Abstract: A validated simple, rapid, and selective spectrofluorimetric method was developed for the determination of some non-sedating antihistamines (NSAs); namely cetirizine (CTZ), ebastine (EBS), fexofenadine (FXD), ketotifen (KET), and loratadine (LOR). The method is based on quenching effect of the cited drugs on the fluorescence intensity of erythrosine B (EB) by the formation of ion-pair complex measured without extraction at lex.. 311 nm/ lex.. 555 nm against a reagent blank. The fluorescence intensity of EB was diminished when the studied drugs were added. There was a linear relationship between the fluorescence quenching value of the system (ΔF = F EB – F Drug–EB) and the concentration of the investigated drug. Under the optimal conditions, the linear ranges of calibration curves for the determination of the studied NSAs were 0.25–2.0, 0.25–3.0, and 0.25–6.0
g/mL for (CTZ, KET, LOR), (EBS), and (FXD), respectively. The factors affecting the formation of the ion-pair complex were carefully studied and optimized. The method was validated according to ICH guidelines. The suggested method is applicable for the determination of the five investigated drugs in bulk and pharmaceutical dosage forms with excellent recoveries (98.23-103.77 %).

Ferutinin (1), the major constituent of Ferula hermonis and other Ferula species, is a sesquiterpene ester with remarkable estrogenic activity, beside other valuable medicinal properties. To investigate the influence of chemical modification of the ferutinin structure on its estrogenic effect and binding affinity toward the cannabinoid CB1 and CB2 receptors, twelve derivatives of 1 were prepared and evaluated in vitro, together with the parent compound, for the respective bioactivities, based on the recent evidence for estrogen–endocannabinoid interaction. Nine of the prepared derivatives (3–11) are new semisynthetic esters of 1. The parent compound ferutinin (1) exhibited the highest level of estrogenic activity (EC50 0.3 μM and a percent maximal 17β-estradiol response of 90 % at 1 µM). Compound 6 was found to be a selective agonist for CB2 receptor (EC50 0.051 μM, Ki 0.025 μM), with much less affinity for CB1 receptor (EC50 97 μM, Ki 48.5 μM). Compound 8 was a selective agonist for CB1 (EC50 62, Ki 0.031 μM) with no affinity toward CB2.

An endophyte Bartalinia pondoensis Marinc of Citrus aurantum L. var. dulcis was isolated and studied for its secondary metabolites and for their Mycobacterium tuberculosis shikimate kinase (MtSK) inhibitory activities. Using LC–MS metabolite fingerprinting of the constituents of the methanol extract, 19 compounds pertaining to various classes were identified: amino acids, proto-alkaloids, fatty acid amides and oxazole, aniline derivatives and aromatic compounds. We report here for the first time the presence of the [N-(ethyloxy, hydroxymethyl)phenylethylamine] as a new proto-alkaloid and 18 other known compounds are reported for the first time in the genus of Bartalinia. MtSK inhibitory activities of methanol extract and fractions obtained by solid phase extraction (SPE) at a concentration of 50 µg/mL may be attributed to the presence of aniline and oxazole derivatives present in all fractions in varying concentrations.

An endophyte Bartalinia pondoensis Marinc of Citrus aurantum L. var. dulcis was isolated and studied for its secondary metabolites and for their Mycobacterium tuberculosis shikimate kinase (MtSK) inhibitory activities. Using LC–MS metabolite fingerprinting of the constituents of the methanol extract, 19 compounds pertaining to various classes were identified: amino acids, proto-alkaloids, fatty acid amides and oxazole, aniline derivatives and aromatic compounds. We report here for the first time the presence of the [N-(ethyloxy, hydroxymethyl)phenylethylamine] as a new proto-alkaloid and 18 other known compounds are reported for the first time in the genus of Bartalinia. MtSK inhibitory activities of methanol extract and fractions obtained by solid phase extraction (SPE) at a concentration of 50 µg/mL may be attributed to the presence of aniline and oxazole derivatives present in all fractions in varying concentrations.

