Proteinase inhibitors in Brazilian leguminosae

Serine proteinase inhitors, in the seeds of several Leguminosae from the Pantanal region (West Brazil), were studied using bovine trypsin, a digestive enzyme, Factor XIIa and human plasma Kallikrein, two blood clotting factors. The inhibitors were purified from Enterolobium contortisiliquum (Mr=23,000), Torresea cearensis (Mr = 13,000), Bauhinia pentandra (Mr = 20,000) and Bauhinia bauhinioides (Mr = 20,000). E. contortisiliquum inhibitor inactivates all three enzymes, whereas the T. cearensis inhibitor inactivates trypsin and Factor XSSa, but does nor affect plasma kallikrein; both Bauhinia inhibitors, on the other hand, inactivate trypsin and plasma kallikrein but only the Bpentandra inhibitor affects Factor XIIa. Ki values were calculated between 10 [raised to the power of] -7 and 10 [raised to the power of] -8 M.

Transport pathways in the malaria-infected erythrocyte: characterization and their use as potential targets for chemotherapy

The intraerythrocytic malarial parasite is involved in an extremely intensive anabolic activity while it resides in its metabolically quiescent host cell. The necessary fast uptake of nutrients and the discharge of waste product, are guaranteed by parasite-induced alterations of the constitutive transporters of the host cell and the production of new parallel pathways. The membrane of the host cell thus becomes permeable to phospholipids, purine bases and nucleosides, small non-electrolytes, anions and cations. When the new pathways are quantitatively unimportant, classical inhibitors of native transporters can be used to inhibit parasite growth. Several compounds were found to effectively inhibit the new pathways and consequently, parasite growth. The pathways have also been used to introduce cytotoxic agents. The parasitophorous membrane consists of channels which are highly permeable to small solutes and display no ion selectivity. Transport of some cations and anions across the parasite membrane is rapid and insensitive to classical inhibitors, and in some cases it is mediated by specific antiporters which respond to their respective inhibitors. Macromolecules have been shown to reach the parasitophorous space through a duct contiguous with the host cell membrane, and subsequently to be endocytosed at the parasite membrane. The simultaneous presence of the parasitophorous membrane channels and the duct, however, is incompatible with experimental evidences. No specific inhibitors were found as yet that would efficiently inhibit transport through the channels or the duct.

The carbohydrate-binding specificity and molecular modelling of Canavalia maritima and Dioclea grandiflora lectins

The carbohydrate-binding specificity of lectins from the seeds of Canavalia maritima and Dioclea grandiflora was studied by hapten-inhibition of haemagglutination using various sugars and sugar derivatives as inhibitors, including N-acetylneuraminic acid and N-acetylmuramic acid. Despite some discrepancies, both lectins exhibited a very similar carbohydrate-binding specificity as previously reported for other lectins from Diocleinae (tribe Phaseoleae, sub-tribe Diocleinae). Accordingly, both lectins exhibited almost identical hydropathic profiles and their three-dimensional models built up from the atomic coordinates of ConA looked very similar. However, docking experiments of glucose and mannose in their monosaccharide-binding sites, by comparison with the ConA-mannose complex used as a model, revealed conformational changes in side chains of the amino acid residues involved in the binding of monosaccharides. These results fully agree with crystallographic data showing that binding of specific ligands to ConA requires conformational chances of its monosaccharide-binding site.

