To study the polyphenols from

Dendrobium loddigesii

and their biological activities

the 80% acetone extract from

D. loddigesii

was isolated and purified by chromatography techniques; the structures of obtained compounds were identified with spectroscopic techniques; the antioxidative

α-glucosidase inhibitory and antiinflammatory activities of compounds were evaluated. Fifteen compounds were isolated and identified as chrysotoxol A (

1

)

neoechinulin A (

2

)

3

6

9trihydroxy-3

4-dihydroanthracen-1(2H)-one (

3

)

4

4′=dihydroxyl-3

5-dimethoxylbibenzyl (

4

)

naringenin (

5

)

5

4′-dihydroxy-7

3′

5′-trimethoxyflavanone  (

6

)

5

7

4′-trihydroxy-3′

5′-dimethoxyflavanone (

7

)

batatasin-III (

8

)

3

3′

5-trihydroxybibenzyl (

9

)

trigonopol B (

10

)

syringaresinol (

11

)

2

4

7-trihydroxyl-9

10dihydrophenanthrene (

12

)

loddigesiinol B (

13

)

loddigesiinol I (

14

)

loddigesiinol J (

15

)

respectively. Compounds

1-11

among them were isolated from

D. loddigesii

for the first time. The biological activities of compounds

1-4

6

7

and

12

were evaluated for the first time under trial conditions. It was reported for the first time that compounds

1

3

and

12

had a strong antioxidant activity

compounds

1

and

9

showed a strong α-glucosidase inhibitory activity

and compounds

1

12

14

and 15 had a strong anti-inflammatory activity.