Toxicologia
Saxitoxina
Alexandre Costa, nº 68001 António Pires, nº 67774 Ema Belchior, nº 69124 Simão Pereira, nº 68246
G11 |
índice
9. Tratamento
1. Introdução
10. Diagnóstico
2. Análise estrutural
11. Prevenção
3. Mecanismo de ação
12. Prevenção
4. Efeitos terapeuticos/Potencial como droga
13. Impactos ambientais
5. Biosintese Molecular
14. Conclusão
6. Caso de estudo
15. Referências
7. Toxicidade
8. Sintomas
Introdução
- A saxitoxina é uma toxina potente
- Produzida por dinoflagelados marinhos e cianobactérias
- Pertence às toxinas paralíticas do marisco (PSTs)
- Bloqueia os canais de sódio dependentes da voltagem
- Impedindo a entrada de iões e o consequente sinal
Análise estrutural
carbamato
guanidina
- C10H17N7O4
- Massa molar: 299,286 g/mol
- Pertence à classe de alcalóides pirrolizidínicos e purínicos
- Estrutura tricíclica
- Elevada polaridade e hidrofilicidade
diól
Mecanismos de Ação
Interação do grupo guanidina da STX com um grupo carboxil.
Ligação ao canal não competitiva.
guanidina
Canal de sódio dependente de voltagem
A STX liga-se ao Sítio 1 da subunidade alpha do canal de sódio.
Inibe a formação e a propagação do potencial de ação.
Biossíntese Molecular
Dose Letal
1- 4
5,7
μg/kg
g/kg
Dose letal mínima em ratos
Dose letal mediana (LD50)
0,6 μg/kg
Dose letal mediana (LD50) por injeção
10 μg/kg
Dose letal mediana (LD50) em ratos
TOxicidade
15%
taxa de mortalidade
Anualmente ocoreem 2000 casos de PSP
Efeitos terapêuticos/ Potencial droga
Os canais de sódio são inibidos, sem causar morte celular.
Potencial uso como anastésico local.
Elevado nível de toxicidade e margem pouco segura
Uso tópico limitado
Mecanismos de difusão paracelular, alterações transitórias na permeabilidade intestinal e variação do estado de ionização com o pH
Rápida absorção
“Regra dos Cinco” de Lipinski
Descartada como terapêutico oral
Sintomas
Alguns dos sintomas incluem...
Vómito induzido
Intubação
Respiração mecanica
Lavagem gástrica
Fatores ambientais
Temperatura
Luz
Nutrientes
Simbiose
Afeta expressão dos genes sxtA e sxtG.Baixas temperaturas aumentam a expressão.
Intensidade luminosa determina o crescimento e metabolismo das algas.
Stress de nitrogénio inibe o crescimento de A. minutum. Mas escassez de fósforo aumenta a produção de STX. NO3- influencia a expressão dos genes sxt.
O zooplancton D. gessneri estimula os genes sxt de R. raciborskii. J. cystaugens induz stress oxidativo, nutritivo e sinais de quorum sensing.
DIagnostico e Prevenção
Controlo da piscicultura
Análise laboratorial
Evitar o consumo
A única maneira de averiguar corretamente a presença do contaminante é com a análise laboratorial.
Para assegurar que a qualidade do alimento é necessário confirmar as suas origens.
38 mg/kg
STX no mexilhão
Caso de estudo
0,8 mg/kg
Limite legal europeu
- Em 2018 na Caparica
- Dois indivíduos consumiram mexilhão pescado nas praias da Caparica
- Continha STX produzida pela microalga Gymnodinium catenatum
- Análises do plasma e urina por ensaios imunoenzimáticos (ELISA) e HPLC-FLD
- Houve recuperação completa
200 g
mexilhão consumido
104 - 120 μg/kg
STX ingerida
100 μg/kg
Limiar de sintomas severos
Conclusão
Droga
Regulação das culturas e do consumo de marisco.
Prevenção
Saxitoxina
alvo
Sintomas
Produzida por dinoflagelados marinhos e cianobactérias
Uso seguro como anastésico tópico ocular.
Afeta o sistema nervoso e músculos, inibindo o potencial de ação por obstrução dos canais de sódio regulados por voltagem.
Desde formigueiro e dormência ligeira até paralisia muscular e insuficiência respiratória. Em casos descontrolados, potencialmente fatal.
veneno
A STX é perigosa e um problema para a segurança alimentar
Obrigada !
