In silico identification of deep-sea fungal alkaloids as potential inhibitors of SARS-CoV-2, Delta and Omicron spikes.

Aim: Virtual screening of deep-sea fungal metabolites against SARS-CoV-2 Delta and Omicron spikes as potential antivirals. Materials & methods: Deep-sea fungal alkaloids (n ≥ 150) were evaluated against SARS-CoV-2, Delta and Omicron spikes, using various in silico approaches, including Admet scores, physiochemical properties, molecular docking (MD) and MD simulation (150 ns). Results: The test alkaloids complied with Admet scores and physiochemical properties within acceptable ranges, and followed Lipinski's rule of five. Of these, Cladosporium sphaerospermum-derived cladosin K (tetramate alkaloid) for SARS-CoV-2, Cystobasidium laryngis-derived saphenol (phenazine alkaloid) for Delta and Chaetomium globosum-derived chaetoglobosin E (quinoline alkaloid) for Omicron were identified as potential spike-inhibitors. Conclusion: Our data therefore, strongly warrants further experimental validations of cladosin K, saphenol and chaetoglobosin E, especially against the Omicron and Delta spikes.

Green extraction of Milletia pinnata oil for the development, and characterization of pectin crosslinked carboxymethyl cellulose/guar gum herbal nano hydrogel.

Milletia pinnata oil and Nardostachys jatamansi are rich sources of bioactive compounds and have been utilized to formulate various herbal formulations, however, due to certain environmental conditions, pure extract form is prone to degradation. Therefore, in this, study, a green hydrodistillation technology was used to extract M. pinnata oil and N. jatamansi root for the further application in development of pectin crosslinked carboxymethyl cellulose/guar-gum nano hydrogel. Both oil and extract revealed the presence of spirojatamol and hexadecanoic acid methyl ester. Varied concentrations (w/w) of cross-linker and gelling agent were used to formulate oil emulsion extract gel (OEEG1, OEG1, OEEG2, OEG2, OEEG3, OEG3, OEEG4, OEG4, OEEG5, OEG5), in which OEEG2 and OEG2 were found to be stable. The hydrogel displayed an average droplet size of 186.7 nm and a zeta potential of -20.5 mV. Endo and exothermic peaks and the key functional groups including hydroxyl, amide II, and amide III groups confirmed thermal stability and molecular structure. The smooth surface confirmed structural uniformity. Bactericidal activity against both Gram-positive (25.41 ± 0.09 mm) and Gram-negative (27.25 ± 0.01 mm) bacteria and anti-inflammatory activity (49.25%-83.47%) makes nanohydrogel a potential option for treating various infections caused by pathogenic microorganisms. In conclusion, the use of green hydrodistillation technology can be used to extract the bioactive compounds that can be used in formulation of biocompatible and hydrophobic nanohydrogels. Their ability to absorb target-specific drugs makes them a potential option for treating various infections caused by pathogenic microorganisms.

Organosulfurs, S-allyl cysteine and N-acetyl cysteine sequester di-carbonyls and reduces carbonyl stress in HT22 cells.

Diabetes, characterized by high blood glucose level, is a progressive metabolic disease that leads to serious health complications. One of the major pathological consequences associated with diabetes is the accumulation of highly reactive carbonyl compounds called advanced glycation end products (AGEs). Most of the AGEs are dicarbonyls and have the potential to covalently modify proteins especially at the lysine residues in a non-enzymatic fashion (a process termed as glycation) resulting in the functional impairment and/or toxic gain in function. Therefore, non-toxic small molecules that can inhibit glycation are of interest for the therapeutic intervention of diabetes. In the present communication, we have investigated the effect of organosulfurs (S-allyl cysteine, SAC and N-acetyl cysteine, NAC) that are major principal components of Allium sativa against the glycation of different proteins. We discovered that both SAC and NAC are potent anti-glycating agents. We also found that both SAC and NAC reduce ROS level and inhibit apoptosis caused by protein glycation.

Inhibition of hepatitis B virus activities by Rhazya stricta­derived acacetin and acetyl­ß­carboline.

