Benzene, coumarin and quinolinone derivatives from roots of Citrus hystrix

Meta-analysis of citrus-derived additives on chicken meat quality and safety: a comprehensive evaluation of acceptability, physicochemical properties, and microbial contamination

Citrus represents a valuable repository of antioxidant substances that possess the potential for the preservation of meat quality. This meta-analysis aimed to comprehensively assess the impact of citrus additives on the quality and safety of chicken meat. Adhering to the PRISMA protocol, we initially identified 103 relevant studies, from which 20 articles meeting specific criteria were selected for database construction. Through the amalgamation of diverse individual studies, this research provides a comprehensive overview of chicken meat quality and safety, with a specific focus on the influence of citrus-derived additives. Minimal alterations were observed in the nutritional quality of chicken meat concerning storage temperature and duration. The findings demonstrated a significant reduction in aerobic bacterial levels, with Citrus aurantiifolia exhibiting the highest efficacy (P < 0.01). Both extracted and nonextracted citrus components, applied through coating, curing, and marinating, effectively mitigated bacterial contamination. Notably, thiobarbituric acid reactive substances (TBARS) concentrations were significantly reduced, particularly with Citrus hystrix (P < 0.01). Total volatile base nitrogen (TVBN), an indicator of protein degradation, exhibited a decrease, with citrus extract displaying enhanced efficacy (P < 0.01). Chemical composition changes were marginal, except for a protein increase after storage (P < 0.01). Hedonic testing revealed varied preferences, indicating improvements in flavor, juiciness, and overall acceptability after storage (P < 0.01). The study underscores the effectiveness of citrus additives in preserving chicken meat quality, highlighting their antibacterial and antioxidant properties, despite some observed alterations in texture and chemical composition. Citrus additives have been proven successful in 1) mitigating adverse effects on chicken meat during storage, especially with Citrus hystrix exhibiting potent antimicrobial properties, and 2) enhancing the hedonic quality of chicken meat. This research strongly advocates for the application of citrus additives to uphold the quality and safety of chicken meat.

Plant Pyranocoumarins: Description, Biosynthesis, Application

This overview article contains information about pyranocoumarins over the last 55 years. The article is based on the authors' phytochemical and physiological studies in vivo and in vitro as well as search and analysis of data in literature available on Google Scholar, Web of Science, PubMed, and ScienceDirect before January 2022. Pyranocoumarins are synthesized in plants of the Apiaceae, Rutaceae families, and one species in each of the Cornaceae, Calophyllaceae, and Fabaceae families can synthesize this class of compounds. The physiological role of these compounds in plants is not clear. It has been proven that these substances have a wide range of biological activities: anti-cancer, anti-spasmatic, and anticoagulant, and they also inhibit erythrocyte lysis and accumulation of triacylglycerides. The overview generalizes the modern understanding of the classification, structure, and biological activity of natural pyranocoumarins, and summarizes dispersed data into a unified scheme of biosynthesis. The review analyzes data on the localization and productivity of these substances in individual organs and the whole plant. It discusses a link between the unique structure of these substances and their biological activity, as well as new opportunities for pyranocoumarins in pharmacology. The article evaluates the potential of different plant species as producers of pyranocoumarins and considers the possibilities of cell cultures to obtain the end product.

Potential Therapeutic Effects of Citrus hystrix DC and Its Bioactive Compounds on Metabolic Disorders

Metabolic disorders like diabetes mellitus, hypertension, dyslipidemia, and obesity are major medical problems globally. The incidence of these disorders has increased tremendously in recent years. Studies have demonstrated that plants with antioxidant and anti-inflammatory properties have beneficial effects on these disorders. One of these plants is Citrus hystrix DC, commonly known as kaffir lime. This review aims to present updates on the progress of research regarding the use of C. hystrix in metabolic disorders. Phytochemical compounds, including β-pinene, sabinene, citronellal, and citronellol, have been detected in the plant; and its extract exhibited potential antidiabetic, antihyperlipidemic and anti-obesity activity, as well as prevention of development of hypertension. These beneficial properties may be attributable to the presence of bioactive compounds which have therapeutic potential in treating these metabolic disorders. The compounds have the potential to be developed as candidate drugs. This review will assist in validating the regulatory role of the extract and its bioactive compounds on metabolic disorders, thus expediting future research in the area.

