Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Limonins”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

Quantitative analysis of limonin in grapefruit juice using an enzyme-linked immunoassay: interlaboratory study.

Eleven laboratories participated in an interlaboratory study of an enzyme-linked immunoassay for limonin in grapefruit juice. Participating laboratories received training and practice samples until familiar with the procedure. Laboratories then received 8 sample pairs of grapefruit juice as blind duplicates. Samples were refrigerated and analyzed within 4 days of receipt. Results from 1 laboratory and 6 individual samples were excluded from the statistical analysis. Method performance was measured by the one-way component of variance analysis. Repeatability relative standard deviations (RSDr) ranged from 7.0 to 15.6%. Reproducibility relative standard deviations (RSDR) ranged from 12.9 to 29.4%.

Beverages↗
PubMed2003

Bioavailability of citrus limonoids in humans.

This study utilizes liquid chromatography/mass spectrometry (LC-MS) to analyze the plasma of four groups of four healthy male and female subjects administered high doses of pure limonin glucoside (0.25-2.0 g in 200 mL of buffered water) for the presence of limonin to establish the absorption, metabolism, and bioavailability of citrus limonoids to humans. The plasma analysis revealed increasing amounts of limonin associated with increasing doses of limonin glucoside among the subject groups in mean maximum concentration amounts ranging from 1.74 to 5.27 nmol/L. A high degree of variability in the analyzed limonin concentration was observed within the subject groups. The mean time to maximum concentration was 6 h. A second compound with MS/MS characteristics identical to limonin was detected in amounts up to 5.13 nmol/L and is hypothesized to be a limonin epimer. Poststudy health evaluation established no ill effects among study subjects consuming high doses of limonin glucoside.

Adult↗
PubMed2005

Suppression of colon carcinogenesis by bioactive compounds in grapefruit.

This study evaluated the hypothesis that untreated and irradiated grapefruit as well as the isolated citrus compounds naringin and limonin would protect against azoxymethane (AOM)-induced aberrant crypt foci (ACF) by suppressing proliferation and elevating apoptosis through anti-inflammatory activities. Male Sprague-Dawley rats (n = 100) were provided one of five diets: control (without added grapefruit components), untreated or irradiated (300 Gy, 137Cs) grapefruit pulp powder (13.7 g/kg), naringin (200 mg/kg) or limonin (200 mg/kg). Rats were injected with saline or AOM (15 mg/kg) during the third and fourth week and colons were resected (6 weeks post second injection) for evaluation of ACF, proliferation, apoptosis, and cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) protein levels. Experimental diets had no effect on the variables measured in saline-injected rats. However, in AOM-injected rats, the experimental diets suppressed (P < or = 0.02) aberrant crypt and high multiplicity ACF (HMACF; P < or = 0.01) formation and the proliferative index (P < or = 0.02) compared with the control diet. Only untreated grapefruit and limonin suppressed (P < or = 0.04) HMACF/cm and expansion (P < or = 0.008) of the proliferative zone that occurred in the AOM-injected rats consuming the control diet. All diets elevated (P < or = 0.05) the apoptotic index in AOM-injected rats, compared with the control diet; however, the greatest enhancement was seen with untreated grapefruit and limonin. Untreated grapefruit and limonin diets suppressed elevation of both iNOS (P < or = 0.003) and COX-2 (P < or = 0.032) levels observed in AOM-injected rats consuming the control diet. Although irradiated grapefruit and naringin suppressed iNOS levels in AOM-injected rats, no effect was observed with respect to COX-2 levels. Thus, lower levels of iNOS and COX-2 are associated with suppression of proliferation and upregulation of apoptosis, which may have contributed to a decrease in the number of HMACF in rats provided with untreated grapefruit and limonin. These results suggest that consumption of grapefruit or limonin may help to suppress colon cancer development.

Animals↗
PubMed1989

The effect of citrus limonoids on hamster buccal pouch carcinogenesis.

