Records of Natural Products Articles

Investigation of EtOAc extract from the fermentation broth of the fungus Neosartorya fischeri led to the isolation of two novel alkaloids and one known compound with antitumor activity against HL-60 cell lines. Their structures were elucidated mainly by NMR and HR-TOF-MS, as well as on comparison with the reported data.

As part of ongoing project on screening plants used in Iranian folk medicine to treatment of diabetes, α-glucosidase inhibition activities of Rosa canina extracts have been tested. The acetone extract of the plant exhibited significant inhibition with IC 50 value of 0.3 µg/ml. The enzyme based assay guided fractionation of the acetone extract led to the isolation of daucosterol (1) and D-glucono-1,4-lactone (2), as highly active α-glucosidase inhibitors. Their structures were determined by 1H- and 13C-NMR spectroscopic evidences. The IC 50 values of daucosterol and D-glucono-1,4-lactone on yeast α-glucosidase were 13.3 and 6.5 µM, respectively, while IC 50 of acarbose was 16.1 µM, as a positive control. The Lineweaver-Burk plots analysis elucidated that both of the compounds inhibited the enzyme competitively. The study suggests that isolated compounds can be good candidates as α-glucosidase inhibitors and provide strong rationale for more in vivo studies.

Phytochemical investigation of the aqueous extract of Pithecellobium clypearia afforded one n ovel compound, clypearoside A(1), and one new stereoisomer , (-)-(2S,3S)-epigallocatechin-7-gallate(2) and four known ones (3-6). Their structures were elucidated on the basis of spectroscopic data, especially 2D NMR, HRESIMS and ECD spectra. Compounds 2-4 showed strong activity against DPPH (diphenylpicrylhydrazyl) and ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonate) with an IC 50 value of 11.9-13.2 μg/mL (DPPH) and 4.5-6.4 μg/mL (ABTS).

A new acylated glycoside, 4-O-( 4’,6’-di-O-galloyl- b - D -glucopyranosyl)-trans-p-coumaric acid, named microcoryn ( 1 ) , together with sixteen known phenolic compounds, 5-O-(6'-O-galloyl- b - D -glucopyranosyl)-gentisic acid (2), ellagic acid (3), gallic acid (4), kaempferol (5), quercetin (6), 3-O-galloyl- b - D -glucose (7), 2,3,6-tri-O-galloyl- b - D -glucose (8), 1,2,4,6-tetra-O-galloyl- b - D -glucose (9), 1,2,3,4,6-penta-O-galloyl- b - D -glucose (10), 4,6-hexahydroxydiphenoyl- b - D -glucose (11), gemin D (12), tellimagrandin I (13), tellimagrandin II (14), isocoriariin F (15), oenothein C (16), and oenothein B (17) were isolated from the leaves of Eucalyptus microcorys . The structure of the new compound was elucidated by spectroscopic data, especially by 2D NMR techniques. This is the first phytochemical investigation of this plant’s leaf extract.

A new compound (1) (named as artemceramide-B) together with eight known compounds (taraxerol (2), taraxerol acetate (3), β-sitosterol (4), stigmasterol (5), trans-ethyl caffeate, dracunculin (7), scoparone (8) and isoscopoletin (9) were isolated from an ethanolic extract of the roots of Artemisia incisa Pamp (Asteracae). The structures of the compounds were determined through IR, 1D NMR ( 1H NMR, 13C NMR) and 2D NMR (COSY, NOESY, HSQC and HMBC) analyses. Accurate mass analyses were done with EI-MS, ESI-MS and acid methanolysis of compound 1 followed by GS-MS studies. The relative stereochemistry of artemceramide-B was determined by comparing its specific rotation and spectroscopic data with the literature. Compounds 1-9 were tested for their anti-bacterial potential against five bacteria strains; Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis and Escherichia coli. Compound 1 (new) (MIC: 0.0157, 0.0313 mg/mL ) and 7 (MIC: 0.0815 , 1.000 mg/mL ) showed excellent activities against S. epidermidis and S. aureuswhile compound 9 showed excellent activities (MIC: 0.0700 , 1.234, 1.890 and 2.286 mg/mL) against S. epidermidis,S. aureus, K. pneumoniae and E. coli, respectively. Compound 6 (MIC: 2.000 mg/mL) was found to be active against E. coli while neither of the compounds showed potential activity against B. subtilis.

