Development of <Emphasis Type="Italic">Brassica oleracea</Emphasis>-<Emphasis Type="Italic">nigra</Emphasis> monosomic alien addition lines: genotypic,cytological and morphological analyses

Key message

We report the development and characterization of Brassica oleracea - nigra monosomic alien addition lines (MAALs) to dissect the Brassica B genome.

Abstract

Brassica nigra (2n = 16, BB) represents the diploid Brassica B genome which carries many useful genes and traits for breeding but received limited studies. To dissect the B genome from B. nigra, the triploid F₁ hybrid (2n = 26, CCB) obtained previously from the cross B. oleracea var. alboglabra (2n = 18, CC) × B. nigra was used as the maternal parent and backcrossed successively to parental B. oleracea. The progenies in BC₁ to BC₃ generations were analyzed by the methods of FISH and SSR markers to screen the monosomic alien addition lines (MAALs) with each of eight different B-genome chromosomes added to C genome (2n = 19, CC + 1B_1?8), and seven different MAALs were established, except for the one with chromosome B2 which existed in one triple addition. Most of these MAALs were distinguishable morphologically from each other, as they expressed the characters from B. nigra differently and at variable extents. The alien chromosome remained unpaired as a univalent in 86.24% pollen mother cells at diakinesis or metaphase I, and formed a trivalent with two C-genome chromosomes in 13.76% cells. Transmission frequency of all the added chromosomes was far higher through the ovules (averagely 14.40%) than the pollen (2.64%). The B1, B4 and B5 chromosomes were transmitted by female at much higher rates (22.38–30.00%) than the other four (B3, B6, B7, B8) (5.04–8.42%). The MAALs should be valuable for exploiting the genome structure and evolution of B. nigra.

     

Design,synthesis, and characterization of 2,2-bis(2,4-dinitrophenyl)-2-(phosphonatomethylamino)acetate as a herbicidal and biological active agent

The present study was designed to synthesize the bioactive molecule 2,2-bis(2,4-dinitrophenyl)-2-(phosphonatomethylamino)acetate (1), having excellent applications in the field of plant protection as a herbicide. Structure of newly synthesized molecule 1 was confirmed by using the elemental analysis, mass spectrometric, NMR, UV-visible, and FTIR spectroscopic techniques. To obtain better structural insights of molecule 1, 3D molecular modeling was performed using the GAMESS programme. Microbial activities of 1 were checked against the pathogenic strains Aspergillus fumigatus (NCIM 902) and Salmonella typhimurium (NCIM 2501). Molecule 1 has shown excellent activities against fungal strain A. fumigates (35 μg/l) and bacterial strain S. typhimurium (25 μg/l). To check the medicinal significance of molecule 1, interactions with bovine serum albumin (BSA) protein were checked. The calculated value of binding constant of molecule 1–BSA complex was 1.4 × 10⁶ M^?1, which were similar to most effective drugs like salicylic acid. More significantly, as compared to herbicide glyphosate, molecule 1 has exhibited excellent herbicidal activities, in pre- and post-experiments on three weeds; barnyard grass (Echinochloa Crus), red spranglitop (Leptochloa filiformis), and yellow nuts (Cyperus Esculenfus). Further, effects of molecule 1 on plant growth-promoting rhizobacterial (PGPR) strains were checked. More interestingly, as compared to glyphosate, molecule 1 has shown least adverse effects on soil PGPR strains including the Rhizobium leguminosarum (NCIM 2749), Pseudomonas fluorescens (NCIM 5096), and Pseudomonas putida (NCIM 2847).     

