytochemical investigation resulted in the identification of two flavonoids: 3,5,7-trihydroxy-2-(4-hydroxy-3-methoxyphenyl)-6-methoxy-4H-chromen-4-one (1) and 2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-6-methoxy-4H-chromen-4-one (2), which were isolated for the first time from Euphorbia pulcherrima. Results: The chemical structures of the two isolated compounds were confirmed by 1H NMR, 13C NMR, and ESI-HRMS spectral data. The Bioactivity activity of these compounds was evaluated; results revealed that compounds 1 & 2 exhibit promising urease inhibitory potential with IC50 values of 15.3 ± 2.13 μM and 19.0 ± 2.43 μM, respectively, whereas the positive control thiourea had an IC50 of 21.0 ± 0.23 μM. Similarly, these compounds were also evaluated against the tyrosinase enzyme; results showed that compound 1 displays significant inhibitory activity with an IC50 value of 48.7 ± 2.19 μM, whereas compound 2 exhibited a moderate effect with an IC50 value of 74.8 ± 1.79 μM, when compared with the standard (alpha-kojic acid, IC50 = 47.6 ± 0.67 μM). Additionally, compounds 1 and 2 also exhibited anti-glycation and phosphodiesterase inhibitory activities. Conclusion: Studies dealing with the drug like properties such as in silico screening (docking study) was also carried out to discover the structural features of both compounds 1 and 2. Results indicated that the docking scores of compounds 1 and 2 are in agreement with their IC50 values. Key messages Isolation and characterization of two bioactive flavonoids (1 and 2) from Euphorbia pulcherrima. In silico and in vitro enzyme inhibition studies were conducted to identify the therapeutic potential of flavonoids 1 and 2. Drug-like properties were calculated to discover important pharmacophoric features.

Digalloyl Glycoside: A Potential Inhibitor of Trypanosomal PFK from Euphorbia abyssinica J.F. Gmel.

Human African trypanosomiasis is an endemic infectious disease caused by Trypanosoma brucei via the bite of tsetse-fly. Most of the drugs used for the treatment, e.g., Suramin, have shown several problems, including the high level of toxicity. Accordingly, the discovery of anti-trypanosomal drugs from natural sources has become an urgent requirement. In our previous study on the anti-trypanosomal potential of Euphorbia species, Euphorbia abyssinica displayed significant anti-trypanosomal activity. Therefore, a phytochemical investigation of the methanolic extract of E. abyssinica was carried out. Twelve compounds, including two triterpenes (1, 2); one sterol-glucoside (4); three ellagic acid derivatives (3, 9, 11); three gallic acid derivatives (5, 6, 10); and three flavonoids (7, 8, 12), were isolated. The structures of isolated compounds were determined through different spectroscopic techniques. Compound (10) was obtained for the first time from genus Euphorbia while all other compounds except compound (4), were firstly reported in E. abyssinica. Consequently, an in silico study was used to estimate the anti-trypanosomal activity of the isolated compounds. Several compounds displayed interesting activity where 1,6-di-O-galloyl-d-glucose (10) appeared as the most potent inhibitor of trypanosomal phosphofructokinase (PFK). Moreover, molecular dynamics (MD) simulations and ADMET calculations were performed for 1,6-di-O-galloyl-d-glucose. In conclusion, 1,6-di-O-galloyl-d-glucose revealed high binding free energy as well as desirable molecular dynamics and pharmacokinetic properties; therefore, it could be suggested for further in vitro and in vivo studies for trypanosomiasis.

Conventional Medicinal Uses, Phytoconstituents, and Biological Activities of Euphorbia officinarum L.: A Systematic Review.