Two citrus limonoids, limonin and nomilin, were tested for their effects on the development of 7,12-dimethylbenz[a]anthracene (DMBA)-induced buccal pouch epidermoid carcinomas. Forty-five female Syrian hamsters were divided into three equal groups. The left buccal pouches of the animals in each group were pretreated topically with two applications of dimethylsulfoxide (DMSO) (group I), a 2.5% solution of limonin dissolved in DMSO (group II) or a 2.5% solution of nomilin dissolved in DMSO (group III). After this initial treatment, 11 hamsters from each group were selected. The left buccal pouches of these animals were painted 2 or 3 times weekly with a 0.5% solution of DMBA in mineral oil. On alternate days the pouches were painted with DMSO (I), the 2.5% solution of limonin (II) or the 2.5% solution of nomilin (III). The 12 remaining hamsters were used as controls and were painted with mineral oil and DMSO (I), mineral oil and the 2.5% solution of limonin (II), or mineral oil and the 2.5% solution of nomilin (III). After 15 weeks the hamsters were killed, the pouches were excised and the tumors were counted and measured. Tumors of variable size were common in the animals treated with DMBA. However, the animals receiving topical applications of limonin exhibited a 60% reduction in tumor burden. Further comparisons between groups I and II showed that this reduction in tumor burden was due to a 20% decrease in tumor number and a 50% decrease in tumor mass. The results for group III showed that nomilin was considerably less effective as an inhibitor of DMBA-induced neoplasia.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2005

Antioxidant activity of citrus limonoids, flavonoids, and coumarins.

A variety of in vitro models such as beta-carotene-linoleic acid, 1,1-diphenyl-2-picryl hydrazyl (DPPH), superoxide, and hamster low-density lipoprotein (LDL) were used to measure the antioxidant activity of 11 citrus bioactive compounds. The compounds tested included two limonoids, limonin (Lim) and limonin 17-beta-D-glucopyranoside (LG); eight flavonoids, apigenin (Api), scutellarein (Scu), kaempferol (Kae), rutin trihydrate (Rut), neohesperidin (Neh), neoeriocitrin (Nee), naringenin (Ngn), and naringin(Ng); and a coumarin (bergapten). The above compounds were tested at concentration of 10 microM in all four methods. It was found that Lim, LG, and Ber inhibited <7%, whereas Scu, Kae, and Rut inhibited 51.3%, 47.0%, and 44.4%, respectively, using the beta-carotene-linoleate model system. Lim, LG, Rut, Scu, Nee, and Kae showed 0.5% 0.25%, 32.2%, 18.3%, 17.2%, and 12.2%, respectively, free radical scavenging activity using the DPPH method. In the superoxide model, Lim, LG, and Ber inhibited the production of superoxide radicals by 2.5-10%, while the flavonoids such as Rut, Scu, Nee, and Neh inhibited superoxide formation by 64.1%, 52.1%, 48.3%, and 37.7%, respectively. However, LG did not inhibit LDL oxidation in the hamster LDL model. But, Lim and Ber offered some protection against LDL oxidation, increasing lag time to 345 min (3-fold) and 160 min (33% increase), respectively, while both Rut and Nee increased lag time to 2800 min (23-fold). Scu and Kae increased lag time to 2140 min (18-fold) and 1879 min (15.7-fold), respectively. In general, it seems that flavonoids, which contain a chromanol ring system, had stronger antioxidant activity as compared to limonoids and bergapten, which lack the hydroxy groups. The present study confirmed that several structural features were linked to the strong antioxidant activity of flavonoids. This is the first report on the antioxidant activity of limonin, limonin glucoside, and neoeriocitrin.

5-Methoxypsoralen↗
PubMed1997

Limonoids from Citrus reticulata and their moult inhibiting activity in mosquito Culex quinquefasciatus larvae.

Three limonoids, namely limonin, nomilin and obacunone, were isolated from the seeds of Citrus reticulata [Blanco Coorg Mandarin]. Their structures were confirmed by spectroscopic studies. With 4th instar larvae of mosquito Culex quinquefasciatus, the EC50 for inhibition of adult emergence was 6.31, 26.61 and 59.57 ppm for obacunone, nomilin and limonin, respectively. The pattern of mortality at around the EC50 levels was indicative of moult inhibiting activity. The efficacy of a limonoid enriched fraction was similar to that of limonin, probably due to the high content (70%) of limonin.

Animals↗
PubMed2006

[Determination of bitter components in citrus juice by high performance liquid chromatography].

Bitterness in citrus juice is primarily due to the presence of both limonin and naringin, and determination of them is a standard in controlling the quality of juice. A high performance liquid chromatographic (HPLC) method was developed for the rapid determination of bitter components in citrus juice. The HPLC conditions were as follows: ODS column with acetonitrile-tetrahydrofuran-water (17.5: 17.5: 65, v/v) as mobile phase, flow rate at 1 mL/min, 207 nm as detection wavelength for limonin, and methanol-100% acetic acid-water (40:1:59, v/v) as mobile phase, flow rate at 1 mL/min, 283 nm as detection wavelength for naringin. As results showed, for limonin and naringin, the linearity was good within the ranges of 1.00 - 50.00 mg/L (r = 0.9992) and 20.00 - 160.00 mg/L (r = 0.9988) respectively, and the detection limits were 0.07 microg and 0.14 microg, then the average recoveries were 98.69% and 100.13% with relative standard deviations of 2.5% and 1.5%, respectively. The method is simple, rapid and accurate for determining limonin and naringin in juice.