An NADPH-dependent <Emphasis Type="Italic">Lactobacillus composti</Emphasis> short-chain dehydrogenase/reductase: characterization and application to (<Emphasis Type="Italic">R</Emphasis>)-1-phenylethanol synthesis

A new anti-Prelog short-chain dehydrogenase/reductase (SDR) encoding gene lcsdr was cloned from Lactobacillus composti DSM 18527, and heterologously expressed in Escherichia coli. LcSDR is nicotinamide adenine dinucleotide phosphate (NADPH)-dependent and has a molecular weight of approximately 30 kDa. The optimal pH and temperature were 6.5 and 30?°C, respectively. The maximal reaction rate V_max was 133.9 U mg^?1; the Michaelis–Menten constant K _m of LcSDR were 0.345 mM for acetophenone (1a), and 0.085 mM for NADPH. Through introducing an EsGDH-catalyzed NADPH regeneration system, a biocatalytic process for (R)-1-phenylethanol ((R)-1b) was developed with outstanding time–space yield. Under the optimized conditions, 50 g l^?1 1a was converted to (R)-1b in 2 h with a yield of 93.8%, enantiomeric excess of product (e.e._p) above 99% and space–time yield of 562.8 g l^?1 d^?1.     

<Emphasis Type="Italic">Synechocystis</Emphasis> PCC 6803 cells heterologously expressing bacterial tyrosine ammonia lyase can use exogenous tyrosine for <Emphasis Type="Italic">p</Emphasis>-coumaric acid production

Phototrophic cyanobacteria may be considered as an alternative host for producing numerous bioactive compounds. We demonstrate that the Synechocystis PCC 6803 expressing tyrosine ammonia-lyase from Rhodobacter sphaeroides under Ptrc1O promoter produce p-coumaric acid at a rate three times higher than that under Ptrc1Ocore promoter, accounting for 18.4 ± 1.5 μg of p-coumaric acid per 10⁸ cells (0.36 mg L^?1). Additionally, our study is the first report to show the biotransformation of tyrosine to p-coumaric acid reaching a maximum 2.4-fold increase when 0.5 mM tyrosine was supplemented to the growth medium. Liquid chromatography-mass spectrometry analysis revealed the occurrence of diverse patterns of metabolites under different concentrations of supplemented tyrosine, suggesting that it is used in additional metabolic pathways.     

Fine root biomass in two black spruce stands in interior Alaska: effects of different permafrost conditions

Key message

In black spruce stands on permafrost, trees and understory plants showed higher biomass allocation especially to ‘thin’ fine roots (diam. < 0.5 mm) when growing on shallower permafrost table.

Abstract

Black spruce (Picea mariana) forests in interior Alaska are located on permafrost and show greater below-ground biomass allocation than non-permafrost forests. However, information on fine roots (roots <2 mm in diameter), which have a key role in nutrient uptake and below-ground carbon flux, is still limited especially for effects of different permafrost conditions. In this study, we examined fine root biomass in two black spruce stands with different depths to the permafrost table. In the shallow permafrost (SP) plot, fine root biomass of black spruce trees was 70 % of that in the deep permafrost (DP) plot. In contrast, ratio of the fine root biomass to above-ground biomass was greater in the SP plot than in the DP plot. Understory plants, on the other hand, showed larger fine root biomass in the SP plot than in the DP plot, whereas their above-ground biomass was similar between the two plots. In addition, biomass proportion of ‘thin’ fine roots (diam. <0.5 mm) in total fine roots was greater in the SP plot than in the DP plot. These results suggest that black spruce trees and understory plants could increase biomass allocation to fine roots for efficient below-ground resource acquisition from colder environments with shallower permafrost table. In the SP plot, fine roots of understory plants accounted for 30 % of the stand fine root biomass, suggesting that understory plants such as Ledum and Vaccinium spp. would have significant contribution to below-ground carbon dynamics in permafrost forests.

     

Highly enantioselective production of a chiral intermediate of sitagliptin by a novel isolate of <Emphasis Type="Italic">Pseudomonas pseudoalcaligenes</Emphasis>

Objective

To produce (S)-3-hydroxy-1-(3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-4-(2,4,5-trifluorophenyl)butan-1-one (S)-1 from 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro [1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)-1-(2,4,5-trifluorophenyl)butan-2-one (2) by microbial bioreduction.

