Characterization of the first two toxins isolated from the venom of the ancient scorpion (Borelli, 1901).

Background: Almost all characterized toxins are from subgenera and , there are only a few data about toxins produced by , an ancient group in genus.

Methods: crude venom was fractionated by high performance liquid chromatography, the major fractions were tested in a frog sciatic nerve single sucrose-gap technique. Two fractions (Tm1 and Tm2) were isolated, partially sequenced by MALDI-TOF/MS and electrophysiological assayed on HEK293 Nav 1.

Pathophysiological effects caused by the venom of the social wasp Synoeca surinama.

Envenomation by wasp stings is a public health preoccupation, and signals after stings have variable effects depending on the number of attacks and individual sensitivities. Even with the high rate of wasp sting cases, the study of phatophysiological effects of the envenomation is still very incipient. In this context, early and accurate assessment of this prognostic can aid in the reduction of the symptomatology and complete remission of the later symptoms.

Anticonvulsant and anxiolytic activity of the peptide fraction isolated from the venom of the social wasp Polybia paulista.

Background: Arthropod venoms have attracted interest because they represent a source of neuroactive compounds that can be useful tools in neuroscience and pharmacological investigations.

Objective: The purpose of the present work was to evaluate the anticonvulsant, anxiolytic, and behavioral effects of the peptide fraction separated from venom of the social wasp.

Materials And Methods: The low- molecular-weight compounds of the venom were separated by ultrafiltration and the bioassays were performed to test anticonvulsant and anxiolytic effects, as well as alterations in the spontaneous behavior of the animals.

OcyKTx2, a new K⁺-channel toxin characterized from the venom of the scorpion Opisthacanthus cayaporum.

Opisthacanthus cayaporum belongs to the Liochelidae family, and the scorpions from this genus occur in southern Africa, Central America and South America and, therefore, can be considered a true Gondwana heritage. In this communication, the isolation, primary structure characterization, and K⁺-channel blocking activity of new peptide from this scorpion venom are reported. OcyKTx2 is a 34 amino acid long peptide with four disulfide bridges and molecular mass of 3807 Da.

Venomic and pharmacological activity of Acanthoscurria paulensis (Theraphosidae) spider venom.

In the present study we conducted proteomic and pharmacological characterizations of the venom extracted from the Brazilian tarantula Acanthoscurria paulensis, and evaluated the cardiotoxicity of its two main fractions. The molecular masses of the venom components were identified by mass spectrometry (MALDI-TOF-MS) after chromatographic separation (HPLC). The lethal dose (LD(50)) was determined in mice.

Pharmacological characterization of Synoeca cyanea venom: an aggressive social wasp widely distributed in the Neotropical region.

The venom of social wasps has been poorly studied so far, despite the high number of accidents in humans and assessment of the use of these wasps as a biological control of pests. The study of the pharmacological effects of the venom is of great importance since the poisoning is dangerous causing serious systemic effects, including death in the case of multiple attacks. In this study, the pharmacological activities of venom from the social wasp Synoeca cyanea were evaluated by the following assays: LD50 in mice, the behavioural effects and the hemorrhagic activity induced by the venom in mice, the oedematogenic activity in rat, the haemolysis in human blood, the stimulating effect on guinea-pig smooth muscle, and the antimicrobial activity.

The new kappa-KTx 2.5 from the scorpion Opisthacanthus cayaporum.

The kappa-KTx family of peptides, which is the newest K⁺-channel blocker family from scorpion venom, is present in scorpions from the families Scorpionidae and Liochelidae. Differently from the other scorpion KTx families, the three-dimensional structure of the known kappa-KTxs toxins is formed by two parallel α-helices linked by two disulfide bridges. Here, the characterization of a new kappa-KTx peptide, designated kappa-KTx 2.

Bites caused by giant water bugs belonging to Belostomatidae family (Hemiptera, Heteroptera) in humans: a report of seven cases.

We report 7 cases of patients bitten by giant water bugs, large predatory insects belonging to the Belostomatidae family (Hemiptera, Heteroptera). These insects have toxic saliva capable of provoking intense pain and paralysis in vertebrates. Victims experienced intense, excruciating pain and 1 manifested hypoesthesia in the forearm.

Mass spectrometry analysis, amino acid sequence and biological activity of venom components from the Brazilian scorpion Opisthacanthus cayaporum.

This communication reports the separation of 80 fractions from the venom of the Ischnuridae scorpion Opisthacanthus cayaporum by high-performance liquid chromatography (HPLC). From these, 93 distinct components were identified by liquid chromatography/electrospray mass spectrometry (LC/ESI-MS) analysis, with molecular weights varying from 229.2 to 61,144.