Many tyrosinase inhibitors have been alleged to have serious side effects. To search for relatively mild and safe tyrosinase inhibitors, two new 8-O-4′ neolignans, named huangnin A (1) and B (2), and four known analogs (3-6) were isolated from the seeds of Crataegus pinnatifida. Their structures were elucidated by spectroscopic analyses (1D, 2D NMR, HRESIMS, CD and Rh 2(OCOCF 3) 4-induced CD). In addition, the in vitroantioxidant and anti-tyrosinase activities of all isolates were evaluated. The results showed that compound 5 has good antioxidant and promising tyrosinase-inhibiting activities.

Phytochemical investigations of extracts from the aerial parts (leaves and flowers) of Perralderia coronopifolia Cosson resulted in the isolation of nine secondary metabolites corresponding to three flavonoids: rhamnazin(1), chrysosplenol D (3), and (2R, 3R) taxifolin (4), two monoterpene glycosides : myrtenol- β-D-glucopyranoside- 6'-O-acetate (2) and myrtenol β-D-glucopyranoside (7), a disaccharide: sucrose (9) and three di-O-caffeoylquinic acid derivatives : methyl 3, 5-di-O-caffeoyl quinate (5 ) and methyl 3,4-di-O-caffeoyl quinate (6 ) as a mixture and 1,5-di-O-caffeoylquinic acid (8). The structures were identified by spectroscopic methods such as 1H and 13C NMR, COSY, HSQC and HMBC experiments, HRESI-MS and comparison with literature data. Myrtenol-β-D-glucopyranoside-6'-O-acetate (2) was isolated in pure and native state for the first time. The other compounds are new for the genus Perralderia Cosson. The ethyl acetate extract showed a high antioxidant effect, especially DPPH radical scavenging activity with IC 50=7.01±0.28µg/mL) compared to ascorbic acid ( IC 50= 5±0.1µg/mL . This extract also showed antiproliferative activity against HeLa (human cervix carcinoma) and C6 (rat brain tumor) cells.

A secoiridoid glucoside dimer derivative, named as 4', 5'-(2'-hydroxy ligustrosidic acid) dimer (1), together with two known secoiridoids were isolated from the aqueous extract of Ligustri lucidi fructus. Structures of these compounds were elucidated by analysis of spectroscopic data including 1D-, 2D-NMR and HR-ESI-MS, and the reported literature data comparison. This is the first report on iridoid dimer derivative isolation from the genus Ligustrum. Their antioxidant activities were evaluated by using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Compound 1 exhibited moderate antioxidant activity.

A rosane type diterpenoid has been isolated from the ethyl acetate soluble fraction of Stachys parviflora. The structure elucidation was based primarily on 1D- and 2D-NMR techniques including correlation spectroscopy (COSY), heteronuclear multiple quantum coherence (HMQC), heteronuclear multiple bond correlation (HMBC), and nuclear Overhauser effect spectroscopy (NOESY). Density functional theory calculations have been performed to gain insight into the geometric, electronic and spectroscopic properties of the isolated diterpenoid. The geometries, vibrational spectrum and electronic properties were modeled at B3LYP/6-31G(d) and the theoretical data correlated nicely with the experimental values. Simulated chemical shifts at B3LYP/6-311+G(2d,p) showed much better correlation with the experimental chemical shifts, compared to B3LYP/6-31G(d) and WP04/6-31G(d).

Four novel cycloheximide derivatives(1-4) and two known compounds—l-cycloheximide(5), and isocycloheximide(6) were obtained from marine-derived Streptomyces sp. h-119, which was isolated from the sediment samples collected in intertidal   zone , Zhangzhou, Fujian Province. Their structures were elucidated by spectroscopic analyses, including 1 D and 2D-NMR experiments, and by HR-Q-TO F mass spectrometry . Their antimicrobial activities were evaluated.

