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Woldemar Lukin
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Phycotoxins Chemistry and Biochemistry: A PDF Download that Covers the Basics and Beyond



Phycotoxins Chemistry and Biochemistry PDF Download




Phycotoxins are a diverse group of natural toxins produced by certain seaweeds and algae in marine and freshwater environments. They can cause serious health problems in humans and animals that consume or come into contact with contaminated seafood, drinking water, or recreational water. Phycotoxins can also have ecological and economic impacts on fisheries, aquaculture, tourism, and public health. Therefore, it is important to understand the chemistry and biochemistry of phycotoxins, as well as their sources, effects, and detection methods.




Phycotoxins Chemistry And Biochemistry Pdf Download


DOWNLOAD: https://www.google.com/url?q=https%3A%2F%2Furlcod.com%2F2ucRy2&sa=D&sntz=1&usg=AOvVaw0jPrchM9FRMLitBW7Q6DUE



In this article, we will provide an overview of the main aspects of phycotoxins, such as their definition, classification, origin, toxicology, and analytical methodology. We will also discuss how to prevent and treat phycotoxin exposure in humans and animals. Finally, we will offer you a chance to download a PDF version of the book "Phycotoxins: Chemistry and Biochemistry", which is a comprehensive and updated reference on this topic.


What are phycotoxins?




Phycotoxins are organic compounds that are synthesized by certain seaweeds and algae, which are collectively known as phytoplankton. Phytoplankton are microscopic organisms that live in the water column and use sunlight and nutrients to produce organic matter through photosynthesis. Phytoplankton are essential for the marine and freshwater ecosystems, as they are the primary producers of organic carbon and oxygen, and the base of the food web.


However, some phytoplankton species can produce toxins that have adverse effects on other organisms, including humans and animals. These toxins are called phycotoxins, which means "plant toxins". Phycotoxins are usually secondary metabolites, which means that they are not directly involved in the growth and reproduction of the phytoplankton, but rather serve other functions, such as defense against predators, competition with other species, or communication with other cells.


Phycotoxins can be classified into different groups based on their chemical structures and biological activities. Some of the main groups of phycotoxins are:


Marine phycotoxins




Marine phycotoxins are produced by seaweeds and algae that live in saltwater environments. They can accumulate in shellfish, fish, or other marine animals that feed on the phytoplankton, and cause various types of seafood poisoning in humans and animals that consume them. Some of the most important marine phycotoxins are:



  • Ciguatoxins: These are polyether compounds that act on sodium channels in nerve cells, and cause ciguatera poisoning, which is characterized by gastrointestinal, neurological, and cardiovascular symptoms. Ciguatoxins are produced by dinoflagellates of the genus Gambierdiscus, which grow on macroalgae or coral reefs in tropical and subtropical regions.



  • Saxitoxins: These are purine derivatives that block sodium channels in nerve cells, and cause paralytic shellfish poisoning (PSP), which is characterized by tingling, numbness, weakness, paralysis, and respiratory failure. Saxitoxins are produced by dinoflagellates of the genera Alexandrium, Gymnodinium, and Pyrodinium, which form harmful algal blooms (HABs) in temperate and tropical regions.



  • Brevetoxins: These are polyether compounds that activate sodium channels in nerve cells, and cause neurotoxic shellfish poisoning (NSP), which is characterized by gastrointestinal, neurological, and respiratory symptoms. Brevetoxins are produced by dinoflagellates of the genus Karenia, which form HABs in subtropical and tropical regions.



Domoic acid: This is a kainic acid analogue that acts on glutamate receptors in nerve cells, and causes amnesic shellfish poisoning (ASP), which is characterized by gastrointestinal, neurological, and memory impairment symptoms. Domoic acid is produced by diatoms of the genera Pseudo-nitzschia


  • and Nitzschia, which form HABs in temperate and subpolar regions.



  • Okadaic acid and dinophysistoxins: These are polyether compounds that inhibit protein phosphatases in cells, and cause diarrhetic shellfish poisoning (DSP), which is characterized by gastrointestinal symptoms. Okadaic acid and dinophysistoxins are produced by dinoflagellates of the genera Dinophysis and Prorocentrum, which grow on macroalgae or shellfish in temperate and tropical regions.



  • Yessotoxins: These are polyether compounds that have unknown mechanisms of action and cause yessotoxin poisoning, which is characterized by gastrointestinal symptoms. Yessotoxins are produced by dinoflagellates of the genera Protoceratium, Lingulodinium, and Gonyaulax, which grow on macroalgae or shellfish in temperate and subpolar regions.