Plant-derived lignans as potential antiviral agents: a systematic review

Medicinal plants are one of the most important sources of antiviral agents and lead compounds. Lignans are a large class of natural compounds comprising two phenyl propane units. Many of them have demonstrated biological activities, and some of them have even been developed as therapeutic drugs. In this review, 630 lignans, including those obtained from medicinal plants and their chemical derivatives, were systematically reviewed for their antiviral activity and mechanism of action. The compounds discussed herein were published in articles between 1998 and 2020. The articles were identified using both database searches (e.g., Web of Science, Pub Med and Scifinder) using key words such as: antiviral activity, antiviral effects, lignans, HBV, HCV, HIV, HPV, HSV, JEV, SARS-CoV, RSV and influenza A virus, and directed searches of scholarly publisher's websites including ACS, Elsevier, Springer, Thieme, and Wiley. The compounds were classified on their structural characteristics as 1) arylnaphthalene lignans, 2) aryltetralin lignans, 3) dibenzylbutyrolactone lignans, 4) dibenzylbutane lignans, 5) tetrahydrofuranoid and tetrahydrofurofuranoid lignans, 6) benzofuran lignans, 7) neolignans, 8) dibenzocyclooctadiene lignans and homolignans, and 9) norlignans and other lignoids. Details on isolation and antiviral activities of the most active compounds within each class of lignan are discussed in detail, as are studies of synthetic lignans that provide structure-activity relationship information.

Investigation of HIV-1 Viral Protein R Inhibitory Activities of Twelve Thai Medicinal Plants and Their Commercially Available Major Constituents

Viral protein R (Vpr) is an accessory protein in Human immunodeficiency virus-1 (HIV-1) and has been suggested as an attractive target for HIV disease treatment. Investigations of the ethanolic extracts of twelve Thai herbs revealed that the extracts of the Punica granatum fruits, the Centella asiatica aerials, the Citrus hystrix fruit peels, the Caesalpinia sappan heartwoods, the Piper betel leaves, the Alpinia galangal rhizomes, the Senna tora seeds, the Zingiber cassumunar rhizomes, the Rhinacanthus nasutus leaves, and the Plumbago indica roots exhibited the anti-Vpr activity in HeLa cells harboring the TREx plasmid encoding full-length Vpr (TREx-HeLa-Vpr cells). Moreover, the investigation of the selected main constituents in Punica granatum, Centella asiatica, A. galangal, and Caesalpinia sappan indicated that punicalagin, asiaticoside, ellagic acid, madecassic acid, madecassoside, zingerone, brazilin, and asiatic acid possessed anti-Vpr activities at the 10 μM concentration. Among the tested extracts and compounds, the extracts from Centella asiatica and Citrus hystrix and the compounds, punicalagin and asiaticoside, showed the most potent anti-Vpr activities without any cytotoxicity, respectively.

Ethnochemometric of plants traditionally utilised as local detergents in the forest dependent culture

The purpose of this study is to access the existing awareness of nearly forgotten Thai detergent plants by the use of chemometrics tool. A Northern Thai forest dependent community was chosen as it played vital role on knowledge retaining of plant utilisations. For initial perception, ethnobotanical survey was conducted to determine usage of plants by the community. Then the utilised plant parts were screened for phytochemicals and their relationships with the defined cleansing terms (viz., shampoo, scrub, detergent, soap, scent and spiritual) were analysed by Principal Component Analysis (PCA). From the results, the most cited plants as known, used and found were Acacia concinna, Clitoria ternetea, Oryza sativa and Citrus hystrix. Biometric analyses advised that knowledge of detergent plant utilisation was well preserved at all age ranges and it was not variable with genders. Cluster analysis described that term 'spiritual' was not narrated with cleansing properties. For phytochemical analysis, plant extracts showed positive variable of bioactive ingredients and the main compounds in the extracts was saponins. These findings confirmed that the knowledge of indigenous plant utilisation was reserved by the forest dependent community and the information is beneficial toward local plant conservation movement.

Coumarin-based derivatives with potential anti-HIV activity

Acquired immunodeficiency syndrome (AIDS), as a result of human immunodeficiency virus (HIV) infection which leads to severe suppression of immune functions, is an enormous world-wide health threat. The anti-HIV agents are critical for the HIV/AIDS therapy, but the generation of viral mutants and the severe side effects of the anti-HIV agents pose serious hurdles in the treatment of HIV infection, and creat an urgent need to develop novel anti-HIV agents. The plant-derived compounds possess structural and mechanistic diversity, and among them, coumarin-based derivatives have the potential to inhibit different stages in the HIV replication cycle, inclusive of virus-host cell attachment, cell membrane fusion, integration, assembly besides the conventional target like inhibition of the reverse transcriptase, protease, and integrase. Moreover, (+)-calanolide A, a coumarin-based natural product, is a potential anti-HIV agent. Thus, coumarin-based derivatives are useful scaffolds for the development of anti-HIV agents. This review article describes the recent progress in the discovery, structural modification, and structure-activity relationship studies of potent anti-HIV coumarin-based derivatives including natural coumarin compounds, synthetic hybrids, dimers, and other synthetic derivatives covering articles published between 2000 and 2020.