Results

A new isolate of Pseudomonas pseudoalcaligenes reduced enantioselectively prochiral ketone 2 to chiral alcohol (S)-1. Whole cells of the bacterium were tolerant towards 20 % (v/v) DMSO and 10 g 2/l. Under the optimal conditions, the preparative-scale bioreduction yielded (S)-1 at 90 % yield and >99 % ee. Cells could be re-used with the yield and ee of product being 45 % and >99 %, respectively, after five cycles.

Conclusion

Bioreduction using whole cells of P. pseudoalcaligenes is an attractive approach to produce (S)-1, as a chiral intermediate of the anti-diabetic drug, sitagliptin.

     

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.     

Genetic diversity and population structure of <Emphasis Type="Italic">Melia azedarach</Emphasis> in North-Western Plains of India

Key message

Genetic structure among M. azedarach populations was detected and two subpopulations were present among them. A significant ‘isolation by distance’ was found in M. azedarach population in North-Western Plains of India.

Abstract

Melia azedarach is an important forest tree with pharmaceutical, insecticidal, pesticidal, and commercial significance. It is a good reforestation tree because of its fast growth and drought hardy nature. Genetic variation in a species allows itself to adapt, evolve and respond to environmental stress. It provides the basis for survival of a species and critically influences its evolutionary potential. Assessment of genetic diversity is necessary for improvement and conservation of a species. For this, microsatellite markers are of particular interest given the attributes like co-dominance, reproducibility, hyper variability and abundance throughout the genome. In the present study, we analyzed the genetic diversity and population structure of M. azedarach, an ecologically imperative species growing in the North-Western Plains of India. We developed 43 microsatellite markers, of which 20 were subsequently employed for analysis of diversity and population structure among 33 populations encompassing 318 genotypes representing North-Western Plains of India. A moderate level of diversity (Na = 5.1, Ho = 0.506, He = 0.712, I = 1.386) was assessed. The highest value of ΔK estimated using STRUCTURE indicated 2 subpopulations (K = 2). AMOVA exhibited 73 % variation within populations and 12 % variation was found among regions. Significant positive correlation between geographical and genetic distance was found (Rxy = 0.365, P = 0.010). The present study lays a foundation on a better understanding of genetic dynamics of the species and reveals its diversity and population structure in North-Western Plains of India.

     

Regional chronologies of <Emphasis Type="Italic">Cedrela</Emphasis><Emphasis Type="Italic">fissilis</Emphasis> and <Emphasis Type="Italic">Cedrela angustifolia</Emphasis> in three forest types and their relation to climate

Key message

Although tree-ring chronologies of Cedrela fissilis and Cedrela angustifolia showed a common climatic signal, local conditions influence growth, suggesting that forest guidelines should be appropriate to the species and context.

Abstract

Cedrela species are highly valued because of the quality of their timber. Understanding the behaviour of each different Cedrela species and their ecology is of importance to ensuring that forest harvesting and management do not endanger the survival of natural populations. These species grow in a wide range of environmental gradients and different types of forests in Bolivia. This study used dendrochronological methods to analyse growth–precipitation relationships of two Cedrela species coming from three locations with different environmental conditions: dry Chiquitano (Concepción), Chiquitano transitional Amazonian (Guarayos), and Bolivian-Tucuman montane forests (Postrervalle). The rainy season in all locations runs from October to April and the dry season runs from May to September. Twelve Cedrela fissilis specimens were sampled from dry Chiquitano, 11 Cedrela fissilis specimens from Chiquitano transitional Amazonian, and 30 Cedrela angustifolia specimens from Bolivian-Tucuman montane forests. The samples were crossdated and exhibited a common signal between trees from three sites, despite tree rings from the Chiquitano transitional Amazonian forest being narrower and displaying blurred bands of parenchyma in the boundaries. Significant inter-series correlation was found for the C. fissilis species series from dry Chiquitano with r = 0.261 (p < 0.01) and Chiquitano transitional Amazonian forests with r = 0.284 (p < 0.01), and for Cedrela angustifolia from Bolivian-Tucuman montane forests with r = 0.374 (p < 0.01). Mean annual growth was 2.07, 1.92, and 2.82 mm year^?1 at the three sites, respectively. Cedrela species from dry Chiquitano and Bolivian-Tucuman montane forests were sensitive to precipitation from October to April of the current growth year (wettest season) and to low temperatures from May to July of the current growth year (driest season). Samples from Chiquitano transitional Amazonian were more sensitive to precipitation during late rainy season (March, April, and May of the current growth year) and high temperatures during the rainy months (November–December). Growth differences between sites and species in response to climate variations and local conditions should be taken into account and handled with different forest management guidelines.