One new lignan named 1-O-acetyl prinsepiol (1),in addition to nineteen known compounds including two lignans; 1α-hydroxypinoresinol (2) and (+)˗cycloolivil (3), one fatty acid; ( ̶ )˗pinellic acid (4), f ive phenolic acids; benzoic acid (5), p-hydroxybenzoic acid (6), protocatechuic acid (7), vanillic acid (8) and gallic acid (9), nine flavonoids; ( ̶ )˗epicatechin (10), ( ̶ )˗catechin (11), ( ̶ )˗epigallocatechin (12), ( ̶ )˗gallocatechin (13), astragalin (14), tiliroside (15), quercetrin (16), isoquercetrin (17) and myricitrin (18), and two phytosterols; β-sitosterol (19) and daucosterol (20) were isolated from the aerial parts of AcOEt extract of medicinal plant Helianthemum sessiliflorum Pers . of the family Cistaceae. The structures of all the isolated compounds 1-20 were determined by spectral methods including 1D ( 1H and 13C NMR) and 2D NMR (COSY, HSQC, HMBC and NOESY), HR-ESI-MS, values of optical rotation and chemical correlations with known compounds that have been described in the literature.

This study investigates the effect of phytochemical constituents from medicinally important plant Curcuma zedoaria (Christm.) Rosc., on hydrogen peroxide induced oxidative stress in mouse neuroblastoma-rat glioma hybridoma cells NG108-15. Phytochemical investigation of C. zedoaria rhizomes resulted in the isolation of nine sesquiterpenes (germacrone 1, dehydrocurdione 2, curcumenol 3, isoprocurcumenol 5, curcumenone 6, procurcumenol 7, zerumbone epoxide 8, zederone 9 and gweicurculactone 10) and one labdane diterpene (zerumin A 4). Curcumenol (3) and dehydrocurdione (2) showed 100% protection of the NG108-15 cells at the concentrations of 4 and 10 µM, respectively. Procurcumenol (7), isoprocurcumenol (5), zerumbone epoxide (8), zerumin A (4) and germacrone (1) showed moderate activity (80-90% protection). In the oxygen radical antioxidant capacity (ORAC) assay, all the test compounds showed strong antioxidant activity except curcumenol (3) which showed moderate antioxidant activity, as compared to the reference standard quercetin.

Triterpenoid saponins are involved in plant defense systems to inhibit bacterial invasion. A new series of hydrophilic ocotillol-type triterpenoid derivatives 5-26 have been synthesi z ed with antibacterial activity against Gram-positive bacteria, including a community associated methicillin-resistant Staphylococcus aureus (CA-MRSA; strain USA300). From this series, compounds 6 and 15 were found to be the most active, both with MIC values of 2 μg/mL against B. subtilis 168 and 8 μg/mL against S. aureus USA300, respectively. Furthermore, subsequent assays showed that compounds 6 and 15 displayed strong synergistic effects at sub-MIC levels against both S. aureus USA300 and B. subtilis 168 when combined with two commercial antibiotics, kanamycin and chloramphenicol. Preliminary structure-activity relationship studies were also performed.

From the MeOH extract of the leaves of Digitalis viridiflora five phenylethanoid glycosides (1-5) including a new one were isolated. The structure of the new compound was established as 3,4-dihydroxy-β-phenylethoxy-O-β-quinovopyranosyl-(1 ® 6)-4-O-caffeoyl-β-glucopyranoside (viridifloroside, 1) based on extensive 1D- and 2D-NMR spectroscopy as well as MS. Compound 1 is the first example of a phenylethnoid glycoside bearing a quinovopyranose in its structure. The chemotaxonomic importance of the isolates was also discussed.

Phytochemical investigation of the 70% aqueous acetone extract of Euphorbia dracunculoides Lam. afforded a new premyrsinane-type diterpenoid polyester, 3β-O-isobutyryl-5α-O-benzoyl-7β,13β-di-O-acetyl-17-O-nicotinoylpremyrsinol (1), and two known analogues, euphorbialoids C (2) and D (3). Their structures were elucidated by means of extensive spectroscopic analysis (NMR and ESI-MS) and comparison with data reported in the literature.

Laurel cherry (Prunus laurocerasus L.), an evergreen tree from Rosaceae family, is used as a folk medicine for various medical purposes and against diabetes as well in Northern Anatolia. The present study was performed to evaluate in-vivo hypoglycaemic and antidiabetic activities of P. laurocerasus. Hypoglycaemic effect of ethanol extracts of the fruit and seeds were tested on normoglycaemic, glucose loaded and streptozotocin induced diabetic rats. The extracts were given orally to rats and blood glucose levels were determined according to the glucose oxidase method. The results indicated that seed extract showed 20% inhibition on blood glucose levels on experimental diabetic animals. Chemical composition of the bioactive seed extract was analyzed by GC-MS. Oleic, linoleic and palmitic acids were detected as the major components of this extract. Therefore, hypoglycaemic activity of the seeds may be arisen from unsaturated fatty acids.

