Phenolic Analysis for Classification of Mulberry (Morus spp.) Leaves according to Cultivar and Leaf Age

Table 2

Quantification of phenolic compounds detected in mulberry leaves from 3 commercial Thai cultivars at different leaf ages.

Parameter	Buriram 60			Sakonnakhon			Khunphai
	Tips	Young leaves	Old leaves	Tips	Young leaves	Old leaves	Tips	Young leaves	Old leaves
Caffeoylquinic acid isomer I^1	0.32 ± 0.01^B,c	0.60 ± 0.01^NS,a	0.55 ± 0.01^B,b	0.39 ± 0.01^A,b	0.68 ± 0.02^NS,a	0.68 ± 0.02^A,a	0.33 ± 0.01^B,b	0.64 ± 0.06^NS,a	0.73 ± 0.01^A,a
5-O-Caffeoylquinic acid	11.03 ± 0.53^B,a	6.76 ± 0.14^A,b	3.88 ± 0.12^NS,c	13.12 ± 0.24^A,a	5.04 ± 0.80^B,b	3.50 ± 0.36^NS,c	10.72 ± 0.13^B,a	5.73 ± 0.85^B,b	5.03 ± 0.91^NS,b
4-O-Caffeoylquinic acid	1.91 ± 0.11^B,a	2.13 ± 0.05^NS,a	1.26 ± 0.03^B,b	2.45 ± 0.05^A,a	1.80 ± 0.25^NS,b	1.38 ± 0.11^B,c	1.84 ± 0.01^B,ns	1.99 ± 0.09^NS,ns	1.88 ± 0.17^A,ns
Caffeoylquinic acid isomer II^1	0.23 ± 0.02^B,a	0.18 ± 0.00^A,b	0.10 ± 0.00^NS,c	0.33 ± 0.02^A,a	0.13 ± 0.02^B,b	0.10 ± 0.01^NS,b	0.23 ± 0.02^B,a	0.15 ± 0.01^B,b	0.14 ± 0.02^NS,b
Total caffeoylquinic acids	13.49 ± 0.66^B,a	9.68 ± 0.20^A,b	5.79 ± 0.17^NS,c	16.29 ± 0.16^A,a	7.59 ± 0.45^B,b	5.65 ± 0.47^NS,c	13.13 ± 0.08^B,a	8.51 ± 0.69^A,b	7.78 ± 0.97^NS,b
Kaempferol-hexoside derivative^3	0.30 ± 0.02^A,a	0.09 ± 0.01^B,b	0.07 ± 0.00^C,b	0.32 ± 0.00^A,a	0.13 ± 0.01	0.11 ± 0.01	0.29 ± 0.00	0.16 ± 0.00	0.01 ± 0.00
Quercetin-rutinoside derivative^2	ND	0.14 ± 0.00^ns	0.15 ± 0.02^ns	ND	ND	ND	ND	ND	ND
Kaempferol-rutinoside derivative^3	ND	0.10 ± 0.00^b	0.13 ± 0.00^a	ND	ND	ND	ND	ND	ND
Quercetin-3-O-rutinoside	3.65 ± 0.26^B,a	1.55 ± 0.05^B,b	1.02 ± 0.04^B,b	4.39 ± 0.05^A,a	1.97 ± 0.18^B,b	1.56 ± 0.12^B,c	3.45 ± 0.02^B,a	2.42 ± 0.20^A,b	2.22 ± 0.29^A,b
Quercetin-hexoside^2	1.00 ± 0.08^B,a	0.28 ± 0.02^B,b	0.05 ± 0.00^B,c	2.03 ± 0.05^A,a	0.46 ± 0.05^A,b	0.38 ± 0.05^A,b	0.94 ± 0.03^B,a	0.36 ± 0.0^5B,b	0.36 ± 0.05^A,b
Kaempferol-3-O-rutinoside	1.11 ± 0.07^B,a	0.61 ± 0.02^B,b	0.41 ± 0.01^C,c	1.59 ± 0.01^A,a	1.07 ± 0.09^A,b	0.84 ± 0.07^B,c	1.05 ± 0.00^B,ns	1.14 ± 0.08^A,ns	1.11 ± 0.09^A,ns
Quercetin-(malonyl)-hexoside^2	ND	2.00 ± 0.08^a	1.46 ± 0.06^b	ND	ND	ND	ND	ND	ND
Kaempferol-hexoside^3	0.25 ± 0.02^B,a	0.22 ± 0.01^NS,a	0.14 ± 0.01^NS,b	0.73 ± 0.02^A,a	0.17 ± 0.01^NS,b	0.14 ± 0.00^NS,b	0.23 ± 0.01^B,ns	0.20 ± 0.04^NS,ns	0.19 ± 0.04^NS,ns
Kaempferol-(malonyl)-hexoside^3	ND	1.67 ± 0.20^a	1.31 ± 0.17^b	ND	ND	ND	ND	ND	ND
Total flavonols	6.31 ± 0.42^B,a	6.66 ± 0.22^A,a	4.74 ± 0.17^A,b	9.06 ± 0.14^A,a	3.67 ± 0.28^B,b	2.92 ± 0.22^B,b	5.67 ± 0.05^B,a	4.12 ± 0.33^B,b	3.88 ± 0.47^B,b

Values are expressed as mean ± SEM. Different capital letters indicate significant differences between cultivars within the same leaf age at . Different small letters indicate significant differences between leaf ages within the same cultivar at . ND: none detectable; NS: no significant difference among cultivars at ; ns: no significant difference among leaf age at . ¹Content expressed as mg chlorogenic acid equivalent/g dry weight. ²Content expressed as mg quercetin-3-rutinoside equivalent/g dry weight. ³Content expressed as mg kaempferol-3-rutinoside equivalent/g dry weight.