Here you can include a relevant data to highlight
Use an image
Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes to us through sight and, moreover, we retain 42% more information when the content moves.
Here you can include a relevant data to highlight
+ info
Wow Effect
'Your content is liked, but it only engages if it's interactive' - Genially
Did you know that Genially allows you to share your creation directly, without the need for downloads? Ready for your audience to visualize it on any device and give it exposure anywhere.
Here you can include a relevant data to highlight
'Including quotes always reinforces our presentation. Breaks the monotony.'
- Author's Name
Structureyour content
Sections like this will help you organize
Timeline
20XX
20XX
20XX
Surprise
Plan
Design
20XX
20XX
Structure
Communicate
20XX
Plan
Timeline
20XX
Structure
You can briefly describe what the timeline of your presentation consists of and orally present the milestones so that no one falls asleep.
20XX
Design
20XX
Communicate
+ info
20XX
Surprise
Charts are highly shareable, making them ideal for social media and, on top of that, they tend to generate quality traffic to the content we create.
60%
Chart + text
Use this space to briefly describe your chart and its evolution.
Graphic + text
The graphics are highly shareable, making them ideal for social media and, moreover: they tend to generate quality traffic to the content we create.
+ info
Table + text
Demonstrate enthusiasm, sketch a smile and maintain eye contact with your audience can be your best allies when it comes to telling stories that excite and awaken the interest of the public: 'The eyes, chico. They never lie'. This will help you make a 'match' with your audience. Leave them open-mouthed!
Table + text
Demonstrate enthusiasm, give a smile, and maintain eye contact with your audience can be your best allies when it comes to telling stories that excite and arouse the audience's interest: 'The eyes, man. They never lie'. This will help you make a 'match' with your audience. Leave them open-mouthed!
Insert a video
Multimedia content is essential in a presentation to leave everyone amazed. Additionally, you will synthesize the content and keep your audience entertained.
Text + icons
Although you should not abuse bulletpoints, icons and schemes can be great allies when telling stories.
Has a WOW effect. Very WOW.
Measures results and experiments
Generates experiences with your content
Is organized, hierarchical, and structured
Makes your audience remember the message
Activates and surprises your audience
Audio
Your content is engaging if it is interactive
This is a paragraph ready to contain creativity, experiences, and great stories.
It is essential to make the relevant checks. Not a single typo!
This is a paragraph ready to contain creativity, experiences, and great stories.
The tone is usually formal and the vocabulary technical, so keep that in mind when writing.
Embedded Content
Map
Social Media
Music
Interactive Question
Interactive Question
Interactive Question
Interactive Question
Conclusion
Disciplines like Visual Thinking facilitate visually rich note-taking thanks to the use of images, graphics, infographics, and simple drawings. Go for it!
Visual content is a cross-cutting language, universal, like music. We are able to understand images from millions of years ago, even from other cultures.
Did you know that Genially allows you to share your creation directly, without the need for downloads? Ready for your audience to view it on any device and give it exposure anywhere.
'Your content is liked, but it engages much more if it is interactive'-Genially
an awesome title here
With Genially's templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or data that remains engraved in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or data that will be etched in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
an awesome title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains engraved in fire in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience open-mouthed. Also, highlight some phrase or specific data that remains etched in your audience's memory and even embed surprising external content: videos, photos, audios... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes to us through sight and, moreover, we retain 42% more information when the content moves.
- Generate experiences with your content.
- It has a WOW effect. Very WOW.
- Make your audience remember the message.
- Activate and amaze your audience.
a great title here
With Genially's templates you can include visual resources to leave your audience speechless. Also highlight some phrase or specific data that remains etched in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes to us through sight and, in addition, we retain 42% more information when the content moves.
- Generate experiences with your content.
- Has a WOW effect. Very WOW.
- Make your audience remember the message.
- Activate and amaze your audience.
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains engraved in the memory of your audience, and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains etched in fire in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains etched in fire in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
an awesome title here
With Genially's templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or data that remains engraved in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains engraved in fire in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains engraved in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially templates, you can include visual resources to leave your audience speechless. You can also highlight a specific phrase or specific data that will be engraved in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes to us through sight and, in addition, we retain 42% more information when the content moves.
an awesome title here
With Genially's templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or data that will be etched in the memory of your audience, and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or data that will remain engraved in the memory of your audience, and even embed external content that surprises: videos, photos, audios... Whatever you want!
