Anthocyanins or anthocyan pigments

The innumerable shades of violet, mauve, blue and red which colour the flowers, fruits, stems and often the leaves of plants are generally due to a class of sap-soluble glycosides. The sugar-free aglucones are phenolic derivatives of 2-phenyl-3:5:7 - trihydroxybenzopyrylium salts. All the anthocyanidins may be referred to one of three main types according to the number of hydroxyls attached to the phenyl group. In cyanidin there are two, in pelargonidin there is one, in delphinidin there are three. Various methyl derivatives of these types occur. The anthocyanins are amphoteric substances forming red oxonium salts with acids and blue phenolic salts with alkalis. Cyanin occurs in red rose petals, and as a potassium salt in the blue cornflower. The colour of cyanin depends on the pH of the solutions; solutions are red at pH 3.0, violet at pH 8.5. and blue at pH 11.0. These colour changes and the solubility in aqueous and alcoholic acid or alkali readily serve for the detection of anthocyanins.

PYRONES. In addition to the flavones and other - pyrone derivatives also occur in plants. Aesculetin occurs as a glucoside, aesculin in the bark of the horse chestnut. Its methyl ether, scopoletin, occurs in the roots of belladonna, scammony and ipomoea. Scopoletin is a crystalline substance, sparingly soluble in water but more soluble in not alcohol and organic solvents. With ferric chloride it gives a green colour, A solution of scopoletin in chloroform when shaken, with dilute ammonia imparts a greyish blue fluorescence to the ammoniacal layer. Ammoniacal umbelliferone also shows a distinct blue fluorescence.

Вправа 8. Дайте відповіді на запитання до тексту.

1. How are red oxonium salt and blue phenolic salts formed?

2. Where does cyanin occur?

3. What serves for the detection of anthocyanins?

4. What occurs in the roots of belladonna, scammony and ipomoea?

5. When does scopoletin give a green colour?

Вправа 9. Перекладіть на англійську мову.

1. При струшуванні в хлороформі розчин скополетина дає сіро-

блакитне забарвлення.

2. Розчинність у водній і спиртній кислоті або лугу може

використовуватися для виявлення актоцианів.

3. Цианін зустрічається в пелюстках червоної троянди.

Вправа 10. Утворити дієслова з протилежною дією за допомогою префіксів та перекладіть їх.

à) de- : freeze, ice, foliate, fame;

á) dis- : acidify, interested, place, order.

Варіант 9

Вправа 1. Визначте видо-часову форму і стан дієслова-присудка, дайте його початкову форму. Перекладіть речення.

1. The temperature above 60 - 80° C has produced a marked change.

2. The reverse process took place after the aminoacid molecules linked

together in chains.

3. The change in density they have observed after the completion of the test

will be recorded.

4. Methods of weed control are determined by the specific weed species.

5. The most interesting changes were taking place when we raised the

temperature above 60° C.

Вправа 2. Перекладіть наступні речення, звертаючи увагу на зворот there + to be.

1. There is a number of requirement for photosynthesis to occur.

2. There are usually six to twelve flowers in an inflorescence.

3. There is an effective means of controlling plant diseases at present.

Вправа 3. Перекладіть речення на українську мову, звертаючи увагу на переклад Participle I та Participle II.

1. Proteins are highly complex compounds produced by living cells.

2. The anthocyanins are amphoteric substances forming red oxonium salts

with acids.

3. Plant nutrients absorbed by the roots are transferred to the other parts of

the growing plant.

Вправа 4. Замініть українські слова англійськими, використовуючи Participle I чи Participle II. Перекладіть словосполучення.

place (захищений) from light

(видаляючи) the external layer of the fruit

(висушені) parto of the herbaceous planto

blood (що йде) from the lungs is rich in oxygen

a (змарніле) face

Вправа 5. Вставити складні прийменники та перекласти речення.

according to, by means of, due to

1. Slowing of the cardiac rate occurs only when the rate was originally rapid ... the failure.

2. ... their clinical course all cases of hypotonia can be divided into three types.

3. Ginseng glycosides are obtained ... precipitation with ether from the hot

alcoholic extracts of the root.

Вправа 6. Підкреcліть модальне дієслово або його еквівалент, перекладіть речення.

1. You have to place 15 ml of the solution in a cylinder.

2. One must dissolve 0.3 g of the preparation in 5 ml of alcohol and add

25 ml of water.

3. You should boil 0.5 mg of the preparation in 5 ml of sodium hydroxide

solution for 3 min.

4. Despite all measures taken by the doctor, he could not induce

respiration in the infant with severe asphyxia.

5. More time may be needed for completing the reaction.

Вправа 7. Перекладить текст.