Schistosomicidal Activity of Dihydrobenzofuran Neolignans

We have evaluated the antischistosomal activity of synthetic dihydrobenzofuran neolignans (DBNs) derived from (±)‐trans‐dehydrodicoumaric acid dimethyl ester ( 1 ) and (±)‐trans‐dehydrodiferulic acid dimethyl ester ( 2 ) against adult Schistosoma mansoni worms in vitro. Compound 4 ((±)‐trans‐4‐O‐acetyldehydrodiferulic acid dimethyl ester) displayed the most promising activity; at 200 μm , it kills 100 ± 0% of worms after 24 h, which resembles the result achieved with praziquantel (positive control) at 1.56 μm . The hydrogenation of the double bond between C7′ and C8′, the introduction of an additional methyl group at C3′, and a double bond between C7 and C8 decreased the schistosomicidal activity of DBNs. On the other hand, the presence of the acetoxy group at C4 played an interesting role in this activity. These results demonstrated the interesting schistosomicidal potential of DBNs, which could be further exploited.     

Schistosomicidal Effects of the Essential Oils of Citrus limonia and Citrus reticulata Against Schistosoma mansoni

We report the in vitro schistosomicidal effects of the essential oil obtained from Citrus limonia leaves (CL ‐EO ) and C. reticulata fruit peels (CR ‐EO ), cultivated in Brazil, against Schistosoma mansoni worms. Limonene (29.9%), β ‐pinene (12.0%), sabinene (9.0%), citronellal (9.0%), and citronellol (5.8%) are the major constituents of CL ‐EO ; limonene (26.5%), γ ‐terpinene (17.2%), linalool (11.1%), octanal (8.0%), myrcene (6.2%), and capraldehyde (3.9%) predominate in CR ‐EO . CL ‐EO displayed moderate lethal concentration 50% (LC ₅₀) of 81.7 and 38.9 μg/ml against male and female worms at 24 and 72 h, respectively. At concentrations of 25 and 100 μg/ml, CL ‐EO separated between 50 and 75% of the coupled worm pairs during the evaluated period. CR ‐EO presented moderate LC ₅₀ of 81.7 μg/ml against male and female worms at 24 and 72 h. However, this oil separated coupled worm pairs more effectively than CL ‐EO and displayed lower cytotoxicity to GM 07492‐A cells (IC ₅₀ = 987.7 ± 88.9 μg/ml) as compared to CL ‐EO (IC ₅₀ = 187.8 ± 2.9 μg/ml). The enantiomers (+)‐(R )‐limonene and (?)‐(S )‐limonene did not affect S. mansoni adult worm pairs significantly. Taken together, these data indicate that CL ‐EO and CR ‐EO exhibit moderate in vitro schistosomicidal activity against adult S. mansoni worms.     

Nematicidal screening of essential oils and potent toxicity of Dysphania ambrosioides essential oil against Meloidogyne incognita in vitro and in vivo

It is known that some plant essential oils have pesticide activities. Among the 29 oils evaluated in this study, 14 showed nematicidal activities of 8 to 100% at the concentration of 1,000 μg/ml, compared with a control of 0.01 g/ml Tween 80^®. At a lower concentration of 500 μg/ml, only Dysphania ambrosioides oil caused >90% mortality of second‐stage juveniles (J2) of Meloidogyne incognita. The LC₅₀ and LC₉₅ values for D. ambrosioides oil were 307 μg/ml and 580 μg/ml, respectively. M. incognita eggs placed in D. ambrosioides oil solutions had a significant reduction in J2 hatching compared with controls. Therefore, the oil had a toxic effect on both eggs and J2 of M. incognita. This was in contrast to nematicides on the market that act efficiently only on J2. When J2 were placed in D. ambrosioides oil at its LC₅₀ concentration and inoculated onto tomato plants, the reduction in numbers of galls and eggs was 99.5% and 100%, respectively. Dysphania ambrosioides oil applied to the potting substrate of plants at a concentration of 1,100 μg/ml significantly reduced the number of galls and eggs of M. incognita, whereas a concentration of 800 μg/ml only reduced the number of eggs compared with the controls (Tween 80^® and water). The main components of the D. ambrosioides oil detected by gas chromatography–mass spectrometry were (Z)‐ascaridole (87.28%), E‐ascaridole (8.45%) and p‐cymene (3.35%), representing 99.08% of the total oil composition. Given its nematicidal activity, D. ambrosioides oil represents an exciting raw material in the search for new bioactive molecules for the pesticide industry.     

