HPLC-MS Analysis of Phenols in Longan (Dimocarpus longan Lour ：在龙眼酚的高效液相色谱-质谱分析（龙眼.ppt

HPLC-MS Analysis of Phenols in Longan (Dimocarpus longan Lour.) Peel
Somkit Jaitrong1, John A. Manthey2,
Nithiya Rattanapanone1 and Elizabeth A. Baldwin2
1Chiang Mai University, Chiang Mai, Thailand
2USDA/ARS Citrus and Subtropical Products Laboratory, Winter Haven, FL
Biology of Longan Fruit
Family: Sapindaceae
Scientific names:
Euphoria longana Lam.
Euphoria longan Strend.
Nephilium longana Camb.
Dimocarpus longan Lour. (Batten, 1986; Choo and Ketsa 1991)
Somatic chromosomes: 2n = 20 (IBPGR, 1986).
Fruit Characteristics
Non-climacteric fruit
Harvesting time:
when skin become yellowish brown
and their flesh reaches optimal
eating quality
Reverse relationship between total phenolic content
and specific activity of PPO
Total phenolic content (mg GAE/g FW)
Specific activity of PPO (unit/mg protein)
0
5000
10000
15000
20000
25000
30000
0
6
8
11
14
Days after storage
Specific activity of PPO
(unit/mg protein)
0
6
8
11
14
Days after storage
Objectives
To evaluate the main classes of phenols in longan peel.
To evaluate the changes in phenolic compounds that occur during the chilling injury response.
Freeze-dried longan peel
Peel extracted solution
Fractionation of the phenols by size-exclusion P2 (Biogel) chromatography
Ellagic acid
80% aqueous methanol
Unknowns
Flavonoids 1 (early eluting)
Flavonoids 2 (later eluting)
Flow chart of Fractionation
HPLC of P2 Column Fractions Illustrating the 4 Main Classes of Phenols in Longan Peel
Fraction # 27
Fraction # 32
Fraction # 54
Flavonoids glycoside
Ellagic acids (EA)
Unknown
Unknown
EA
EA
EA
Q
Q
Q
Q
K
Q
K
Quercetin (Q)
Kaempferol (K)
UV/MS of Ellagic acid conjugates
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
m/z
0
100
%
0
100
%
303
129
121
147
153
177
275
219
201
257
247
285
304
611
465
305
435
345
407
355
369
477
595
577
533
519
545
757