belajar metabolit primer dan metabolit sekunder.pptx

ppt mempelajari perbedaan metabolit primer dan metabollit sekunder

1. Perbedaan Metabolit Primer dan Sekunder There are approximately more than 200,000 chemicals isolated and identified with diverse structures and classes from higher plants around the planet. Such chemicals are divided into two main groups: primary and secondary metabolites ( Chikezie et al ., 2015). The primary metabolites are essential to cell maintenance, such as fatty acids, proteins, carbohydrates, and nucleic acids. The secondary metabolites are no less important, despite not participating directly in photosynthetic or respiratory metabolism, they are known to be essential to plant survival ( Chikezie et al., 2015). Their structures and chemicals are diverse when compared to primary metabolites and they are responsible for plant defense ( Chikezie et al., 2015).

2. Pengelompokan metabolit sekunder they are divided into three major groups: (1) flavonoids, allied phenolic, and polyphenolic compounds; (2) terpenoids, and (3) nitrogen-containing alkaloids and sulfur-containing compounds. Such compounds are linked to primary metabolites by building blocks and biosynthetic enzymes (Vora, 2017)

3. The most important phenolic compound classes found in the human diet are phenolic acids, flavonoids, and tannins. Chemically, phenolic acids have at least one aromatic ring where at least one hydrogen is substituted by a hydroxyl group

4. Flavonoids constitute the largest group of phenolic compounds. They comprise more than 6000 compounds within more than 8000 phenolic compounds found in plant food. They are low molecular weight, characterized by a 15-carbon skeleton, arranged as C6–C3–C6, with different substitutions, unsaturation degree, and arrangement of the basic skeleton, resulting in different subclasses ( Lafay and Gil-Izquierdo, 2008). flavonoid molecules are from the acetate/malonate pathway, in which ring A is derivated and the shikimate pathway in which ring B is derived from phenylalanine ( Birt and Jeffery, 2013). In addition, C rings are mainly responsible for the varieties of flavonoid classes; variations in their substitution patterns provide the major flavonoid classes, such as flavonols , flavones, flavanones, flavanols (cat- echins ), isoflavones, flavanonols, and anthocyanidins. Variations

5. A large part of flavonoids have a yellow to red color, this is because of conjugated chromophores present in the molecules, which are responsible for the color range of flowers, seeds, and fruits ( Erlund , 2004). An example is the anthocyanidins, such as Cyanidin, which demon- strates colors from red to magenta (Navarre et al., 2013)

6. tannin Tannins, commonly referred to as tannic acid, have value in interactions between plants and their ecosystems, as an example, they can act against herbivores or have a exert role as antimicrobial agents. They are water-soluble and their molecular weight is from 500 to 3000 Da, furthermore, they can make an insoluble complex with water and proteins, gelatin, and alkaloids. These compounds contain a large number of hydroxyl or other functional groups and therefore are found in the form of esters or heterosis (Ferrer et al., 2008). Tannins are easily oxidized by metals, ferric chloride, or even specific vegetable enzymes, leading to darkening of solutions (Chung et al., 1998).

7. They can be classified chemically into two groups: hydrolyzable and nonhydrolyzable or condensed tannins. Hydrolyzable tannins are formed from shikimate producing gallic acid esters ( gallotannins ), partially or wholly esterified by gallic acid and glycosylated ellagic acid (ellagitannins). After hydrolysis by certain enzymes, acids, bases, and gallic acid esters yield glucose and gallic acids. The ellagitannins undergo lactonization to produce ellagic acid (Ferrer et al., 2008; Ozawa et al., 1987).

8. Condensed tannins are structurally more complex and uniform than hydrolyzable tannins. They are oligomers and polymers of flavan-3-old flavan and/or flavan-3,4-diols, the structure of condensed tannins in food plants differs in stereochemistry, type of flavan linkages intra- molecularly, the degree of polymerization, and hydroxylation (De Bruyne et al., 1999). Procyanidins and prodelphinidins are the most characterized tannins, both are linked via flavan-3-ol monomers (C4–C8), but differ in the flavonoid B-ring by the degree of hydroxyl- ation . The degree of polymerization can vary from dimers to polymers by up to 30 or more subunits. Condensed tannins are widely distributed in food plants such as fruits, vegetables, red wine, cocoa, and some grains (sorghum and finger millets) and legumes (Tsao, 2010)