Hepatitis B virus (HBV) causes acute and chronic liver diseases, leading to cirrhosis and hepatocellular carcinoma. Although direct-acting nucleoside analogs, such as lamivudine (LAM), adefovir and famciclovir, are available, emergence of drug-resistance due to mutations in HBV polymerase (POL) restricts their further use. Alternatively, numerous plant products and compounds isolated from plants have been reported to confer anti-HBV efficacies without any sign of resistance in vitro or in vivo. As, flavonoids and alkaloids are the most widely reported antivirals, the anti-HBV activities of the flavonoid acacetin (ACT) and the alkaloid acetyl-ß-carboline (ABC) from the aerial parts of Rhazya stricta were assessed in the present study. Both compounds were isolated from the ethyl acetate fraction of the total methanol extract using column and thin-layer chromatography, and their structures were determined by nuclear magnetic resonance spectroscopy (NMR). Both compounds (at 6.25-50 µg/ml) showed a lack of hepatocytotoxicity in cultured HepG2.2.15 cells. Anti-HBV ELISA [hepatitis B surface antigen (HBsAg) and hepatitis B pre-core-antigen (HBeAg)] on HepG.2.2.15 cells following treatment with selected concentrations (12.5, 25 and 50 µg/ml) of both compounds showed dose- and time-dependent anti-HBV activities. Compared with those in the untreated control at day 5, ACT and ABC (25 µg/ml, each) maximally inhibited HBsAg synthesis by 43.4 and 48.7%, respectively, whilst also maximally inhibiting HBeAg synthesis by 41.2 and 44.2%, respectively, in HepG2.2.15 cells. Comparatively, quercetin and LAM (standards; POL inhibitors) suppressed HBsAg (63.9 and 60.2%, respectively) and HBeAg synthesis (87.1 and 84.3%, respectively) by larger magnitudes. Molecular docking of ACT and ABC structures performed in AutoDock revealed their hydrogen bonding with the drug-sensitive [wild-type (wt)-POL] 'Tyr-Met-Asp-Asp' motif, in addition to the drug-resistant [mutant (mut)-POL] 'Tyr-Ile-Asp-Asp' motif residues of the polymerase binding-pocket, along with other electrostatic interactions. In the wt-POL complex, both compounds showed good interactions with Asp205. In the mut-POL complex, ACT and ABC interacted with Tyr203-Asp205 and Tyr203-Ile204, respectively. In conclusion, to the best of our knowledge, the present study demonstrates anti-HBV efficacies of ACT and ABC in vitro for the first time, endorsed by in silico data. However, further molecular and pharmacological studies are required to validate their pre-clinical therapeutic potential.

The anti-oxidative, anti-cell proliferative and anti-microbial efficacies of cold-adapted Crepis flexuosa: HPTLC and GC/MS analyses.

The genus Crepis constitutes cold-adapted plant spp., of these some are traditionally used in folk medicine against inflammation or fungal infections without scientific validations. Here, we report the biological activities of Crepis flexuosa total ethanol-extract (CF-EtOH) and its hexane (CF-Hex), ethyl acetate (CF-EtOA), butanol (CF-ButOH), and aqueous (CF-Aqua) fractions. Our in vitro DPPH and ABTS radical-scavenging assays showed CF-EtOH, CF-ButOH and CF-Aqua with maximal, CF-EtOA with moderate, and CF-Hex with mild anti-oxidant activities. When tested on human cancer cell lines, high cytotoxicity was demonstrated by CF-EtOH (IC50: 42.45 µg/ml) and CF-Aqua (IC50: 46.37 µg/ml) on HepG2, followed by CF-Hex (IC50: 63.24 µg/ml) and CF-ButOH (IC50: 65.32 µg/ml) on MCF7 cells. The human primary cell line (HUVEC) had comparatively lower cytotoxicity for the tested samples. Moreover, when assessed for anti-microbial efficacy, CF-ButOH and CF-Aqua exhibited the strongest activity (MIC: 156.25 µg/ml) against S. aureus, E. faecalis and C. albicans. Further, while the developed RP-HPTLC identified the bioactive flavonoid luteolin-7-O-glucoside (17.58 mg/g), GS/MS analysis revealed sixteen compounds in C. flexuosa extract. In conclusion, we for the first time show the promising anti-oxidative, anti-cell proliferative and anti-microbial efficacies of C. flexuosa. This warrants further phytochemical and bio-efficacy studies towards isolations and identifications of active principles.

