Coumarins Scopoletin Research Articles

Transcriptome responses of Arabidopsis to necrotrophic fungus Alternaria brassicae reveal pathways and candidate genes associated with resistance.

Alternaria leaf blight (ALB), caused by a necrotrophic fungus Alternaria brassicae is a serious disease of oleiferous Brassicas resulting in significant yield losses worldwide. No robust resistance against A. brassicae has been identified in the Brassicas. Natural accessions of Arabidopsis show a spectrum of responses to A. brassicae ranging from high susceptibility to complete resistance. To understand the molecular mechanisms of resistance/ susceptibility, we analysed the comparative changes in the transcriptome profile of Arabidopsis accessions with contrasting responses- at different time points post-infection. Differential gene expression, GO enrichment, pathway enrichment, and weighted gene co-expression network analysis (WGCNA) revealed reprogramming of phenylpropanoid biosynthetic pathway involving lignin, hydroxycinnamic acids, scopoletin, anthocyanin genes to be highly associated with resistance against A. brassicae. T-DNA insertion mutants deficient in the biosynthesis of coumarin scopoletin exhibited enhanced susceptibility to A. brassicae. The supplementation of scopoletin to medium or exogenous application resulted in a significant reduction in the A. brassicae growth. Our study provides new insights into the transcriptome dynamics in A. brassicae-challenged Arabidopsis and demonstrates the involvement of coumarins in plant immunity against the Brassica pathogen A. brassicae.

Overexpression of the scopoletin biosynthetic pathway enhances lignocellulosic biomass processing.

Lignin is the main factor limiting the enzymatic conversion of lignocellulosic biomass into fermentable sugars. To reduce the recalcitrance engendered by the lignin polymer, the coumarin scopoletin was incorporated into the lignin polymer through the simultaneous expression of FERULOYL-CoA 6′-HYDROXYLASE 1 (F6′H1) and COUMARIN SYNTHASE (COSY) in lignifying cells in Arabidopsis. The transgenic lines overproduced scopoletin and incorporated it into the lignin polymer, without adversely affecting plant growth. About 3.3% of the lignin units in the transgenic lines were derived from scopoletin, thereby exceeding the levels of the traditional p-hydroxyphenyl units. Saccharification efficiency of alkali-pretreated scopoletin-overproducing lines was 40% higher than for wild type.

The soil-borne ultimatum, microbial biotechnology and sustainable agriculture.

The soil-borne ultimatum, microbial biotechnology and sustainable agriculture.

A coumarin exudation pathway mitigates arbuscular mycorrhizal incompatibility in Arabidopsis thaliana.

Overexpression of genes involved in coumarin production and secretion can mitigate mycorrhizal incompatibility in nonhost Arabidopsis plants. The coumarin scopoletin, in particular, stimulates pre-penetration development and metabolism in mycorrhizal fungi. Although most plants can benefit from mutualistic associations with arbuscular mycorrhizal (AM) fungi, nonhost plant species such as the model Arabidopsis thaliana have acquired incompatibility. The transcriptional response of Arabidopsis to colonization by host-supported AM fungi switches from initial AM recognition to defense activation and plant growth antagonism. However, detailed functional information on incompatibility in nonhost-AM fungus interactions is largely missing. We studied interactions between host-sustained AM fungal networks of Rhizophagus irregularis and 18 Arabidopsis genotypes affected in nonhost penetration resistance, coumarin production and secretion, and defense (salicylic acid, jasmonic acid, and ethylene) and growth hormones (auxin, brassinosteroid, cytokinin, and gibberellin). We demonstrated that root-secreted coumarins can mitigate incompatibility by stimulating fungal metabolism and promoting initial steps of AM colonization. Moreover, we provide evidence that major molecular defenses in Arabidopsis do not operate as primary mechanisms of AM incompatibility nor of growth antagonism. Our study reveals that, although incompatible, nonhost plants can harbor hidden tools that promote initial steps of AM colonization. Moreover, it uncovered the coumarin scopoletin as a novel signal in the pre-penetration dialogue, with possible implications for the chemical communication in plant-mycorrhizal fungi associations.