Background: Seventy percent aqueous methanolic extract of the leaves of Lantana montevidensis exhibited antibacterial, anti-inflammatory, anti-pyretic, antioxidant, and analgesic activities. Previous phytochemical study of the leaves led to the isolation of various flavones, pentacyclic triterpenoids, β-sitosterol and benzoic acid. Materials and Methods: The 70% aqueous methanolic extract of L. montevidensis (Spreng.) Briq. leaves was partitioned between water and n-hexane, CHCl3, EtOAc, and n-BuOH, successively. By using a series of different chromatographic techniques, the CHCl3 and EtOAc extracts afforded nine compounds. The isolated compounds were identified by spectroscopic techniques and by comparison with literature values and/or authentic samples. The free radical scavenging activity of some of the isolated compounds was evaluated. Results: Hispidulin-7-O-glucurnoide methyl ester (1), hispidulin-7-O-glucoside (2), cinaroside (3), nepetin-7-O-glucoside (4) pectolinarigenin (5), apigenin (6), luteolin (7) in addition to salicylic acid (8) and β-sitosterol-3-O-glucoside (9) have been isolated. Compounds 1-4 are first report from the genus Lantana, whereas compounds 5, 8 and 9 are first report from this plant. The structures of these compounds were elucidated on the basis of spectral methods, including 2D nuclear magnetic resonance experiments, and confirmed by comparing with the literature data and/or authentic samples. Additionally, some of the isolated flavonoids exhibited free radical scavenging activity. Conclusion: L. montevidensis (Spreng.) Briq. cultivated in Egypt is rich in biologically active ingredients.

Background: Seventy percent aqueous methanolic extract of the leaves of Lantana montevidensis exhibited antibacterial, anti-inflammatory, anti-pyretic, antioxidant, and analgesic activities. Previous phytochemical study of the leaves led to the isolation of various flavones, pentacyclic triterpenoids, β-sitosterol and benzoic acid. Materials and Methods: The 70% aqueous methanolic extract of L. montevidensis (Spreng.) Briq. leaves was partitioned between water and n-hexane, CHCl3, EtOAc, and n-BuOH, successively. By using a series of different chromatographic techniques, the CHCl3 and EtOAc extracts afforded nine compounds. The isolated compounds were identified by spectroscopic techniques and by comparison with literature values and/or authentic samples. The free radical scavenging activity of some of the isolated compounds was evaluated. Results: Hispidulin-7-O-glucurnoide methyl ester (1), hispidulin-7-O-glucoside (2), cinaroside (3), nepetin-7-O-glucoside (4) pectolinarigenin (5), apigenin (6), luteolin (7) in addition to salicylic acid (8) and β-sitosterol-3-O-glucoside (9) have been isolated. Compounds 1-4 are first report from the genus Lantana, whereas compounds 5, 8 and 9 are first report from this plant. The structures of these compounds were elucidated on the basis of spectral methods, including 2D nuclear magnetic resonance experiments, and confirmed by comparing with the literature data and/or authentic samples. Additionally, some of the isolated flavonoids exhibited free radical scavenging activity. Conclusion: L. montevidensis (Spreng.) Briq. cultivated in Egypt is rich in biologically active ingredients.

Background: Seventy percent aqueous methanolic extract of the leaves of Lantana montevidensis exhibited antibacterial, anti-inflammatory, anti-pyretic, antioxidant, and analgesic activities. Previous phytochemical study of the leaves led to the isolation of various flavones, pentacyclic triterpenoids, β-sitosterol and benzoic acid. Materials and Methods: The 70% aqueous methanolic extract of L. montevidensis (Spreng.) Briq. leaves was partitioned between water and n-hexane, CHCl3, EtOAc, and n-BuOH, successively. By using a series of different chromatographic techniques, the CHCl3 and EtOAc extracts afforded nine compounds. The isolated compounds were identified by spectroscopic techniques and by comparison with literature values and/or authentic samples. The free radical scavenging activity of some of the isolated compounds was evaluated. Results: Hispidulin-7-O-glucurnoide methyl ester (1), hispidulin-7-O-glucoside (2), cinaroside (3), nepetin-7-O-glucoside (4) pectolinarigenin (5), apigenin (6), luteolin (7) in addition to salicylic acid (8) and β-sitosterol-3-O-glucoside (9) have been isolated. Compounds 1-4 are first report from the genus Lantana, whereas compounds 5, 8 and 9 are first report from this plant. The structures of these compounds were elucidated on the basis of spectral methods, including 2D nuclear magnetic resonance experiments, and confirmed by comparing with the literature data and/or authentic samples. Additionally, some of the isolated flavonoids exhibited free radical scavenging activity. Conclusion: L. montevidensis (Spreng.) Briq. cultivated in Egypt is rich in biologically active ingredients.