The chemical composition of volatiles from the stem barks of three different Kadsura species has been studied. The essential oils were obtained by hydrodistillation and analyzed by GC and GC-MS. The components were identified by MS libraries and their LRIs. The essential oils content varied between 0.15% and 0.20% (v/w), calculated on a dry weight basis. Sesquiterpene hydrocarbons (25.2% - 57.9%) and oxygenated sesquiterpenes (27.1%- 64.4%) are the main oil fractions . Kadsura coccinea(Lemaire) A. C. Smith., afforded oil whose major compounds were b -caryophylene (23.6%), d -cadinene (8.6%), caryophyllene oxide (7.8%) , epi- a -bisabolol (7.5%) and a -copaene (6.6%) . On the other hand, a -muurolol (43.5%) was the most singly abundant constituent of Kadsura longipeduculata Finet & Gagnepain. , with minor amounts of a -cadinol (5.4%), b -caryophylene (5.4%) and d -cadinene (5.0%). However, we have identified a -acorenol (10.1%), d -cadinene (9.6%), g -cadinene (8.1%) and d -elemene (6.8%) as the major constituents of Kadsura induta A. C. Smith.

In Turkish traditional medicine, Tripleurospermum species have been used for the treatment of inflammatory diseases. The present study was designed to investigate the anti-inflammatory potential and fatty acid composition of the extracts prepared from Tripleurospermumparviflorum (Willd.) Pobed. and T. tenuifolium (Kit.). Anti-inflammatory activity was assessed by using carrageenan-, and serotonin- induced hind paw edema and acetic acid-induced increase in capillary permeability models. The fatty acid compositions of the plants were investigated by gas chromatography (GC). EtOAc extracts of T. tenuifolium and T.parviflorum exerted notable inhibitory effect in the all in vivo anti-inflammatory activity models tested. Generally, C 16:0 palmitic acid and C 18:2 linoleic acid were found to be the major fatty acids in two species. Saturated fatty acids (SFAs) were found in higher amounts than monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) in two species. SFAs were determinated at 63.15% and 58.68% in T. tenuifolium and T. parviflorum, respectively. The high content of linoleic acid and palmitic acid may be primarily responsible for significant anti-inflammatory activity. The present study confirms the anti-inflammatory activity of T. parviflorum and T. tenuifolium. Further phytochemical and biological activity studies are needed for the determination of the active principle/s and anti-inflammatory activity mechanism.

Essential oil isolated from the aerial parts of Nepeta meyeri Benth. by hydrodistilation was analysed by GC and GC-MS methods. A total 18 components were identified in the oil representing 100.0% of the oil. Main components were 4aα,7α,7aβ-nepetalactone (80.3%), 4aα,7α,7aα–nepetalactone (10.3%), trans-pulegol (3.1%), 1, 8-cineole (3.0%) and β-bourbonene (2.0%). In addition, n-hexane extract of N. meyeri was analysed by using GC and GC-MS methods and 18 components were identified. Likewise, nepetalactones, 4aα,7α,7aβ-nepetalactone (83.7%), 4aα,7α,7aα–nepetalactone (3.6%), 1, 8-cineole (1.9%) and α-terpinene (1.5%) were the predominat compounds in the hexane extract. Three concentrations (0.5, 1.0 and 2.0 mg/mL) of the essential oil and n-hexane, chloroform, acetone and methanol extracts isolated from the aerial partsand roots were tested for the herbicidal effects on the germination of the seeds of four weed species including Amaranthus retroflexus L., Chenopodium album L., Cirsium arvense L. and Sinapsis arvensis L. The essential oil of N. meyeri completely inhibited the germination of all weed seeds whereas the extracts showed various inhibition effects on the germination of the weed species. Herbicidal effect was increased with the increasing application concentrations of the extracts. In general, the acetone extract was found to be more effective as compared to the other extracts. All extracts also exhibited various inhibition effects on the seedling growths of the weed species. All extracts also tested for their phytotoxic effects on the weeds at greenhouse condition and the results showed that the oil and extracts caused mortality with 22.00-66.00% 48h after the treatments. These findings suggest that the essential oil and the extracts of N. meyeri have potentials for use as herbicides against those weed species.