A REVIEW of Anisoon (Pimpinella anisum Linn) WITH UNANI PRESPECTIVE AND MODERN ON PHARMACOLOGICAL

Anisoon, Pimpinella anisun is a plant which belongs to umbellifera family. In unani medicine it is also known as anisun. It is usually grown for its seeds (aniseeds). It isan annualgrassyherb. Since centuries its extract of seed it has been used in unani medicine which is a colorless and pale-yellow liquid in nature which has a particular odor and taste. It contains 1.5 to 3.5% volatile oil, 10% fixed oil, protein mucilage and starch. Anisun oil is also used an essential oil which contains transethanol methyl chavicol anisaldehyde estragole coumarins scopoletin umbelliferon estrol etc. Its therapeutic uses in unani medicineare in sailanur reham (leucorrhea), sudade jigar wa tihal masana wa rahem, istisqa (ascites), bawasir specially bawasir e rehi (piles), qillate laban (insufficiency of lactation), darde shikam (abdominal pain), dama (asthma), nazla (common cold), laqwa (facial palsy), istarkhaeye (paralysis), dawar (vertigo) this present article reviews about all unani literature about Anisoon.

Target screening of plant secondary metabolites in river waters by liquid chromatography coupled to high-resolution mass spectrometry (LC\u2013HRMS)

BackgroundSubstantial efforts have been made to monitor potentially hazardous anthropogenic contaminants in surface waters while for plant secondary metabolites (PSMs) almost no data on occurrence in the water cycle are available. These metabolites enter river waters through various pathways such as leaching, surface run-off and rain sewers or input of litter from vegetation and might add to the biological activity of the chemical mixture. To reduce this data gap, we conducted a LC–HRMS target screening in river waters from two different catchments for 150 plant metabolites which were selected from a larger database considering their expected abundance in the vegetation, their potential mobility, persistence and toxicity in the water cycle and commercial availability of standards.ResultsThe screening revealed the presence of 12 out of 150 possibly toxic PSMs including coumarins (bergapten, scopoletin, fraxidin, esculetin and psoralen), a flavonoid (formononetin) and alkaloids (lycorine and narciclasine). The compounds narciclasine and lycorine were detected at concentrations up to 3 µg/L while esculetin and fraxidin occurred at concentrations above 1 µg/L. Nine compounds occurred at concentrations above 0.1 µg/L, the Threshold for Toxicological Concern (TTC) for non-genotoxic and non-endocrine disrupting chemicals in drinking water.ConclusionsOur study provides an overview of potentially biologically active PSMs in surface waters and recommends their consideration in monitoring and risk assessment of water resources. This is currently hampered by a lack of effect data including toxicity to aquatic organisms, endocrine disruption and genotoxicity and demands for involvement of these compounds in biotesting.

Metabolic profiling of coumarins by the combination of UPLC-MS-based metabolomics and multiple mass defect filter

Coumarins have aroused high interests due to their diverse bioactivities. Understanding of its metabolism contributes to determine the druggability of coumarin in vivo.A sensitive and efficient strategy based on ultra-performance liquid chromatography-mass spectrometer (UPLC-MS) analysis combined with various data-processing techniques including metabolomics and multiple mass defect filter (MMDF) was established for the comprehensive screening and elucidation of potential coumarin metabolites.Total 20 metabolites of scoparone were identified in this study, including 14 undescribed metabolites. The metabolism of two other similar coumarins scopoletin and esculetin also could be determined using this strategy.By the established strategy, this study gives the insights about the major metabolic pathways of scoparone in vivo and in vitro metabolism, including demethylation, hydroxylation, hydration, cysteine conjugation, glucuronide conjugation and sulfate conjugation. Additionally, the metabolic pathways of scopoletin and esculetin were determined as hydroxylation, glucuronidation and sulfation. These results contribute to the understanding of metabolic characterization of coumarins, and demonstrate that the combination of UPLC-MS-based metabolomics and MMDF is a powerful approach to determine the metabolic pathways of coumarin compounds.

