Preparation of limonin monoclonal antibody and establishment of a sensitive icELISA for analyzing limonin in citrus and herbal samples.

Limonin is an intensely bitter and highly oxidized tetracyclic triterpenoid secondary metabolite, which is abundant in the Rutaceae and Meliaceae, especially in Citrus. In order to detect limonin content in complex substrates such as citrus and traditional Chinese medicine, monoclonal antibodies specifically recognizing limonin were prepared and an indirect competitive enzyme-linked immunosorbent assay (icELISA) was established. The median inhibition concentration (IC50) was 5.40 ng/mL and the linear range was 1.25-23.84 ng/mL. The average recoveries from citrus peel and pulp samples were 95.9%-118.8% and 77.5%-113.1%, respectively. Moreover, the contents of limonin in 6 citrus samples and 4 herbal samples were analyzed by icELISA and UPLC-MS, and the results of the two methods were consistent. This validation is sufficient to demonstrate that the developed immunoassay is applicable for the detection of limonin in citrus and herbal samples and has the advantage of high efficiency, sensitivity, and convenience.

Detection of azadirachtin from neem kernels using a paper-based sandwich sensor.

In this work, a microfluidic paper-based analytical device (µPAD) was developed to detect the biopesticide azadirachtin (Aza) through a colorimetric assay. High precision estimation of Aza is classically carried out using high performance liquid chromatography (HPLC), which requires highly skilled personnel. Acidified vanillin is a commonly used colorimetric indicator in thin layer chromatography for detection of various phytochemicals. However, the assay involves concentrated acid, which limits the choice of paper substrates for paper-based sensors and raises safety concerns. In this work, we show how the assay can be extended from the liquid phase to a paper substrate. Glass microfiber (GMF) filter paper was found to be suitable paper as it was acid resistant; besides, its hydrophilicity enabled smooth flow of reagents. A microfluidic paper-based sensor (µPAD) was developed by sandwiching 5 mm sized GMF dots between two parafilm sheets. We demonstrate the use of colorimetric assay on the µPAD for on-site detection of Aza in neem kernels. The magenta color developed upon the reaction of acidified vanillin with Aza was captured using a smart-phone and analysed using RGB levels in the image. Calibration was established using neem kernel extract of known concentration. Linearity was seen in the concentration range of 5 to 25 mg L-1 Aza. A limit of detection of 2.3 mg L-1 was obtained using this method. The colorimetric assay showed a relative recovery of >85% when compared with the values obtained from HPLC. The stability of the reagents on the GMF sensor was investigated to understand the storage conditions and shelf life of the reagents and sensor. The present work demonstrates the development of a portable sensor for on-site detection of phytochemicals that can be an integral part of the agricultural supply chain.

Chemical profile of persian lime seeds (Citrus Limettioides T.): Focus on limonoids and polyphenols.

Citrus fruit industrial processing generates tons of waste composed of peels, seeds and pulp. Incorrect disposal of these residues may harm the environment. The extraction of oil and bioactive compounds from citrus fruit seeds may be considered a sustainable alternative to the disposal of waste by the citrus agroindustry. In order to provide safe disposal of citrus waste an evaluation of its composition is necessary. Here we report the results of the application of a methodology to evaluate the composition the seeds of Citrus limettioides. In the first step, extraction with supercritical carbon dioxide was used. This work allowed the isolation and identification of four aglycone-type limonoids by High Performance Liquid Chromatography and Nuclear Magnetic Resonance, identified as limonin, nomilin, deacetylnomilin, and obacunone. In addition, six other polar limonoids and two glycosyl flavonoids were identified by HPLC-ESI/MS/MS.

Antiplasmodial and Antileishmanial Activities of a New Limonoid and Other Constituents from the Stem Bark of Khaya senegalensis.