Isolation and Characterization of Two Chalcone Derivatives with Anti-Hepatitis B Virus Activity from the Endemic Socotraen Dracaena cinnabari (Dragon's Blood Tree).

Hepatitis B virus (HBV) infection is prevalent and continues to be a global health concern. In this study, we determined the anti-hepatitis B virus (HBV) potential of the Socotra-endemic medicinal plant Dracaena cinnabari and isolated and characterized the responsible constituents. A bioassay-guided fractionation using different chromatographic techniques of the methanolic extract of D. cinnabari led to the isolation of two chalcone derivatives. Using a variety of spectroscopic techniques, including 1H-, 13C-, and 2D-NMR, these derivatives were identified as 2,4'-dihydroxy-4-methoxydihydrochalcone (compound 1) and 2,4'-dihydroxy-4-methoxyhydrochalcone (compound 2). Both compounds were isolated for the first time from the red resin (dragon's blood) of D. cinnabari. The compounds were first evaluated for cytotoxicity on HepG2.2.15 cells and 50% cytotoxicity concentration (CC50) values were determined. They were then evaluated for anti-HBV activity against HepG2.2.15 cells by assessing the suppression of HBsAg and HBeAg production in the culture supernatants and their half maximum inhibitory concentration (IC50) and therapeutic index (TI) values were determined. Compounds 1 and 2 indicated inhibition of HBsAg production in a dose- and time-dependent manner with IC50 values of 20.56 and 6.36 µg/mL, respectively.

Structural exploration of Y-domain reveals its essentiality in HEV pathogenesis.

Hepatitis E virus (HEV) is a major causative agent of hepatitis E infections across the globe. Although the essentiality of HEV nonstructural polyprotein (pORF1) putative Y-domain (Yd) has been established in viral pathogenesis, its structural-functional role remains elusive. The current research discusses the novel exploration on Yd protein expression, purification, biophysical characterization and structure-based docking analysis. The codon optimized synthetic gene and optimized expression parameters i.e., 5 h induction with 0.25 mM IPTG at 37 °C, resulted in efficient production of Yd protein (~40 kDa) in E. coli BL21(DE3) cells. Majority of the recombinant Yd (rYd) protein expressed as inclusion bodies was solubilized in 0.5% N-lauroylsarcosine and purified using Ni-NTA chromatography. Circular dichroism (CD) and UV visible absorption spectroscopic studies on Yd revealed both secondary and tertiary structure stability in alkaline range (pH 8.0-10.0), suggesting correlation with its physiological activity. Thus, loss in structure at low pH perhaps play crucial role in cytoplasmic-membrane interaction. The biophysical data were in good agreement with insilico structural analyses, which suggested mixed α/ß fold, non-random and basic nature of Yd protein. Furthermore, due to Yd protein essentiality in HEV replication and pathogenesis, it was considered as a template for docking and drug-likeness analyses. The 3D modeling of Yd protein and structure-based screening and drug-likeness of inhibitory compounds, including established antiviral drugs led to the identification of top nine promising candidates. Nonetheless, in vitro studies on the predicted interaction of Yd with intracellular-membrane towards establishing replication-complexes as well as validations of the proposed therapeutic agents are warranted.

The first bioactivity studies of Acantholimon lycopodioides from high altitude Karakoram-Himalayan desert.