Anthelmintic Effects of the Essential Oil of Fennel (Foeniculum vulgare Mill., Apiaceae) against Schistosoma mansoni

Foeniculum vulgare Mill . (Apiaceae), known as fennel, is a widespread aromatic herbaceous plant, and its essential oil is used as additive in the food, pharmaceutical, cosmetic, and perfume industries. The in vitro antischistosomal activity and cytotoxic effects against V79 cells of the essential oil of F. vulgare cultivated in southeastern Brazil (FV‐EO) was investigated. The FV‐EO was obtained by hydrodistillation and characterized by GC‐FID and GC/MS analyses. (E)‐Anethole (69.8%) and limonene (22.5%) were identified as the major constituents. Its anthelmintic activity against Schistosoma mansoni was evaluated at concentrations of 10, 50, and 100 μg/ml, and it was found to be active against adult S. mansoni worms, although it was less effective than the positive control praziquantel (PZQ) in terms of separation of the coupled pairs, mortality, and decreased motor activity. However, FV‐EO elicited an interesting dose‐dependent reduction in the number of S. mansoni eggs. On their own, (E)‐anethole and the limonene enantiomers were much less effective than FV‐EO and PZQ. An XTT‐cytotoxicity‐based assay evidenced no FV‐EO cytotoxicity against V79 cells. In summary, FV‐EO displayed moderate in vitro schistosomicidal activity against adult S. mansoni worms, exerted remarkable inhibitory effects on the egg development, and was of low toxicity.     

Antagonistic Potential of Bacillus pumilus L1 Against Root‐Knot Nematode,Meloidogyne arenaria

This study was conducted to estimate the potential of Bacillus pumilus L1 against root‐knot nematode, Meloidogyne arenaria, in both in vitro and in vivo conditions. B. pumilus L1 was found to produce both protease and chitinase. When various concentrations (1–10%) of the bacterial culture (BC) or 0.02–0.11 mg/ml of the crude enzymes produced by B. pumilus L1 were used to treat M. arenaria eggs and second‐stage juveniles (J2), inhibition of hatching and J2 mortality were significantly increased under in vitro conditions. In addition, the hatching inhibition and J2 mortality rate were improved with increasing concentrations of BC and the crude enzymes. Similarly, these effects also increased over time after treatment with BC. Moreover, the crude enzymes caused partial degradation of the eggshell and juvenile body when treated at 0.11 mg/ml. The pot experiment also demonstrated that the application of BC to potted soil caused significant reduction in the number of galls and egg masses in the plant roots and of the J2 population as compared to the untreated control 6 weeks after M. arenaria infestation. In addition, the simultaneous application of BC upon nematode inoculation proved more effective than application 2 days postinoculation with nematode. B. pumilus L1 inoculation (BC, BCs and BC2) also promoted tomato plant growth as compared to the controls (TW, Ne, GM and NeT). Thus, our results demonstrated the ability of B. pumilus L1 as a potential biocontrol agent against root‐knot nematode, with additional activity as a plant growth promoter for tomato.     

Inhibitory Activities of Butanol Fraction from Butea monosperma (Lam.) Taub. Bark Against Free Radicals,Genotoxins and Cancer Cells