Plasmodium falciparum and Leishmania sp. resistance to antiparasitic drugs has become a major concern in malaria and leishmaniasis control. These diseases are public health problems with significant socioeconomic impacts, and mostly affect disadvantaged populations living in remote tropical areas. This challenge emphasizes the need to search for new chemical scaffolds that preferably possess novel modes of action to contribute to antimalarial and antileishmanial research programs. This study aimed to investigate the antimalarial and antileishmanial properties of a methanol extract (KS-MeOH) of the stem bark of the Cameroonian medicinal plant Khaya senegalensis and its isolated compounds. The purification of KS-MeOH led to the isolation of a new ordered limonoid derivative, 21ß-hydroxybourjotinolone A (1a), together with 15 known compounds (1bc-14) using a repeated column chromatography. Compound 1a was obtained in an epimeric mixture of 21α-melianodiol (1b) and 21ß-melianodiol (1c). Structural characterization of the isolated compounds was achieved with HRMS, and 1D- and 2D-NMR analyses. The extracts and compounds were screened using pre-established in vitro methods against synchronized ring stage cultures of the multidrug-resistant Dd2 and chloroquine-sensitive/sulfadoxine-resistant 3D7 strains of Plasmodium falciparum and the promastigote form of Leishmania donovani (1S(MHOM/SD/62/1S). In addition, the samples were tested for cytotoxicity against RAW 264.7 macrophages. Positive controls consisted of artemisinin and chloroquine for P. falciparum, amphotericin B for L. donovani, and podophyllotoxin for cytotoxicity against RAW 264.7 cells. The extract and fractions exhibited moderate to potent antileishmanial activity with 50% inhibitory concentrations (IC50) ranging from 5.99 ± 0.77 to 2.68 ± 0.42 µg/mL, while compounds displayed IC50 values ranging from 81.73 ± 0.12 to 6.43 ± 0.06 µg/mL. They were weakly active against the chloroquine-sensitive/sulfadoxine-resistant Pf3D7 strain but highly potent toward the multidrug-resistant PfDd2 (extracts, IC50 2.50 ± 0.12 to 4.78 ± 0.36 µg/mL; compounds IC50 2.93 ± 0.02 to 50.97 ± 0.37 µg/mL) with selectivity indices greater than 10 (SIDd2 > 10) for the extract and fractions and most of the derived compounds. Of note, the limonoid mixture [21ß-hydroxylbourjotinolone A (1a) + 21α-melianodiol (1b) + 21ß-melianodiol (1c)] exhibited moderate activity against P. falciparum and L. donovani. This novel antiplasmodial and antileishmanial chemical scaffold qualifies as a promising starting point for further medicinal chemistry-driven development of a dually active agent against two major infectious diseases affecting humans in Africa.

Comparison of Chemical Compositions and Antioxidant Activities for the Immature Fruits of Citrus changshan-huyou Y.B. Chang and Citrus aurantium L.

Quzhou Aurantii Fructus (QAF), the dried immature fruit of Citrus changshan-huyou Y.B. Chang, is similar to Aurantii Fructus (AF), the dried immature fruit of Citrus aurantium L. or its cultivars, in terms of composition, pharmacological action, and appearance. However, potential chemical markers to distinguish QAF from AF remain unknown owing to the lack of a comprehensive systematic chemical comparison aligned with discriminant analysis. To achieve a better understanding of the differences in their composition, this study aimed to identify the basic chemical compounds in QAF (n = 42) and AF (n = 8) using ultra-performance liquid chromatography coupled with electron spray ionization and quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) and gas chromatography coupled with mass spectrometry (GC-MS). Principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and hierarchical clustering analysis (HCA) were used to further analyze, screen, and verify potential chemical markers; the antioxidant capacity was assayed in vitro. A total of 108 compounds were found in QAF and AF, including 25 flavonoids, 8 limonoids, 2 coumarins, and 73 volatile components. The chemometric analysis indicated that the main components in QAF and AF were very similar. Trace differential components, including 9 flavonoids, 2 coumarins, 5 limonoids, and 26 volatile compounds, were screened as potential chemical markers to distinguish between QAF and AF. Additionally, the antioxidant capacity of QAF was found to be greater than that of AF. This research provides insights into the quality control and clinical application of QAF.

Metabolomic Analysis of Phytochemical Compounds from Ethanolic Extract of Lime (Citrus aurantifolia) Peel and Its Anti-Cancer Effects against Human Hepatocellular Carcinoma Cells.