The Moroccan endemic plant Euphorbia officinarum is a traditional medicinal plant, known locally as “Daghmus.” Plants in the genus Euphorbia are well known for the chemical diversity of their diterpenoids and isoprenoid constituents, which perform many activities such as cytotoxic, antimicrobial, and anti-inflammatory activities, as well as different biological properties, that cannot be overlooked. The effect of bioactive compounds (antiviral, antidiabetic, anticancer, and antioxidant). Euphorbia officinarum is an important conventional medicine for the treatment of various conditions, including skin and ophthalmological diseases. It is also used against human pathogens (intestinal parasites). E. officinarum latex is the major part of the plant used for conventional medicine and synthesizing new bioactive compounds. The characterization and isolation of its components are necessary to exploiting and enhancing its therapeutic potential. However, to the best of our knowledge, no review is available to date. In order to have and define a research question, we adopt a strategy by considering the items of the PRISMA checklist. Therefore, this review aims to cover E. officinarum taxonomy, botanical description, distribution, conventional uses, and phytochemical compounds of this plant, including the biological activities of compounds isolated and of these semisynthesized compounds. This article provides a foundation for any further studies from this plant.

Analisis Hubungan Kekerabatan Fenetik Famili Euphorbiaceae di Kota Salatiga berdasarkan Karakter Morfologi serta Sifat Kimia

Euphorbiaceae is the most diverse angiosperm plant with one of the largest number of species widely used in various industries. Exploration and inventory of the Euphorbiaceae family has not been maximized, including in Salatiga City. Its great potential requires an initial step, namely plant breeding, but knowledge of its phenetic relationships is needed so that plant breeding produces superior individuals. In addition to morphological characters, chemical properties such as milk clotting activity are important in understanding the phenetic relationships. This study aims to analyze the phenetic relationships of Euphorbiaceae members in Salatiga City based on their morphological and chemical characteristics as well as from the milk clotting activity. Twenty five individual members of the Euphorbiaceae were analyzed for their morphological and chemical characteristics, and 30 characters were obtained. The results of the study using Cluster Analysis method showed that 25 individuals formed cluster A which was divided into 2 parts (clusters C and D) and cluster B formed cluster G (consists of individuals of Codiaeum variegatum (L.) Bl.). The closest phenetic relationships between Jatropha multifida Sidomukti C09 and Jatropha multifida Sidorejo C18 with a dissimilarity index of 0.03% or the equation 99.97%. The most distant phenetic relationships in Codiaeum variegatum (L.) Bl. Sidorejo C11 and Codiaeum variegatum (L.) Bl. Sidomukti C03 with a dissimilarity index of 19.13% or the equivalent percentage of 80.87%. The genus Euphorbia formed cluster F. The genus Manihot and Jatropha formed cluster C, the genus Codiaeum formed clusters E and B. All individuals, except Codiaeum variegatum (L.) Bl. Sidorejo C11, can coagulate milk so that it has potential as a protease enzyme in various industries. The highest protease enzyme activity value was in Codiaeum variegatum (L.) Bl. Sidorejo C11 (15.84 U/mg) and the lowest was in Euphorbia tirucalli Sidomukti C07 (2.34 U/mg).

Rod Euphorbia L. (Euphorbiaceae juss.) u Srbiji - herbarijumski podaci u zbirkama BEO i BEOU

This paper contains information on specimens of the genus Euphorbia L. collected in Serbia and deposited in the Herbarium of the Natural History Museum in Belgrade (BEO) and in the Herbarium of the University of Belgrade (BEOU). A total of 2199 herbarium sheets were examined, of which 915 are deposited in BEO and 1284 in BEOU. The catalogue with herbarium data on 37 taxa of the genus Euphorbia distributed in Serbia is presented as well as distribution maps for all recorded taxa.

Investigation of Phytochemical in Euphorbia heterophylla and Euphorbia rothiana

The genus Euphorbia attracted the attention of many researchers as it is poorly studied. Euphorbia heterophyla and Euphorbia rothiana were selected and aimed to investigate the presence of phytochemicals screenings in leaf and stem. Aqueous, Acetone and Methanol Solvents were used for phytochemical analysis. The phytochemical analysis reveals the presence of phenolic compound in leaf and stem of the plants in all extracts and flavonoid using aqueous and methanol extracts. Our findings provides evidence, that aqueous and organic solvent extracts of these plants contain medicinally important bioactive compounds.