     

Activity of phosphino palladium(II) and platinum(II) complexes against HIV-1 and <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis>

Treatment of human immunodeficiency virus (HIV) is currently complicated by increased prevalence of co-infection with Mycobacterium tuberculosis. The development of drug candidates that offer the simultaneous management of HIV and tuberculosis (TB) would be of great benefit in the holistic treatment of HIV/AIDS, especially in sub-Saharan Africa which has the highest global prevalence of HIV-TB coinfection. Bis(diphenylphosphino)-2-pyridylpalladium(II) chloride (1), bis(diphenylphosphino)-2-pyridylplatinum(II) chloride (2), bis(diphenylphosphino)-2-ethylpyridylpalladium(II) chloride (3) and bis(diphenylphosphino)-2-ethylpyridylplatinum(II) (4) were investigated for the inhibition of HIV-1 through interactions with the viral protease. The complexes were subsequently assessed for biological potency against Mycobacterium tuberculosis H37Rv by determining the minimal inhibitory concentration (MIC) using broth microdilution. Complex (3) showed the most significant and competitive inhibition of HIV-1 protease (p = 0.014 at 100 µM). Further studies on its in vitro effects on whole virus showed reduced viral infectivity by over 80 % at 63 µM (p < 0.05). In addition, the complex inhibited the growth of Mycobacterium tuberculosis at an MIC of 5 µM and was non-toxic to host cells at all active concentrations (assessed by tetrazolium dye and real time cell electronic sensing). In vitro evidence is provided here for the possibility of utilizing a single metal-based compound for the treatment of HIV/AIDS and TB.     

Dietary Supplementation of Selenium-Enriched Probiotics Enhances Meat Quality of Broiler Chickens (<Emphasis Type="Italic">Gallus gallus domesticus</Emphasis>) Raised Under High Ambient Temperature

We investigated the effects of selenium-enriched probiotics (SP) on broiler meat quality under high ambient temperature and explore their underlying mechanisms. A total of 200 1-day-old male broiler chicks (Ross 308) were randomly allotted to four treatment groups, each with five replicates, in groups of ten birds. These birds were fed a corn-soybean basal diet (C), a basal diet plus probiotics supplementation (P), a basal diet plus Se supplementation in the form of sodium selenite (SS, 0.30 mg Se/kg), and a basal diet with the addition of selenium-enriched probiotics (SP, 0.30 mg Se/kg). The experiment lasted for 42 days. The birds were sacrificed by cervical dislocation, and the breast muscles were removed for further process. Our results showed that SP diet significantly increased (p < 0.05) the physical (pH, colors, water holding capacity, drip loss, shear force) and sensory characteristics of breast meat. All P, SS, and SP supplementation enhanced the antioxidant system by increasing (p < 0.05) the Se concentrations, glutathione (GSH) levels, activities of glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) whereas decreasing (p < 0.05) malondialdehyde (MDA) levels, with SP being higher than P and SS. Moreover, SP diet significantly upregulated (p < 0.05) the mRNA levels of glutathione peroxidase genes (GPx1, GPx4) while it downregulated heat stress biomarkers such as heat shock protein (HSP) 70 as compared to C, P, and SS diets. In conclusion, our findings suggest that SP may function as beneficial nutritive supplement that is capable of improving meat quality during the summer season.     