Lime peels are food waste from lime product manufacturing. We previously developed and optimized a green extraction method for hesperidin-limonin-rich lime peel extract. This study aimed to identify the metabolomics profile of phytochemicals and the anti-cancer effects of ethanolic extract of lime (Citrus aurantifolia) peel against liver cancer cells PLC/PRF/5. The extract's metabolomics profile was analyzed by using LC-qTOF/MS and GC-HRMS. The anti-cancer effects were studied by using MTT assay, Annexin-PI assay, and Transwell-invasion assay. Results show that the average IC50(s) of hesperidin, limonin, and the extract on cancer cells' viability were 165.615, 188.073, and 503.004 µg/mL, respectively. At the IC50 levels, the extract induced more apoptosis than those of pure compounds when incubating for 24 and 48 h (p < 0.0001). A combination of limonin and hesperidin showed a synergistic effect on apoptosis induction (p < 0.001), but the effect of the combination was still less than that of the extract at 48 h. Furthermore, the extract significantly inhibited cancer cell invasion better than limonin but equal to hesperidin. At the IC50 level, the extract contains many folds lower amounts of hesperidin and limonin than the IC50 doses of the pure compounds. Besides limonin and hesperidin, there were another 60 and 22 compounds detected from the LCMS and GCMS analyses, respectively. Taken altogether, the superior effect of the ethanolic extract against liver cancer cells compared to pure compound likely results from the combinatorial effects of limonin, hesperidin, and other phytochemical components in the extract.

New Triterpenoids from Lansium domesticum Corr. cv kokossan and Their Cytotoxic Activity.

Lansium domesticum Corr. is a member of the Meliaceae family that is widely spread in tropical and subtropical region of Asia and America. Traditionally, the fruit of this plant has been consumed because of its sweet taste. However, the fruit peels and the seeds of this plant have been rarely utilized. The previous chemical investigation of this plant showed the presence of secondary metabolites with many biological activities, including cytotoxic triterpenoid. Triterpenoids is a class of secondary metabolites which contain thirty carbon atoms in the main skeleton. The high modification of this type of compound, including the ring opening, highly oxygenated carbons, and the degradation of its carbon chain to give the nor-triterpenoid structure, is responsible for its cytotoxic activity. In this paper, we isolated and elucidated the chemical structure of two new onoceranoid triterpenes, kokosanolides E (1) and F (2), from the fruit peels of L. domesticum Corr., along with a new tetranortriterpenoid, kokosanolide G (3), from the seeds of L. domesticum Corr. The structural determination of compounds 1-3 was undertaken through FTIR spectroscopic analysis, 1D and 2D NMR, mass spectrometry, as well as through a comparison of the chemical shifts of the partial structures of compounds 1-3 with the literature data. The cytotoxic properties of compounds 1-3 were tested against MCF-7 breast cancer cells using the MTT assay. Moderate activity was shown by compounds 1 and 3, with IC50 values of 45.90 and 18.41 µg/mL, respectively, while compound 2 showed no activity (IC50 168.20 µg/mL). For the onoceranoid-type triterpene, the high symmetrical structure of compound 1 is presumably the reason for its better cytotoxic activity compared with that of compound 2. Compound 3 showed moderate activity, mainly because of the presence of the furan ring, which, based on the literature, gives better cytotoxic activity in a tetranortriterpenoid-type structure. The findings of three new triterpenoid compounds from L. domesticum indicate the significant value of this plant as a source of new compounds.

[Study on characteristic chromatogram and content determination of Wuzhuyu Decoction reference sample].