Acridone alkaloids and flavones from the leaves of Citrus reticulata

A new acridone alkaloid, reticarcidone A (1), decorated with an oxygenated isopentenyl group between C-1 and C-2, was isolated from the leaves of Citrus reticulata Blanco, together with nine known acridone alkaloids (2-10) and fifteen flavones compounds (11-25). The structure of those compounds were confirmed by analysis of comprehensive 1D and 2D NMR, and MS data. Reticarcidone A (1) was the first pyrano[2,3-a]acridone isolated from the genus Citrus. Some of these compounds showed moderated cytotoxicity against the five human tumor cell lines MCF-7, SMMC-7721, HL-60, A549 and SW480.

Citrus species: A Review of Traditional Uses, Phytochemistry and Pharmacology

The Citrus species from family Rutaceae has worldwide applications such as cardiovascular and gastrointestinal problems. Phytochemical investigations have shown that these plants have constituents including flavonoids, limonoids and carotenoids. There are many reports on a wide range of activities such as antiinflammatory, anti-oxidant, immunomodulatory, metabolic, cardiovascular and neuroprotective effects. In the current review, we discuss information regarding botany, phytochemistry, ethnobotany uses, traditional knowledge and pharmacological aspects of the Citrus species.

Citrus hystrix leaf extract attenuated diabetic-cataract in STZ-rats

Diabetic cataract causes severe vision loss. This study evaluated the effects of hesperidin-standardized Citrus hystrix leaf flavonoids-rich extract (CLE) on diabetic-cataract development. Streptozotocin-induced diabetic rats were orally given 150 and 300 mg CLE/kg body-weight. These were compared with non-treated diabetic or healthy rats as controls, over 8 weeks. The CLE gradually attenuated fasting blood glucose (FBG), biomarkers for inflammation (Tumor necrosis factor alpha TNF-α; prostaglandin E2 PGE2); vascular permeability, (Vascular endothelial growth factor VEGF); and oxidative stress, (malondialdehyde MDA). The diabetic cataract was significantly mitigated by the 150 mg CLE/kg dose. Good correlations were found between cataract incidence with FBG (r²  = 0.90), serum PGE2 (r²  = 0.91), MDA (r²  = 0.99), VEGF (r²  = 0.71), but not with TNF-α levels (r²  = 0.49) suggesting the serum FBG, PGE2, MDA, and possibly the VEGF levels may help to predict the cataract risks. The CLE mitigated cataract probably by attenuating hyperglycaemia, inflammation, lens fluid influx, vascular leakage, lens osmotic-imbalance, and fibers over-hydration. PRACTICAL APPLICATIONS: The study shows the flavonoids-rich Citrus hystrix leaf consumption, effectively attenuated diabetes (fasting blood glucose) and mitigated diabetic cataract. It help reduce diabetes-related hyperglycaemia, oxidative stress, inflammation, and vascular leakage. The evidences were the CLE consumptions reduced the serum biomarkers tumor necrosis factor-alpha TNF-α; prostaglandin E2 PGE2, vascular endothelial growth factor (VEGF), and malondialdehyde (MDA). The C. hystrix leaf contains hesperidin, apiin, diosmin, saponarin, apigetrin, rutin and xanthotoxol, and other flavonoid glucosides. The study also showed good correlations between cataract incidence with fasting blood glucose FBG (r²  = 0.90), serum PGE2 (r²  = 0.91), and MDA (r²  = 0.99), and less closely with VEGF (r²  = 0.71) suggesting these serum biomarkers may help predict cataract risks. The CLE indicated cataract mitigation properties probably by attenuating FBG, inflammation, lens fluid influx, lens osmotic-imbalance, and fibers over-hydration.

Acridone alkaloids from the stem bark of Citrus aurantium display selective cytotoxicity against breast, liver, lung and prostate human carcinoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Citrus aurantium L. (Rutaceae) is used, either singly or as a part of a polyherbal preparation, in Nigerian traditional medicine for the management of cancer and inflammatory diseases. Currently, there is a dearth of knowledge demonstrating its anticancer potential.

AIM OF THE STUDY

This study was carried out to determine the in vitro cytotoxicity of the crude extract of the stem bark of C. aurantium, identify and isolate the bioactive constituents and to establish the cytotoxicity of such constituents.