Bunchosia armeniaca (B. armeniaca) is a native plant to America, and popularly called “cafezinho”, “ciruela” or “falso-guaraná”. In traditional medicine is used to treat different pathologies including infectious and inflammatory diseases. From ethanolic extract of B. armeniaca leaves (Malpighiaceae) afforded a flavonoid mixture consisting of rutin 1 (83.5%), isoquercitrin 2 (5.6%) and afzelin 5 (10.9%), which were identified and individually quantified as helpful for capillary electrophoresis and 1H and 13C NMR spectroscopy. The ethanolic extract showed an excellent antibacterial activity against Staphylococcus aureus (S.aureus) and moderate activity against Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa). The flavonoid mixture showed antibacterial activity, mainly against the gram negative bacteria. Moreover, this plant demonstrated significant anti-inflammatory action, inhibiting the leukocyte influx and exudate formation in pleural cavity caused by carrageenan. The inflammation mediators involved in this model study, myeloperoxidase, nitric oxide and tumor necrosis factor alpha were significantly inhibited by ethanolic extract and flavonoid mixture of B. armeniaca. The results show that B. armeniaca has a significant antibacterial and anti-inflammatory effects and that these effects is due, at least in part, to the presence of rutin, isoquercetrin and afzelin in large amounts. Hence, these compounds have potential as novel lead compounds for the future development of therapeutic interventions for the treatment of patients with infectious and inflammatory disorders.

A further investigation on Tanacetum chilliophyllum var. monocephalum ethyl acetate extract afforded a new triterpene lactone Ulubelenolide (olean-12-ene-3β,10β-olide) (1).The structure of (1) was determined with spectral analysis including FTIR, 1H, 13C NMR, APT, DEPT, COSY, HMQC, HMBC, and APCI-MS.

Fresh leaves, stems and roots of Cachrys cristata, were subjected to hydrodistillation and the oils obtained were analyzed by means of GC and GC-MS. Sixty eight constituents were in total identified, with (Z)- β -ocimene (44.2% and 30.5%) dominating in leaves and stems oils, while the major metabolite of the roots was found to be p-tolualdehyde (39.6%), followed by (Z)- β -ocimene (15.2%). The microbial growth inhibitory properties of the essential oils were determined using the broth microdilution method against seven laboratory strains of bacteria - Gram positive: Staphylococcus aureus, S. epidermidis, Micrococcus luteus, Еnterococcus faecalis and Gram negative: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, a nd two strains of the yeast Candida albicans. The essential oils exhibited considerable activity against certain strains of the microorganisms tested, with the leaves oil demonstrating higher antimicrobial activity among the tested samples.

From leaves and bark of Amyris pinnata Kunth twelve compounds were isolated, corresponding to six lignans 1-6, three coumarins 7-9, a sesquiterpene 10, an oxazole alkaloid 11, and a prenylated flavonoid 12,. Metabolites were identified by spectroscopic techniques ( 1H and 13C NMR, EIMS) and by comparison with published data in the literature. C ytotoxicity against leukemia, solid tumors, and normal cells was evaluated for all isolated compounds. Lignans were found to be the most cytotoxic compounds occurring in A. pinnata.

Vitexin (1), isovitexin (2), orientin (3), isoorientin (4) and 1, 3 - dih y d roxy - 6, 7 - dimethoxyxanthone (5) were isolated from the whole plant of Begonia picta , a Nepalese crude drug commonly known as “ Magarkaanche ”. Structures were elucidated on the basis of chemical and spectroscopic methods. All of these compounds were isolated for the first time from B. picta and their in vitro antioxidant activity was evaluated by diphenyl-2-picrylhydrazyl ( DPPH ) free radical scavenging assay. Compounds 3 and 4 showed significant free radical scavenging activity.

Antioxidant properties of Filipendula ulmaria (meadowsweet) extracts obtained with increasing polarity solvents, acetone, methanol and water were evaluated by the DPPH · and ABTS · + scavenging, oxygen radical absorbance capacity (ORAC) assays and by the content of total phenols. Methanol extract was screened by the on-line HPLC-UV-DPPH · scavenging assay, while phytochemical composition of extracts isolated at different plant vegetation phases was determined by HPLC-PDA-ESI-MS and UPLC-Q-TOF-MS 2. Eight compounds were identified and quantified, some other compounds were identified tentatively based on the obtained fragments and comparison with literature data . As a conclusion, the results demonstrate that F. ulmaria is a promising species for the development of novel high added value preparations.