The present study was undertaken to investigate antioxidant, antigenotoxic, and antiproliferative activity of butanol fraction (Bmbu) from bark of medicinal plant Butea monosperma. Antioxidant potency of Bmbu was examined by various in vitro assays. It was also investigated for antigenotoxic activity using Escherichia coli. PQ37 employing SOS chromotest. Further, cytotoxic and apoptosis inducing activity of Bmbu was evaluated in MCF‐7 breast cancer cells. Bmbu showed potent free radical scavenging ability in ABTS assay (IC₅₀ 56.70 μg/ml) and anti‐lipid peroxidation ability (IC₅₀ 40.39 μg/ml). 4NQO and H₂O₂ induced genotoxicity was suppressed by Bmbu in SOS chromotest by 74.26% and 82.02% respectively. It also inhibited the growth of MCF‐7 cells with GI₅₀ value of 158.71 μg/ml. Induction of apoptosis in MCF‐7 cells by Bmbu treatment was deciphered using confocal microscopy, flow cytometry, and neutral comet assay. Bmbu treatment increased cell population in sub‐G₁ phase (69.6%) indicating apoptotic cells. Further, Bmbu treatment resulted in increased reactive oxygen species generation and decreased mitochondrial membrane potential indicating involvement of mitochondrial dependent pathway of apoptosis. HPLC profiling showed the presence of polyphenols such as ellagic acid, catechin, quercetin, and gallic acid as its major constituents. Consequently, it is suggested that the phytoconstituents from this plant may be further exploited for development of novel drug formulation with possible therapeutic implication.     

Variation in Polyphenolic Profiles,Antioxidant and Antimicrobial Activity of Different Achillea Species as Natural Sources of Antiglycative Compounds

A comparative study was carried out on the methanolic extracts from six Achillea species and the examined polyphenols from these plants on the formation of advanced glycation end‐products (AGE) in vitro. A. pachycephala which was richer in flavonoids (15 mg quercetin/g W) and phenolics (111.10 mg tannic acid/g DW) with substantial antioxidant activity (IC₅₀ = 365.5 μg/ml) presented strong anti‐AGE properties. Chlorogenic acid, luteolin, quercetin and caffeic acid were identified as the major polyphenols in the extracts by HPLC. In general, polyphenolic content follows the order of A. pachycephalla > A. nobilis > A. filipendulina > A. santolina > A. aucheri > A. millefolium. Most extracts exhibited marked anti‐AGE ability in the bovine serum albumin (BSA)/methylglyoxal (MG) system, though A. pachycephala showed the highest potential. The formation of AGEs was assessed by monitoring the production of fluorescent products and circular dichroism (CD) spectroscopy. Diminution in free radical production (assessed by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) assays) is discussed as potential mechanism for delay or reduced AGE. The results demonstrate the antiglycative, antioxidant and antimicrobial potential of Achillea species which can be attributed to polyphenols content and the effectiveness on generation of AGEs, thus Achillea species can be considered as natural sources for slowing down glycation related diseases.     

Production and Application of Syringomycin E as an Organic Fungicide Seed Protectant against Pythium Damping‐off

Syringomycin E (SRE) is a cyclic lipodepsinonapeptide with potent antifungal activity and is produced by certain strains of Pseudomonas syringae pv. syringae. In this study, its potential as an organic‐compatible agrofungicide and vegetable seed treatment against the soilborne pathogen Pythium ultimum var. ultimum was examined. A variant of P. syringae pv. syringae strain B301D with enhanced SRE‐producing capabilities was isolated and grown in a bioreactor with SRE yields averaging 50 mg/l in 40 h. SRE was extracted and purified through a large‐scale chromatography system using organic‐compatible processes and reagents. The minimum concentrations of the purified product required to inhibit 50 and 90% of P. ultimum oospore germination were determined as 31.3 and 250 μg/ml, respectively. Drench treatment of cucumber seeds in P. ultimum‐infested potting medium (500 oospores/g) with 50 μg/ml SRE or water with no SRE resulted in 90.2 ± 4.5% and 65.7 ± 4.6% germination rates, respectively. Seed coating with 0.03% (w/w) SRE allowed 65.7 ± 4.6% seedlings to germinate on naturally infested soil while 100.0 ± 0.0% of non‐coated seeds were unable to germinate due to Pythium infection. Organic‐compatible and scalably produced SRE is potentially a novel organic fungicide seed protectant.     