In this study, the critical quality attributes of Wuzhuyu Decoction reference sample were explored by using characteristic chromatogram, index component content and dry extract rate as indexes.The dissemination relationship of quantity value between medicinal materials-decoction pieces-reference sample was investigated to preliminarily formulate the quality standard of the reference sample.The characteristic chromatogram of 15 batches of Wuzhuyu Decoction was established by high performance liquid chromatography(HPLC) and the similarity analysis was conducted.Common peaks were demarcated and assigned to medicinal materials.Moreover, quantitative determination of limonin, evodiamine, rutaecarpine and ginsenoside Rb_1 of Wuzhuyu Decoction were performed.The dissemination of quantity value was explored combined with dry extract rate, similarity of characteristic chromatogram and transfer rate of index component content.A total of 18 common peaks were identified in the corresponding materials of Wuzhuyu Decoction reference sample, with the similarity of characteristic chromatogram greater than 0.9, and Fructus Evodiae, Radix Ginseng, Rhizoma Zingiberis Recens and Fructus Jujubae contributed 9, 5, 8 and 2 chromatographic peaks, respectively.The index component content of corresponding materials and the transfer rates of medicinal materials-decoction pieces and decoction pieces-reference sample of different batches of Wuzhuyu Decoction reference sample were as follows: the content of limonin was 0.16%-0.51%, and the transfer rates were 83.66%-115.60% and 38.54%-54.58%, respectively; the content of evodiamine was 0.01%-0.11%, the transfer rated were 80.80%-116.15% and 3.23%-12.93%, respectively; the content of rutaecarpine was 0.01%-0.05%, the transfer rates were 84.33%-134.53% and 5.72%-21.24%, respectively; the content of ginsenoside Rb_1 was 0.06%-0.11%, and the transfer rates were 90.00%-96.92% and 32.45%-67.24%, respectively.The dry extract rate of the whole prescription was 22.58%-29.89%.In this experiment, the dissemination of quantity value of Wuzhuyu Decoction reference sample was analyzed by the combination of characteristic chromatogram, index component content and dry extract rate.A scientific and stable quality evaluation method of the reference sample was preliminarily established, which provided basis for the subsequent development of Wuzhuyu Decoction and the quality control of related preparations.

Identification of Chemical Constituents in Zhizhu Pills Based on UPLC-QTOF-MSE.

BACKGROUND: Zhizhu pills (ZZP) are a traditional Chinese medicine (TCM) prescription, mainly used for clinically treating digestive diseases such as functional dyspepsia, constipation, and peptic ulcer. However, the chemical constituents of ZZP have rarely been reported. OBJECTIVE: To establish an ultrahigh-performance liquid chromatography-quadrupole time of flight-mass spectrometry (UPLC-QTOF-MSE) method for the identification of chemical constituents in ZZP, including individual herbs and a complicated Chinese medicinal formula. METHODS: The extracts of ZZP and its individual herb samples were analyzed by a UPLC-QTOF-MSE method on an ACQUITY UPLC HSS T3 column (100 × 2.1 mm id, 1.8 µm particle size) using a gradient elution of 0.1% formic acid in acetonitrile - 0.1% formic acid water (v/v) at a constant flow rate of 0.4 mL/min. With the MSE technique, both precursor ion and fragmentation information of compounds can be simultaneously acquired by alternating between low and high collision energy during a single chromatographic run. The data were analyzed on UNIFI. RESULTS: A total of 154 compounds, including 67 flavonoids, 17 coumarins, 11 terpenoids, 10 alkaloids, six limonoids, six sequiterpene lactones, and 37 other components, were ultimately identified based on accurate masses and fragmentation patterns in ZZP and its individual herbs. CONCLUSIONS: This paper summarized fragmentation patterns of flavonoids, sequiterpene lactones, alkaloids, coumarins, and limonoids. A rapid, accurate, and comprehensive UPLC-QTOF-MSE method has been developed for the identification of chemical compounds and applied to simultaneously evaluate the quality and effectiveness of ZZP. HIGHLIGHTS: A total of 154 compounds were ultimately identified in ZZP and its individual herbs by UPLC-QTOF-MSE; the fragmentation patterns of flavonoids, sequiterpene lactones, alkaloids, coumarins, and limonoids in ZZP and its individual herbs are summarized.

Ultra-high performance liquid chromatography Q-Orbitrap MS/MS-based profiling and quantification of limonoids in Meliaceae plants.

Meliaceae plants have been extensively used in agriculture, folklore, and traditional medicine. They are the major storehouses for structurally diverse limonoids (meliacins) possessing various bioactivities like antifeedant, insecticidal, antimicrobial, etc. However accurate detection of these tetranortriterpenes from the vast pool of metabolites in plant tissue extracts or biological sample is a crucial challenge. Though the mass spectrum (MS) provides the molecular mass and the corresponding elemental composition, it cannot be relied precisely. The exact identification of a specific metabolite demands the MS/MS spectrum containing the signature product ions. In the present study, we have developed the UHPLC Q-Orbitrap-based method for identification, quantification, and characterization of limonoids in different plant tissue extracts requiring minimum plant material. Using this method, we carried out the limonoid profiling in different tissue extracts of sixteen Meliaceae plants and the identification of limonoids was performed by comparing the retention time (RT), ESI-( +)-MS spectrum, and HCD-MS/MS of the purified fifteen limonoids used as reference standards. Our results revealed that early intermediates of the limonoid biosynthetic pathway such as azadiradione, epoxyazadiradione, and gedunin occurred more commonly in Meliaceae plants. The MS/MS spectrum library of the fifteen limonoids generated in this study can be utilized for identification of these limonoids in other plant tissue extracts, botanical fertilizers, agrochemical formulations, and bio pesticides.