Saponins from Swartzia langsdorffii: biological activities

The presence of saponins and the molluscicidal activity of the roots, leaves, seeds and fruits of Swartzia langsdorffii Raddi (Leguminosae) against Biomphalaria glabrata adults and eggs were investigated. The roots, seeds and fruits were macerated in 95% ethanol. These extracts exerted a significant molluscicidal activity against B. glabrata, up to a dilution of 100 mg/l. Four mixtures (A2, B2, C and D) of triterpenoid oleanane type saponins were chromatographically isolated from the seed and fruit extracts. Two known saponins (1 and 2) were identified as beta-D-glucopyranosyl-[alpha-L-rhamnopyranosyl-(1->3)- beta-D-glucuronopyranosyl-(1->3)]-3beta-hydroxyolean-12-ene-28 -oate, and beta-D-glucopyranosyl-(1->3)-beta-D-glucuronopyranosyl-(1 ->3)]-3beta-hydroxyolean-12-ene-28-oate, respectively. These two saponins were present in all the mixtures, together with other triterpenoid oleane type saponins, which were shown to be less polar, by reversed-phase HPLC. The saponin identifications were based on spectral evidence, including ¹H-¹H two-dimensional correlation spectroscopy, nuclear Overhauser and exchange spectroscopy, heteronuclear multiple quantum coherence, and heteronuclear multiple-bond connectivity experiments. The toxicity of S. langsdorffii saponins to non-target organisms was prescreened by the brine shrimp lethality test.

Palaeoparasitology in Japan: discovery of toilet features

The development of palaeoparasitology in Japan has occurred in recent decades. Despite the fact that archaeology in Japan has been slow to develop techniques for excavating ancient toilets, important information about the development of sanitation has been derived from the analysis of a few sites. This shows that the earliest people had very simple methods of sanitation. As populations increased, sanitation became more complex. Ditches surrounding early towns were used for excrement disposal. Eventually distinct toilets were developed followed by cesspit type toilets and flushing toilets. The parasites recovered from these toilets include many species that infect humans today. These parasite spectra reflect local use of aquatic, marine, and land animals. Fecal borne disease was an increasing problem as represented by whipworm and ascarid roundworm eggs. Interestingly, ascarid roundworms were absent in the earliest cultures and only became common with rice agriculture. Finds of pollen and seeds in toilet sediments reveal the use of medicinal plants to control the emerging problem of parasites.

Antibacterial potentiality of Argemone mexicana solvent extracts against some pathogenic bacteria

The sensitivity of two Gram positive (Staphylococcus aureus and Bacillus subtilis) and two Gram negative (Escherichia coli and Pseudomonas aeruginosa) pathogenic multi-drug resistant bacteria was tested against the crude extracts (cold aqueous, hot aqueous, and methanol extracts) of leaves and seeds of Argemone mexicana L. (Papaveraceae) by agar well diffusion method. Though all the extracts were found effective, yet the methanol extract showed maximum inhibition against the test microorganisms followed by hot aqueous extract and cold aqueous extract.

Paleoparasitologic, paleogenetic and paleobotanic analysis of XVIII century coprolites from the church La Concepción in Santa Cruz de Tenerife, Canary Islands, Spain

We present the results of a paleoparasitologic, paleogenetic and paleobotanic analysis of coprolites recovered during the excavation of the church La Concepción in Santa Cruz de Tenerife. Coprolites (n = 4) were rehydrated and a multidisciplinary analysis was conducted. The paleobotanic analysis showed numerous silicates, seeds and fruits of the family Moraceae. In the paleoparasitologic study, Ascaris sp. eggs (n = 344) were identified. The paleogenetic results confirmed the Ascaris sp. infection as well as the European origin of human remains. These findings contribute to our knowledge of ancient helminthes infections and are the first paleoparasitological record of Ascaris sp. infection in Spain.

Correlation between the infestation level of Sitophilus zeamais Motschulsky, 1855 (Coleoptera, Curculionidae) and the quality factors of stored corn, Zea mays L. (Poaceae)

This experiment was carried out in order to evaluate the effect of Sitophilus zeamais on physical, physiological and sanitary quality of stored corn. Samples of 500 g of the hybrid OC-705, in three replicates, were conditioned in glasses covered with a screened lid, and kept in chamber at 25±2ºC, 70±5% RH and 12 h of photophase, for 150 days. The infestation levels were 0, 5, 15 and 50 adults/replicate, for the storage periods of 30, 60, 90, 120 and 150 days. The moisture content, classification, weight loss, germination and internal infestation were evaluated monthly. Significant inverse correlations were verified between the number of insects and both the germination and the weight loss; also between the internal infestation and the germination and the standard type. The presence of S. zeamais showed a positive correlation with the weight loss, what means that the internal and external infestations contribute to the reduction of physiological and physical quality of corn seeds. The mean dry matter loss was 0,36%/day, corresponding to a consumption of 0,0001%/insect/month. As the result of those damages, the product suffered reduction of the commercial grade in 30 days, with significant loss in all quality factors.

