Flavonoids fromIris spuria (Zeal) cultivated in Egypt

Antifungal Compounds from the Leaves of Rhynchosia minima

Rhynchosia minima, commonly known as jumby bean, is used as a remedy for respiratory ailments in various parts of the world. It is also used by South African traditional healers to treat heart or chest pain. This study aimed to investigate the bioactive constituents of the leaf extracts of R. minima against selected fungal isolates that have been identified as risk factors in respiratory illness. Rhynchosia minima leaves were extracted sequentially using hexane, dichloromethane, ethyl acetate and methanol in increasing order of polarity. The extracts were subjected to repeated chromatographic techniques, for phytochemical isolation. The extracts and isolated compounds were screened against Candida albicans and Cryptococcus neoformans by determining the minimum concentration that inhibited fungal growth. Six flavonoids, one norisoprenoid and one cyclitol were isolated and characterized by 1D and 2D NMR and HR-ESI-MS. The extracts obtained in the study had moderate to weak antifungal activities, with MICs ranging from 312.5 to 1250.0 μg/mL against both fungi. Four isolated compounds were also screened, with two of them exhibiting activity against C. albicans (MIC=6.25 μg/mL) that was comparable to amphotericin B, the positive control. These two compounds also had better antifungal potential against C. neoformans with an MIC=6.25 μg/mL, compared to the MIC of 12.5 μg/mL of amphotericin B. Seven of the eight isolated compounds were obtained from the extracts of Rhynchosia minima for the first time. Two of the isolated compounds demonstrated activity comparable or superior to amphotericin B activity. The notable potency displayed by these compounds warrants further investigation on their development as antifungal agents.

Irigenin, a novel lead from Iris confusa for management of Helicobacter pylori infection with selective COX-2 and HpIMPDH inhibitory potential

The development of new natural drugs for Helicobacter pylori (H. pylori) management has recently received significant attention. Iris confusa (I. confusa) was long used for the treatment of bacterial infections and gastritis. This study aimed at evaluating its effect on management of H. pylori infection and exploring its bioactive metabolites. The inhibitory potential of the polar (PF), non-polar (NPF) fractions and the isolated compounds against H. pylori using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay in addition to their cyclooxygenases (COX-1 and COX-2), and nitric oxide (NO) inhibitory activities were assessed. The most biologically active compound was tested for its selective H. pylori inosine-5'-monophosphate dehydrogenase (HpIMPDH) inhibitory potential. Chromatographic purification of PF and NPF allowed isolation of tectoridin, orientin, irigenin, tectorigenin, isoarborinol and stigmasterol. The PF exhibited significant anti-H. pylori (MIC 62.50 µg/mL), COX-1, COX-2 (IC50 of 112.08 ± 0.60 and 47.90 ± 1.50 µg/mL respectively, selectivity index SI of 2.34), and NO (IC50 47.80 ± 0.89 µg/mL) inhibitory activities, while irigenin was the most potent isolated compound. Irigenin was found to have a promising activity against HpIMPDH enzyme (IC50 of 2.07 ± 1.90 μM) with low activity against human hIMPDH2 (IC50 > 10 μM) than clarithromycin, assuring its selectivity. Overall, I. confusa and its isolated compounds may serve as a potential source of plant-based drugs for H. pylori control. This study scientifically validated the claimed anti-bacterial activity of I. confusa and revealed irigenin potential as a novel lead exhibiting anti H. pylori activity in a first record.

Chemical Constituents of the Flowers of Pueraria lobata and Their Cytotoxic Properties