English Abstract↗
PubMed1989

Inhibition of benzo[a]pyrene-induced forestomach neoplasia in mice by citrus limonoids.

The limonoids, limonin and nomilin, are bitter principles found in common edible citrus fruits. Nomilin, when given three times (at 5 and 10 mg per animal) every two days, induced increased glutathione S-transferase activity 2.48 and 3.44 times over the control, respectively, in the liver of female ICR/Ha mice. The increases of GST activity in the small intestinal mucosa were 3.00 and 4.17, respectively, over the control. Limonin, when given at the same dose levels, was not active in the liver. However, marginal activity was obtained in the small intestinal mucosa. Nomilin, which is the more active enzyme inducer, was found to inhibit benzo[a]pyrene (BP)-induced neoplasia in the forestomach of ICR/Ha mice. The number of mice with tumors was reduced from 100 to 72%, and the number of tumors per mouse was significantly decreased as a result of nomilin treatment. Limonin, which is a weak enzyme inducer, was less potent as an inhibitor of BP-induced neoplasia. These findings suggest limonoids as a class of regularly consumed natural products may be effective chemopreventive agents.

Animals↗
PubMed1992

[Limonoids in Phellodendron amurense (Kihada)].

Limonoids and their glucosides in the seeds and barks of Phellondendron amurense (Kihada) were analyzed. The seeds contained limonin (1950 ppm), obakunone (20 ppm), limonin 17-beta-D-glucopyranoside (820 ppm) and obakunone 17-beta-D-glucopyranoside (1360 ppm). The barks contained limonin (6760 ppm), obakunone (1240 ppm) and nomilin (270 ppm).

Chromatography, High Pressure Liquid↗
PubMed2003

Mass spectrometry and tandem mass spectrometry of citrus limonoids.

Methods for atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS/MS) of citrus limonoid aglycones and electrospray ionization tandem mass spectrometry (ESI-MS/MS) of limonoid glucosides are reported. The fragmentation patterns of four citrus limonoid aglycones (limonin, nomilin, obacunone, and deacetylnomilin) and six limonoid glucosides, that is, limonin 17-beta-D-glucopyranoside (LG), nomilin 17-beta-D-glucopyranoside (NG), nomilinic acid 17-beta-D-glucopyranoside (NAG), deacetyl nomilinic acid 17-beta-D-glucopyranoside (DNAG), obacunone 17-beta-D-glucopyranoside (OG), and obacunoic acid 17-beta-D-glucopyranoside (OAG) were investigated using a quadruple mass spectrometer in low-energy collisionally activated dissociation (CAD). The four limonoid aglycones and four limonoid glucosides (LG, OG, NAG, and DNAG) were purified from citrus seeds; the other two limonoid glucosides (NG and OAG) were tentatively identified in the crude extract of grapefruit seeds by ESI mass spectrometry in both positive and negative ion analysis. Ammonium hydroxide or acetic acid was added to the mobile phase to facilitate ionization. During positive ion APCI analysis of limonoid aglycones, protonated molecular ion, [M + H]+, or adduct ion, [M + NH3 + H]-, was formed as base peaks when ammonium hydroxide was added to the mobile phase. Molecular anions or adduct ions with acetic acid ([M + HOAc - H] and [M + HOAc]-) or a deprotonated molecular ion were produced during negative ion APCI analysis of limonoid aglycones, depending on the mobile-phase modifier used. Positive ion ESI-MS of limonoid glucosides produced adduct ions of [M + H + NH3]+, [M + Na]+, and [M + K]+ when ammonium hydroxide was added to the mobile phase. After collisionally activated dissociation (CAD) of the limonoid aglycone molecular ions in negative ion APCI analysis, fragment ions indicated structural information of the precursor ions, showing the presence of methyl, carboxyl, and oxygenated ring structure. CAD of the adduct ion [M + H + NH3]+ of limonoid glucosides produced the aglycone moiety corresponding to each glucoside. The combination of mass spectrometry and tandem mass spectrometry provides a powerful technique for identification and characterization of citrus limonoids.

Benzoxepins↗