Isolation and structure elucidation of constituents of Citrus limon , Isodon japonicus , and Lansium domesticum as the cancer prevention agents

Table 3 Antimutagenic activity of coumarins (1 and 2), limonoids (19 and 20), oxime and synthetic intermediates (21, 21a, and 21b), ent-kaurane diterpenoids (25, 26, 29, 30, and 33), and onoceranoid-type triterpenoids (47–49, 53, and 54) against PhIP (1.0 μg/plate) using the Ames test [4,5,6,7,8] ^a,b

	Inhibition % (Based on number of revertant colonies)
	50 nmol/plate	100 nmol/plate	200 nmol/plate	400 nmol/plate	800 nmol/plate
Coumarins
1^b	17.5%	29.1%	48.4%	48.6%	81.4%
2^b	18.2%	35.4%	62.2%	77.6%	86.3%
Limonoids
19^b	27.0%	39.0%	25.5%	50.3%	46.7%
20^b	23.6%	44.2%	74.9%	79.8%
Oxime
21^b	12.2%	11.1%	29.7%	47.1%	63.7%
Synthetic intermediates of 21
21a^b	8.6%	7.4%	0.7%	–	–
21b^b	10.7%	18.0%	39.0%	53.3%	68.1%
ent-Kaurane diterpenoids
25^b	55.8%	62.8%	73.7%	80.7%
26^b	54.3%	72.0%	79.5%	85.5%
29^b	24.0%	43.2%	62.3%	74.2%
30^b	51.0%	64.8%	81.4%	85.5%
33^b	71.0%	79.5%	80.4%
Onoceranoid-type triterpenoids
47^b	30.8%	72.7%	93.7%	94.9%
48^b	14.3%	33.7%	54.3%	74.4%
49^b	4.1%	17.2%	22.5%	41.0%
53^b	36.8%	65.2%	94.1%	93.9%
54^c	18.6%	32.4%	63.2%	95.4%

^a Nobiletin was used as a reference compound. It showed 56% inhibition at 20 nmol/plate
^b Compounds showed no antibacterial activity [< 5.0% inhibition at highest concentration] against the S. typhimurium TA98 strain
^c Compound showed weak antibacterial activity [54: 23.0% inhibition at 400 nmol/plate] against the S. typhimurium TA98 strain

ISSN: 1880-7062