Couple of ethnopharmacological surveys in the Indian Ladakh and Pakistani Shigar valleys has reported the medicinal use of Acantholimon lycopodioides against cardiac and gastric disorders that however, remains without scientific rationale or experimental validations. Here, we assess the in vitro bio/therapeutic activities of A. lycopodioides extracts as well as chloroform, ethyl acetate, n-butanol and aqueous fractions. The in vitro ß-carotene-linoleic acid bleaching and DPPH radical scavenging methods demonstrated a very high anti-oxidative property of chloroform and ethyl acetate fractions compared to others. Cell viability assay (MTT) on human cervical (HeLa), breast (MDA-MB321) and liver (HepG2) cancer cells revealed their differential cytotoxicity, except the chloroform fraction. Of these, the precipitate exerted highest cytotoxicity on HepG2 cells followed by aqueous fraction on MDA-MB321 cells. Notably, the non-cytotoxicity of chloroform fraction coincided with its highest anti-oxidative activity. Further, the chloroform fraction showed marked hepatoprotection (up to 84%) against 3'7'dichlorofluorescin triggered free radicals induced oxidative damage. Also, the hepatoprotective chloroform fraction mildly activated CYP3A4 in HepG2 cells (dual-luciferase assay). Moreover, the A. lycopodioides extracts and fractions showed differential anti-bacterial and anti-fungal activities. Of these, while S. aureus was more sensitive to the water-insoluble extract, ethyl acetate fraction showed moderate activity against E. coli and C. albicans. On the other hand, the chloroform fraction showed promising activity against S. Aureus, C. albicans, P. vulgaris and E. faecalis. In conclusion, our data for the first time, demonstrated promising anti-oxidative, hepatoprotective, anti-cancer, anti-microbial and CYP3A4 activating salutations of A. lycopodioides. This warrants further studies towards isolation and identification of its therapeutically active principles.

Oncoglabrinol C, a new flavan from Oncocalyx glabratus protects endothelial cells against oxidative stress and apoptosis, and modulates hepatic CYP3A4 activity.

Active herbal or natural compounds have high chemical diversity and specificity than synthetic drugs. Recently, we have validated the hypoglycemic salutation of Oncocalyx glabratus in rodent model, and demonstrated the activation of PPARα/γ by its newly ioslated flavan derivative Oncoglabrinol C (5,3'-Dihydroxyflavan 7-4'-O-digallate) in liver cells (HepG2). Here we evaluated the potential of Oncoglabrinol C against Dichlorofluorescin (DCFH) and Methylglyoxal (MGO) induced endothelial cells (HUVEC) oxidative and apoptotic damage, including activation of PXR-mediated hepatic CYP3A4. Our MTT assay showed protection of ~57% and ~63.5% HUVEC cells by 10 and 20 µg/ml doses of Oncoglabrinol C, respectively through attenuating DCFH triggered free-radicals. Also, the two doses effectively protected ~53% and ~65.5% cells, respectively by reversing MGO toxicity. In DCFH and MGO treated cells, Oncoglabrinol C (20 µg/ml) effectively downregulated caspase 3/7 activity by ~33% and ~43.5%, respectively. Moreover, in reporter gene (dual-luciferase) assay, Oncoglabrinol C (20 µg/ml) moderately activated hepatic CYP3A4. Molecular docking of Oncoglabrinol C indicated its strong interactions with cellular caspase 3/7, PPARα/γ and PXR proteins, which supported its anti-apoptotic (antagonistic) as well as pro-hypoglycemic and PXR/CYP activating (agonistic) activities. Taken together, our findings demonstrated the potential of Oncoglabrinol C in reversing the endothelial oxidative and apoptotic damage as well as in the activation of hepatic CYP3A4. This warrants further evaluations of Oncoglabrinol C and related compounds towards developing effective and safe drugs against diabetes associated cardiovascular disorders.

Bioassay-guided isolation of anti-hepatitis B virus flavonoid myricetin-3-O-rhamnoside along with quercetin from Guiera senegalensis leaves.

