Nematicidal metabolites from <Emphasis Type="Italic">Gliocladium roseum</Emphasis> YMF1.00133

A strain of the fungus Gliocladium roseum YMF1.00133 was found to secrete nematicidal metabolites against nematodes Panagrellus redivivus, Caenothabditis elegans and Bursaphelenchus xylophilus in experiments searching for nematicidal fungi. Through bioassay-guided fractionations, a unique trioxopiperazine alkaloid, gliocladin C (compound 1), and an alkylane resorcinol, 5-n-heneicosylresorcinol (compound 2) were obtained from the methanol extract of the fungus and determined by single-crystal X-ray analysis and spectroscopic data. In vitro immersion experiments showed that the ED₅₀ values of compounds 1 and 2 after 24 h incubation were 15 and 30 μg/mL against C. elegans, 50 and 80 μg/mL against P. redivivus, and 200 and 180 μg/mL against B. xylophilus, respectively. The X-ray diffraction data of compound 1 and the nematicidal activity of compounds 1 and 2 were reported for the first time.     

<Emphasis Type="Italic">In vitro</Emphasis> leishmanicidal,antibacterial and antitumour potential of anhydrocochlioquinone A obtained from the fungus <Emphasis Type="Italic">Cochliobolus</Emphasis> sp.

The bioassay-guided fractionation of the ethyl acetate extract of the fungus Cochliobolus sp. highlighted leishmanicidal activity and allowed for anhydrocochlioquinone A (ANDC-A) isolation. MS, 1D and 2D NMR spectra of this compound were in agreement with those published in the literature. ANDC-A exhibited leishmanicidal activity with EC₅₀ value of 22.4 µg/mL (44 μM) and, when submitted to the microdilution assay against Gram-positive and Gram-negative bacteria, showed a minimal inhibitory concentration against Staphylococcus aureus ATCC 25295 of 128 μg/mL (248.7 μM). It was also active against five human cancer cell lines, showing IC₅₀ values from 5.4 to 20.3 μM. ANDC-A demonstrated a differential selectivity for HL-60 (SI 5.5) and THP-1 (SI 4.3) cell lines in comparison with Vero cells and was more selective than cisplatin and doxorubicin against MCF-7 cell line in comparison with human peripheral blood mononuclear cells. ANDC-A was able to eradicate clonogenic tumour cells at concentrations of 20 and 50 μM and induced apoptosis in all tumour cell lines at 20 μM. These results suggest that ANDC-A might be used as a biochemical tool in the study of tumour cells biochemistry as well as an anticancer agent with durable effects on tumours.     

In Vitro Anticancer Activity of Staphyloxanthin Pigment Extracted from <Emphasis Type="Italic">Staphylococcus gallinarum</Emphasis> KX912244, a Gut Microbe of <Emphasis Type="Italic">Bombyx mori</Emphasis>

The present study reports the in vitro biological nature of the pigment produced by Staphylococcus gallinarum KX912244, isolated as the gut microflora bacterium of the insect Bombyx mori. The purified pigment was characterized as Staphyloxanthin based on bio-physical characterization techniques like Fourier transform infrared spectroscopy, high performance liquid chromatography, Proton nuclear magnetic resonance spectroscopy (¹H NMR), Liquid chromatography-Mass spectroscopy and Gas chromatography-Mass spectroscopy. The Staphyloxanthin pigment presented considerable biological properties including in vitro antimicrobial activity against pathogens Staphylococcus aureus, Escherichia coli and Candida albicans; in vitro antioxidant activity by % DPPH free radical scavenging activity showing IC₅₀ value of 54.22 µg/mL; DNA damage protection activity against reactive oxygen species and anticancer activity evaluated by cytotoxicity assay against 4 different cancer cell lines like the Dalton’s lymphoma ascites with IC₅₀ value 6.20?±?0.02 µg/mL, Ehrlich ascites carcinoma having IC₅₀ value 6.48?±?0.15 µg/mL, Adenocarcinomic human alveolar basal epithelial cells (A549 Lung carcinoma) bearing IC₅₀ value 7.23?±?0.11 µg/mL and Mus mucus skin melanoma (B16F10) showing IC₅₀ value 6.58?±?0.38 µg/mL and less cytotoxicity towards non-cancerous human fibroblast cell lines (NIH3T3) with IC₅₀ value of 52.24 µg/mL. The present study results suggest that Staphyloxanthin acts as a potential therapeutic agent especially due to its anticancer property.     