Chemical Characterization and Biological Activities of Phenolic‐Rich Fraction from Cauline Leaves of Isatis tinctoria L. (Brassicaceae) Growing in Sicily,Italy

The present work focused on the evaluation of the antioxidant and cytotoxic activities of the phenolic‐rich fraction (ItJ‐EAF) obtained from cauline leaves collected in January from Isatis tinctoria L. (Brassicaceae) growing wild around Acireale (Sicily, Italy). The total phenolic, flavonoid, and condensed tannin contents of the fraction were determined spectrophotometrically, whereas the phenolic profile was assessed by HPLC‐PDA/ESI‐MS analysis. A total of 20 compounds were positively identified and twelve out of them were never previously reported in I. tinctoria leaves. The fraction exhibited good radical scavenging activity in DPPH test (IC₅₀ = 0.6657 ± 0.0024 mg/ml) and reducing power (3.87 ± 0.71 ASE/ml), whereas, it neither showed chelating activity nor was able to counteract H₂O₂ induced oxidative stress damage in Escherichia coli. The antiproliferative effect was evaluated in vitro on two human anaplastic thyroid carcinoma cell lines (CAL‐62 and 8505C) by MTT assay. At the highest tested concentration ItJ‐EAF significantly reduced (80%) the growth of CAL‐62 cells. No cytotoxicity against Artemia salina was observed. It can be concluded that I. tinctoria cauline leaves represent a source of phenolic compounds which could be potentially used as chemopreventive or adjuvant agents against cancer.     

Correlation between the Chemical and Genetic Relationships among Thymus saturejoides Genotypes Cultured under in vitro and in vivo Environments

In this study, the in vitro and in vivo essential oil (EO) composition and genetic variability in six micropropagated genotypes of Thymus saturejoides Coss ., a Mediterranean medicinal and aromatic plant, were analyzed by GC/MS and randomly amplified polymorphic DNA (RAPD). Yield and composition of the EO varied between genotypes. Cluster analysis based on RAPD data and EO grouped the six genotypes in three groups in both culture conditions, thus showing considerable intraspecific genetic and chemical variations. Applying the Mantel test, the result showed a significant correlation between the two proximity matrices RAPD and EO obtained from in vitro genotypes, whereas this correlation was not observed when using the EO obtained from the in vivo genotypes.     

Essential Oil and Bioactive Compounds Variation in Myrtle (Myrtus communis L.) as Affected by Seasonal Variation and Salt Stress

The effect of different NaCl concentrations (control, 2, 4 and 6 dS/m) and three harvesting times in different seasons including spring (9 April), summer (5 July), and fall (23 September) was evaluated on essential oil (EO) yield, composition, phenolic, flavonoid content, and antioxidant activity of myrtle. Essential oil yield ranged from 0.2% in control and fall to 1.6% in moderate salinity (4 dS/m) and spring season. The main constituents obtained from gas chromatography/mass spectrometry analysis were α‐pinene, 1,8‐cineole, limonene, linalool, α‐terpineol, and linalyl acetate in which α‐pinene ranged from 11.70% in moderate and fall to 30.99% in low salinity (2 dS/m) and spring, while 1,8‐cineole varied from 7.42% in high salinity (6 dS/m) and summer to 15.45% in low salinity and spring, respectively. Salt stress also resulted in an increase in total phenolic, flavonoid content, and antioxidant activity. The highest antioxidant activity based on DPPH radical scavenging activity, reducing power (FTC) and β‐carotene/linoleic acid model systems was found in plants harvested in spring and summer in high stress condition. The lowest IC₅₀ values obtained in 6 dS/m in spring (375.23 μg/ml) followed by summer (249.41 μg/ml) and fall (618.38 μg/ml). Eight major phenolic and flavonoid compounds were determined in three harvesting times using high performance liquid chromatography analysis. In overall, late harvesting time of myrtle in fall can lead to reduce the most of major EO components, while it can improve the amount of phenolic acids.     

