Phytochemical investigation of Cassia italica Mill. (Fabaceae) aerial parts collected from Saudi Arabia gave nine compounds: β-sitosterol (1), (22E)-3--hydroxycycloart-22-en-24-one (2), uvaol (3), daucosterol (4), methyl 3,4-dihydroxybenzoate (5), emodin (6), 4-hydroxyphenyl-O-β-D-glucopyranoside (7), aloin B (8), and rutin (9). Their structures were established by extensive spectroscopic study, in addition to co-chromatography with authentic samples. The total MeOH extract (TME), different fractions, and compounds 1-9 were assessed for their antimicrobial effects using agar plate diffusion assay. The TME, EtOAc fraction, and compounds 5-9 showed significant antimicrobial activity against the tested microbial strains.

Terrenolide S, a new butenolide derivative (6), together with six known compounds: (22E,24R)-stigmasta-5,7,22-trien-3-β-ol (1), stigmast-4- ene-3-one (2), stigmasta-4,6,8(14),22-tetraen-3-one (3), terretonin A (4), terretonin (5) and butyrolactone VI (7) have been isolated from the endophytic fungus Aspergillus terreus isolated from the roots of Carthamus lanatus (Asteraceae). Their structures were established by extensive spectroscopic analyses (1D, 2D NMR and HRESIMS), as well as optical rotation measurement and comparison with literature data. Compound 1 displayed a potent activity towards methicillinresistant Staphylococcus aureus (MRSA) and Cryptococcus neoformans with IC50 values of 2.29 and 10.68 µM, respectively. Moreover, 1, 2 and 6 exhibited antileishmanial activity towards Leishmania donovani with IC50 values of 11.24, 15.32 and 27.27 µM, respectively and IC90 values of 14.68, 40.56 and 167.03 µM, respectively.

Investigation of the EtOAc fraction of Tagetes minuta L. (Asteraceae) aerial parts has afforded a new flavonol glucoside, minutaside A (quercetagetin 6-O-(6-O-hexanoyl)-b-D-glucopyranoside) (1), together with four known flavonoids: axillarin 7-O-b-D-glucopyranoside (2), quercetagetin 3,7-dimethoxy-6-O-b-D-glucopyranoside (3), quercetagetin 7-methoxy-6-O-b-D-glucopyranoside (4), and quercetagetin 6-O-b-D-glucopyranoside (5). Their structures were established by multiple spectroscopic methods in addition to HRESIMS (high-resolution electrospray ionisation mass spectra) and comparison with literature data. The antioxidant and anti-diabetic activities of the isolated flavonoids were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and a-amylase inhibition assays. Compounds 1 and 5 showed significant antioxidant activity (84.1 and 83.0% at a 20 mM dose, respectively). Compounds 1, 4, and 5 exhibited strong aamylase inhibitory activity compared with acarbose (a reference a-amylase inhibitor). However, 2 and 3 showed moderate activity. Molecular modeling studies of 1–5 that included docking, flexible alignment, and surface mapping were performed to evaluate their recognition profile aamylase receptor. In docking simulations, 5 displayed a binding mode similar to that of acarbose in the active site of a-amylase enzyme.

lkaloids namely 6-methoxy-7,9-dimethyl-8-oxoguanine (1), 6-methoxy-9-methyl-8-oxoguanine (2), and 2-methoxy-7-methyl-8-oxoadenine (4) together with seven known compounds: 6-methoxy-7- methyl-8-oxoguanine (3), 9-methyl-8-oxoadenine (5), 7-methyl-8-oxoadenine (6), 8-oxoadenine (7), 3- methylxanthine (8), inosine (9), and homarine (pyridinium-2-carboxylic acid-1-methyl) (10). Compound 6 was reported here for the first time from a natural source. The structure determination of the compounds was accomplished by extensive interpretation of their spectroscopic data including 1D (1H and 13C) and 2D (1H–1H COSY, HSQC, and HMBC) NMR and high-resolution mass spectral data. The isolated compounds were evaluated for their protein kinase inhibitory activity against different kinases (CDK5, CK1, DyrK1A, and GSK3) at 10 mg/mL. The compounds showed moderate activity against these kinases

Re-investigation of the culture broth of the marine bacterium Staphylococcus sp. (no. P-100826-4-6) afforded a new cyclic tetrapeptide namely staphylopeptide A (1), along with five known compounds, cyclo (L-prolyl-L-valine) (2), cyclo (L-prolyl-L-tyrosine), (3), cyclo (L-prolyl-L-alanine) (4), L-phenylalanine (5), and L-tryptophan (6). The structures of the isolated compounds were determined by extensive IR, 1D (1H and 13C) and 2D (1H-1H COSY, HSQC, HMBC, and NOESY) NMR and HRFABMS spectral measurements. The antimicrobial activity of the isolated compounds (1–6) was evaluated.

Thiophenes are a class of heterocyclic aromatic compounds based on a five-membered ring made up of one sulfur and four carbon atoms. The thiophene nucleus is well established as an interesting moiety, with numerous applications in a variety of different research areas. Naturally occurring thiophenes are characteristic secondary metabolites derived from plants belonging to the family Asteraceae, such as Tagetes, Echinops, Artemisia, Balsamorhiza, Blumea, Pluchea, Porophyllum and Eclipta. Furthermore, naturally occurring thiophenes are generally composed of one to five thiophene rings that are coupled together through their a-carbons, and carry alkyl chains on their free ortho-positions. Thiophene-containing compounds possess a wide range of biological properties, such as antimicrobial, antiviral, HIV-1 protease inhibitor, antileishmanial, nematicidal, insecticidal, phototoxic and anticancer activities. This review focuses on naturally occurring thiophene derivatives; their sources, physical and spectral data, and biological activities.

Thiophenes are a class of heterocyclic aromatic compounds based on a five-membered ring made up of one sulfur and four carbon atoms. The thiophene nucleus is well established as an interesting moiety, with numerous applications in a variety of different research areas. Naturally occurring thiophenes are characteristic secondary metabolites derived from plants belonging to the family Asteraceae, such as Tagetes, Echinops, Artemisia, Balsamorhiza, Blumea, Pluchea, Porophyllum and Eclipta. Furthermore, naturally occurring thiophenes are generally composed of one to five thiophene rings that are coupled together through their a-carbons, and carry alkyl chains on their free ortho-positions. Thiophene-containing compounds possess a wide range of biological properties, such as antimicrobial, antiviral, HIV-1 protease inhibitor, antileishmanial, nematicidal, insecticidal, phototoxic and anticancer activities. This review focuses on naturally occurring thiophene derivatives; their sources, physical and spectral data, and biological activities.

2-(2-Phenylethyl) chromone (PEC), an uncommon class of chromones, possesses a phenylethyl substituent at the C2 position. They have been isolated from a few plant species. They have promising biological activities such as neuro-protective, cytotoxic, acetylcholinesterase inhibitory, antibacterial and anti-inflammatory. This review focuses on the naturally occurring PEC derivatives, their sources, physical and spectral data, as well as biological activities.

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