Terpenoid bioactive compound from <Emphasis Type="Italic">Streptomyces rochei</Emphasis> (M32): taxonomy,fermentation and biological activities

The present study emphasized the production of biologically active terpenoid compound from Streptomyces rochei M32, which was isolated from Western Ghats ecosystem, South India. The presence of resistant genes like mecA, vanA of Staphylococcus aureus and bla _SHV, bla _TEM of Pseudomonas aeruginosa was confirmed by molecular studies. The isolated compound from Streptomyces rochei M32 inhibited wide range of standard and clinical drug resistant pathogens and enteric pathogens. The rice bran supplemented basal medium influenced the active compound production on 8th day of fermentation and yielded 1875 mg of crude extract from 10 g of rice bran substrate. Purification and characterization of crude ethyl acetate extract was achieved by preparative thin layer chromatography. The active fraction was identified as terpenoid class compound by chemical screening. Based on the results of spectral studies (NMR, LC–MS, FTIR, etc.), the active compound was tentatively identified as 1, 19-bis (3-hydroxyazetidin-1-yl) nonadeca-5, 14-diene-1, 8, 12, 19-tetraone with molecular weight 462.41 g/mol. Minimum inhibitory concentration value ranges between 7.6 and 31.2 µg/mL against test organisms was observed. The cytotoxicity results on cervical cancer (HeLa) cell line showed IC₅₀ value of 2.034 µg/mL. The corresponding compound is not previously reported from any microbial resources.     

Phylogeny,antimicrobial, antioxidant and enzyme-producing potential of fungal endophytes found in <Emphasis Type="Italic">Viola odorata</Emphasis>

Viola odorata, a medicinal plant, is traditionally used to treat common cold, congestion and cough. Given its medicinal properties and occurrence in the northwestern Himalayas, we isolated and characterized endophytic fungi from this plant morphologically, microscopically and by internal transcribed spacer-based rDNA sequencing. In total, we isolated 27 morphotypes of endophytes belonging to phyla Ascomycota and Basidiomycota. The roots showed the highest diversity of endophyte as well as fungal dominance, followed by leaves and leaf nodes. The fungal extract of VOR16 (Fusarium oxysporum) displayed potent antimicrobial activity against Salmonella typhimurium, Klebsiella pneumoniae and Escherichia coli, with a minimum inhibitory concentration of 0.78, 0.78 and 1.56 μg/mL, respectively, while fungal extract VOLF4 (Aspergillus sp.) exhibited promising antioxidant activity (IC₅₀ of 17.4 μg/mL). To identify the components responsible for various bioactivities, we analyzed the content of penicillin G in the extract of bioactive endophytes. The results suggested that the expression of penicillin G under the fermentation conditions applied was too low to display antimicrobial effects. Thus, the activity may be contributed by a different, novel secondary metabolite. The antioxidant activity of VOLF4 may be attributed to its high content of flavonoids. Of the endophytic fungi assessed, 27% were found to be enzyme producers. The highest zone of clearance was observed in VOLN5 (Colletotrichum siamense) for protease production. Only VOR5 (Fusarium nematophilum) was found to be a producer of cellulase, glutenase, amylase and protease. In summary, this is the first report of the isolation of endophytes, namely Fusarium nematophilum, Colletotrichum trifolii, C. destructivum, C. siamense and Peniophora sp., from V. odorata and their bioactive and enzyme-producing potential.     