<Emphasis Type="Italic">Ponticoccus alexandrii</Emphasis> sp. nov., a novel bacterium isolated from the marine toxigenic dinoflagellate <Emphasis Type="Italic">Alexandrium minutum</Emphasis>

During an investigation of the biodiversity of the cultivable bacterial community associated with paralytic shellfish poisoning toxin-producing marine dinoflagellate, Alexandrium minutum a novel algal-associated bacterium, designated strain AT2-A^T was isolated. 16S rRNA gene sequence similarity analysis showed that the strain is a member of the genus Ponticoccus, with high sequence similarity to Ponticoccus litoralis DSM 18986^T (97.9%) and Ponticoccus lacteus JCM 30379^T (96.0%). However, based on the data obtained for the physiological and biochemical characteristics, and low level of DNA–DNA relatedness analysis, the strain could be genotypically and phenotypically differentiated from two type strains of the genus Ponticoccus. Therefore, this algal-associated bacterial strain is concluded to represent a novel species of the genus Ponticoccus, for which the name Ponticoccus alexandrii sp. nov. is proposed. The type strain is AT2-A^T (CCTCC AB 2017228 ^T = KCTC 52626 ^T ).     

Madurastatin B3, a rare aziridine derivative from actinomycete <Emphasis Type="Italic">Nocardiopsis</Emphasis> sp. LS150010 with potent anti-tuberculosis activity

Since the discovery of the first antibiotic, natural products have played an important role in chemistry, biology and medicine. To explore the potential of bioactive compounds from microbes isolated from the southeast of Tibet, China, a crude extract library was constructed and screened against Staphylococcus aureus. The strain Nocardiopsis sp. LS150010 was scaled up and subjected to further chemical studies, resulting in the identification of N-salicyloyl-2-aminopropan-1,3-diol (2) and its rare aziridine derivative, madurastatin B3 (1). Their structures were determined by detailed analysis of 1D, 2D NMR and HRMS data. Compounds 1 and 2 displayed significant inhibitory activity against S. aureus and methicillin resistant S. aureus, with MIC values of 6.25 µg/mL. Compound 1 also showed potent inhibitory activity against Bacillus subtilis and Escherichia coli, as well as activity in a Mycobacterium tuberculosis Bacillus Calmette-Guérin infected THP-1 cell model.     

Unreduced gamete formation in wheat × <Emphasis Type="Italic">Aegilops</Emphasis> spp. hybrids is genotype specific and prevented by shared homologous subgenomes

Key message

The presence of homologous subgenomes inhibited unreduced gamete formation in wheat × Aegilops interspecific hybrids. Unreduced gamete rates were under the control of the wheat nuclear genome.

Abstract

Production of unreduced gametes is common among interspecific hybrids, and may be affected by parental genotypes and genomic similarity. In the present study, five cultivars of Triticum aestivum and two tetraploid Aegilops species (i.e. Ae. triuncialis and Ae. cylindrica) were reciprocally crossed to produce 20 interspecific hybrid combinations. These hybrids comprised two different types: T. aestivum × Aegilops triuncialis; 2n = ABDU^tC^t (which lack a common subgenome) and T. aestivum × Ae. cylindrica; 2n = ABDD^cC^c (which share a common subgenome). The frequency of unreduced gametes in F₁ hybrids was estimated in sporads from the frequency of dyads, and the frequency of viable pollen, germinated pollen and seed set were recorded. Different meiotic abnormalities recorded in the hybrids included precocious chromosome migration to the poles at metaphase I and II, laggards in anaphase I and II, micronuclei and chromosome stickiness, failure in cell wall formation, premature cytokinesis and microspore fusion. The mean frequency of restitution meiosis was 10.1 %, and the mean frequency of unreduced viable pollen was 4.84 % in T. aestivum × Ae. triuncialis hybrids. By contrast, in T. aestivum × Ae. cylindrica hybrids no meiotic restitution was observed, and a low rate of viable gametes (0.3 %) was recorded. This study present evidence that high levels of homologous pairing between the D and D^c subgenomes may interfere with meiotic restitution and the formation of unreduced gametes. Variation in unreduced gamete production was also observed between T. aestivum × Ae. triuncialis hybrid plants, suggesting genetic control of this trait.