Saxitoxina
Ema
Created on September 26, 2025
Start designing with a free template
Discover more than 1500 professional designs like these:
View
Corporate Christmas Presentation
View
Snow Presentation
View
Nature Presentation
View
Halloween Presentation
View
Tarot Presentation
View
Winter Presentation
View
Vaporwave presentation
Explore all templates
Transcript
Toxicologia
Saxitoxina
Alexandre Costa, nº 68001 António Pires, nº 67774 Ema Belchior, nº 69124 Simão Pereira, nº 68246
G11 |
índice
9. Tratamento
1. Introdução
10. Diagnóstico
2. Análise estrutural
11. Prevenção
3. Mecanismo de ação
12. Prevenção
4. Efeitos terapeuticos/Potencial como droga
13. Impactos ambientais
5. Biosintese Molecular
14. Conclusão
6. Caso de estudo
15. Referências
7. Toxicidade
8. Sintomas
Introdução
Análise estrutural
carbamato
guanidina
diól
Mecanismos de Ação
Interação do grupo guanidina da STX com um grupo carboxil.
Ligação ao canal não competitiva.
guanidina
Canal de sódio dependente de voltagem
A STX liga-se ao Sítio 1 da subunidade alpha do canal de sódio.
Inibe a formação e a propagação do potencial de ação.
Biossíntese Molecular
Dose Letal
1- 4
5,7
μg/kg
g/kg
Dose letal mínima em ratos
Dose letal mediana (LD50)
0,6 μg/kg
Dose letal mediana (LD50) por injeção
10 μg/kg
Dose letal mediana (LD50) em ratos
TOxicidade
15%
taxa de mortalidade
Anualmente ocoreem 2000 casos de PSP
Efeitos terapêuticos/ Potencial droga
Os canais de sódio são inibidos, sem causar morte celular.
Potencial uso como anastésico local.
Elevado nível de toxicidade e margem pouco segura
Uso tópico limitado
Mecanismos de difusão paracelular, alterações transitórias na permeabilidade intestinal e variação do estado de ionização com o pH
Rápida absorção
“Regra dos Cinco” de Lipinski
Descartada como terapêutico oral
Sintomas
Alguns dos sintomas incluem...
Vómito induzido
Intubação
Respiração mecanica
Lavagem gástrica
Fatores ambientais
Temperatura
Luz
Nutrientes
Simbiose
Afeta expressão dos genes sxtA e sxtG.Baixas temperaturas aumentam a expressão.
Intensidade luminosa determina o crescimento e metabolismo das algas.
Stress de nitrogénio inibe o crescimento de A. minutum. Mas escassez de fósforo aumenta a produção de STX. NO3- influencia a expressão dos genes sxt.
O zooplancton D. gessneri estimula os genes sxt de R. raciborskii. J. cystaugens induz stress oxidativo, nutritivo e sinais de quorum sensing.
DIagnostico e Prevenção
Controlo da piscicultura
Análise laboratorial
Evitar o consumo
A única maneira de averiguar corretamente a presença do contaminante é com a análise laboratorial.
Para assegurar que a qualidade do alimento é necessário confirmar as suas origens.
38 mg/kg
STX no mexilhão
Caso de estudo
0,8 mg/kg
Limite legal europeu
200 g
mexilhão consumido
104 - 120 μg/kg
STX ingerida
100 μg/kg
Limiar de sintomas severos
Conclusão
Droga
Regulação das culturas e do consumo de marisco.
Prevenção
Saxitoxina
alvo
Sintomas
Produzida por dinoflagelados marinhos e cianobactérias
Uso seguro como anastésico tópico ocular.
Afeta o sistema nervoso e músculos, inibindo o potencial de ação por obstrução dos canais de sódio regulados por voltagem.
Desde formigueiro e dormência ligeira até paralisia muscular e insuficiência respiratória. Em casos descontrolados, potencialmente fatal.
veneno
A STX é perigosa e um problema para a segurança alimentar
Obrigada !
Here you can include a relevant data to highlight
Use an image
Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes to us through sight and, moreover, we retain 42% more information when the content moves.