A review of evolution of oviposition guilds in the Bruchidae (Coleoptera)

Three guilds of bruchid beetles oviposit on seeds at different times and in different ways, i. e., in these guilds some species only oviposit on fruits while on the plant (Guild A), other species only oviposit on seeds exposed in fruits while still on the plant (Guild B) and some only oviposit on seeds once they are exposed on the substrate (Guild C). It has been established that one plant species may be oviposited upon by all three guilds, some only by two guilds and some by only one guild. Before and after the inception of this concept many papers have been published that seem to establish that early oviposition behavior of bruchids was probably onto fruits where they burrowed through the fruit wall and fed on seeds (Guild A). Then, as evolution of the fruits developed for dispersal of seeds and possible escape from bruchid predation, bruchids developed to feed in seeds in various other ways (Guilds B and C). Our data show that about 78% of extant bruchids oviposit on fruits, and the other 22% with behavior of Guilds B and C. A review of these papers and new data on oviposition guilds and bruchid evolution are presented and discussed here.

A new spermophagous species of Heilipus Germar from the Amazonian Region (Coleoptera, Curculionidae, Molytinae)

Heilipus odoratus sp. nov. (type locality: Brazil, Amazonas, Manaus) is described based on adults reared from seeds of Aniba rosaeodora Ducke (Lauraceae), popularly called "pau-rosa". The species is spermophagous and develops from egg to adult inside the seeds. The new taxon is compared with the similar Heilipus draco (Fabricius, 1801). Illustrations of larva, pupa, adult and of important structures for species identification are given, including the male and female genitalia, figured for the first time for a species of Heilipus.

Nymph developmental time and survivorship, adult longevity, reproduction and body weight of Dichelops melacanthus (Dallas) feeding on natural and artificial diets

The biology of nymphs and adults of the neotropical pentatomid, Dichelops melacanthus (Dallas), feeding on the natural foods, soybean, Glycine max (L.) Merrill immature pods, and corn, Zea mays L. immature seeds, and on an artificial dry diet, was studied in the laboratory. Nymph developmental time was shorter on the natural foods (ca. 21-22 days) than on the artificial diet (28 days), and most nymphs reached adulthood on the food plants (55% on soybean and 73% on corn) than on the artificial diet (40%). Fresh body weight at adult emergence was similar and higher for females raised as nymphs on the natural foods, compared to females from nymphs raised on the artificial diet; for males, weights were similar on all foods. Mean (female and male) survivorship up to day 20, decreased from 55% on soybean to 40% on corn, down to 0% on the artificial diet. Total longevity for females was higher on soybean, while for males was similar on all foods. About three times more females oviposited on soybean than on corn, but fecundity/female was similar on both foods. On the artificial diet, only one out of 30 females oviposited. Fresh body weight of adults increased significantly during the first week of adult life, and at the end of the 3rd week, weight gain was similar on all foods.

Bioactivity of Indonesian mahogany, Toona sureni (Blume) (Meliaceae), against the red flour beetle, Tribolium castaneum (Coleoptera, Tenebrionidae)