The flower of Pueraria lobata (Puerariae Flos) is a reddish-purple to violet-purple flower that blooms between July and September. In our preliminary study, Puerariae Flos extract exhibited significant activity against a human ovarian cancer cell line. This research aims to identify the active compounds in Pueraria Flos. By repeated chromatography, one new tryptophan derivative (1), two new flavanones (4 and 5), and 19 known compounds, including tryptophan derivatives (2 and 3), flavonoids (6–9), isoflavonoids (10–20), a flavonolignan (21), and a phenolic compound (22), were isolated from a methanol extract of Puerariae Flos. The structures of new compounds were elucidated as 13-N-benzoyl-l-tryptophan-1-N-β-d-glucopyranoside (1), 2-hydroxy-5-methoxy-naringenin (4), and 2-hydroxy-5-methoxy-naringenin 7-O-β-d-glucopyranoside (5). Among the isolates, afromosin (17), tectorigenin (11), apigenin (8), glycitein (16), (-)-hydnocarpin (21), irilin D (12), irisolidone 7-O-glucoside (14), and genistein (10) showed cytotoxicity against human ovarian cancer cell line A2780. Apigenin (8) and (-)-hydnocarpin (21) were the most active (IC₅₀ values of 9.99 and 7.36 μM, respectively).

Medicinal Importance, Pharmacological Activities and Analytical Aspects of an Isoflavone Glycoside Tectoridin

Background:

Polyphenols are a group of plant secondary metabolites that are produced in plants as a protective system against oxidative stress, UV radiation, pathogens and predator’s attack. Flavonoids are major class of plant phenolics found to be present in fruits, vegetables, tea and red wine. Tectoridin also called 40,5,7-thrihydroxy-6-methoxyisoflavone-7-Ob-D-glucopyranoside is an isoflavone glycoside found to be present in the flower of Porites lobata.

Methods:

Present work focused on the biological importance, therapeutic potential and pharmacological activities of tectoridin in medicine. Numerous scientific data has been collected from different literature databases such as Google Scholar, Science Direct, PubMed and Scopus in order to know the health beneficial potential of tectoridin. Pharmacological data have been analyzed in the present work to know the biological effectiveness of tectoridin against human disorders. Analytical data of tectoridin have been collected and analyzed in the present work in order to know the importance of modern analytical method in the isolation, separation and identification of tectoridin.

Results:

Scientific data analysis revealed the biological importance and therapeutic benefit of tectoridin in medicine, signifying the therapeutic potential of tectoridin in the healthcare systems. Biological activities of tectoridin are mainly due to its anti-inflammatory, anti-platelet, anti-angiogenic, hepatoprotective, anti-tumor, estrogenic, antioxidant and hypoglycemic activity. However effectiveness of tectoridin against rat lens aldose reductase, nitric oxide, skeletal and cardiac muscle sarcoplasmic reticulum and enzymes have been also presented in this work. Analytical data signified the importance of modern analytical techniques for the separation, identification and isolation of tectoridin.

Conclusion:

Present work signified the biological importance and therapeutic benefit of tectoridin in the medicine and other allied health sectors.

The inhibition of inducible nitric oxide production in lipopolysaccharide-stimulated rat macrophages and in silico studies by flavonoids from Iris spuria L. rhizomes

ETHNOPHARMACOLOGICAL RELEVANCE

Iris is the largest genus in the family Iridaceae. Iris plants are distributed in tropical regions of the world. They are used as ornamentals and traditionally used to treat a variety of ailments.

AIM

This study aimed to evaluate the anti-inflammatory effect of flavonoids isolated from Iris spuria L.

MATERIALS AND METHODS

The isolated flavonoids (1-4) were identified on the basis of different spectroscopic methods (1D- and 2D-NMR) and co-TLC with authentic samples. The anti-inflammatory effect was tested on lipopolysaccharide (LPS)-induced nitric oxide (NO) production from rat-isolated peritoneal macrophages. Modeling and docking simulations of the compounds were performed using Molecular Operating Environment software and the crystal structure of the murine inducible nitric oxide synthase (iNOS).

RESULTS

Four flavonoids (1-4) had been isolated from the rhizomes of Iris spuria L. (Hocka Hoona) for the first time. They were characterized as 5,7,2'-trihydroxy-6-methoxyflavanone (1), tectorigenin 7-O-β-D-glucopyranoside (2), tectorigenin 4'-O-β-D-glucopyranoside (3), and tectorigenin 4'-O-[β-D-glucopyranosyl(1 → 6)-β-D-glucopyranoside] (4). The selective inducible NO synthase inhibitor; aminoguanidine was used as a positive control. The production of nitric oxide (NO) was inhibited in a dose-dependent manner of the isolated compounds along with isoflavonoids (5-9) previously isolated from Iris spuria L. (Calizona). A concentration of 60 μg/ml of all tested compounds showed a significant inhibitory effect compared to media with LPS. Molecular modeling experiments supported the obtained biological data.