Here you can include a relevant data to highlight
+ info
Wow Effect
'Your content is liked, but it only engages if it's interactive' - Genially
Did you know that Genially allows you to share your creation directly, without the need for downloads? Ready for your audience to visualize it on any device and give it exposure anywhere.
Here you can include a relevant data to highlight
'Including quotes always reinforces our presentation. Breaks the monotony.'
- Author's Name
Structureyour content
Sections like this will help you organize
Timeline
20XX
20XX
20XX
Surprise
Plan
Design
20XX
20XX
Structure
Communicate
20XX
Plan
Timeline
20XX
Structure
You can briefly describe what the timeline of your presentation consists of and orally present the milestones so that no one falls asleep.
20XX
Design
20XX
Communicate
+ info
20XX
Surprise
Charts are highly shareable, making them ideal for social media and, on top of that, they tend to generate quality traffic to the content we create.
60%
Chart + text
Use this space to briefly describe your chart and its evolution.
Graphic + text
The graphics are highly shareable, making them ideal for social media and, moreover: they tend to generate quality traffic to the content we create.
+ info
Table + text
Demonstrate enthusiasm, sketch a smile and maintain eye contact with your audience can be your best allies when it comes to telling stories that excite and awaken the interest of the public: 'The eyes, chico. They never lie'. This will help you make a 'match' with your audience. Leave them open-mouthed!
Table + text
Demonstrate enthusiasm, give a smile, and maintain eye contact with your audience can be your best allies when it comes to telling stories that excite and arouse the audience's interest: 'The eyes, man. They never lie'. This will help you make a 'match' with your audience. Leave them open-mouthed!
Insert a video
Multimedia content is essential in a presentation to leave everyone amazed. Additionally, you will synthesize the content and keep your audience entertained.
Text + icons
Although you should not abuse bulletpoints, icons and schemes can be great allies when telling stories.
Has a WOW effect. Very WOW.
Measures results and experiments
Generates experiences with your content
Is organized, hierarchical, and structured
Makes your audience remember the message
Activates and surprises your audience
Audio
Your content is engaging if it is interactive
This is a paragraph ready to contain creativity, experiences, and great stories.
It is essential to make the relevant checks. Not a single typo!
This is a paragraph ready to contain creativity, experiences, and great stories.
The tone is usually formal and the vocabulary technical, so keep that in mind when writing.
Embedded Content
Map
Social Media
Music
Interactive Question
Interactive Question
Interactive Question
Interactive Question
Conclusion
Disciplines like Visual Thinking facilitate visually rich note-taking thanks to the use of images, graphics, infographics, and simple drawings. Go for it!
Visual content is a cross-cutting language, universal, like music. We are able to understand images from millions of years ago, even from other cultures.
Did you know that Genially allows you to share your creation directly, without the need for downloads? Ready for your audience to view it on any device and give it exposure anywhere.
'Your content is liked, but it engages much more if it is interactive'-Genially
an awesome title here
With Genially's templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or data that remains engraved in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or data that will be etched in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
an awesome title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains engraved in fire in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience open-mouthed. Also, highlight some phrase or specific data that remains etched in your audience's memory and even embed surprising external content: videos, photos, audios... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes to us through sight and, moreover, we retain 42% more information when the content moves.
a great title here
With Genially's templates you can include visual resources to leave your audience speechless. Also highlight some phrase or specific data that remains etched in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes to us through sight and, in addition, we retain 42% more information when the content moves.
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains engraved in the memory of your audience, and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains etched in fire in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains etched in fire in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
an awesome title here
With Genially's templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or data that remains engraved in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains engraved in fire in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. Also, highlight a specific phrase or data that remains engraved in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially templates, you can include visual resources to leave your audience speechless. You can also highlight a specific phrase or specific data that will be engraved in the memory of your audience and even embed external content that surprises: videos, photos, audios... Whatever you want! Need more reasons to create dynamic content? Well: 90% of the information we assimilate comes to us through sight and, in addition, we retain 42% more information when the content moves.
an awesome title here
With Genially's templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or data that will be etched in the memory of your audience, and even embed external content that surprises: videos, photos, audios... Whatever you want!
a great title here
With Genially's templates, you can include visual resources to leave your audience amazed. You can also highlight a specific phrase or data that will remain engraved in the memory of your audience, and even embed external content that surprises: videos, photos, audios... Whatever you want!