Background: Seventy percent aqueous methanolic extract of the leaves of Lantana montevidensis exhibited antibacterial, anti-inflammatory, anti-pyretic, antioxidant, and analgesic activities. Previous phytochemical study of the leaves led to the isolation of various flavones, pentacyclic triterpenoids, β-sitosterol and benzoic acid. Materials and Methods: The 70% aqueous methanolic extract of L. montevidensis (Spreng.) Briq. leaves was partitioned between water and n-hexane, CHCl3, EtOAc, and n-BuOH, successively. By using a series of different chromatographic techniques, the CHCl3 and EtOAc extracts afforded nine compounds. The isolated compounds were identified by spectroscopic techniques and by comparison with literature values and/or authentic samples. The free radical scavenging activity of some of the isolated compounds was evaluated. Results: Hispidulin-7-O-glucurnoide methyl ester (1), hispidulin-7-O-glucoside (2), cinaroside (3), nepetin-7-O-glucoside (4) pectolinarigenin (5), apigenin (6), luteolin (7) in addition to salicylic acid (8) and β-sitosterol-3-O-glucoside (9) have been isolated. Compounds 1-4 are first report from the genus Lantana, whereas compounds 5, 8 and 9 are first report from this plant. The structures of these compounds were elucidated on the basis of spectral methods, including 2D nuclear magnetic resonance experiments, and confirmed by comparing with the literature data and/or authentic samples. Additionally, some of the isolated flavonoids exhibited free radical scavenging activity. Conclusion: L. montevidensis (Spreng.) Briq. cultivated in Egypt is rich in biologically active ingredients.

Photo-switchable α-helical peptides offer a valuable tool to probe protein-biomacromolecule interactions in a spatiotemporally controlled manner. We synthesized a series of 32 residue peptides (AA32 s) with the core structure Ac-W-(E1A2A3A4R5)6-Q-NH2 and introduced the azobenzene based cross-linker BSBCA via reaction with Cys residues spaced at i, i + 7 intervals in different positions along the helix. UV/Vis measurements show that the composition of the photostationary state as well as thermal relaxation rates do not change considerably with changes in cross-linker position. CD analysis shows that photo-control of helix folding/unfolding is most effective when the cross-linker is targeted to the middle of the peptide so long as this segment has a high intrinsic helical propensity. The largest degree of photo-controlled conformational change occurred when a cross-linked central region of high intrinsic helicity was followed on the C-terminal side by a region of lower intrinsic helicity. This indicates the BSBCA cross-linker can act as a nucleation site for N-to-C propagation of a helix. These data help to guide the choice of cross-linking site in larger peptides and proteins where photo-control of conformation is desired.

A new 7-methoxy-2-benzoxazolinone dimer named zeaoxazolinone (2), together with four known compounds; 9-Z-hexadecenoic acid (1), 6-methoxy-benzoxazolinone (3), gallic acid (4), and -sitosterol-3-O--D-glucopyranoside (5) were isolated from Zea mays L. roots. The structural elucidation of isolatedmetabolites was established on the basis of UV, IR, 1D, 2D NMR, and MS spectral analyses. Compound 2 exhibited a potent antifungal activity against Aspergillus flavus, Fusarium oxysporum, and Candida albicans.