     

In vitro assessment of antimicrobial activity of aqueous and alcoholic extracts of moss <Emphasis Type="Italic">Atrichum undulatum</Emphasis> (Hedw.) P. Beauv.

Bryophytes, the shade loving plants, have tremendous medicinal properties. The aqueous and alcoholic extracts of Atrichum undulatum (Hedw.) P. Beauv. were analysed for antimicrobial properties against the fungi Aspergillus fumigatus and Fusarium oxysporum and the bacteria Escherichia coli, Bacillus mycoides, Proteus mirabilis, Staphylococcus aureus and Salmonella typhi. The study is an attempt to investigate the medicinal properties of Atrichum undulatum (Hedw.) P. Beauv. using disc-diffusion method. No inhibition was observed against A. fumigatus and P. mirabilis. For bacteria S. typhi and E. coli (20 and 15 mm), aqueous and alcoholic extracts of Atrichum showed significant inhibition. However, alcoholic extract was found remarkably effective against bacteria rather than aqueous extract.     

Mechanisms of thaxtomin A-induced root toxicity revealed by a thaxtomin A sensitive <Emphasis Type="Italic">Arabidopsis</Emphasis> mutant (<Emphasis Type="Italic">ucu2</Emphasis>-<Emphasis Type="Italic">2/gi</Emphasis>-<Emphasis Type="Italic">2</Emphasis>)

Key message

The Arabidopsis mutant ( ucu2 - 2/gi - 2 ) is thaxtomin A, isoxaben and NPA-sensitive indicated by root growth and ion flux responses providing new insights into these compounds mode of action and interactions.

Abstract

Thaxtomin A (TA) is a cellulose biosynthetic inhibitor (CBI) that promotes plant cell hypertrophy and cell death. Electrophysiological analysis of steady-state K⁺ and Ca²⁺ fluxes in Arabidopsis thaliana roots pretreated with TA for 24 h indicated a disturbance in the regulation of ion movement across the plant cell membrane. The observed inability to control solute movement, recorded in rapidly growing meristematic and elongation root zones, may partly explain typical root toxicity responses to TA treatment. Of note, the TA-sensitive mutant (ucu2-2/gi-2) was more susceptible with K⁺ and Ca²⁺ fluxes altered between 1.3 and eightfold compared to the wild-type control where fluxes altered between 1.2 and threefold. Root growth inhibition assays showed that the ucu2-2/gi-2 mutant had an increased sensitivity to the auxin 2,4-D, but not IAA or NAA; it also had increased sensitivity to the auxin efflux transport inhibitor, 1-naphthylphthalamic acid (NPA), but not 2,3,5- Triiodobenzoic acid (TIBA), when compared to the WT. The NPA sensitivity data were supported by electrophysiological analysis of H⁺ fluxes in the mature (but not elongation) root zone. Increased sensitivity to the CBI, isoxaben (IXB), but not dichlobenil was recorded. Increased sensitivity to both TA and IXB corresponded with higher levels of accumulation of these toxins in the root tissue, compared to the WT. Further root growth inhibition assays showed no altered sensitivity of ucu2-2/gi-2 to two other plant pathogen toxins, alternariol and fusaric acid. Identification of a TA-sensitive Arabidopsis mutant provides further insight into how this CBI toxin interacts with plant cells.