Distribution of ingenol derivatives in Euphorbia plants and UV-dependent promotion of ingenol production in greenhouse-grown Euphorbia plants

Resource discovery for producing biologically active phytochemicals plays an important role in industrial crops area. Ingenol-3-angelate, one of the most concerned macrocyclic diterpenoids, has been approved for clinical treatment of actinic keratosis and industrially produced by a semi-synthesis approach using hydrolysis products of ingenol derivatives. Ingenol derivatives are considered exclusive among Euphorbia genus at a quite low level. In search for high-ingenol plant species from the Euphorbiaceae family, ultra-high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS) was performed for the quantitative analysis of the free ingenol content in the hydrolyzed methanol extract of 61 selected plant species, including 50 Euphorbia plants, 9 plants from other Euphorbiaceae genera, and 2 Phyllanthaceae plants. The ingenol derivatives in E. milii and E. cotinifolia which contained high level of ingenol esters were further identified by UHPLC-MS. Amounts of ingenol diterpenes varied among the samples. The highest free ingenol content (527.82 ± 38.19 μmol/kg of dry herb weight) was found in a variation, E. tithymaloides 'Nanus', followed by E. tithymaloides (402.81 ± 28.89 μmol/kg), E. milii (391.30 ± 43.51 μmol/kg), E. ammak (379.75 ± 34.68 μmol/kg), and E. trigona (357.07 ± 34.29 μmol/kg). The results revealed the trace amount of ingenol derivatives in some Jatropha, Acalypha, Codiaeum, and Excoecaria plants for the first time and confirmed the higher level of ingenol esters in some Euphorbia plants cultivated under polycarbonate panel with higher UV transmission than those grown under double layer glass. The secondary metabolites varied distinctively among different Euphorbia sections. This work suggested more applicable sources for ingenol production and better greenhouse covering material for Euphorbia plants cultivation in consideration of ingenol derivatives.

Comparative Pollination Ecology of Five EuropeanEuphorbiaSpecies

Premise of research. Flowers of the genus Euphorbia are arranged in a unique type of inflorescence called cyathia, packed into more or less dense synflorescences. These synflorescences can be showy or inconspicuous, suggesting different pollination strategies.Methodology. We described and compared the morphology, color, scent, and insect guilds visiting the synflorescences of five European Euphorbia species, two with inconspicuous synflorescences and three with showy ones.Pivotal results. All five species present their reproductive structures openly, with easily accessible nectaries. In the inconspicuous E. peplus and E. dulcis, there was little color contrast between the reproductive parts and the vegetative parts. Both species attracted low numbers of insects (Diptera and Hymenoptera), and these insects carried little (E. peplus) or no (E. dulcis) pollen. We did not detect any floral scent for E. peplus. In the showy E. amygdaloides, E. virgata, and E. verrucosa, the color of the reproductive parts and of the relatively large nectaries was standing out clearly against vegetative organs. These species attracted up to 14 times more insects (Diptera, Hymenoptera, Coleoptera) than the inconspicuous species, and these insects carried larger amounts of pollen on their bodies. In E. verrucosa, nearly half of the pollinators were sawflies from the genus Tenthredo feeding and mating on the synflorescences. All Euphorbia species except E. peplus were also visited by ants. However, the role of ants as pollinators remains to be tested. Finally, E. peplus and E. dulcis can reproduce without insect pollination, whereas among the showy species, E. virgata did not produce seeds when pollinators were excluded.Conclusions. We found that all study species had similar generalist pollination systems, with the showy species attracting significantly more insects and the inconspicuous species being largely independent of insect visits for reproduction. Our study tentatively indicates that the degree of entomophily seems positively correlated with showiness and size of attractive and rewarding organs.