Evaluation of antioxidant and antiproliferative metabolites of <Emphasis Type="Italic">Penicillium flavigenum</Emphasis> isolated from hypersaline environment: Tuz (Salt) Lake by Xcelligence technology

The aim of the study is the determination of antioxidant and antiproliferative activities of fungal isolates’ metabolites belonging to Penicillium flavigenum isolated from Lake Tuz, Turkey. Evaluation of the antioxidant activity, the total phenolic content and antiproliferative effect were evaluated with DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay, Folin-ciocalteu method, Xcelligence real-time cell analysis. The total phenolic content of these isolates were found 62–82 mg/GAE. Ethyl acetate extracts from identified isolates, P. flavigenum, showed cytotoxic effects on A549, MCF7, Caco-2 cell lines. IC₅₀ values of P. flavigenum ethyl acetate extracts were found 96.7 μg/mL for A549, 33.4 μg/mL for MCF7, 43.4 μg/mL for Caco-2 and 97.3 μg/mL for 3T3. Phenolic acids in the extracts from P. flavigenum were identified with HPLC and GC-MS. Penicillium flavigenum is a new report for Turkey. According to these findings, fungi-related secondary metabolites are very important sources in terms of antioxidant and antiproliferative effects.     

Characterization of chickpea (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.) lectin for biological activity

Lectins are proteins that are subject of intense investigations. Information on lectin from chickpea (Cicer arietinum L.) with respect to its biological activities are very limited. In this study, we purified lectin from the seeds of chickpea employing DEAE-cellulose and SP-Sephadex ion exchange chromatography and identified its molecular subunit mass as 35 kDa. The free radical scavenging activity of lectin measured by the DPPH assay has IC₅₀ of 0.88 µg/mL. Lectin exerted antifungal activity against Candida krusei, Fusarium oxysporium oxysporium, Saccharomyces cerevisiae and Candida albicans, while antibacterial activity against E. coli, B. subtilis, S. marcescens and P. aeruginosa. The minimum inhibitory concentrations were 200, 240, 160 and 140 µg for C. krusei, F. oxysporium, S. cerevisiae and C. albicans respectively. Lectin was further examined for its antiproliferative potential against cancerous cell line. The cell viability assay indicated a high inhibition activity on Ishikawa, HepG2, MCF-7 and MDA-MB-231 with IC₅₀ value of 46.67, 44.20, 53.58 and 37.46?µg/mL respectively. These results can provide a background for future research into the benefits of chickpea lectin to pharmacological perspective.     

Lasalliapustulata lichen as possible natural antigenotoxic,antioxidant, antimicrobial and anticancer agent

The methanol extract of the lichen Lasallia pustulata was tested for genotoxic, antioxidant, antimicrobial and anticancer activities. We did this using a cytokinesis block micronucleus (MN) assay on peripheral blood lymphocytes, by measuring free radical and superoxide anion scavenging activity, reducing power, determining of total phenolic compounds and determining the total flavonoid content, measuring the minimal inhibitory concentration by the broth microdilution method against five species of bacteria and five species of fungi and by using the microculture tetrazolium test on FemX (human melanoma) and LS174 (human colon carcinoma) cell lines. As a result of this study, we found that the methanol extract of L. pustulata did not modify the frequency of the MN and nuclear division index in comparison to untreated cells (p > 0.05). These results revealed that the methanol extract had moderate free radical scavenging activity with IC₅₀ values of 395.56 μg/mL. Moreover, the extract tested had effective reducing power and superoxide anion radical scavenging. The values of the minimum inhibitory concentration against the tested microorganisms ranged from 0.625 to 20 mg/mL. In addition, the extract tested had strong anticancer activity against both cell lines with IC₅₀ values of 46.67 and 71.71 μg/mL.     