Recently, we have shown in vitro anti-hepatitis B virus (HBV) activity of G. senegalensis J.F. Gmel leaves, and Identified quercetin and other flavonoids by HPTLC. Here we report bioassay-directed fractionation of G. senegalensis leaves using column chromatography and isolation of two flavonoinds from the n-butanol fraction, their structure determination (1H NMR, 13C NMR and 2D-NMR) and assessment of antiviral activities (HBsAg and HBeAg assay) in HBV-reporter HepG2.2.2.15 cells. Further molecular docking was performed against HBV polymerase (Pol/RT) and capsid (Core) proteins as well as host-receptor sodium taurocholate co-transporting polypeptide (NTCP). The two isolated bioactive compounds were identified as quercetin and myricetin-3-O-rhamnoside. Quercetin significantly inhibited synthesis of HBsAg and HBeAg by about 60% and 62%, respectively as compared to myricetin-3-O-rhamnoside by 44% and 35%, respectively. Molecular docking of the two anti-HBV flavonoids revealed their higher binding affinities towards Pol/RT than Core and NTCP. In conclusion, this is the first report on anti-HBV active myricetin-3-O-rhamnoside along with quercetin isolated from G. senegalensis leaves. Their possible mode of anti-HBV activities are suggested through binding with viral Pol/RT and Core as well as host NTCP proteins.

Novel polycyclic pyrroloquinazoline alkaloids from Anisotes trisulcus and their biological activity.

Two new polycyclic pyrroloquinazoline alkaloids with unprecedented skeleton, anisulcusines A (1) and B (2), along with four known compounds (3-6), were identified from the aerial parts of Anisotes trisulcus (Forssk.) Nees. To our knowledge, anisulcusines A and B are the first polycyclic pyrroloquinazoline alkaloids that possess a unique N-methyl-1,2-dihydro-1'H-spiro[benzo[d][1,3]oxazine moiety. The chemical structures of the new compounds were elucidated through extensive spectroscopic analyses and high-resolution mass spectroscopy. Anisulcusine B (2) exerted moderate cytotoxic effect on cultured human hepatoma (HuH7) cells, whereas compounds 1 and 3-5 exhibited mild cell proliferative or growth stimulatory activity. HIGHLIGHTS Two new polycyclic pyrroloquinazoline alkaloids from Anisotes trisulcus. Structures were elucidated on the basis of 1D- and 2D-NMR and HR-ESI-MS spectra. Compound (2) exerted moderate cytotoxic effect against human hepatoma (HuH7) cells. Compounds (1, 3-5) exhibited mild cell proliferative or growth stimulatory activity.

The anti-hepatitis B virus therapeutic potential of anthraquinones derived from Aloe vera.

Although the approved hepatitis B virus (HBV)-polymerase inhibitors (e.g., lamivudine) often lead to drug-resistance, several natural products have shown promising efficacies. Though Aloe vera (AV) gel and its constituents are shown inhibitors of many viruses, their anti-HBV activity still remains elusive. We therefore, tested the anti-HBV potential of AV extract and its anthraquinones in hepatoma cells, including molecular docking, high-performance thin layer chromatography (HPTLC), and cytochrome P450 (CYP3A4) activation analyses. Our anti-HBV assays (HBsAg/HBeAg Elisa) showed maximal inhibition of viral antigens production by aloe-emodin (~83%) > chrysophanol (~62%) > aloin B (~61%) > AV extract (~37%) in HepG2.2.15 cells. Interestingly, the effect of aloe-emodin was comparable with lamivudine (~86%). Moreover, sequential treatment with lamivudine (pulse) followed by aloe-emodin (chase) enhanced the efficacy of monotherapy by ~12%. Docking (AutoDock Vina) of the anthraquinones indicated strong interactions with HBV-polymerase residues that formed stable complexes with high Gibbs's free energy. Further, identification of aloe-emodin and aloin B by validated HPTLC in AV extract strongly endorsed its anti-HBV potential. In addition, our luciferase-reporter gene assay of transfected HepG2 cells showed moderate induction of CYP3A4 by aloe-emodin. In conclusion, this is the first report on anti-HBV potential of AV-derived anthraquinones, possibly via HBV-polymerase inhibition. Of these, although aloin B exhibits novel antiviral effect, aloe-emodin appears as the most promising anti-HBV natural drug with CYP3A4 activating property towards its enhanced therapeutic efficacy.