Insecticidal Activity of the Leaf Essential Oil of Peperomia borbonensis Miq. (Piperaceae) and Its Major Components against the Melon Fly Bactrocera cucurbitae (Diptera: Tephritidae)

The essential oil from the leaves of Peperomia borbonensis from Réunion Island was obtained by hydrodistillation and characterized using GC‐FID, GC/MS and NMR. The main components were myristicin (39.5%) and elemicin (26.6%). The essential oil (EO) of Peperomia borbonensis and its major compounds (myristicin and elemicin), pure or in a mixture, were evaluated for their insecticidal activity against Bactrocera cucurbitae (Diptera: Tephritidae) using a filter paper impregnated bioassay. The concentrations necessary to kill 50% (LC₅₀) and 90% (LC₉₀) of the flies in three hours were determined. The LC₅₀ value was 0.23 ± 0.009 mg/cm² and the LC₉₀ value was 0.34 ± 0.015 mg/cm² for the EO. The median lethal time (LT₅₀) was determined to compare the toxicity of EO and the major constituents. The EO was the most potent insecticide (LT₅₀ = 98 ± 2 min), followed by the mixture of myristicin and elemicin (1.4:1) (LT₅₀ = 127 ± 2 min) indicating that the efficiency of the EO is potentiated by minor compounds and emphasizing one of the major assets of EOs against pure molecules.     

Antimicrobial Activity of Monoketone Curcuminoids Against Cariogenic Bacteria

We evaluated the antimicrobial activity of 25 monoketone curcuminoids (MKCs) against a representative panel of cariogenic bacteria in terms of their minimum inhibitory concentration (MIC) values. Curcumin A ( 10 ) displayed promising activity against Streptococcus mutans (MIC = 50 μg/ml) and Streptococcus mitis (MIC = 50 μg/ml) as well as moderate activity against S. sanguinis (MIC = 100 μg/ml), Lactobacillus casei (MIC = 100 μg/ml), and Streptococcus salivarius (MIC = 200 μg/ml). Results indicated higher activity of compound 10 than that of its bis‐β‐diketone analog. Additionally, compounds 3a (1,5‐bis(4‐methylphenyl)pentan‐3‐one) and 7b (1,5‐bis(4‐bromophenyl)pentan‐3‐ol) were moderately active against S. mitis (MIC = 100 μg/ml) and S. salivarus (MIC = 200 μg/ml).     

Chemical Composition and Antimicrobial Activity of Origanum libanoticum,Origanum ehrenbergii,and Origanum syriacum Growing Wild in Lebanon

The essential oils (EOs) of the aerial parts of Origanum libanoticum and Origanum ehrenbergii, endemic to Lebanon, and Origanum syriacum, endemic to the Levantine, were obtained by distillation with a Clevenger apparatus. GC and GC/MS allowed identification of 96.4%, 93.5%, and 95.2% of their constituents, respectively. Carvacrol was the major component of both O. syriacum EO (79%) and O. ehrenbergii EO (60.8%). This compound was absent in O. libanoticum EO and the major compounds were β‐caryophyllene (26.8%), caryophyllene oxide (22.6%), and germacrene D (17.2%). The assessment of their antimicrobial activity against Candida albicans and six pathogenic bacteria revealed that O. libanoticum EO was inactive, while O. syriacum and O. ehrenbergii showed moderate antimicrobial activity with minimal inhibitory concentrations varying from 400 to 1200 μg/ml. These results support the traditional use of these last two species in traditional herbal preparations in Lebanon.     

Investigations on Antioxidant,Antiproliferative and COX‐2 Inhibitory Potential of Alkaloids from Anthocephalus cadamba (Roxb.) Miq. Leaves

In the present study, an ayurvedic medicinal plant, Anthocephalus cadamba (Roxb .) Miq . commonly known as ‘Kadamb’ was explored for its potential against oxidative stress and cancer. The fractions namely AC‐4 and ACALK (alkaloid rich fraction) were isolated from A. cadamba leaves by employing two different isolation methods and evaluated for their in vitro antioxidant and antiproliferative activity. The structure of the isolated AC‐4 was characterized tentatively as dihydrocadambine by using various spectroscopic techniques such as ESI‐QTOF‐MS, ¹H‐ and ¹³C‐NMR, DEPT, COSY, HMQC, and HMBC. Results of various antioxidant assays viz. 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), ABTS cation radical, superoxide anion radical scavenging, and plasmid nicking assay demonstrated that both the fractions viz. AC‐4 and ACALK possess ability to scavenge DPPH, ABTS radicals and effectively protected plasmid pBR322 DNA from damage caused by hydroxyl radicals. Further, when both fractions were evaluated for their potential to suppress growth of HeLa and COLO 205 cells, only ACALK fraction showed antiproliferative effects. ACALK exhibited GI₅₀ of 205.98 and 99.54 μg/ml in HeLa and COLO 205 cell lines, respectively. Results of Hoechst staining in cervical carcinoma (HeLa) cells confirmed that ACALK induced cell death in HeLa cells via apoptotic mode. Both the fractions also inhibited COX‐2 enzyme activity.     