In vitro anticancer properties of selected <Emphasis Type="Italic">Eucalyptus</Emphasis> species

In spite of the recent advancements in oncology, the overall survival rate for pancreatic cancer has not improved over the last five decades. Eucalypts have been linked with cytotoxic and anticancer properties in various studies; however, there is very little scientific evidence that supports the direct role of eucalypts in the treatment of pancreatic cancer. This study assessed the anticancer properties of aqueous and ethanolic extracts of four Eucalyptus species using an MTT assay. The most promising extracts were further evaluated using a CCK-8 assay. Apoptotic studies were performed using a caspase 3/7 assay in MIA PaCa-2 cells. The aqueous extract of Eucalyptus microcorys leaf and the ethanolic extract of Eucalyptus microcorys fruit inhibited the growth of glioblastoma, neuroblastoma, lung and pancreatic cancer cells by more than 80% at 100 μg/mL. The E. microcorys and Eucalyptus saligna extracts showed lower GI₅₀ values than the ethanolic Eucalyptus robusta extract in MIA PaCa-2 cells. Aqueous E. microcorys leaf and fruit extracts at 100 μg/mL exerted significantly higher cell growth inhibition in MIA PaCa-2 cells than other extracts (p < 0.05). Statistically similar IC₅₀ values (p > 0.05) were observed in aqueous E. microcorys leaf (86.05 ± 4.75 μg/mL) and fruit (64.66 ± 15.97 μg/mL) and ethanolic E. microcorys leaf (79.30 ± 29.45 μg/mL) extracts in MIA PaCa-2 cells using the CCK-8 assay. Caspase 3/7-mediated apoptosis and morphological changes of cells were also witnessed in MIA PaCa-2 cells after 24 h of treatment with the extracts. This study highlighted the significance of E. microcorys as an important source of phytochemicals with efficacy against pancreatic cancer cells. Further studies are warranted to purify and structurally identify individual compounds and elucidate their mechanisms of action for the development of more potent and specific chemotherapeutic agents for pancreatic cancer.     

In vitro and in silico characterization of angiogenic inhibitors from <Emphasis Type="Italic">Sophora interrupta</Emphasis>

Sophora interrupta Bedd, (Fabaceae) is used in Indian folk medicine to treat cancer. Angiogenesis is one of the crucial characteristics of cancer metastasis and is regulated by vascular endothelial growth factor (VEGF). In this study, we examined the antiangiogenic properties of the root ethyl acetate extract of Sophora interrupta by various methods. In vitro antioxidant activity (100–600 μg/ml) of S. interrupta ethyl acetate (SEA) extract was evaluated by DPPH and ABTS, anti-inflammatory activity (50, 100 and 150 μg/ml) by estimating nitric oxide (NO) levels, anti-angiogenic activity (200 and 500 μg/ml) was validated by chorio allantoic membrane (CAM) assay and in silico molecular dynamic (MD) simulations analyses (25 ns) were performed to identify the anti-angiogenic compounds extracted from root extract. The antioxidative activity of SEA extract at IC₅₀ (200?±?0.6 μg/mL) is equal to that of ascorbic acid at IC₅₀ (50?±?0.6 μg/mL), and the anti-inflammatory activity of SEA extract at IC₅₀ (150?±?0.2 μg/mL) was inhibited significantly by nitric oxide (NO) production. The SEA extract significantly reduced the sprouting of new blood vessels at ID₅₀ 500?±?0.13 μg/mL in the CAM assay. Gas chromatography–mass spectrometry analysis of the SEA extract detected 34 secondary metabolites, of which 6a,12a-dihydro-6H-(1,3)dioxolo(5,6)benzofuro(3,2-c)chromen-3-ol (maackiain) and funiculosin formed strong hydrogen bond interactions with Lys 920, Thr 916 and Cys 919 (2H), as well as Glu 917 of VEGFR2, and these interactions were similar to those of the anti-angiogenic compound axitinib. Significant findings in all the assays performed indicate that SEA extract has potential anti-angiogenic compounds that may interfere with VEGF-induced cancer malignancy.     