Bioactivity of Indonesian mahogany, Toona sureni (Blume) (Meliaceae), against the red flour beetle, Tribolium castaneum (Coleoptera, Tenebrionidae). The insecticidal activity of Toona sureni (Blume) Merr. was evaluated considering repellency, mortality and progeny production of F1 adults of Tribolium castaneum (Herbst, 1797) (Coleoptera, Tenebrionidae). Dried extract of seeds of T. sureni was dissolved in acetone to prepare solution of various concentrations (0.5, 1.0, 2.5 and 5.0%). To test for repellency, the insects were exposed to treated filter paper. Mortality of larvae, pupae and adults was evaluated by the treatment of spraying the insects with different concentrations of T. sureni extract. Residual effect of the extract was also evaluated considering the production of progeny of F1 adults. The highest repellency (93.30%) of T. castaneum occurred at the highest concentration (5.0% suspension of T. sureni); while the lowest (0.0%) repellency occurred at 0.5% suspension after 1 day of treatment. The highest mortality against adults (86.71%), larvae (88.32%) and pupae (85%) occurred at 5% suspension at 8 days after application. There was a negative correlation between the concentrations of T. sureni and the production of F1 adult's progeny of T. castaneum. The highest number of progeny (147) of T. castaneum occurred in the control at 7 days after treatment; and the lowest number of progeny (43) occurred at 5.0% concentration in 1 day after treatment. The results show that T. sureni is toxic to T. castaneum and has the potential to control all stages of this insect in stored wheat.

Volatilização de N-NH3 na cultura de milho: I. efeito da irrigação e substituição parcial da uréia por sulfato de amônio

Foi desenvolvido um experimento em latossolo vermelho-escuro muito argiloso fase cerrado, no Centro de Pesquisas Novartis-Seeds, Uberlândia (MG), para avaliar o efeito da irrigação e do N-uréia, em cobertura no milho, e de sua substituição parcial por sulfato de amônio, nas perdas de N-NH3 volatilizado. O N foi aplicado aos 25 e 36 dias após plantio, sendo os tratamentos dispostos em blocos casualizados com quatro repetições: testemunha, uréia com irrigação anterior e posterior à aplicação de N nas duas coberturas e uréia + sulfato de amônio (relação N:S = 2,1:1) na primeira cobertura e uréia na segunda com irrigação anterior e posterior à aplicação. Nove amostragens de N-NH3 volatilizado foram efetuadas em intervalos de quatro a cinco dias, utilizando-se coletores do tipo semi-aberto estático, instalados logo após a primeira aplicação de N. Com irrigação posterior à adubação, as perdas acumuladas de N-NH3 foram de 40,6 e 23,0 % do N aplicado para os tratamentos com adubação exclusiva de uréia e substituição parcial com sulfato de amônio respectivamente. Com irrigação prévia, as perdas acumuladas foram, respectivamente, de 42,8 e 38,6 % do N aplicado. Embora não tenha havido diferença significativa entre os tratamentos, a substituição da uréia por sulfato de amônio foi positiva quando a irrigação foi efetuada após a adubação. Esse tratamento mostrou também o maior diâmetro de caule, altura de planta e teor foliar de nutrientes. O rendimento de grãos respondeu positivamente à aplicação de N. A correlação das perdas por volatilização de N-NH3 mostrou um ajuste linear inverso à produtividade dos tratamentos adubados, de tal forma que 19,3 kg ha-1 de grãos deixaram de ser produzidos por quilograma de N volatilizado.

Volatilização de N-NH3 na cultura de milho:: II. avaliação de fontes sólidas e fluidas em sistema de plantio direto e convencional