Chromones and coumarins from Saposhnikovia divaricata (Turcz.) Schischk. Growing in Buryatia and Mongolia and their cytotoxicity

Ethnopharmacological relevanceSaposhnikovia divaricata (family Apiaceae) a traditional medicinal plant distributed in many provinces of China, is well known for the pharmaceutical value and has been used for rheumatic arthritis, and anxiety in children. Antiviral, antioxidant and antiproliferative activities were also mentioned. The application of this plant are recorded in the Chinese Medicine (CM) classical text the Shen Nong's Materia Medica (Shen Nong Ben Cao Jing). In this monograph S. divaricata (syn Radix Ledebouriella divaricata) is graded as a premium-grade herb, with their broad-spectrum of therapeutic applications for the treatment of cough, common cold, arthralgia, as well as in rheumatic disorders. Aim of the studyTo isolate and identify chemical constituents (chromones and coumarins) from S. divaricata, collected in Buryatia and Mongolia and to study their in vitro anticancer activity against MEL-8, U-937, DU-145, MDA-MB-231 and ВТ-474 cell lines. Materials and methodsAn 40% aqueous ethanol extract of the roots of S. divaricata was prepared and further successively fractionated by extraction with petroleum ether, diethyl ether, tert-butyl methyl ether and ethyl acetate. The obtained extracts were subjected to a series of chromatographic separations on silica gel for isolation of individual compounds. Isolated compounds were tested for their cytotoxicity with respect to model cancer cell lines using the conventional MTT assays. Results: Total of 15 individual compounds: coumarins scopoletin 2, bergapten 3, isoimperatorin 4, marmesin 5, (+)-decursinol 9, (−)-praeruptorin B 10, oxypeucedanin hydrate 11, chromones: hamaudol 6, cimifugin 7, 5-О-methylvisamminol 8, chromone glycosides: prim-O-glucosylcimifugin 12, sec-O-glucosylhamaudol 13, 4′-O-β-D-glucopyranosyl-5-О-methylvisamminol 14, 4′-O-β-D-glucopyranosylvisamminol (15) and also polyyne compound panaxinol 1 were isolated and characterized. The structure of dihydropyranocoumarin 10 was confirmed by X-ray diffraction analyses. HPLC-UV method was used for determination of the content of most abundant chromones 7, 12 and 14 in the roots of S. divaricata, collected in Mongolia. Compounds 3–11 and 13, 14 were evaluated for their cytotoxicity with respect to model cancer cell lines. All the compounds were non-toxic in the hemolysis test. Conclusion: This report about the phytochemical profiles of S. divaricata growing in Mongolia and Buryatia led to the identification of 14 compounds including coumarins and chromones. The available coumarins and chromones may serve as new leads for the discovery of anticancer drugs.

Tomato glycosyltransferase Twi1 plays a role in flavonoid glycosylation and defence against virus.

BackgroundSecondary metabolites play an important role in the plant defensive response. They are produced as a defence mechanism against biotic stress by providing plants with antimicrobial and antioxidant weapons. In higher plants, the majority of secondary metabolites accumulate as glycoconjugates. Glycosylation is one of the commonest modifications of secondary metabolites, and is carried out by enzymes called glycosyltransferases.ResultsHere we provide evidence that the previously described tomato wound and pathogen-induced glycosyltransferase Twi1 displays in vitro activity toward the coumarins scopoletin, umbelliferone and esculetin, and the flavonoids quercetin and kaempferol, by uncovering a new role of this gene in plant glycosylation. To test its activity in vivo, Twi1-silenced transgenic tomato plants were generated and infected with Tomato spotted wilt virus. The Twi1-silenced plants showed a differential accumulation of Twi1 substrates and enhanced susceptibility to the virus.ConclusionsBiochemical in vitro assays and transgenic plants generation proved to be useful strategies to assign a role of tomato Twi1 in the plant defence response. Twi1 glycosyltransferase showed to regulate quercetin and kaempferol levels in tomato plants, affecting plant resistance to viral infection.

Sesquiterpene Lactones and Flavonoids from Psephellus pyrrhoblepharus with Antiproliferative Activity on Human Gynecological Cancer Cell Lines.