CONCLUSION

Our results reveal that flavonoids isolated from I. spuria L. (Hocka Hoona) and I. spuria L. (Calizona) appear to have a potential anti-inflammatory effect via inhibition of iNOS.

Flavonoids and Xanthones From the Genus Iris: Phytochemistry, Relationships with Flower Colors and Taxonomy, and Activities and Function

The genus Iris consists of approximately 360 species and is distributed to Eurasia, North Africa, and North America. Belamcanda chinensis was incorporated into the genus Iris by APG III as Iris domestica. Iris species have also been cultivated as ornamentals since ancient times. Many flavonoids are isolated and identified from the flowers, leaves, and rhizomes. So far as we know, 6 anthocyanidins, 13 flavones, 20 flavonols, 20 C-glycosylflavones, 14 flavanones, 11 dihydroflavonols, 6 flavan and proanthocyanidins, and 85 isoflavonoids were reported as aglycones and glycosides. However, chalcones, dihydrochalcones, aurones, biflavonoids, and neoflavonoids are not found in the genus Iris. Fifteen xanthones that are related to flavonoids were also isolated from Iris species. In this review, we describe the flavonoids and xanthones that were isolated and characterized from Iris species. Moreover, their phytochemistry, contribution to the flower colors, relationships with taxonomy, and activities and functions are also discussed.

Renoprotective effect of tectorigenin glycosides isolated from Iris spuria L. (Zeal) against hyperoxaluria and hyperglycemia in NRK-49Fcells

Oxidative stress has been identified as an underlying factor in the development of insulin resistance, β-cell dysfunction, impaired glucose tolerance and type 2 diabetes mellitus and it also play major role in kidney stone formation. The present study is aimed to elucidate the in vitro nephroprotective activity of two isoflavonoid glycosides, tectorigenin 7-O-β-D-glucosyl-(1→6)-β-D-glucoside (1) and tectorigenin 7-O-β-D-glucosyl-4'-O-β-D-glucoside (2) isolated from the n-BuOH fraction of Iris spuria L. (Zeal) rhizome MeOH extract against oxalate and high glucose-induced oxidative stress in NRK-49F cells. The results revealed that compounds 1 and 2 significantly increased the antioxidant enzyme activities and decreased MDA levels in both oxalate and high glucose stress. Treatment with these phytochemicals effectively down-regulated expression of crystal modulator genes and pro-fibrotic genes in oxalate and high glucose-mediated stress respectively. This study indicates cytoprotective, antioxidant, anti-urolithic and anti-diabetic effects of compounds 1 and 2 against oxalate and high glucose stress.[Figure: see text].

Antimicrobial Activity of the Constituents of Dalbergia tonkinensis and Structural-Bioactive Highlights

The vulnerable plant Dalbergia tonkinensis Prain, is a rare species, native to Vietnam. Phytochemical investigations and biological evaluations of this species are quite limited. Antimicrobial screening has suggested that, at the low dose of 1.0 mg/mL, the methanol extracts of the leaf, stem bark, and root, as well as chloroform fraction of heartwood can serve as useful sources against seven gram-positive skin microbacteria, Bacillus cereus (ATCC27522), Escherichia coli (JM109), Staphylococcus aureus (ATCC25923), Staphylococcus epidermidis (ATCC14990), Streptococcus pneumonia (ATCC49619), Streptococcus pyogenes (ATCC12344), and Vibrio parahaemolyticus (RIMD2210010), and four oral gram-positive microbacteria Streptococcus mutans (ATCC 25175), Streptococcus mitis (ATCC903), Streptococcus sobrinus (ATCC 33478), and Porphyromonas gingivalis (ATCC33277), with an inhibitory percentage of 60-80% growth for several strains Bacillus cereus, Escherichia coli, and Streptococcus pneumonia. We further assessed antimicrobial activities of the enriched diverse flavonoids from chloroform fraction of its heartwood. Extensive structural activity relationship studies showed structure function closely related to the antimicrobial activity, in which methoxylation at C-2’, and 4’ in isoflavanones, hydroxylation at C-3’ in flavones, substitution at C-5 in isoflavones, and lactone opened ring in neoflavonoids were found to increase the effective inhibitions. In the second antimicrobial assessment, the isolated flavonoid liquiritigenin showed the MIC values of 50, and 100 μg/mL against the microbacterial strains Staphylococcus aureus subsp. aureus (ATCC 11632), and Aspergillus niger (439), respectively, whereas the MIC value of 100 μg/mL was assignable to biochanin A against microbacterium Staphylococcus aureus subsp. aureus.