Isolation and characterization of trichalasin-producing endophytic fungus from <Emphasis Type="BoldItalic">Taxus baccata</Emphasis>

An endophytic fungus (strain T1) isolated from Taxus baccata was studied for the production of metabolites with anticancer and antioxidant activities. This fungus was identified as Diaporthe sp. based on rDNA-internal transcribed spacer (ITS) sequence analysis. The crude extract showed cytotoxic activity against MCF-7 and HeLa cancer cell lines, with IC₅₀ (concentration inhibiting 50% of growth rate) values of 1058?±?44 and 1257?±?80 μg ml^?1, respectively. The scavenging activity of fungal extract increased significantly with increasing concentration [IC₅₀ (concentration required to scavenge 50% of free radicals) 482?±?9 μg ml^?1]. Ultra-high-performance liquid chromatography-quadrupole-time of flight analysis revealed the presence of three trichalasins (trichalasin E, F and H) in the crude extract of T1 which are known to have antitumour and antioxidant activities. These results suggest that Diaporthe sp. has the potential to be used for therapeutic purposes because of its antiproliferative and antioxidant potential and also for the production of cytochalasins.     

Effect of various factors on the biosynthesis of piscarinines,secondary metabolites of the fungus <Emphasis Type="Italic">Penicillium piscarium</Emphasis> Westling

Piscarinines A and B were synthesized most actively during the surface cultivation of the fungus Penicillium piscarium in a complex medium (5.5 mg/l). Under conditions of submerged cultivation in a mineral medium, the yield of piscarinines was two times lower. An increase in the inoculum quantity of conidia treated with Tween-80 increased the culture productivity. The biosynthesis of the alkaloid was completely suppressed when mannitol was replaced with glucose or when zinc, iron, or copper ions were added to the culture medium. The metabolites were active against the prostate cancer cell line LNCAP (IC₅₀ were 2.195 and 1.914 μg/ml for piscarinines A and B, respectively).     

Antibiofilm potential of biogenic silver nanoparticles against <Emphasis Type="Italic">Kocuria rosea</Emphasis> And <Emphasis Type="Italic">Kocuria rhizophila</Emphasis>

The present study aims at biosynthesizing, characterizing and evaluating the biogenic silver nanoparticles (AgNPs) as antimicrobial and antibiofilm against Kocuria rosea and Kocuria rhizophila. Cellfree supernatant of Proteus mirabilis culture was used for biosynthesizing AgNPs, which confirmed by visualizing color change and X-ray diffraction. Transmission electron microscopy showed the formation of AgNPs in the range of 5–40 nm. ART-FTIR spectra provided evidence for presence of proteins as possible biomolecules responsible for stability of AgNPs and act as capping agent. AgNPs had ability to inhibit growth of K. rosea and K. rhizophila. The minimum inhibitory concentration (MIC₉₀) of AgNPs against both strains was 25 μg/mL. Antiadhesive effect of AgNPs was verified at sub-MIC₉₀ dose (12.5 μg/mL). The AgNPs concentrations up to 100 μg/mL were not effective for complete removing the already established biofilms with maximum removing percentage of 30.5–34.9%. In conclusion, the present study demonstrated an unprecedented green process for biosynthesizing stable spherical-shaped AgNPs. Early control is suggested by preventing biofilm formation using low AgNPs concentration (12.5 μg/mL) as a potential ingredient for formulating effective chemical sanitizers.     

Bioactive compounds from marine <Emphasis Type="Italic">Streptomyces</Emphasis> sp. VITPSA as therapeutics

Background

Marine actinomycetes are efficient producers of new secondary metabolites that show different biological activities, including antibacterial, antifungal, anticancer, insecticidal, and enzyme inhibition activities.

Methods

The morphological, physiological, and biochemical properties of the strain Streptomyces sp. VITPSA were confirmed by conventional methods. Antibacterial, anti-oxidant, anti-inflammatory, anti-diabetic, and cytotoxic activities of Streptomyces sp. VITPSA extract were determined. The media were optimized for the production of secondary metabolites. Characterization and identification of secondary metabolites were conducted by high-performance liquid chromatography, gas chromatography-mass spectroscopy, and Fourier transform infrared spectroscopy analysis.