MATERIALS AND METHODS

The powdered bark of C. aurantium was extracted by MeOH at room temperature (25-34 °C) and the crude extract was partitioned successively, with n-hexane, dichloromethane and methanol. Amongst the fractions, the DCM fraction was the most active and compounds were isolated from this fraction using a combination of chromatographic techniques. The structures of the isolated compounds were elucidated by spectroscopic means (MS, 1D and 2D NMR). The cytotoxicity of the extract, and the isolated compounds were evaluated by the MTT assay against four human cancer cell lines: A549 (lung), HepG2 (liver), MCF7 (breast) and PC3 (prostate). The selectivity of the isolated compounds was assessed using the normal human prostate epithelium cells (PNT2).

RESULTS AND DISCUSSION

Of the three plant fractions, the DCM fraction showed significant cytotoxicity, with its highest activity against A549 cells (IC₅₀ = 3.88 µg/mL) and the least activity on HepG2 cells (IC₅₀ = 5.73 µg/mL). Six acridone alkaloids, citrusinine-I (1), citracridone-I (2), 5-hydroxynoracronycine (3), natsucitrine-I (4), glycofolinine (5) and citracridone-III (6), were isolated from the DCM fraction of C. aurantium. The isolated compounds demonstrated potent to moderate cytotoxicity (IC₅₀ = 12.65-50.74 µM) against the cancer cells under investigation. It is noteworthy that the compounds exerted cytotoxicity at least four times more selective towards the carcinoma cells than the PNT2 cells.

CONCLUSION

The results obtained from this study have provided some evidence for the ethnomedicinal use of C. aurantium against cancer and the acridone alkaloids present in its stem bark, have appeared to be responsible for the anticancer effects.

New coumarin from the roots of Prangos pabularia

The new coumarin 1, yuganin A (7-methoxy-8-((1S,2S)-1,2,3-trihydroxy-3-methylbutyl)-2H-chromen-2-one) along with nine known coumarins, heraclenol 3'-O-β-D-glucopyranoside (2), oxypeucedanin hydrate 3'-O-β-D-glucopyranoside (3), heraclenol (4), oxypeucedanin hydrate (5), osthole (6), oxypeucedanin (7), heraclenin (8), isoimperatorin (9), imperatorin (10) and the disaccharide sucrose (11), have been isolated from the roots of Prangos pabularia, and the structures of these isolated compounds were elucidated by spectroscopic means, especially, UV, HR-ESIMS, and 1D and 2D NMR spectroscopy. Furthermore, the anti-melanogenic effect of yuganin A and its inhibitory effect on B16 cells were evaluated. Yuganin A may be useful in the treatment of hyperpigmentation and as a skin-whitening agent in the cosmetics industry.

Anti-Inflammatory and Neuroprotective Constituents from the Peels of Citrus grandis

A series of chromatographic separations performed on the ethanol extracts of the peels of Citrus grandis has led to the characterization of forty compounds, including seventeen coumarins, eight flavonoids, two triterpenoids, four benzenoids, two steroids, one lignan, one amide, and five other compounds, respectively. The chemical structures of the purified constituents were identified on the basis of spectroscopic elucidation, including 1D- and 2D-NMR, UV, IR, and mass spectrometric analysis. Most of the isolated compounds were examined for their inhibition of superoxide anion generation and elastase release by human neutrophils. Among the isolates, isomeranzin (3), 17,18-dihydroxybergamottin (12), epoxybergamottin (13), rhoifolin (19), vitexicarpin (22) and 4-hydroxybenzaldehyde (29) displayed the most significant inhibition of superoxide anion generation and elastase release with IC₅₀ values ranged from 0.54 to 7.57 μM, and 0.43 to 4.33 μM, respectively. In addition, 7-hydroxy-8-(2′-hydroxy-3′-methylbut-3′-enyl)coumarin (8) and 17,18-dihydroxybergamottin (12) also exhibited the protection of neurons against Aβ-mediated neurotoxicity at 50 μM.