Hepatoprotective effect of Solanum surattense leaf extract against chemical- induced oxidative and apoptotic injury in rats.

BACKGROUND: Of over 35 Saudi plants traditionally used to treat liver disorders, majority still lack scientific validations. We therefore, evaluated the anti-oxidative, anti-apoptotic and hepatoprotective potential of Solanum surattense leaves total ethanol-extract (SSEE). METHODS: The cytoprotective (4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide/ MTT assay) and anti-apoptotic (caspase-3/7) potential of SSEE (25-200 µg/mL) were assessed in cultured HepG2 cells against dichlorofluorescein (DCFH)-induced toxicity. The hepatoprotective salutation of SSEE (100 and 200 mg/kg.bw/day) in carbon tetrachloride (CCl4)-intoxicated rats was evaluated by serum biochemistry and histopathology. The anti-oxidative activity of SSEE (31.25-500 µg/mL) was tested by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging and linoleic acid bleaching assays. Also, SSEE was subjected to qualitative phytochemical analysis, and standardized by validated high-performance liquid chromatography (HPTLC). RESULTS: SSEE at doses 50, 100 and 200 µg/mL showed HepG2 cell proliferative and protective potential by about 61.0, 67.2 and 95%, respectively through inhibition of caspase-3/7 against DCFH-toxicity. In CCl4-injured rats, SSEE (200 mg/kg) significantly (P < 0.001) normalized serum transaminases, alkaline phosphatase, bilirubin, cholesterol, triglycerides, and total protein, including tissue malondialdehyde and nonprotein sulfhydryls levels, supported by the liver histopathology. SSEE further showed strong in vitro anti-oxidative and anti-lipid peroxidative activities, evidenced by the presence of alkaloids, flavonoids, tannins, sterols and saponins. Identification of ß-sitosterol (3.46 µg/mg) strongly supported the anti-oxidative and hepatoprotective salutation of SSEE. CONCLUSION: Our findings suggest the therapeutic potential of S. surattense against chemical-induced oxidative stress and liver damage. However, isolation of the active principles and elucidation of mechanism of action remain to be addressed.

Protective effect of Atriplex suberecta extract against oxidative and apoptotic hepatotoxicity.

Atriplex suberecta I. Verd is a known phytomedicinal species of Atriplex; however, studies into its bioactivity remain inconclusive. The in vitro and in vivo antioxidative and hepatoprotective potential of A. suberecta ethanol-extract (ASEE) was assessed in the present study. 1,1-diphenyl-2-picrylhydrazyl radical scavenging and ß-carotene bleaching assays revealed that ASEE possesses free radical scavenging and anti-lipid peroxidative activities. These results were supported by the in vitro protection of HepG2 hepatoblastoma cells via abating 2,7-dichlorofluorescein-activated oxidative and apoptotic molecules (caspase-3/-7). In carbon tetrachloride-treated rats, the oral administration of ASEE significantly normalized serum biomarkers of liver function (serum glutamate oxaloacetate, serum pyruvate transaminase, alkaline phosphatase, γ-glutamyl transferase and bilirubin) and the lipid profile (total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides and malondialdehyde), including tissue non-protein sulfhydryl and total protein levels. These results were also supported by liver histopathology, which demonstrated that the therapeutic effect of ASEE was comparable to silymarin. Furthermore, phytochemical analysis of ASEE revealed the presence of flavonoids, alkaloids, tannins and saponins. Rutin, an antioxidant flavonoid, was identified using the validated high-performance thin-layer chromatography method. In conclusion, this is the first report on the therapeutic potential of A. suberecta against chemical-induced oxidative stress and liver damage.

Isolation and validated HPTLC analysis of four cytotoxic compounds, including a new sesquiterpene from aerial parts of Plectranthus cylindraceus.