  • Pectenotoxins: These are polyether compounds that bind to actin filaments and alter cellular cytoskeleton, and cause pectenotoxin poisoning, which is characterized by gastrointestinal symptoms. Pectenotoxins are produced by dinoflagellates of the genus Dinophysis, which grow on macroalgae or shellfish in temperate and subpolar regions.



  • Azaspiracids: These are polyether compounds that have unknown mechanisms of action and cause azaspiracid poisoning, which is characterized by gastrointestinal symptoms. Azaspiracids are produced by dinoflagellates of the genus Azadinium, which grow on macroalgae or shellfish in temperate and subpolar regions.



  • Palytoxins and ostreocins: These are polyhydroxylated compounds that act on sodium-potassium pumps in cell membranes, and cause palytoxin poisoning, which is characterized by gastrointestinal, neurological, respiratory, and dermatological symptoms. Palytoxins and ostreocins are produced by dinoflagellates of the genus Ostreopsis, which grow on macroalgae or coral reefs in tropical and subtropical regions.



  • Gambierols: These are polyether compounds that act on voltage-gated calcium channels in nerve cells, and cause gambierol poisoning, which is characterized by neurological symptoms. Gambierols are produced by dinoflagellates of the genus Gambierdiscus, which grow on macroalgae or coral reefs in tropical and subtropical regions.



Freshwater phycotoxins




Freshwater phycotoxins are produced by algae that live in freshwater environments. They can contaminate drinking water sources, irrigation water, recreational water, or aquatic animals that feed on the algae, and cause various health problems in humans and animals that consume or come into contact with them. Some of the most important freshwater phycotoxins are:



  • Cyanobacterial toxins: These are a diverse group of toxins produced by cyanobacteria (also known as blue-green algae), which are photosynthetic bacteria that form HABs in freshwater environments. Cyanobacterial toxins can be classified into hepatotoxins, neurotoxins, cytotoxins, dermatotoxins, and irritants, depending on their effects on different organs and systems.



  • Microcystins and nodularins: These are cyclic peptides that inhibit protein phosphatases in cells, and cause hepatotoxicity and tumor promotion. Microcystins and nodularins are produced by cyanobacteria of the genera Microcystis, Planktothrix, Nostoc, Anabaena, and Nodularia, which form HABs in freshwater environments.



  • Anatoxins: These are alkaloids that act on nicotinic acetylcholine receptors in nerve cells, and cause neurotoxicity and paralysis. Anatoxins are produced by cyanobacteria of the genera Anabaena, Aphanizomenon, Oscillatoria, and Cylindrospermum, which form HABs in freshwater environments.



  • Cylindrospermopsins: These are alkaloids that inhibit protein synthesis in cells, and cause hepatotoxicity, nephrotoxicity, genotoxicity, and cytotoxicity. Cylindrospermopsins are produced by cyanobacteria of the genera Cylindrospermopsis, Aphanizomenon, Umezakia, and Raphidiopsis, which form HABs in freshwater environments.



  • Lyngbyatoxins: These are polyketides that act on protein kinase C in cells, and cause dermatotoxicity and inflammation. Lyngbyatoxins are produced by cyanobacteria of the genus Lyngbya, which grow on aquatic plants or sediments in freshwater environments.



How do phycotoxins affect humans and animals?




Phycotoxins can have various toxicological effects on humans and animals, depending on the type, dose, route, and duration of exposure, as well as the susceptibility of the individual. Phycotoxins can affect different organs and systems, such as the nervous system, the gastrointestinal system, the liver, the kidneys, the skin, and the immune system. Some of the most common effects of phycotoxins are:


Neurotoxic phycotoxins




Neurotoxic phycotoxins are phycotoxins that interfere with the normal functioning of the nervous system, by altering the transmission of nerve impulses or the activity of neurotransmitters. Neurotoxic phycotoxins can cause various neurological symptoms, such as tingling, numbness, burning, itching, pain, weakness, paralysis, dizziness, vertigo, nausea, vomiting, headache, confusion, memory loss, hallucinations, seizures, coma, and death. Some of the most important neurotoxic phycotoxins are:



  • Ciguatoxins: These are marine phycotoxins that activate sodium channels in nerve cells, and cause ciguatera poisoning, which is characterized by gastrointestinal, neurological, and cardiovascular symptoms. Ciguatera poisoning is one of the most common seafood poisonings in the world, and affects millions of people every year. Ciguatera poisoning can occur after consuming fish or shellfish that have accumulated ciguatoxins from dinoflagellates of the genus Gambierdiscus, which grow on macroalgae or coral reefs in tropical and subtropical regions. Ciguatera poisoning can cause acute symptoms such as nausea, vomiting, diarrhea, abdominal pain, sweating, hypotension, bradycardia, and arrhythmias, as well as chronic symptoms such as paresthesia, dysesthesia, pruritus, arthralgia, myalgia, fatigue, depression, and anxiety. Ciguatera poisoning can also cause temperature reversal sensation, which is a peculiar symptom where cold objects feel hot and hot objects feel cold.