Multistep chromatographic separations of the chloroform extract of the Turkish endemic plant Psephellus pyrrhoblepharus (Boiss.) Wagenitz (syn. Centaurea pyrrhoblephara Boiss.) resulted in the isolation of six guaianolid-type sesquiterpenes, chlorojanerin (1), 19-deoxychlorojanerin (2), 15-hydroxyjanerin (3), aguerin B (4), cynaropicrin (5), eleganin (6); three flavonoids, apigenin, 6-methoxyluteolin and jaceosidine; two glycosides, benzyl-1-O-β-d-glucoside and 3(Z)-hexenyl-1-O-β-d-glucoside; and the coumarin scopoletin. The structures were established by the interpretation of their ESI-MS and 1D and 2D NMR data including 1H-NMR, JMOD, 1H,1H-COSY, HSQC, HMBC, and NOESY experiments. All compounds were isolated for the first time from P. pyrrhoblepharus. Compounds 1–6, the isolated flavonoids and scopoletin were evaluated for their antiproliferative activities on human gynecological cancer cell lines (SiHa, HeLa, and MDA-MB-231 cells) using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Chlorojanerin (1), 19-deoxychlorojanerin (2), aguerin B (4), cynaropicrin (5), eleganin (6) were shown to have noteworthy effects on all of the tested cell lines, while apigenin, jaceosidine, and 6-methoxyluteolin were moderately active on HeLa cells. The highest activities were demonstrated by the chlorine-containing derivatives chlorojanerin (1) and 19-deoxychlorojanerin (2) with IC50 values of 2.21 and 2.88 µM, respectively, against the triple negative breast cancer model MDA-MB-231 cells.

Uncommon fatty acids, Iridoids and other secondary metabolites from the medicinal plant species Ixora cibdela Craib (Rubiaceae)

Phytochemical investigation of methanolic extracts from the so far unstudied plant species Ixora cibdela Craib (Rubiaceae) led to the isolation and identification of an uncommon and novel fatty acid and the related methyl ester named as cibdelin A and cibdelin B. Additionally, the five known iridoid glucosides 11-methylixoside, shanzhiside, mussaenosidic acid, geniposidic acid, and apodanthoside together with the proanthocyanidin cinnamtannin B-1 were isolated from the root bark, as well as the lignan dihydrocubebin and the two coumarins scopoletin and isofraxidin from the stem bark extract. The structures of all isolated compounds were elucidated from 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy. The results are discussed briefly in biological context.

The Arabidopsis non-host defence-associated coumarin scopoletin protects soybean from Asian soybean rust.

SummaryThe fungus Phakopsora pachyrhizi (Pp) causes Asian soybean rust (SBR) disease which provokes tremendous losses in global soybean production. Pp is mainly controlled with synthetic fungicides to which the fungus swiftly develops fungicide resistance. To substitute or complement synthetic fungicides in Asian soybean rust control, we aimed to identify antifungal metabolites in Arabidopsis which is not a host for Pp. Comparative transcriptional and metabolic profiling of the Pp‐inoculated Arabidopsis non‐host and the soybean host revealed induction of phenylpropanoid metabolism‐associated genes in both species but activation of scopoletin biosynthesis only in the resistant non‐host. Scopoletin is a coumarin and an antioxidant. In vitro experiments disclosed fungistatic activity of scopoletin against Pp, associated with reduced accumulation of reactive oxygen species (ROS) in fungal pre‐infection structures. Non‐antioxidant and antioxidant molecules including coumarins with a similar structure to scopoletin were inactive or much less effective at inhibiting fungal accumulation of ROS and germination of Pp spores. When sprayed onto Arabidopsis leaves, scopoletin also suppressed the formation of Pp pre‐infection structures and penetration of the plant. However, scopoletin neither directly activated defence nor did it prime Arabidopsis for enhanced defence, therefore emphasizing fungistatic activity as the exclusive mode of action of scopoletin against Pp. Because scopletin also protected soybean from Pp infection, the coumarin may serve as a natural fungicide or as a lead for the development of near‐to‐nature fungicides against Asian soybean rust.

MYB72-dependent coumarin exudation shapes root microbiome assembly to promote plant health