We report isolation of a new sesquiterpene (compound 2: plectranol A) along with three known compounds (1: maaliol, 3: penduletin and 4: chrysosplenol D) from the aerial parts of Plectranthus cylindraceus Hoechst. Ex. Benth ethyl acetate extract (PCEAE). Their structures were established by UV, IR, NMR (1H & 13C), HRESIMS and HSQC methods. The MTT cell proliferation assay of the compounds and the extract performed on human breast, skin and cervical cancer cell lines showed high toxicity, and their IC50 (µg/mL) values were determined. The validated HPTLC analyses of maaliol and PCEAE (method I) and, penduletin, chrysosplenol D and PCEAE (method II) furnished sharp and compact peaks. The estimated high contents (µg/mg) of maaliol (17.06), penduletin (39.36) and chrysosplenol D (31.66) in PCEAE approved the plant's cytotoxic property. Since, P. cylindraceus contains a variety of cytotoxic terpenoids and flavonoids; our data warrant its further phytochemical and biological characterisation towards developing promising anti-cancer drugs.

Quantitative analysis of rutin, quercetin, naringenin, and gallic acid by validated RP- and NP-HPTLC methods for quality control of anti-HBV active extract of Guiera senegalensis.

CONTEXT: Guiera senegalensis J.F. Gmel (Combretaceae) is a folk medicinal plant used in various metabolic and infectious diseases. In addition to its antiviral activities against herpes and fowlpox, the anti-HBV efficacy is very recently reported. OBJECTIVE: To develop and validate simple, sensitive RP-/NP-HPTLC methods for quantitative determination of biomarkers rutin, quercetin, naringenin, and gallic acid in the anti-HBV active G. senegalensis leaves ethanol-extract. MATERIALS AND METHODS: RP-HPTLC (rutin & quercetin; phase- acetonitrile:water, 4:6) and NP-HPTLC (naringenin & gallic acid; phase- toluene:ethyl acetate:formic acid, 6:4:0.8) were performed on glass-backed silica gel plates 60F254-RP18 and 60F254, respectively. The methods were validated according to the ICH guidelines. RESULTS: Well-separated and compact spots (Rf) of rutin (0.52 ± 0.006), quercetin (0.23 ± 0.005), naringenin (0.56 ± 0.009) and gallic acid (0.28 ± 0.006) were detected. The regression equations (Y) were 12.434x + 443.49, 10.08x + 216.85, 11.253x + 973.52 and 11.082x + 446.41 whereas the coefficient correlations (r2) were 0.997 ± 0.0004, 0.9982 ± 0.0001, 0.9974 ± 0.0004 and 0.9981 ± 0.0001, respectively. The linearity ranges (ng/spot) were 200-1400 (RP-HPTLC) and 100-1200 (NP-HPTLC). The LOD/LOQ (ng/band) were 33.03/100.1 (rutin), 9.67/29.31 (quercetin), 35.574/107.8 (naringenin), and 12.32/37.35 (gallic acid). Gallic acid (7.01 µg/mg) was the most abundant biomarker compared to rutin (2.42 µg/mg), quercetin (1.53 µg/mg) and naringenin (0.14 µg/mg) in the extract. CONCLUSION: The validated NP-/RP-HPTLC methods were simple, accurate, and sensitive for separating and quantifying antiviral biomarkers in G. senegalensis, and endorsed its anti-HBV activity. The developed methods could be further employed in the standardization and quality-control of herbal formulations.

New Cytotoxic Seco-Type Triterpene and Labdane-Type Diterpenes from Nuxia oppositifolia.

Chromatographic purification of the n-hexane and dichloromethane extracts of Nuxia oppositifolia aerial parts, growing in Saudi Arabia, resulted in the isolation and characterization of three new labdane-type diterpene acids, 2ß-acetoxy-labda-7-en-15-oic acid (1), 2ß-acetoxy-7-oxolabda-8-en-15-oic acid (2), 2ß-acetoxy-6-oxolabda-7-en-15-oic acid (3), and one new seco-triterpene, 3,4-seco olean-12-en-3,30 dioic acid (4), together with 10 known lupane, oleanane and ursane-type triterpenes, as well as the common phytosterols, ß-sitosterol and stigmasterol (5-16). Their structures have been assigned on the basis of different spectroscopic techniques including 1D and 2D NMR. Moreover, 13 of the isolated compounds were tested on the human cancer cell lines HeLa (cervical), A549 (lung) and MDA (breast), and most of the compounds showed potent cytotoxic activities in vitro.