Hepatoprotective activity of LC-ESI-MS standardized Iris spuria rhizome extract on its main bioactive constituents

The study was designed to evaluate the hepatoprotective activity of Iris spuria against paracetamol induced toxicity at two different doses 100 and 200 mg/kg. The extract showed significant protective activity (p>0.01) at both the doses in dose dependent manner. Administration of the plant extract restored the paracetamol induced elevated levels of serum marker and distorted hepatic tissue architecture. The lipid peroxides (LPO) and glutathione (GSH) levels were also restored towards normal in liver tissue significantly. The main chemical constituents of the extract identified by the liquid chromatography-tandem mass spectrometry (LC-ESI-MSMS) were found to be flavones and isoflavonoids. Tectoridin and iristectorigenin A were the principal compounds present in the methanolic extract of Iris spuria.

Tissue-specific metabolites profiling and quantitative analyses of flavonoids in the rhizome of Belamcanda chinensis by combining laser-microdissection with UHPLC-Q/TOF-MS and UHPLC-QqQ-MS

The rhizome of Belamcanda chinensis (L.) DC. is a traditionally used medicinal material in China. Due to increasing demand, B. chinensis has been cultivated widely, and thus the study on its rational utilization of medicinal part and guidelines for the optimal cultivation and harvest is an important issue. Considering flavonoids were the main bioactive secondary metabolites of B. chinensis, fluorescence microscopy, laser microdissection (LMD), ultra-high performance liquid chromatography-quadrupole/time-of-flight-mass spectrometry (UHPLC-Q/TOF-MS), and UHPLC coupled with triple quadrupole mass spectrometer (UHPLC-QqQ-MS) were applied to profile and determine flavonoids in various tissues in this study. Consequently, 43 peaks were detected by UHPLC-Q/TOF-MS, and 26 flavonoid compounds combined with seven triterpene compounds were identified or tentatively identified in the tissue extractions. The results indicated that the hydrophobic compounds, especially flavonoid or isoflavonoid aglycones and xanthone mainly accumulated in the cork, whereas the hydrophilic compounds, namely the flavonoid and isoflavonoid glycosides were usually found in the cortex or center (the part inside of endodermis). Samples of rhizomes from different growth ages and origins were simultaneously analyzed. It was shown that the bulb or lateral part of the rhizome generally possessed more total flavonoids than the vertical part or the primordium. The present study established a new practical method to evaluate the quality of the rhizome of B. chinensis and to explore the relationship between distribution patterns of secondary metabolites and growth years of plants, thus important information for cultivation and processing was provided.

Qualitative and quantitative evaluation of phenolic compounds in Iris dichotoma Pall

INTRODUCTION

The rhizome of Iris dichotoma Pall., a traditional Chinese herbal medicine that contains (iso) flavonoids as the main bioactive compound, has been used to treat several disorders such as inflammation, throat disorders, asthma and coughs. However, there is a lack of suitable methods for its qualitative and quantitative analysis as well as quality control.

OBJECTIVES

To establish an HPLC method for the simultaneous determination of phenolic constituents, the identification of characteristic metabolites in the rhizomes of I. dichotoma and to compare their contents in samples from different areas of China.