Plant roots nurture a tremendous diversity of microbes via exudation of photosynthetically fixed carbon sources. In turn, probiotic members of the root microbiome promote plant growth and protect the host plant against pathogens and pests. In the Arabidopsis thaliana-Pseudomonas simiae WCS417 model system the root-specific transcription factor MYB72 and the MYB72-controlled β-glucosidase BGLU42 emerged as important regulators of beneficial rhizobacteria-induced systemic resistance (ISR) and iron-uptake responses. MYB72 regulates the biosynthesis of iron-mobilizing fluorescent phenolic compounds, after which BGLU42 activity is required for their excretion into the rhizosphere. Metabolite fingerprinting revealed the antimicrobial coumarin scopoletin as a dominant metabolite that is produced in the roots and excreted into the rhizosphere in a MYB72- and BGLU42-dependent manner. Shotgun-metagenome sequencing of root-associated microbiota of Col-0, myb72, and the scopoletin biosynthesis mutant f6'h1 showed that scopoletin selectively impacts the assembly of the microbial community in the rhizosphere. We show that scopoletin selectively inhibits the soil-borne fungal pathogens Fusarium oxysporum and Verticillium dahliae, while the growth-promoting and ISR-inducing rhizobacteria P. simiae WCS417 and Pseudomonas capeferrum WCS358 are highly tolerant of the antimicrobial effect of scopoletin. Collectively, our results demonstrate a role for coumarins in microbiome assembly and point to a scenario in which plants and probiotic rhizobacteria join forces to trigger MYB72/BGLU42-dependent scopolin production and scopoletin excretion, resulting in improved niche establishment for the microbial partner and growth and immunity benefits for the host plant.

Auxin-like effects of the natural coumarin scopoletin on Arabidopsis cell structure and morphology

The mode of action and phytotoxic potential of scopoletin, a natural compound belonging to the group of coumarins, has been evaluated in detail. Analysis conducted by light and electron transmission microscopy showed strong cell and tissue abnormalities on treated roots, such as cell wall malformations, multi-nucleated cells, abnormal nuclei and tissue disorganization. Scopoletin compromised root development by inducing wrong microtubule assembling, mitochondrial membrane depolarization and ultimate cell death, in a way similar to auxin herbicides. The structural similarities of the natural compound scopoletin and the auxin herbicide 2,4-D, as well as the ability of scopoletin to fit into the auxin-binding site TIR1, were analyzed, suggesting that the phytotoxic activity of scopoletin matches with that exhibited by auxinic herbicides.

RNAi inhibition of feruloyl CoA 6\u2032-hydroxylase reduces scopoletin biosynthesis and post-harvest physiological deterioration in cassava (Manihot esculenta Crantz) storage roots

Cassava (Manihot esculenta Crantz) is a major world crop, whose storage roots provide food for over 800 million throughout the humid tropics. Despite many advantages as a crop, the development of cassava is seriously constrained by the rapid post-harvest physiological deterioration (PPD) of its roots that occurs within 24–72 h of harvest, rendering the roots unpalatable and unmarketable. PPD limits cassava’s marketing possibilities in countries that are undergoing increased development and urbanisation due to growing distances between farms and consumers. The inevitable wounding of the roots caused by harvesting triggers an oxidative burst that spreads throughout the cassava root, together with the accumulation of secondary metabolites including phenolic compounds, of which the coumarin scopoletin (7-hydroxy-6-methoxy-2H-1-benzopyran-2-one) is the most abundant. Scopoletin oxidation yields a blue-black colour, which suggests its involvement in the discoloration observed during PPD. Feruloyl CoA 6′-hydroxylase is a controlling enzyme in the biosynthesis of scopoletin. The cassava genome contains a seven membered family of feruloyl CoA 6′-hydroxylase genes, four of which are expressed in the storage root and, of these, three were capable of functionally complementing Arabidopsis T-DNA insertion mutants in this gene. A RNA interference construct, designed to a highly conserved region of these genes, was used to transform cassava, where it significantly reduced feruloyl CoA 6′-hydroxylase gene expression, scopoletin accumulation and PPD symptom development. Collectively, our results provide evidence that scopoletin plays a major functional role in the development of PPD symptoms, rather than merely paralleling symptom development in the cassava storage root.

Structural Insights into Substrate Specificity of Feruloyl-CoA 6'-Hydroxylase from Arabidopsis thaliana.

Coumarins belong to an important class of plant secondary metabolites. Feruloyl-CoA 6’-hydroxylase (F6’H), a 2-oxoglutarate dependent dioxygenase (2OGD), catalyzes a pivotal step in the biosynthesis of a simple coumarin scopoletin. In this study, we determined the 3-dimensional structure of the F6’H1 apo enzyme by X-ray crystallography. It is the first reported structure of a 2OGD enzyme involved in coumarin biosynthesis and closely resembles the structure of Arabidopsis thaliana anthocyanidin synthase. To better understand the mechanism of enzyme catalysis and substrate specificity, we also generated a homology model of a related ortho-hydroxylase (C2’H) from sweet potato. By comparing these two structures, we targeted two amino acid residues and verified their roles in substrate binding and specificity by site-directed mutagenesis.