Novel quinolines carrying pyridine, thienopyridine, isoquinoline, thiazolidine, thiazole and thiophene moieties as potential anticancer agents.

As a part of ongoing studies in developing new anticancer agents, novel 1,2-dihydropyridine 4, thienopyridine 5, isoquinolines 6-20, acrylamide 21, thiazolidine 22, thiazoles 23-29 and thiophenes 33-35 bearing a biologically active quinoline nucleus were synthesized. The structure of newly synthesized compounds was confirmed on the basis of elemental analyses and spectral data. All the newly synthesized compounds were evaluated for their cytotoxic activity against the breast cancer cell line MCF7. 2,3-Dihydrothiazole-5-carboxamides 27, 25, 4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide (34), 1,2-dihydroisoquinoline-7-carbonitrile (7), 5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carboxamide (35), 1,2-dihydroisoquinoline-7-carbonitrile (6), 2-cyano-3-(dimethylamino)-N-(quinolin-3-yl)acrylamide (21), 1,2-dihydroisoquinoline-7-carbonitriles (11) and (8) exhibited higher activity (IC50 values of 27-45 µmol L-1) compared to doxorubicin (IC50 47.9 µmol L-1). LQ quinolin-3-yl)-1,2-dihydroisoquinoline-7-carbonitrile (12), 2-thioxo-2,3-dihydrothiazole-5-carboxamide (28) and quinolin-3-yl)-1,2-dihydroisoquinoline-7-carbonitrile (15) show activity comparable to doxorubicin, while (quinolin-3-yl)-1,2-dihydroisoquinoline-7-carbonitrile (9), 2,3-dihydrothiazole-5-carboxamide (24), thieno [3,4-c] pyridine-4(5H)-one (5), cyclopenta[b]thiophene-3-carboxamide (33) and (quinolin-3-yl)-6-stryl-1,2-dihydroisoquinoline-7-carbonitrile (10) exhibited moderate activity, lower than doxorubicin.

Novel chloroquinoline derivatives incorporating biologically active benzenesulfonamide moiety: synthesis, cytotoxic activity and molecular docking.

BACKGROUND: Quinoline derivatives have diverse biological activities including anticancer activity. On the other hand, many sulfonamide derivatives exhibited good cytotoxic activity. Hybrids of both moieties may present novel anticancer agents. RESULTS: Chloroquinoline incorporating a biologically active benzene-sulfonamide moieties 5-21 and diarylsulfone derivatives 22 and 23 were prepared using (E)-1-(4-((E)-7-chloro-1-methylquinolin-4(1H)-ylideneamino)phenyl)-3-(dimethyl-amino)prop-2-en-1-one 4 as strategic starting material. The structure of the newly synthesized compounds were confirmed by elemental analyses and spectral data. Compound 4 was confirmed by X-ray crystallographic analysis. The prepared compounds were evaluated for their anticancer activity against Lung, HeLa, Colorectal and breast cancer cell lines. Compounds 2, 4, 7, 11, 14 and 17 showed better or comparable activity to 2', 7'-dichlorofluorescein (DCF) as reference drug. Molecular docking of the active compounds on the active site of PI3K enzyme was performed in order to explore the binding mode of the newly synthesized compounds. CONCLUSION: Compounds 2, 4, 7, 11, 14 and 17 are novel quinoline derivatives that may represent good candidates for further evaluations as anticancer agents. The mechanism of action of these compounds could be through inhibition of PI3K enzyme.Graphical abstractCompound 17 on the active site of PI3K.

In-Vitro Anticancer Evaluation of Some Novel Thioureido-Benzensulfonamide Derivatives.

A novel series of sulfonamide derivatives (14 compounds) bearing thiourea moieties were efficiently synthesized and evaluated for their possible in vitro anticancer activity against four human tumor cell lines. The results indicated that compound 6 was the most potent, showing effectiveness on all the tested cell lines. Compounds 7 and 10 also showed promising results.