METHODOLOGY

HPLC coupled with diode-array detection (DAD) and electrospray ionisation multistage mass spectrometry (ESI-MS(n) ), and principal component analysis (PCA) were used for the qualitative and quantitative analysis of phenolic compounds in I. dichotoma samples.

RESULTS

Twenty characteristic compounds were identified or tentatively characterised. A quantitative HPLC-UV method allowing the simultaneous quantification of 10 phenolic compounds was optimised and validated in terms of linearity, precision, accuracy, and limits of detection and quantification.

CONCLUSION

The methodology developed proved to be effective for the identification and quantification of phenolic compounds in the rhizomes of I. dichotoma. Samples were classified into three groups according to their geographical origin based on their phenolic composition using principal component analysis.

Purification and structure determination of gelatinase and collagenase inhibitors from Viola patrinii fermentation extracts

Investigation of collagenase and gelatinase inhibitory natural components afforded two isoflavonoids. Two isoflavonoids, tectorigenin-7-O-β-D-glucoside (1) and luteolin-7-O-β-D-glucuronopyranoside (2), were isolated from ethyl acetate fraction of Viola patrinii fermentation extracts (VPFE). Of these, compounds 1 and 2 exhibited collagenase inhibitory activity (IC(50)) at a concentration of less than 1.5 μM, and compound 2 showed gelatinases A and B inhibitory activity (IC(50)) at 0.3 μM and 0.8 μM, respectively.

Anti-platelet effects of flavonoids and flavonoid-glycosides from Sophora japonica

A methanol extract of Sophora japonica was subjected to anti-platelet activity guided fractionation affording the isolation of four flavonoids and six flavonoid-glycosides: biochanin A (1), irisolidone (2), genistein (3), sissotrin (4), sophorabioside (5), genistin (6), tectoridin (7), apigenin (8), quercitrin (9), and rutin (10). The structure of each compound was determined by a variety of spectroscopic methods. Among the compounds, 1, 3, and 7 showed approximately 2.5-6.5 fold greater inhibitory effects on arachidonic acid (AA) and U46619 induced platelet aggregation (IC50: 19.9 and 99.8 microM; 20.3 and 53.8 microM; 25.9 and 123.4 microM, respectively) than acetylsalicylic acid (ASA, IC50: 63.0 and 350.0 microM). Compound 2 was an approximately 22-40 fold stronger inhibitor than ASA on AA and U46619 induced aggregation (IC50: 1.6 and 15.6 microM, respectively).

Aldose reductase inhibitory effect by tectorigenin derivatives from Viola hondoensis

Aldose reductase (AR), the key enzyme of the polyol pathway, is known to play important roles in the diabetic complication. The inhibitors of AR, therefore, would be potential agents for the prevention of diabetic complication. The AR inhibition activity of several isoflavonoids was evaluated in vitro against rat lens. Tectoridin-4'-O-beta-D-glucoside exhibited strong AR inhibition activity on rat lens with an IC50 of 0.54 microM. Similar activities were recorded for the natural tectorigenin and tectoridin. In contrast, tectoridin-4'-O-beta-D-glucoside showed a stronger inhibitory activity than tectorigenin and tectoridin. Our results indicate that glucose conjugation position in this type of isoflavonoids may be required for the activity.

A Glycosidic Isoflavonoid from Viola hondoensis W. BECKER et H. BOISSIEU (Violaceae), and Its Effect on the Expression of Matrix Metalloproteinase-1 Caused by Ultraviolet Irradiation in Cultured Human Skin Fibroblasts

Isolation of the ethyl acetate soluble fraction from aerial parts of Viola hondoensis W. BECKER et H. BOISSIEU yielded one major isoflavonoid glycoside, tectoridin-4'-O-beta-D-glucoside. The structure of the compound was certainly determined by chemical analyses, as well as 1D- and 2D-NMR spectroscopy. The compound exhibited potent inhibitory activity against the expression of matrix metalloproteinase-1 caused by UV-irradiation in cultured human skin fibroblasts.