Antibacterial activity and chemical compounds of leaves and branches of Protium hebetatum

ABSTRACT The extracts and fractions of leaves and branches of Protium hebetatum D. C. Daly (Burseraceae) were investigated for their antibacterial activity and chemical composition. The methanol extract of branches (EMG) was considered active against the Escherichia coli and the Proteus vulgaris, showing an inhibition zone of 13 mm, and was selected for bioassay-guided phytochemical fractionation. From the technique of broth microdilution, the extract was considered a moderate inhibitor against Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis, with a minimum inhibitory concentration (MIC) of 1 mg/mL. The dichloromethane fraction was considered a moderate inhibitor against S. aureus (MIC of 1 mg/mL) and a potent inhibitor against E. faecalis (MIC of 0.5 mg/mL). F1, F2, F5 and F6 from chromatographic column of dichloromethane fraction were considered moderate inhibitors against S. aureus (MIC of 1 mg/mL). Through analysis by a gas chromatography mass spectrometry, eighteen compounds were identified, from which thirteen (isoeugenol, p-vinylguaiacol, metoxyeugenol, coumarin, 5-hydroxy-scopoletin, 4,7-dihydroxy-6-metoxicromam-2-one, 4[(1E]-3-hydroxy-1-propenyl)-2-methoxyphenol, piperonal, scoparon, o-guaiacol, spathulenol, seringol and antiarol) are unprecedented in these species. We also identified the triterpenes α-amyrin and β-amyrin, the steroids stigmasterol and sitosterol and the coumarin scopoletin, which was closely linked to the antibacterial activity of the samples.

Flavonoids from Artemisia santolinifolia

Artemisia santolinifolia Turcz. ex Besser is a perennial plant indigenous to Central Asia, southern Siberia, Mongolia, and Yakutia [1, 2]. The flavonoids quercetin, luteolin, rutin, and kaempferol and its glycoside [3] and coumarins scopoletin and umbelliferone [4] were isolated previously from A. santolinifolia. The roots yielded a phenolic natural compound [5]. We studied the aerial part of A. santolinifolia collected in 2008 in the vicinity of Bayanaul, Pavlodar Oblast, Republic of Kazakhstan. The aerial part was extracted with MeOH. The extract was evaporated in a rotary evaporator. The resulting condensed extract was worked up with aqueous alcohol. The filtrate was extracted with CHCl3. Then, the obtained total compounds (74 g) were separated over a column of silica gel (compound–sorbent ratio 1:1.5). Elution by hexane–EtOAc (3.5:6.5) afforded yellow crystalline 1 and 2. Comparison of physicochemical constants and spectral data (PMR and 13C NMR) with the literature identified 1 as the flavonoid 5,4 -dihydroxy-7-methoxyflavone (genkwanin) [6]. 5,4 -Dihydroxy-7-methoxyflavone (genkwanin) (1). 1H NMR spectrum (300 MHz, DMSO-d6, , ppm, J/Hz): 6.78 (1H, s, H-3), 6.32 (1H, d, J = 2, H-6), 6.7 (1H, d, J = 2, H-8), 7.92 (1H, d, J = 9, H-2 , 6 ), 7.05 (1H, d, J = 9, H-3 , 5 ), 3.82 (3H, s, 7-OCH3), 10.7 (1H, br.s, 4 -OH), 12.92 (1H, s, 5-OH). 13C NMR spectrum (125.76 MHz, DMSO-d6, , ppm): 163.75 (s, C-2), 102.82 (d, C-3), 181.56 (s, C-4), 156.92 (s, C-5), 97.70 (d, C-6), 164.81 (s, C-7), 92.43 (d, C-8), 161.01 (s, C-8a), 104.48 (s, C-4a), 120.88 (s, C-1 ), 128.25 (d, C-2 , 6 ), 115.75 (d, C-3 , 5 ), 160.95 (s, C-4 ), 55.90 (s, C-9). The mass spectrum of 1 showed a peak for a molecular ion with m/z 284.2 [M]+. Compound 1 was isolated earlier from other Artemisia species, e.g., A. capillaris Thunb., A. lessingiana Bess., A. sacrorum Ledeb., and A. pontica L. [6, 7]. An analysis of spectral data (PMR and 13C NMR) suggested that isolated compound 2 was the flavonoid 5,7-dihydroxy4 -methoxyflavone (acacetin). 5,7-Dihydroxy-4 -methoxyflavone (acacetin) (2). 1H NMR spectrum (300 MHz, DMSO-d6, , ppm, J/Hz): 6.8 (1H, s, H-3), 6.18 (1H, d, J = 2, H-6), 6.45 (1H, d, J = 2, H-8), 7.98 (1H, d, J = 9, H-2 , 6 ), 6.92 (1H, d, J = 9, H-3 , 5 ), 3.82 (3H, s, 7-OCH3), 12.88 (1H, s, 5-OH). 13C NMR spectrum (125.76 MHz, DMSO-d6, , ppm): 162.98 (s, C-2), 103.33 (d, C-3), 181.42 (s, C-4), 157.07 (s, C-5), 98.71 (d, C-6), 163.93 (s, C-7), 93.83 (d, C-8), 162.00 (s, C-8a), 103.60 (s, C-4a), 122.63 (s, C-1 ), 127.99 (d, C-2 , 6 ), 113.60 (d, C-3 , 5 ), 162.00 (s, C-4 ), 55.39 (s, C-9). The mass spectrum of 2 showed a peak for a molecular ion with m/z 284.2 [M]+. Compound 2 was isolated earlier from A. filifolia Torrey, A. gmelinii Weber ex Stechm, A. herba-alba Asso, and A. judaica L. [7]. Thus, the flavonoids genkwanin and acacetin were isolated for the first time from the aerial part of A. santolinifolia as a result of the chemical study.

