PRODUCT IDENTIFICATION

TOXICITY

H.S. CODE

CLASSIFICATION

EXTRA NOTES

PHYSICAL AND CHEMICAL PROPERTIES

-0.72 (octanol-water)

REFRACTIVE INDEX

NFPA RATINGS

AUTOIGNITION

FLASH POINT

EXTERNAL LINKS & GENERAL DESCRIPTION

Wikipedia Linking

Google Scholar Search

http://www.actahort.org/
Phytochemicals present in citrus fruits, such as triterpenoids and related bitter compounds were of great concern to citrus industries during last decade due to their unpleasant taste. These same compounds are gaining importance during recent years, due to their proven benefits in prevention of cancer and other chronic diseases. Both limonin and its glucoside isolated and purified (purity of >99%) from Citrus aurantium L. seeds, were subjected to proliferation inhibitory activity of cultured human colon adenocarcinoma cells (SW480). Limonin has shown significant inhibitory activity at 25 μM concentration, with inhibition of cancer cell proliferation by 42, 58 and 67% after 24, 48 and 72 Hrs of incubation, respectively. However the activity was not increased proportionately at 50 and 100 μM (67.8 and 68.9% after 72 hrs). On the other hand, inhibitory effect of Limonin glucoside (LG) was significant at 6.25μM concentration (inhibition of 61% after 24 hrs). Inhibition of proliferatation by 77% was observed in cells incubated with 100 μM LG for 72 Hrs. These results were also confirmed by content of lactate dehydrogenase (LDH) leached by cells following treatment with compounds to medium indicating cytotoxicity. Compounds treated at 100μM have shown DNA fragmentation of 200bp indicating apoptosis induction to cytotoxicity. The results of the current study indicates oxygenated terpenoids limonin and its glucoside may help in prevention of colon cancer. Further investigations are necessary to understand the possible mechanism of colon cancer prevention.

http://apjcn.nhri.org.tw/
Limonoids: Citrus limonoids are responsible for the bitter taste in citrus fruits. The most prevalent limonoids are limonin and nomilin. They are present in the rutaceous plants that include lemon, lime, orange and grapefruits. An important characteristic of this class of compound is a substituted furan moiety. It has been determined by animal studies that citrus limonoids and derivatives have certain biological activities that may be used as chemopreventive agents for cancer. Glutathione S-transferase (GST) is a major detoxifying enzyme system that catalyses the conjugation of glutathione with electrophiles that induce activated carcinogens. The glutathione conjugates are usually less reactive and more water soluble, and hence, facilitate excretion. An increase in GST activity caused by a substance is therefore an elevation in the mechanism that protects against the noxious effects of xenobiotics, including carcinogens. Many chemicals that are GST enhancers have been found to inhibit chemically induced carcinogenesis.12,13 The structures of the naturally occurring furanoids that have been found to induce GST activity range from the simple 2-alkyl substituted compound 2-n-heptyl furan and the sulphur analogue 2-n-butyl thiophen, formed during the roasting of meat, to more complex molecules such as kahweol and cafestol, isolated from green coffee beans, and salannin, identified in the seed of the mythical neem tree of India. The presence of the furan moiety appears to be essential for enzyme induction. When the furan ring in cafestol is saturated by hydrogenation, its activity as a GST inducer is lost. In the case of limonin and nomilin, the triterpene structure appears to play a part in determining the relative GST-inducing activity of these compounds. The structure–activity relationships of limonin and nomilin have been studied and discussed. The chemical structures of limonin, nomilin and their glucoside derivatives are shown in Fig.1.

http://pubs.acs.org/
SOME OBSERVATIONS ON THE STRUCTURE OF LIMONIN

APPEARANCE

white powder

PURITY

98.0% min (HPLC)

LOSS ON DRYING

0.5%