Metabolomic navigated Citrus waste repurposing to restore amino acids disorder in neural lesion.

The fruit juice food industry produces huge waste annually, mainly Citrus peel and seeds. We investigated their chemical composition using hydrophilic interaction chromatography (HILIC-) and reverse phase liquid chromatography tandem mass spectrometry (RPLC-MS/MS), revealing 277 compounds, mainly containing flavonoids and limonoids. As the primary representative component in Citrus waste, limonin was selected to be explored new bio-functions. We applied Zebrafish larvae to study the metabolomic response invoked by limonin. The differential metabolites (DMs) varied depending on the exposing concentration of limonin. Enrichment analysis indicated that the identified DMs related to inflammation and neurologic disorders, including epilepsy which were newly discovered for limonoids and Citrus waste. Limonin was found to restore amino acids disorder to take neuroprotection against epilepsy. Our findings provided a new bio-function and purpose for Citrus waste and limonoids. Also, we demonstrated a concise case to repurpose food waste for new applications under metabolome investigation.

A novel electrochemical interdigitated electrodes sensor for limonin quantification and reduction in citrus limetta juice.

Limonin, a highly oxygenated triterpene biomolecule of citrus fruits is responsible for delayed bitterness of its juice lowering consumer's acceptability. Hence, limonin detection is essential for appropriate debittering intrusions. A novel interdigitated capacitive sensor using magnesium silicate-poly vinyl alcohol (MgSiO3.xH2O-PVA) composite has been introduced for quantification of limonin and debittering through selective adsorption of limonin from the citrus limetta juice. The sensor showed high sensitivity of 2.392 µF/ppm and fast response time of ∼6s. The sensor enables both quantification as well as measure debittering of citrus juice showing a reduction in limonin content from 5.77 ppm to 4.29 ppm with an exposure time of 60s to the sensing material making it distinctive in comparison to other methods. The sensor's results were validated with HPLC analysis. The device is simple, low-cost and reusable which promises easy, on-site and rapid quantification and reduction of limonin content in citrus juices without having toxicity.

Trichilianones A-D, Novel Cyclopropane-Type Limonoids from Trichilia adolfi.

The fractionation of an ethanol extract of the bark of Trichilia adolfi yielded four novel limonoids (trichilinones A-D, 1-4), with five fused rings and related to the hortiolide-type limonoids. Starting with an ε-lactone, which is α,ß-unsaturated in trichilinones A and D (1 and 4), attached to a tetrahydrofuran ring that is connected to an unusual bicyclo [5.1.0] hexane system, joined with a cyclopentanone with a 3-furanyl substituent [(2-oxo)-furan-(5H)-3-yl in trichilinone D (4)], the four compounds isolated display a new 7/5/3/5/5 limonoid ring system. Their structures were established based on extensive analysis of NMR spectroscopic data. As the crude extract possessed anti-leishmanial properties, the compounds were assayed for cytotoxic and anti-parasitic activities in vitro in murine macrophages cells (Raw 264.7) and leishmania promastigotes (L. amazoniensis and L. braziliensis), respectively. The compounds showed moderate cytotoxicity (approximately 70 µg/mL), but are not responsible for the leishmanicidal effect of the extract.

Identification of lipophilic components in Citri Reticulatae Pericarpium cultivars by supercritical CO2 fluid extraction with ultra-high-performance liquid chromatography-Q Exactive Orbitrap tandem mass spectrometry.