Bioassay-Guided Chromatographic Isolation and Identification of Antibacterial Compounds from Artemisia annua L. That Inhibit Clostridium perfringens Growth.

Clostridium perfringens is the causative agent of necrotic enteritis leading to significant losses in the poultry industry. Dichloromethane and n-hexane extracts of aerial parts of Artemisia annua (Asteraceae) exhibited activity against C. perfringens with minimum inhibitory concentrations (MIC) of 185 and 270 μg/mL, respectively. Bioassay-guided fractionation of the extracts gave several active fractions (MIC between 75 and 600 μg/mL). Investigations of the most active fractions resulted in the isolation and characterization of the polyacetylene ponticaepoxide (MIC between 100 and 200 μg/mL) and (+)-threo-(5E)-trideca-1,5-dien-7,9,11-triyne-3,4-diol (MIC between 400 and 800 μg/mL), the flavonols chrysosplenol D (MIC between 200 and 400 μg/mL) and casticin (slight inhibition at 800 μg/mL), and 2,4-dihydroxy-6-methoxyacetophenone (slight inhibition at 800 μg/mL). Also, the coumarin scopoletin and the sesquiterpene lactone artemisinin were isolated from active fractions but showed no inhibition of C. perfringens growth at 800 and 2000 μg/mL, respectively. Fractions containing essential oil components with camphor constituting >60% did not show inhibition of C. perfringens up to 1600 μg/mL. Extracts and some active fractions showed higher antibacterial effect than individual bioactive compounds, suggesting that synergistic effects may underlie the observed antibacterial effect. The present study adds new valuable information on the antibacterial effect of A. annua against C. perfringens.

Hepatic Necrosis and Degenerative Myopathy Associated with Cassava Feeding in Pigs.

Forty-three deaths were recorded among pigs fed boiled cassava meal at a private piggery over a period of two years. There were signs of sudden death in some cases with blood exuding from the external nares, vomiting, muscular weakness and pain or reluctance to move, emaciation, and stunted growth. The necropsy lesions included skeletal and cardiac muscle degeneration and necrosis, icterus, hepatic necrosis, and oedema of the dependent parts. The deaths and clinical signs are thought to be due to a non cyanide toxic principle in cassava, possibly the coumarins (scopoletin), which is found in high levels in cassava diet even after heat treatment. Therefore, the use of proper processing technology to obtain cassava products of high quality is recommended.