     

Differential alkaloid profile in <Emphasis Type="Italic">Uncaria tomentosa</Emphasis> micropropagated plantlets and root cultures

The alkaloids of Uncaria tomentosa micropropagated plantlets and root cultures were isolated and identified by NMR and mass spectrometry. Plantlets yielded pteropodine (1), isopteropodine (2), mitraphylline (3), isomitraphylline (4), uncarine F (5), speciophylline (6), rhynchophylline (7) and isorhynchophylline (8). In plantlets growing under continuous light, tetracyclic alkaloids 7 and 8 decreased from 20 ± 1.8 at 2 months to 2.2 ± 0.33 mg/g dry wt at 6 months, while the pentacyclic alkaloids 1–4 increased from 7.7 ± 1.4 to 15 ± 0.05 mg/g dry wt, supporting their biogenetic conversion. Micropropagated plantlets produced four times more alkaloids (27.6 ± 3.1 mg/g dry wt) than greenhouse plants. Plantlet roots yielded 3, 4, 8 and the glucoindole alkaloids 3α-dihydrocadambine (9) and dolichantoside (10), the last one not previously found in Uncaria.     

Synthesis and evaluation of copper(II) complexes with isoniazid-derived hydrazones as anticancer and antitubercular agents

In this study, the N,N,O metal chelator 2-pyridinecarboxaldehydeisonicotinoyl hydrazone (HPCIH, 1) and its derivatives 2-acetylpyridine-(HAPIH 2), 2-pyridineformamide-(HPAmIH, 3) and pyrazineformamide-(HPzAmIH, 4) were employed in the synthesis of four copper(II) complexes, [Cu(HPCIH)Cl₂]·0.4H₂O (5), [Cu(HAPIH)Cl₂]·1.25H₂O (6), [Cu(HPAmIH)Cl₂]·H₂O (7) and [Cu(HPzAmIH)Cl₂]·1.25H₂O (8). The compounds were assayed for their action toward Mycobacterium tuberculosis H37Rv ATCC 27294 strain and the human tumor cell lines OVCAR-8 (ovarian cancer), SF-295 (glioblastoma multiforme) and HCT-116 (colon adenocarcinoma). All copper(II) complexes were more effective in reducing growth of HCT-116 and SF-295 cells than the respective free hydrazones at 5 µg/mL, whereas only complex 7 was more cytotoxic toward OVCAR-8 lines than its ligand HPAmIH. 6 proved to be cytotoxic at submicromolar doses, whose IC₅₀ values (0.39–0.86 µM) are similar to those ones found for doxorubicin (0.23–0.43 µM). Complexes 5 and 6 displayed high activity against M. tuberculosis (MIC = 0.85 and 1.58 µM, respectively), as compared with isoniazid (MIC = 2.27 µM), which suggests the compounds are attractive candidates as antitubercular drugs.     

Isolation and Antibiotic Screening of Fungi from a Hydrothermal Vent Site and Characterization of Secondary Metabolites from a <Emphasis Type="Italic">Penicillium</Emphasis> Isolate

Five new compounds were isolated from Penicillium sp. Y-5-2 including an austin derivative 4, four isocoumarins 9, 11, 12, and 13, together with two known isocoumarins 8 and 10, and six known austin derivatives 1, 2, 3, 5, 6, and 7 and one phenol 14. Their structures and relative configurations were established by spectroscopic means. The absolute configurations of 4, 11, and 13 were defined mainly by comparison of quantum chemical TDDFT calculated and experimental ECD spectra. The cyclization of the pentan-2-ol pendant at C-3 in compound 13 allowed the assignment of a new 2,3,4,4a,6,10b-hexahydro-1H-benzo[c]chromene isocoumarin skeleton. New compounds 9, 11, and 13 revealed inhibitory activities against E. coli at MIC values around 32 μg/mL. The known compound 14 showed potent antibiotic activity against Staphylococcus aureus and Bacillus subtilis with MIC values 8 and 2 μg/mL, respectively, with no cytotoxicity when tested in vitro. A rapid and efficient technique for selecting antibiotic fungal strain among eight marine-derived fungi was also described.