To systematically identify the lipophilic constituents of Citri Reticulatae Pericarpium from different cultivars, supercritical CO2 fluid extraction and ultra-high-performance liquid chromatography-Q Exactive Orbitrap tandem mass spectrometry were integrated for the component analysis of 18 batches of Citri Reticulatae Pericarpium from 12 cultivars for the first time. A total of 57 components from the supercritical CO2 fluid extracts were demonstrably or tentatively identified by the obtained parent peaks, fragment peaks, and retention times. In total, two flavonoids, six organic acids, nine coumarins, three aldehydes, seven esters, three terpenes, one limonoid, and five other compounds were detected for the first time; notably, coumarin components have not yet been reported in Citri Reticulatae Pericarpium. Furthermore, the extract constituents differed between cultivars. In particular, organic acids were more abundant in Citrus reticulata "Chachi" than in other cultivars, and pterostilbene was exclusively found in Citrus reticulata "Yichangju". The results showed that a greater variety of compounds in Citri Reticulatae Pericarpium could be extracted by supercritical CO2 fluid extraction and detected by ultra-high-performance liquid chromatography-Q Exactive Orbitrap tandem mass spectrometry. This study provides a more scientific basis for further analysis of the pharmacological activity and quality of Citri Reticulatae Pericarpium components from different cultivars.

Hedychium coronarium Rhizomes: Promising Antidiabetic and Natural Inhibitor of α-Amylase and α-Glucosidase.

Hedychium coronarium Koen., commonly known as ginger lily, is considered an endemic medicinal plant. In the present study, the antidiabetic action of its rhizomes was investigated by α-amylase and α-glucosidase inhibition assay, and the active compounds were identified through bioactivity guided isolation technique. Among the six different extracts, the EA extract has shown highest inhibition, and the subfractions from active EA extract were separated by silica gel column chromatography. The subfraction showing highest inhibition was investigated for its chemical composition by high-resolution liquid chromatography-mass spectroscopy (HRLC-MS/MS). The fatty acids such as suberic acid and terpenes such as triparanol, ginkgolide C, and swietenine were found to be the major compounds in the subfractions. The present work revealed that H. coronarium rhizome extract and its active constituent could be used as a natural inhibitor of these two carbohydrate-metabolizing enzymes and may play a key role in the management of diabetes.

Identification and determination of chemical constituents of Citrus reticulata semen through ultra high performance liquid chromatography combined with Q Exactive Orbitrap tandem mass spectrometry.

Citrus reticulata semen, a traditional Chinese medicinal material, has desirable medicinal and dietary properties. In this study, a method combining ultra high performance liquid chromatography with Q Exactive Orbitrap tandem mass spectrometry was established and validated for the identification and analysis of the chemical components of C. reticulata semen for the first time. The evaluation of different retention times and fragmentation characteristics, as well as comparative analysis with the literature, resulted in the identification of 35 chemical constituents, including 21 flavonoids and 14 other compounds. The 21 flavonoids derived from C. reticulata semen were reported for the first time. Seven of the chemical components of C. reticulata semen were quantitatively analyzed using the developed method under the optimal conditions. The results showed that the content of limonin, hesperidin, nobiletin, synephrine, tangeretin, 3,5,6,7,8,3',4'-heptamethoxyflavone and 5-hydroxide-6,7,8,3',4'-pentamethoxyflavone in C. reticulata semen was 11.1666, 0.0404, 0.0092, 0.0255, 0.0087, 0.0010, and 0.0008 mg/g, respectively. This study demonstrated that the ultra high performance liquid chromatography Q Exactive Orbitrap mass spectrometry based method can be used to rapidly and reliably analyze the chemical constituents of C. reticulata semen. These results provide a scientific basis for further studies of C. reticulata semen.

Antinociceptive compounds and LC-DAD-ESIMSn profile from Dictyoloma vandellianum leaves.

Limonoids, quinolone alkaloids and chromones have been reported as constituents of Dictyoloma vandellianum Adr. Juss. (Rutaceae). Although those compounds are known for their biological activities, only the anti-inflammatory activity of chromones isolated from the underground parts has been evaluated. There are no studies of the pharmacological properties of the aerial parts of D. vandellianum. The present study was carried out to determine the phytochemical profile and antinociceptive activity of the methanol extract, fractions and isolated compounds of leaves of D. vandellianum. The phytochemical profile was performed by HLPC-DAD-ESIMSn and pure substances obtained were characterized by MS and NMR spectroscopy. The antinociceptive activity was assessed using the formalin assay in mice, and the motor function in the rotarod test. ME and all the fractions obtained from ME produced antinociceptive effects. Among them, the ethyl ether fraction was the most active. Data from HPLC-DAD-ESIMSn showed that the ethyl ether fraction presented 42 compounds. The major compounds isolated from this fraction-gallic acid, methyl gallate and 1,2,6-tri-O-galloyl-ß-d-glucopyranose-were tested and produced antinociceptive effects. Gallic acid, methyl gallate and 1,2,6-tri-O-galloyl-ß-d-glucopyranose at antinociceptive doses did not affect the motor performance in mice in the rotarod test. This work is the first report of the occurrence of gallotanins in D. vandellianum. In addition, the pharmacological study showed that D. vandellianum leaves present antinociceptive activity, probably induced by gallic acid, methyl gallate and 1,2,6-tri-O-galloyl-ß-d-glucopyranose.