Chemical Composition,Antioxidant Properties, α‐Glucosidase Inhibitory,and Antimicrobial Activity of Essential Oils from Acacia mollissima and Acacia cyclops Cultivated in Tunisia

The genus Acacia is quite large and can be found in the warm subarid and arid parts, but little is known about its chemistry, especially the volatile parts. The volatile oils from fresh flowers of A. mollissima and A. cyclops (growing in Tunisia) obtained by hydrodistillation were analyzed by GC then GC/MS. Eighteen (94.7% of the total oil composition) and 23 (97.4%) compounds were identified in these oils, respectively. (E,E)‐α‐Farnesene (51.5%) and (E)‐cinnamyl alcohol (10.7%) constituted the major compounds of the flower oil of A. mollissima, while nonadecane (29.6%) and caryophyllene oxide (15.9%) were the main constituents of the essential oil of A. cyclops. Antioxidant activity of the isolated oils was studied by varied assays, i.e., 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2‐azinobis 3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS); the isolated oils showed lowest IC₅₀ (4 – 39 μg/ml) indicating their high antioxidant activity. The α‐glucosidase inhibitor activity was also evaluated and Acacia oils were found to be able to strongly inhibit this enzyme with IC₅₀ values (81 – 89 μg/ml) very close to that of acarbose which was used as positive control. Furthermore, they were tested against five Gram‐positive and Gram‐negative bacteria and one Candida species. Essential oil of A. mollissima was found to be more active than that of A. cyclops, especially against Pseudomonas aeruginosa (MIC = 0.31 mg/ml and MBC = 0.62 mg/ml).     

Chemical Composition and Allelopathic Potential of Essential Oils from Citharexylum spinosum L. Grown in Tunisia

Citharexylum spinosum L. (Verbenaceae) also known as Citharexylum quadrangulare Jacq . or Citharexylum fruticosum L. is an exotic tree introduced many years ago in Tunisia, specially used as a street and park ornamental tree. Essential oils (EOs) were obtained by hydrodistillation of the different parts (roots, stems, leaves, flowers and fruits; drupes) collected from trees grown in the area of Monastir (Tunisia). In total, 84 compounds, representing 90.1 – 98.4% of the whole oil composition, were identified by GC‐FID and GC/MS analyses. The root EO was distinguished by its high content in monoterpene hydrocarbons (α‐phellandrene; 30.8%) whereas that obtained from stems was dominated by sesquiterpene hydrocarbons (cuparene; 16.4%). The leaf oil was rich in an apocarotenoid derivative (hexahydrofarnesylacetone; 26%) and an aliphatic hydrocarbon (nonadecane; 14.5%). Flowers oil was rich in esters (2‐phenylethyl benzoate; 33.5%). Finally, drupes oil was rich in oxygenated sesquiterpenes (β‐eudesmol; 33.1%). Flowers oil showed a significant phytotoxic effect against lettuce seeds germination, it induces a total inhibition when tested at 1 mg/ml. Root and shoot elongation seemed to be more affected than germination. The inhibition of the shoot length varied from 3.6% to 100% and that of the root from 16.1% to 100%. The highest inhibition of 100% was detected for flower oil tested at 1 mg/ml. Our in vitro studies suggest a possible and new alternative use of C. spinosum EOs in herbicidal formulations, further experiments involving field conditions are necessary to confirm its herbicidal potential.     

