Đánh giá hàm lượng phlorotannin với hoạt tính chống oxy hóa của rong nâu sargassum thu ở vịnh Nha Trang, Việt Nam

Đặng Xuân Cường và Đtg Tạp chí KHOA HỌC & CÔNG NGHỆ 111(11): 137 - 141

137

EVALUATION OF PHLOROTANNIN CONTENT WITH ANTIOXIDANT

ACTIVITIES OF BROWN ALGAE SARGASSUM COLLECTED IN

NHA TRANG BAY, VIET NAM

Dang Xuan Cuong1*, Tran Thi Thanh Van1

Vu Ngoc Boi2

, Le Nhu Hau1

1Nha Trang Institute of Technology Application and Researching, VAST

2Nha Trang University

SUMMARY

Brown algae Sargassum has many bioactive subtances such as: phlorotannin, fucoidan, alginate,

laminaran,…. Bioactive subtances have bioactives such as: antioxidant, antibacterial, antifungal,

anticancer, anti HIV, radioprotective effect, antiallergic effect,…. Phlorotannin content with reducing

power and total antioxidant activity of 16 brown algae species Sargassum collected in Nha Trang bay,

Viet Nam were researched. These species were collected in the growth time. The result showed

phlorotannin/ polyphenol content was the highest in brown algae Sargassum swartzii. Reducing power

and total antioxidant activity were the highest in S. crassifolium species. Phlorotannin content and

antioxidant activities were the lowest in S. baccularia species. Reducing power activity was the stronger

than total antioxidant activity in 16 the researched brown algae species.

Key words: antioxidant, brown algae, Nha Trang, phlorotannin, Sargassum, reducing power

INTRODUCTION*

Brown algae was natural resources with

abundance and diversification of bioactive

such as antioxidant, antibacterial, antifungal,

anticoagulant and antiradiation UV-B, wound

healing and cell structure regeneration [8].

Many recent research showed that antioxidant

activity from brown algae was one of

bioactives which was focused in the most

research on the world and this activity was

studied by [2]; [8]. It is interesting that most

of the studies on the antioxidant activity were

indicated a close relationship between

contents, structure and antioxidant

mechanisms of polyphenols / phlorotannin in

the brown seaweed.

The before research showed phlorotannins

were phenolic compounds with polymer

nature of phloroglucinol, identified in many

families of brown algae phylum, such as:

Alariaceae, Fucaceae and Sargassaceae.

Many research showed phenolic compounds

in brown algae was phlorotannin [8]; [18].

Strong antioxidant activity of purification

phlorotannin from some brown algae species

*

Email: [email protected]

had close relationship with skeleton molecule

[2]. Simultaneous, high antioxidant

polyphenols had close relationship with

phenol ring and through electronic trap on

phenol ring to scavenge OH-

, ROO-

, O2

-

.

Phlorotannins in brown algae had 8 phenol

ring linked to each other. So, their free radical

scavenging activity was higher than

polyphenol of terrestrial plant, such as

catechins in green tea with 4 phenol ring [5].

Molecular size spectrum of phlorotannin was

very wide, from (400 - 400.000 Da) and

phlorotannins content in each seaweed

species was also different (0.5 - 20% dry

matter) [8].

Move over, free radical was a molecule that

lack of a electron, so that their electrolysis

was usually not equal, they trended to take

electrolysis from other molecule and took

form new free radicals, this thing caused

function disturbance of cell [1]. Free radical

effect on human health popular follow 3

pathway: adaptive with antioxidant system,

cause injury to life cell and kill living cell in

human that showed [3]. Inside, mechanism of

living cell killing could make necrosis or

living cell death in a synmatic way. Radicals