science

Vicine

Vicine is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Vicine rather than just read about it. In short: Vicine is an alkaloid glycoside found mainly in fava beans, which are also called broad beans (Vicia faba). Vicine is toxic in individuals who have a hereditary loss of the enzyme glucose-6-phosphate dehydrogenase.

Key takeaways

Vicine belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Vicine to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Vicine from memory before moving on to harder problems.

Reference excerpt

Vicine is an alkaloid glycoside found mainly in fava beans, which are also called broad beans (Vicia faba). Vicine is toxic in individuals who have a hereditary loss of the enzyme glucose-6-phosphate dehydrogenase. It causes haemolytic anaemia, called favism. The formation of vicine in Vicia faba has been studied, but this natural formation has not yet been found.

History Vicine was initially isolated in 1870 from the seeds of Vicia sativa by a method of extraction with sulfuric acid and subsequent precipitation with mercury sulfate (HgSO4). Later vicine was also found in other Vicia species, namely Vicia faba, beet juice and peas. The chemical structure of the compound was built gradually. First the glycosidic nature of the compound was recognized in 1896. The same year the aglycone of vicine, divicine, was isolated. In the beginning of the 20th century the pyrimidine structure was recognized. Despite these initial successes, the correct formula of vicine was determined only in 1953 and it is 2,4-diamino-6-oxypyrimidine-5-(β-D-glucopyranoside).

Metabolism Vicine is an inactive compound in the body. When vicine enters the body through food, it is hydrolysed by intestinal microflora to the highly reactive free radical generating aglycone divicine. Upon hydrolysis, the glucose part of the molecule is split off and that results in the reduced divicine. Divicine is then taken up in the blood through the intestinal epithelium.

Adverse effects Adverse effects almost solely occur in humans that suffer from glucose-6-phosphate dehydrogenase deficiency. This deficiency causes a shortage of glutathione in erythrocytes and glutathione is needed for the neutralization of ROS (reactive oxygen species) created by the strongly oxidizing agent divicine. Glucose-6-phosphate dehydrogenase deficiency is a common genetic condition, with a global prevalence of approximately 4.9%, affecting over 400 million individuals worldwide. It is important to recognize that glucose-6-phosphate dehydrogenase deficiency can still be life-threatening if not promptly diagnosed and managed. Effective management often includes interventions as blood transfusions, but with appropriate care, full recovery from favism without lasting complications is the expected outcome.

Indications Persons with G6PD deficiency are asymptomatic. An attack of acute haemolytic anaemia can appear out of nowhere and can be very severe and life-threatening. Indications of such a sudden attack of favism are dark urine, pallor, jaundice, abdominal pain and in most cases fever.

Toxicity The β-glycosidic bond between glucose and the hydroxyl group at C5 on the pyrimidine ring are hydrolysed to yield the aglycone of vicine, divicine (2,6-diamino-4,5-dihydroxypyrimidine). These aglycones have a strong oxidising capacity for glutathione. In healthy individuals, this is not a problem, as glutathione can be reduced quickly enough to regenerate it. In individuals with a deficiency for glucose 6-phosphate dehydrogenase (G6PD) however, this results in haemolytic anaemia.

Effects on animals A 10 g vicine /kg diet in laying hens led to reduced feed intake, egg weight, haemoglobin levels and fertility and increased liver weights, liver glutathione levels and plasma lipid levels. A diet with comparable levels of vicine per kg in pigs showed only small effects on protein and energy digestibility. In another study, laying and broiler hens were fed grains that were soaked for different periods of time, which partly or totally removed vicine. Hens that had had grains with vicine still in them showed a significant decrease in corpuscular haemoglobin, while the others did not. An in vivo study in rats showed that oral administration of vicine resulted in only small reductions in glutathione concentrations and no mortality. Intraperitoneal administration however, led to a rapid decrease in glutathione followed by death because of anoxia.

References

External links Media related to Vicine at Wikimedia Commons Cornell University page on vicine

Illustrations

Worked examples

Example 1 — a first encounter with Vicine

Start with the simplest possible case. Write down what Vicine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Vicine before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Vicine ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Vicine

In research: Vicine appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Vicine in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Vicine is common in secondary-school and first-year university syllabi. It links to neighbouring topics Alkaloid glycosides, Alkaloids found in Fabaceae, Plant toxins, so understanding it makes those chapters shorter.
In everyday life: Look for Vicine outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Vicine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Vicine means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Vicine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Vicine in simple terms?

Why does Vicine matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Vicine?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Vicine.