Anti‐HSV‐1 and HSV‐2 Flavonoids and a New Kaempferol Triglycoside from the Medicinal Plant Kalanchoe daigremontiana

Kalanchoe daigremontiana (Crassulaceae) is a medicinal plant native to Madagascar. The aim of this study was to investigate the flavonoid content of an aqueous leaf extract from K. daigremontiana (Kd), and assess its antiherpetic potential. The major flavonoid, kaempferol 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside ( 1 ), was isolated from the AcOEt fraction (Kd‐AC). The BuOH‐soluble fraction afforded quercetin 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside ( 2 ) and the new kaempferol 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside‐7‐O‐β‐d ‐glucopyranoside ( 3 ), named daigremontrioside. The crude extract, Kd‐AC fraction, flavonoids 1 and 2 were evaluated using acyclovir‐sensitive strains of HSV‐1 and HSV‐2. Kd‐AC was highly active against HSV‐1 (EC₅₀ = 0.97 μg/ml, SI > 206.1) and HSV‐2 (EC₅₀ = 0.72 μg/ml, SI > 277.7). Flavonoids 1 and 2 showed anti‐HSV‐1 (EC₅₀ = 7.4 μg/ml; SI > 27 and EC₅₀ = 5.8 μg/ml; SI > 8.6, respectively) and anti‐HSV‐2 (EC₅₀ = 9.0 μg/ml; SI > 22.2 and EC₅₀ = 36.2 μg/ml; SI > 5.5, respectively) activities, suggesting the contribution of additional substances to the antiviral activity.     

Evidence of Phytoalexins in Rhizome of Atractylodis Maceocephalae Koidz Infected with Sclerotium rolfsii sacc Following Treatment with the Polysaccharides of Chrysanthemum indicum

Atractylenolides compounds (atractylenolide‐I, atractylenolide‐II and atractylenolide‐III) extracted from Atractylenolides macrocephala were analysed for their differential presence in the rhizome of both the infected and healthy plants and its fungitoxicity on prophylactic treatment with polysaccharides of Chrysanthemum indicum against Sclerotium rolfsii. It was evident that the plant under stress by pathogen has instigated the significant synthesis and accumulation of atractylenolide‐II and atractylenolide‐III in the rhizome of plants as a result of elicitation with polysaccharides of C. indicum. Our results also showed that the absence of atractylenolide‐II in the rhizome made the plant susceptible to S. rolfsii. Furthermore, on in vitro antifungal studies, exogenous application of atractylenolide‐II with the concentration of 200 μg/ml showed a significant inhibitory effect on mycelial growth by achieving a 77.23% antifungal activity rate, and a minimal inhibitory effect at a concentration of 12.5 μg/ml with atractylenolide‐II. To our knowledge, this novel study on phytoalexins in A. macrocephala suggested that A. macrocephala plants produce elevated levels of atractylenolide‐II and atractylenolide‐III in a pattern typical of phytoalexins, in response to an eliciting treatment after infection.     

Copaifera duckei Oleoresin and Its Main Nonvolatile Terpenes: In Vitro Schistosomicidal Properties

In this article, the in vitro schistosomicidal effects of three Brazilian Copaifera oleoresins (C. duckei, C. langsdorffii, and C. reticulata) are reported. From these botanical sources, the oleoresin of C. duckei (OCd) demonstrated to be the most promising, displaying LC₅₀ values of 75.8, 50.6, and 47.2 μg/ml at 24, 48, and 72 h of incubation, respectively, against adult worms of Schistosoma mansoni, with a selectivity index of 10.26. Therefore, the major compounds from OCd were isolated, and the diterpene, (?)‐polyalthic acid (PA), showed to be active (LC₅₀ values of 41.7, 36.2, and 33.4 μg/ml, respectively, at 24, 48, and 72 h of incubation). Moreover, OCd and PA affected the production and development of eggs, and OCd modified the functionality of the tegument of S. mansoni. Possible synergistic and/or additive effects of this balsam were also verified when a mixture of the two of its main compounds (PA and ent‐labd‐8(17)‐en‐15,18‐dioic acid) in the specific proportion of 3:1 (w/w) was tested. The obtained results indicate that PA should be considered for further investigations against S. mansoni, such as, synergistic (combination with praziquantel (PZQ)) and in vivo studies. It also shows that diterpenes are an important class of natural compounds for the investigation of agents capable of fighting the parasite responsible for human schistosomiasis.