Rubescins F-H, new vilasinin-type limonoids from the leaves of Trichilia rubescens (Meliaceae).

Three new limonoids, designated as rubescins F (1), G (2), and H (3), together with two known compounds of this type, TS1 (4) and trichirubine A (5), were isolated from methylene chloride/methanol extracts of Trichilia rubescens leaves. The structures of these compounds were elucidated based on 1D and 2D nuclear magnetic resonance (NMR) analysis and complemented by electrospray ionization high-resolution mass spectrometry results and by comparison to data of related compounds described in the literature and ab initio calculations. Rubescin F (1) is the first limonoid from Trichilia spp. with an oxetane ring between C-7 and C-14, which seems to be formed by the isomerization of TS1 (4). The γ-hydroxybutenolide rubescin G (2) is a potential precursor of trichirubine A (5), whereas rubescin H (3) is the first example of a triterpenoid with a single bond between C-7/C-14, forming a cyclopropane ring. The absolute configuration of these limonoids was derived from biosynthetic considerations and ab initio calculations of NMR and optical rotation dispersion data.

Influence of Pickling Process on Allium cepa and Citrus limon Metabolome as Determined via Mass Spectrometry-Based Metabolomics.

Brine, the historically known food additive salt solution, has been widely used as a pickling media to preserve flavor or enhance food aroma, appearance, or other qualities. The influence of pickling, using brine, on the aroma compounds and the primary and secondary metabolite profile in onion bulb Allium cepa red cv. and lemon fruit Citrus limon was evaluated using multiplex metabolomics technologies. In lemon, pickling negatively affected its key odor compound "citral", whereas monoterpene hydrocarbons limonene and γ-terpinene increased in the pickled product. Meanwhile, in onion sulphur rearrangement products appeared upon storage, i.e., 3,5-diethyl-1,2,4-trithiolane. Profiling of the polar secondary metabolites in lemon fruit via ultra-performance liquid chromatography coupled to MS annotated 37 metabolites including 18 flavonoids, nine coumarins, five limonoids, and two organic acids. With regard to pickling impact, notable and clear separation among specimens was observed with an orthogonal projections to least squares-discriminant analysis (OPLS-DA) score plot for the lemon fruit model showing an enrichment of limonoids and organic acids and that for fresh onion bulb showing an abundance of flavonols and saponins. In general, the pickling process appeared to negatively impact the abundance of secondary metabolites in both onion and lemon, suggesting a decrease in their food health benefits.

A New Method for Simultaneous Determination of Phenolic Acids, Alkaloids and Limonoids in Phellodendri Amurensis Cortex.

Phellodendri Amurensis Cortex (PAC) is a well-known herbal medicine in China with complex components, but the previous research has mostly focused on its alkaloids analysis. For the first time, a simpler and more efficient method was proposed in this paper to simultaneously determine the content of three different kinds of compounds-phenolic acids, alkaloids and limonoids-in PAC. The phenolic acids included 3-O-feruloylquinic acid, 4-O-feruloylquinic acid and syringin. The alkaloids include magnoflorine, phellodendrine, jatrorrhizine, palmatine and berberine, while the limonoids include obaculactone and obacunone. An approach combining multi-wavelength and HPLC-DAD was used in this study due to the great difference in maximum absorption wavelength of the various components. Four wavelengths at 215, 275, 280 and 310 nm, respectively, were chosen for monitoring. It has been indicated through appropriate tests that this approach is of high accuracy, good repeatability and stability and provides a scientific basis for the quality assessment of PAC and associated derivatives. In addition, the chromatographic fingerprints method combined with multivariate statistical analysis chosen in this study was proved to be effective and reasonable for an accurate classification of 33 batches of samples collected from different locations.