Results

The strain showed significant antibacterial, anti-oxidant, and cytotoxic activities, moderate anti-inflammatory activity, and no satisfactory anti-diabetic activity. The ethyl acetate extract of Streptomyces sp. VITPSA showed maximum antibacterial activity against two gram-positive and gram-negative bacteria at 0.5 mg/mL. The antioxidant potential of the crude extract exhibited strong reducing power activity at 0.5 mg/mL with 95.1% inhibition. The cytotoxic effect was found to be an IC₅₀ of 50 μg/mL on MCF-7 cell lines. Experimental design of optimization by one-factor analysis revealed the most favorable sucrose, yeast extract, pH (7.25), and temperature (28°C) conditions for the effective production of secondary metabolites.

Conclusion

This study revealed that Streptomyces sp. VITPSA is an excellent source of secondary metabolites with various bioactivities.

     

Novel aromatic polyketides from soil <Emphasis Type="Italic">Streptomyces</Emphasis> spp.: purification,characterization and bioactivity studies

Aromatic polyketides are important therapeutic compounds which include front line antibiotics and anticancer drugs. Since most of the aromatic polyketides are known to be produced by soil dwelling Streptomyces, 54 Streptomyces strains were isolated from the soil samples. Five isolates, R1, B1, R3, R5 and Y8 were found to be potent aromatic polyketide producers and were identified by 16S rRNA gene sequencing as Streptomyces spectabilis, Streptomyces olivaceus, Streptomyces purpurascens, Streptomyces coeruleorubidus and Streptomyces lavendofoliae respectively. Their sequences have been deposited in the GenBank under the accession numbers KF468818, KF681280, KF395224, KF527511 and KF681281 respectively. The Streptomyces strains were cultivated in the media following critically optimised culture conditions. The resulting broth extracts were fractionated on a silica gel column and preparative TLC to obtain pure compounds. The pure compounds were tested for bioactivity and the most potent compound from each isolate was identified by UV–Vis, IR and NMR spectroscopic methods. Isolated S. spectabilis (R1), yielded one potent compound identified as dihydrodaunomycin with an MIC of 4 µg/ml against Bacillus cereus and an IC₅₀ value of 24 µM against HeLa. S. olivaceus (B1), yielded a comparatively less potent compound, elloramycin. S. purpurascens (R3) yielded three compounds, rhodomycin, epelmycin and obelmycin. The most potent compound was rhodomycin with an MIC of 2 µg/ml against B. cereus and IC₅₀ of 15 µM against HeLa. S. coeruleorubidus (R5), yielded daunomycin showing an IC₅₀ of 10 µM and also exhibiting antimetastatic properties against HeLa. S. lavendofoliae (Y8), yielded a novel aclacinomycin analogue with IC₅₀ value of 2.9 µM and potent antimetastatic properties at 1 µM concentration against HeLa. The study focuses on the characterization of aromatic polyketides from soil Streptomyces spp., which can serve as potential candidates for development of chemotherapeutic drugs in future.     

An in vitro study of alkaline phosphatase sensitivity to mixture of aflatoxin B<Subscript>1</Subscript> and fumonisin B<Subscript>1</Subscript> in the hepatopancreas of coastal lagoon wild and farmed shrimp <Emphasis Type="Italic">Litopenaeus vannamei</Emphasis>

This study aimed to establish the combined effect of aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁) on wild Litopenaeus vannamei hepatopancreas alkaline phosphatase (AP) activity compared with that of farmed shrimp. AP activity in hepatopancreas extract was confirmed by several specific inhibitor assays. AP activity of wild shrimp was higher than that of farmed shrimp (p?<?0.05). However, AP activity from both wild and farmed shrimp was inhibited when incubated with AFB₁ and FB₁. The greatest inhibition occurred when AP was incubated with a mixture of AFB₁ and FB₁. The IC₅₀ for AFB₁ on AP activity of wild and farmed shrimp hepatopancreases was 0.790 and 0.398 μg/mL, respectively. The IC₅₀ of FB₁ was 0.87 μg/mL for wild shrimp and 0.69 μg/mL for farmed shrimp. These results suggest that, at the mycotoxins concentrations used in the study, AP from farmed L. vannamei was sensitive to the presence of both mycotoxins; however, AP is more sensitive to the combination of AFB₁?+?FB₁ suggesting a possible synergistic or potentiating inhibitory effect.     