HgeTx1, the first K+-channel specific toxin characterized from the venom of the scorpion Hadrurus gertschi Soleglad.

A novel toxin was identified, purified and characterized from the venom of the Mexican scorpion Hadrurus gertschi (abbreviated HgeTx1). It has a molecular mass of 3950 atomic mass units (a.m.

Toxicity and toxin identification in Colomesus asellus, an Amazonian (Brazil) freshwater puffer fish.

Toxicity and toxin identification in Colomesus asellus, an Amazonian (Brazil) freshwater puffer fish. By using four different techniques--mouse bioassay, ELISA, HPLC and mass spectrometry-we evaluated the toxicity in the extracts of C. asellus, a freshwater puffer fish from the rivers of the Amazon, and identified for the first time the components responsible for its toxicity.

Antimicrobial activity of the bufadienolides marinobufagin and telocinobufagin isolated as major components from skin secretion of the toad Bufo rubescens.

The increase in the emergence of antibiotic-resistant microorganisms and difficult to treat infections caused by these pathogens stimulate research aiming the identification of novel antimicrobials. Skin secretion of amphibian contains a large number of biologically active compounds, including compounds that performance defense mechanisms against microorganisms. In the present work, two antimicrobial bufadienolides, telocinobufagin (402.

Ocellatins: new antimicrobial peptides from the skin secretion of the South American frog Leptodactylus ocellatus (Anura: Leptodactylidae).

The emergence, in recent years, of microbial resistance to commonly used antibiotics has aroused a search for new naturally occurring bactericidal and fungicidal agents that may have clinical utility. In the present study, three new antimicrobial peptides were purified from the electrical-stimulated skin secretion of the South American frog Leptodactylus ocellatus by reversed-phase chromatographic procedures. Ocellatin 1 (1GVVDILKGAGKDLLAHLVGKISEKV25-CONH2), ocellatin 2 (1GVLDIFKDAAKQILAHAAEKQI25-CONH2) and ocellatin 3 (1GVLDILKNAAKNILAHAAEQI21-CONH2) are structurally related peptides.

Further report of the occurrence of tetrodotoxin and new analogues in the Anuran family Brachycephalidae.

Tetrodotoxin (TTX) is one of the most potent toxin already isolated, which occurs in a wide range of marine as well as terrestrial animals such as in newts and anurans. In this work, the occurrence of TTX and analogues was examined in three brachycephalid species: Brachycephalus ephippium, B. nodoterga and B.

Main alkaloids from the Brazilian dendrobatidae frog Epipedobates flavopictus: pumiliotoxin 251D, histrionicotoxin and decahydroquinolines.

Epipedobates flavopictus, Dendrobatidae, is a small aposematic frog found in Brazilian Cerrado bioma. In the present work, we isolated and characterized chemically the most abundant alkaloids present in the cutaneous extract of E. flavopictus.

The occurrence of 11-oxotetrodotoxin, a rare tetrodotoxin analogue, in the brachycephalidae frog Brachycephalus ephippium.

11-oxoTTX is an analogue 4-5 times more toxic than TTX itself, been rare even in marine animals. Two ions at m/z 320 and 336 corresponding to TTX and 11-oxoTTX (M+H(+)), respectively, were detected in the Brachycephalidae frog Brachycephalus ephippium extracts. The fragment ion pattern of 11-oxoTTX is similar to that TTX, although its possible to verify some specific fragments.

Purification and primary structure determination of Tf4, the first bioactive peptide isolated from the venom of the Brazilian scorpion Tityus fasciolatus.

In the present study Tityus fasciolatus crude venom toxicity was evaluated and we also report the purification and characterization of a 6.6 kDa neurotoxin isolated from T. fasciolatus venom.

Composition of indolealkylamines of Bufo rubescens cutaneous secretions compared to six other Brazilian bufonids with phylogenetic implications.

The composition of indolealkylamines of Bufo rubescens cutaneous secretions was compared to those from six other Brazilian bufonids. Skin, parotoid and tibial gland secretions were obtained for analysis by thin-layer chromatography. A triple-quadrupole mass spectrometer was used to confirm the indolealkylamines standards (serotonin, 5-HT; bufotenin, BTN; dehydrobufotenin, DHB and bufotenidin, BTD).

Occurrence of tetrodotoxin and its analogues in the Brazilian frog Brachycephalus ephippium (Anura: Brachycephalidae).

Brachycephalus ephippium is a diurnal frog, that shows aposematic colouration and inhabits Atlantic forest leaf litter in south-eastern Brazil. The presence of tetrodotoxin (TTX) in the skin, liver and ovaries of B. ephippium was demonstrated.