Joseph D. Connolly and Robert A. Hill*. Nat. Prod. Rep., 2010, 27, 79–132
A review covering the biological activities of the citrus limonoids has been published. 17-epi-Limonin 481 has been reported from a Citrus species. Evolimorutanin 482 from the unripe fruit of Evodia rutaecarpa and methyl uguenenoate 483 from Vepris uguenensis are presumably transformation products of limonin. The obacunol derivatives 484 and 485, the nomilin derivatives 486 and 487 (odoralide) and 8b,14a-dihydroswietenolide 488 are constituents of the stembark of Cedrela odorata.
2. Limonoids and their anti-proliferative and anti-aromatase properties in human breast cancer cells
Jinhee Kim, Guddadarangavvanahally K. Jayaprakasha and Bhimanagouda S. Patil*. Food Funct., 2013, 4, 258–265
The retention time and mass spectra of compounds (1–9) were confirmed and matched to our previously reported values. Based on the HPLC and mass spectral data, compounds 1–9 were identified and characterized as obacunone, nomilin, limonin, limonexic acid (LNA), isolimonexic acid (ILNA), obacunone glucoside (OG), nomilinic acid glucoside (NAG), deacetyl nomilinic acid glucoside (DNAG), and limonin glucoside (LG), respectively. The structures of purified limonoids were presented in Fig. 3. The modifiied compounds such as DL, LM, LO, and DN were prepared using purified limonin and nomilin and used for biological activities.
3. Citrus limonoids and curcumin additively inhibit human colon cancer cells
Kotamballi N. Chidambara Murthy, G. K. Jayaprakasha* and Bhimanagouda S. Patil*. Food Funct., 2013, 4, 803–810
Limonoids are colorless tetracyclic triterpenoids, which are found in citrus fruits with relatively higher concentrations in the seed compared to the juice. Limonin, the most abundant limonoid from citrus is an oxygenated compound known to possess various biological activities including larvicidal activity against the mosquito Culex quinquefasciatus, and suppression of coronary heart disease markers. Our group has characterized and explored several biological activities of citrus limonoids and other phytochemicals with emphasis on cancer chemoprevention. This research in our laboratory has demonstrated inhibition of colon cancer cell proliferation by limonin and other limonoids. In a recent study, we also demonstrated a possible mechanism of apoptosis induction by both limonin and LG in SW480 cells. One of our previous studies demonstrated the ability of citrus limonoids to inhibit leukemia, ovarian, cervical, stomach, liver and breast cancer cells. An animal study has also shown that freeze-dried grapefruit powder, naringin and limonin were capable of inhibiting aberrant crypts through suppression of cyclo-oxy-genase-2 and inducible nitric oxide synthase (iNOS) in an azoxymethane-induced colon cancer model.
4. Metabolomics strategy reveals therapeutical assessment of limonin on nonbacterial prostatitis
Aihua Zhang, Huiyu Wang, Hui Sun, Yue Zhang, Na An, Guangli Yan, Xiangcai Meng and Xijun Wang*. Food Funct.,2015, 6,3540–3549
Limonoids are highly oxygenated, modified terpenoids with a prototypical structure either containing or derived from a precursor with a 4,4,8-trimethyl-17-furanylsteroid skeleton found abundantly in plant families such as Meliaceae and Rutaceae. Limonin (Fig. S1†), also called obaculactone or limonoic acid, is one of the most prevalent limonoids, widely used as a dietary supplement. In 1938, Highby first isolated limonin from Washington navel orange. Ongoing studies show that limonin has exhibited a range of biological activities like antibacterial, antifungal, antimalarial, anticancer, antiviral, antimicrobial, anti-HIV, and a number of other pharmacological activities on humans. Limonin could inhibit chemically induced carcinogenesis and a series of human cancer cell lines, with a remarkable cytotoxicity against lung, colon, oral and skin cancer in animal test and human breast cancer cells. In recent years a large number of pharmacological studies have been carried out to indicate its beneficial eﬀects.