Bioactive compounds of <Emphasis Type="Italic">Aspergillus terreus</Emphasis>—F7, an endophytic fungus from <Emphasis Type="Italic">Hyptis suaveolens</Emphasis> (L.) Poit

The compounds terrein (1), butyrolactone I (2), and butyrolactone V (3) were isolated from the ethyl acetate extract (EtOAc) of the endophytic fungus Aspergillus terreus—F7 obtained from Hyptis suaveolens (L.) Poit. The extract and the compounds presented schistosomicidal activity against Schistosoma mansoni; at 100 µg/mL for EtOAc extract, 1297.3 µM for compound 1, 235.6 µM for compound 2, and 454.1 µM for compound 3, they killed 100% of the parasites after 72 h of treatment. Compounds 1, 2, and 3 exerted moderate leishmanicidal activity against Leishmania amazonensis (IC₅₀ ranged from 23.7 to 78.6 µM). At 235.6 and 227.0 µM, compounds 2 and 3, respectively, scavenged 95.92 and 95.12% of the DPPH radical (2,2-diphenyl-1-picryl-hydrazyl), respectively. Regarding the cytotoxicity against the breast tumor cell lines MDA-MB-231 and MCF-7, compound 2 gave IC₅₀ of 34.4 and 17.4 µM, respectively, while compound 3 afforded IC₅₀ of 22.2 and 31.9 µM, respectively. At 117.6 µM, compound 2 inhibited the growth of and killed the pathogen Escherichia coli (ATCC 25922). Compounds 1, 2, and 3 displayed low toxicity against the normal line of human lung fibroblasts (GM07492A cells), with IC₅₀ of 15.3?×?10³, 3.4?×?10³, and 5.8?×?10³ µM, respectively. This is the first report on (i) the in vitro schistosomicidal and leishmanicidal activities of the EtOAc extract of A. terreus—F7 and compounds 1, 2, and 3; and (ii) the antitumor activity of compounds 2 and 3 against MDA-MB-231 and MCF-7 cells.     

Anti‐hepatitis C virus compounds obtained from Glycyrrhiza uralensis and other Glycyrrhiza species

Development of complementary and/or alternative drugs for treatment of hepatitis C virus (HCV) infection is still much needed from clinical and economic points of view. Antiviral substances obtained from medicinal plants are potentially good targets to study. Glycyrrhiza uralensis and G. glabra have been commonly used in both traditional and modern medicine. In this study, extracts of G. uralensis roots and their components were examined for anti‐HCV activity using an HCV cell culture system. It was found that a methanol extract of G. uralensis roots and its chloroform fraction possess anti‐HCV activity with 50%‐inhibitory concentrations (IC₅₀) of 20.0 and 8.0 μg/mL, respectively. Through bioactivity‐guided purification and structural analysis, glycycoumarin, glycyrin, glycyrol and liquiritigenin were isolated and identified as anti‐HCV compounds, their IC₅₀ being 8.8, 7.2, 4.6 and 16.4 μg/mL, respectively. However, glycyrrhizin, the major constituent of G. uralensis, and its monoammonium salt, showed only marginal anti‐HCV activity. It was also found that licochalcone A and glabridin, known to be exclusive constituents of G. inflata and G. glabra, respectively, did have anti‐HCV activity, their IC₅₀ being 2.5 and 6.2 μg/mL, respectively. Another chalcone, isoliquiritigenin, also showed anti‐HCV activity, with an IC₅₀ of 3.7 μg/mL. Time‐of‐addition analysis revealed that all Glycyrrhiza‐derived anti‐HCV compounds tested in this study act at the post‐entry step. In conclusion, the present results suggest that glycycoumarin, glycyrin, glycyrol and liquiritigenin isolated from G. uralensis, as well as isoliquiritigenin, licochalcone A and glabridin, would be good candidates for seed compounds to develop antivirals against HCV.     