  • Saxitoxins: These are marine phycotoxins that block sodium channels in nerve cells, and cause paralytic shellfish poisoning (PSP), which is characterized by tingling, numbness, weakness, paralysis, and respiratory failure. PSP is one of the most severe seafood poisonings in the world, and can be fatal within hours if not treated promptly. PSP can occur after consuming shellfish or fish that have accumulated saxitoxins from dinoflagellates of the genera Alexandrium, Gymnodinium, and Pyrodinium, which form harmful algal blooms (HABs) in temperate and tropical regions. PSP can cause acute symptoms such as paresthesia, dysphagia, dysarthria, diplopia, ataxia, muscle weakness, respiratory distress, and hypotension, as well as chronic symptoms such as memory impairment, cognitive dysfunction, and neuropathy.



  • Brevetoxins: These are marine phycotoxins that activate sodium channels in nerve cells, and cause neurotoxic shellfish poisoning (NSP), which is characterized by gastrointestinal, neurological, and respiratory symptoms. NSP is a mild to moderate seafood poisoning that affects thousands of people every year. NSP can occur after consuming shellfish or fish that have accumulated brevetoxins from dinoflagellates of the genus Karenia, which form HABs in subtropical and tropical regions. NSP can also occur after inhaling aerosolized brevetoxins from sea spray or red tide events. NSP can cause acute symptoms such as nausea, vomiting, diarrhea, abdominal pain, paresthesia, dizziness, vertigo, ataxia, my algia, bronchospasm, and rhinorrhea, as well as chronic symptoms such as asthma, chronic obstructive pulmonary disease, and hypersensitivity pneumonitis.



Domoic acid: This is a marine phycotoxin that acts on glutamate receptors in nerve cells, and causes amnesic shellfish poisoning (ASP), which is characterized by gastrointestinal, neurological, and memory impairment symptoms. ASP is a rare but serious seafood poisoning that can cause permanent brain damage or death. ASP can occur after consuming shellfish or fish that have accumulated domoic acid from diatoms of the genera Pseudo-nitzschia


  • and Nitzschia, which form HABs in temperate and subpolar regions. ASP can cause acute symptoms such as nausea, vomiting, diarrhea, abdominal pain, dizziness, headache, confusion, disorientation, memory loss, seizures, coma, and death, as well as chronic symptoms such as anterograde amnesia, cognitive impairment, and dementia.



  • Palytoxins and ostreocins: These are marine phycotoxins that act on sodium-potassium pumps in cell membranes, and cause palytoxin poisoning, which is characterized by gastrointestinal, neurological, respiratory, and dermatological symptoms. Palytoxin poisoning is a rare but severe seafood poisoning that can be fatal within minutes if not treated promptly. Palytoxin poisoning can occur after consuming fish or shellfish that have accumulated palytoxins or ostreocins from dinoflagellates of the genus Ostreopsis, which grow on macroalgae or coral reefs in tropical and subtropical regions. Palytoxin poisoning can also occur after handling or inhaling aerosolized palytoxins or ostreocins from marine organisms or aquariums. Palytoxin poisoning can cause acute symptoms such as nausea, vomiting, diarrhea, abdominal pain, paresthesia, dyspnea, coughing, wheezing, chest pain, hypotension, tachycardia, cardiac arrhythmias, cardiac arrest, muscle spasms, paralysis, and death.



Hepatotoxic phycotoxins




Hepatotoxic phycotoxins are phycotoxins that interfere with the normal functioning of the liver, by damaging the liver cells or disrupting the liver metabolism. Hepatotoxic phycotoxins can cause various liver problems, such as inflammation, necrosis, fibrosis, cirrhosis, cancer, and liver failure. Some of the most important hepatotoxic phycotoxins are:



  • Microcystins and nodularins: These are freshwater phycotoxins that inhibit protein phosphatases in cells, and cause hepatotoxicity and tumor promotion. Microcystin and nodularin poisoning is one of the most common freshwater poisonings in the world, and affects millions of people every year. Microcystin and nodularin poisoning can occur after consuming drinking water, irrigation water, recreational water, or aquatic animals that have been contaminated by cyanobacteria of the genera Microcystis, Planktothrix, Nostoc, Anabaena, and Nodularia, which form HABs in freshwater environments. Microcystin and nodularin poisoning can cause acute symptoms such as nausea, vomiting, diarrhea, abdominal pain, jaundice, hepatomegaly, elevated liver enzymes, and liver necrosis, as well as chronic symptoms such as liver fibrosis, cirrhosis, cancer, and liver failure.