Foram desenvolvidos dois experimentos em campo, em sistema de plantio direto (SPD) sobre cobertura de aveia-preta, em latossolo vermelho-escuro, distrófico, argiloso, e em sistema de plantio convencional (SPC), após cultivo de soja, em latossolo vermelho-amarelo distrófico arenoso, no Centro de Pesquisa Novartis-Seeds e na Fazenda Stª. Teresinha, Uberlândia (MG) respectivamente. O estudo objetivou avaliar as perdas por volatilização de N-NH3 da cobertura nitrogenada na cultura de milho com cerca de 100 kg ha-1 de N, de cinco fontes nitrogenadas em ambos os sistemas de plantio. As fontes nitrogenadas - sulfato de amônio, nitrato de amônio, uréia e duas soluções nitrogenadas constituídas de uréia + nitrato de amônio (uran) e uréia + nitrato de amônio + sulfato de amônio (sulfuran) - foram aplicadas na superfície e incorporadas no meio da entrelinha. Após a aplicação da cobertura, instalaram-se, ao acaso, três coletores do tipo semi-aberto estático, por tratamento, sendo efetuadas seis amostragens de N-NH3 volatilizado, em intervalos de quatro a cinco dias. No SPD, as perdas acumuladas de N-NH3 provenientes das fontes uréia, uran e sulfuran aplicadas na superfície foram, respectivamente, de 78,0; 37,2 e 26,9% do N aplicado. No SPC, as perdas mais significativas foram de uréia (30,7%) e uran (9,7%). O nitrato de amônio e o sulfato de amônio apresentaram perdas inferiores a 15,0% do N aplicado à superfície. A correlação das perdas por volatilizacão de N-NH3 e a produtividade dos dois experimentos mostraram um ajuste linear negativo, de tal forma que no SPD houve uma queda de produção de 13,3 kg de grãos e no SPC, de 11,8 kg de grãos para cada quilograma de N volatilizado.

Balanço da adubação nitrogenada sólida e fluida de cobertura na cultura de milho, em sistema plantio direto no Triângulo Mineiro (MG)

Foi desenvolvido um experimento com as fontes uréia e uran aplicadas superficialmente ou incorporadas (5-7 cm) na cobertura nitrogenada de milho, no sistema plantio direto, com o objetivo de efetuar, na colheita, um balanço do N-uréia (15N) e quantificar as perdas por volatilização de N-NH3 nesses tratamentos, assim como nos adicionais, testemunha e misturas de uréia + KCl (sólida) e uran + KCl (fluida), na formulação 6-0-9 (N-P2O5-K2O), aplicadas somente em superfície. Os tratamentos originaram-se de um fatorial 1 + (2 x 2) + 2, sendo a testemunha + o fatorial 2 x 2 (duas fontes; uréia e uran x duas formas de localização) + dois tratamentos adicionais, misturas uréia + KCl (sólida) e uran + KCl (fluida), dispostos em blocos casualizados com quatro repetições. O ensaio foi realizado em Latossolo Vermelho-Escuro muito argiloso fase cerrado relevo plano, no Centro de Pesquisa Novartis - Seeds do município de Uberlândia (MG). Cerca de 100 kg ha-1 de N foram aplicados no estádio fenológico de seis a oito folhas. Após 26 dias da adubação, as perdas acumuladas de N-NH3 nos tratamentos em superfície foram de 54, 41, 17 e 14% do N aplicado, para uréia, uréia + KCl, uran e uran + KCl, respectivamente. Quando a uréia e o uran foram incorporados ao solo, as perdas acumuladas de N-NH3 foram de 5,0 e 3,5% do N aplicado, respectivamente. Na colheita, o N da uréia absorvido pela planta (raízes + colmos + folhas + grãos) foi de 19,9 kg ha-1 (20,8% do N aplicado) e de 29,5 kg ha-1 (29,5% do N aplicado), quando aplicado na superfície e incorporado, respectivamente. O N-uréia do uran absorvido pela planta foi de 11,4 kg ha-1 (26,1% do N aplicado) e de 11,7 kg ha-1 (26,8% do N aplicado), quando aplicado na superfície ou incorporado, respectivamente. O N da uréia imobilizado na camada de 0-45 cm de profundidade foi, em média, de 9,9 kg ha-1 (10,0% do N aplicado), da aplicação superficial ou incorporada, e do N-uréia do uran foi de 3,3 kg ha-1 (7,6% do N aplicado). O N-mineral no solo derivado do N da uréia e do N-uréia do uran aplicados na superfície, no perfil de 0-150 cm, foi, respectivamente, de 2,4 e 3,2%, e de 5,9 e 2,5%, com as fontes incorporadas. No balanço global de N, em média, 13,7 e 50,3% do N da uréia não foram recuperados no sistema solo-planta, respectivamente, para a aplicação superficial ou incorporada; para o N-uréia do uran, obtiveram-se, respectivamente, 47,7 e 57,6%.