Assessment of genetic fidelity of <Emphasis Type="Italic">Dioscorea bulbifera</Emphasis> L. and <Emphasis Type="Italic">Dioscorea hirtiflora</Emphasis> Benth. and medicinal bioactivity produced from the induced tuberous roots

Wild tubers of Dioscorea bulbifera (Db) and Dioscorea hirtiflora (Dh) mainly used as sources of famine food and in herbal preparations are often indiscriminately collected in Africa and Asia. Therefore, there is the need to complement wild sourcing of the tubers to promote their conservation. The present study reports in vitro tuberous induction (80%) for the first time from Dh cultured on MS?+?NAA (2.5 mg/L) with IC₅₀ of 472.5?±?1.77 µg/mL using DPPH, whereas tuberous root (60%) from Db on MS?+?Kn (2.5 mg/L)?+?NAA (0.25 mg/L) had IC₅₀ of 26.97?±?1.00 µg/mL. Genetic fidelity assessment of in vitro plants compared to the wild plants revealed similar amplicon size of amplified DNA using trnH–psbA and rbcL. Similarly, micromorphological diagnostic features like oil gland, crystals (raphides), trichome and stomata type were obtained from the epidermal peels of the wild and in vitro plants. The ethyl acetate (EtOAc) extract of the flesh of Dh (wild) had the highest catechin content (108.3?±?0.69 µg/g DW). Protocatechuic acid was highest in the methanol (MeOH) extract of the flesh of Dh (0.42?±?0.02 µg/g DW), while it was detected in trace amount in the in vitro tuberous roots of MeOH extracts of Dh treated with NAA. The in vitro protocol developed in this study could be employed to multiply Dioscorea bulbifera L. and Dioscorea hirtiflora Benth. to offer genetically stable clones for the optimization of bioactive compounds and germplasms conservation.     

Radio-protective and antioxidative activities of astaxanthin from newly isolated radio-resistant bacterium <Emphasis Type="Italic">Deinococcus</Emphasis> sp. strain WMA-LM9

A radio-resistant bacterium, designated as strain WMA-LM9, was isolated from desert soil. 16S rRNA gene sequencing indicated that the bacterium belongs to genus Deinococcus with maximum similarity to Deinococcus radiopugnans. Deinococcus sp. strain WMA-LM9 was found to be resistant to a ultraviolet (UV) dose of 5 × 10³ J/m², hydrogen peroxide (50 mM) and mitomycin C (10 μg/ml). A carotenoid pigment was extracted using chloroform/methanol/acetone (7:5:3) and purified by high-performance liquid chromatography on a C₁₈ analytical column. The compound was characterised as mono-esterified astaxanthin by ¹H, ¹³C nuclear magnetic resonance and mass spectrometry. It was tested for antioxidant activity, total flavonoids and phenolic content, radioprotective potential in correlation to the prevention of protein oxidation and DNA strand breaks in vitro. The carotenoid pigment showed a very potent antioxidant activity and significantly stronger scavenging ability against superoxides, with an IC₅₀ (concentration causing 50% inhibition of the desired activity) of 41.6 μg/ml. The total phenolic and flavonoid contents were 12.1 and 7.4 μg in terms of gallic acid and quercetin equivalents per milligram of dried mass, respectively. astaxanthin also showed a higher inhibitory action against oxidative damage to collagen, elastin and bovine serum albumin than did β-carotene. The carotenoid also inhibited breaks to DNA strands, as indicated by the results of the DNA damage prevention assay. We conclude that astaxanthin from Deinococcus sp. strain WMA-LM9 has protective effects against radiation-mediated cell damage, and it also protects cellular protein and DNA against oxidative stress and other anti-oxidant activities.