  • Cylindrospermopsins: These are freshwater phycotoxins that inhibit protein synthesis in cells, and cause hepatotoxicity, nephrotoxicity, genotoxicity, and cytotoxicity. Cylindrospermopsin poisoning is a rare but emerging freshwater poisoning that can cause serious health problems in humans and animals. Cylindrospermopsin poisoning can occur after consuming drinking water, irrigation water, recreational water, or aquatic animals that have been contaminated by cyanobacteria of the genera Cylindrospermopsis, Aphanizomenon, Umezakia, and Raphidiopsis, which form HABs in freshwater environments. Cylindrospermopsin poisoning can cause acute symptoms such as nausea, vomiting, diarrhea, abdominal pain, jaundice, hepatomegaly, elevated liver enzymes, and liver damage, as well as chronic symptoms such as kidney damage, DNA damage, and cancer.



Dermatotoxic phycotoxins




Dermatotoxic phycotoxins are phycotoxins that interfere with the normal functioning of the skin, by causing irritation, inflammation, or necrosis of the skin cells or tissues. Dermatotoxic phycotoxins can cause various skin problems, such as rash, itching, burning, pain, swelling, blistering, ulceration, and infection. Some of the most important dermatotoxic phycotoxins are:



  • Lyngbyatoxins: These are freshwater phycotoxins that act on protein kinase C in cells, and cause dermatotoxicity and inflammation. Lyngbyatoxin poisoning is a common freshwater poisoning that affects thousands of people every year. Lyngbyatoxin poisoning can occur after coming into contact with water or aquatic plants that have been contaminated by cyanobacteria of the genus Lyngbya, which grow on aquatic plants or sediments in freshwater environments. Lyngbyatoxin poisoning can cause acute symptoms such as rash, itching, burning, pain, swelling, blistering, ulceration, and infection, as well as chronic symptoms such as hyperpigmentation, hypersensitivity, and scarring.



  • Palytoxins and ostreocins: These are marine phycotoxins that act on sodium-potassium pumps in cell membranes, and cause dermatotoxicity and inflammation. Palytoxin and ostreocin poisoning is a rare but severe marine poisoning that can be fatal within minutes if not treated promptly. Palytoxin and ostreocin poisoning can occur after handling or inhaling aerosolized palytoxins or ostreocins from marine organisms or aquariums. Palytoxin and ostreocin poisoning can cause acute symptoms such as rash, itching, burning, pain, swelling, blistering, ulceration, and infection.



Other effects of phycotoxins




Besides the effects mentioned above, some phycotoxins can have other effects on humans and animals, such as tumor promotion, immunosuppression, genotoxicity, and allergenicity. For example:



  • Okadaic acid and related compounds: These are marine phycotoxins that inhibit protein phosphatases in cells, and cause diarrhetic shellfish poisoning (DSP), which is characterized by gastrointestinal symptoms. Okadaic acid and related compounds can also act as tumor promoters by stimulating cell proliferation and inhibiting apoptosis. Okadaic acid and related compounds can also induce immunosuppression by affecting cytokine production and lymphocyte activation.



  • Anatoxins: These are freshwater phycotoxins that act on nicotinic acetylcholine receptors in nerve cells, and cause neurotoxicity and paralysis. Anatoxins can also induce genotoxicity by causing DNA damage and mutations.



  • Brevetoxins: These are marine phycotoxins that activate sodium channels in nerve cells, and cause neurotoxic shellfish poisoning (NSP), which is characterized by gastrointestinal, neurological, and respiratory symptoms. Brevetoxins can also induce allergenicity by causing IgE-mediated hypersensitivity reactions.



How are phycotoxins detected and measured?




Phycotoxins can be detected and measured in biological and environmental samples using various analytical methods. These methods can be classified into chemical and biochemical methods or biological methods, depending on the principle of detection. Some of the most common analytical methods for phycotoxins are:


Chemical and biochemical methods




Chemical and biochemical methods are based on the separation, identification, and quantification of phycotoxins using physical or chemical properties or reactions. Chemical and biochemical


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