Targeting the dengue β-OG with serotype-specific alkaloid virtual leads

The dengue envelope β-OG pocket is a crucial hinge for mediating virus-host fusion via conformational changes in the envelope to the fusion-competent form. The β-OG pocket is a small molecule target site for inhibition of virus-host fusion. As of date, the only structure of the β-OG pocket known is of serotype 2. Studies of β-OG inhibition by small molecules primarily target viral serotype 2. Envelope and β-OG sequence alignments, reveal dissimilarities across serotypes. In light of protein sequence-structure-function correlation, sequence variations suggest serotypic variations in β-OG druggability. This, together with the fact that dengue viral proteins do have serotype-specific variations of structure and function, lead to the study of the serotype-specificity of the dengue β-OG ligand binding behaviour. β-OG druggability was compared using comparative models of envelope proteins containing the β-OG pocket in four serotypes of the dengue virus. β-OG ligand binding was found to vary with respect to hydrophobicity, hydrophilicity, hydrogen bonding, van der Waals interactions with ligands and tightness of the binding site. The study also reports serotype-specific virtual leads identified from a library of 9175 alkaloids, using a consensus docking and scoring approach. The docking algorithms of Glide SP and XP, together with the Lamarckian genetic algorithm were employed for consensus docking. For consensus scoring, the Glide empirical score was employed along with the scoring function of AutoDock. A multi-dimensional lead optimisation approach was performed for optimising affinity, ligand efficiency, lipophilic ligand efficiency, ADMET and molecular torsional strains. The study proposes the serotype-specific inhibition of the β-OG for an effective inhibition of virus-host fusion, in contrast to a pan inhibitor.

The Chemistry and Pharmacology of Citrus Limonoids

Citrus limonoids (CLs) are a group of highly oxygenated terpenoid secondary metabolites found mostly in the seeds, fruits and peel tissues of citrus fruits such as lemons, limes, oranges, pumellos, grapefruits, bergamots, and mandarins. Represented by limonin, the aglycones and glycosides of CLs have shown to display numerous pharmacological activities including anticancer, antimicrobial, antioxidant, antidiabetic and insecticidal among others. In this review, the chemistry and pharmacology of CLs are systematically scrutinised through the use of medicinal chemistry tools and structure-activity relationship approach. Synthetic derivatives and other structurally-related limonoids from other sources are include in the analysis. With the focus on literature in the past decade, the chemical classification of CLs, their physico-chemical properties as drugs, their biosynthesis and enzymatic modifications, possible ways of enhancing their biological activities through structural modifications, their ligand efficiency metrics and systematic graphical radar plot analysis to assess their developability as drugs are among those discussed in detail.

Prenylated Coumarins from Heracleum stenopterum, Peucedanum praeruptorum, Clausena lansium, and Murraya paniculata

Four hitherto unknown prenylated coumarins, namely 6″-O-β-D-apiofuranosylapterin (1), 4'-O-isobutyroylpeguangxienin (2), 6-(3-methyl-2-oxobutyroyl)-7-methoxycoumarin (3), and 6-hydroxycoumurrayin (4), were isolated from the ethanol extract of Heracleum stenopterum, Peucedanum praeruptorum, Clausena lansium, and Murraya paniculata, respectively. Their chemical structures were established on the basis of extensive spectroscopic analysis. Compound 2 exhibited in vitro cytotoxic activity against five human cancer cell lines (HL-60, A-549, SMMC-7721, MCF-7, and SW-480) with IC₅₀ values ranging from 15.9 to 23.2 μM.

Prenylfuranocoumarin-HMGA-flavonol glucoside conjugates and other constituents of the fruit peels of Citrus hystrix and their anticholinesterase activity

Sixteen compounds including dihydroxy prenylfuranocoumarins/3-hydroxy-3-methylglutaric acid conjugates and dihydroxy prenylfuranocoumarins/3-hydroxy-3-methylglutaric acid/1-O-flavonyl-β-d-glucopyranoside conjugates, together with other dihydroxyprenylfuranocoumarins conjugates, were isolated from the ethyl acetate extract of the fruit peels of Citrus hystrix. Some of the isolates were evaluated for their cholinesterase inhibitory activity, but only one compound possessing a 3-O-β-d-glucopyranosyl-3,5,7,4'-tetrahydroxy-6,8,3'-trimethoxyflavonol nucleus in the prenylfuranocoumarin-HMGA conjugate showed strong activity.

Recent investigations of bioactive natural products from endophytic, marine-derived, insect pathogenic fungi and Thai medicinal plants

Living organisms in Thailand are very diverse due to the unique geographical location of Thailand. The diversity of Thai bioresources has proven to be a rich source of biologically active compounds. The present review covers bioactive substances from Thai endophytic, marine-derived, insect pathogenic fungi and medicinal plants. Many new compounds isolated from Thai bioresources have diverse skeletons belonging to various classes of natural products. These compounds exhibited an array of biological activities, and some are of pharmaceutical interest. Bioactive compounds from Thai bioresources have not only attracted organic chemists to develop strategies for total synthesis, but also attracted (chemical) biologists to investigate the mechanisms of action. The chemistry and biology of some selected compounds are also discussed in this review.