Armatenols A-C, new antioxidant isoflavanols from Colutea armata.

Armatenols A-C (1-3), new isoflavan-4-ols, have been isolated from the CHCl3-soluble sub-fraction of Colutea armata Hemsl. & Lace, along with two known compounds namely 8-methoxyvestitol (4) and colutequinone (5), reported for the first time from this species. Their structures have been elucidated through spectroscopic techniques including MS, IR, UV, CD, 1 D and 2 D NMR. Compounds 1-2 invariably showed significant antioxidant activity using the methods of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (DPPH), Fe3+ reducing antioxidant power (FRAP) assay and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) radical scavenging activity (ABTS).

Brahucins A and B, new triterpene lactones from Spiraea brahuica.

Brahucins A (1) and B (2), the new oleanane-type triterpene lactones, have been isolated from the EtOAc-soluble fraction of Spiraea brahuica Boiss, along with betulinic acid (3), oleanolic acid (4), 3-O-(ß-D-glucopyranosyl) oleanolic acid (5), vanillic acid (6) and caffeic acid (7), reported for the first time from this species. The structures of these compounds were elucidated by spectroscopic studies including MS, IR, 1D and 2D NMR.

Laceioside, a new cycloartane saponin from Astragalus tephrosioides Boiss. var. lacei (Ali) Kirchoff.

Phytochemical investigation of the aerial parts of Astragalus tephrosioides Boiss. var. lacei (Ali) Kirchoff. (Family Fabaceae) resulted in the isolation of a new cycloartane glycoside laceioside (1). The structure of the previously undescribed compound 1 was established as 16ß-acetyloxy-3- O-ß-d-glucopyranosyloxy-cycloartan-11α,24ξ, 25-triol. The structure elucidation of compound 1 was based primarily on 1D and 2D-NMR techniques including 1H and 13CNMR spectra, DEPT and by 2D COSY, HSQC and HMBC experiments.

Chemical composition, antioxidant and antimicrobial potential of essential oils from different parts of Daphne mucronata Royle.

This research work was executed to determine chemical composition, anti-oxidant and anti-microbial potential of the essential oils extracted from the leaves and stem of Daphne mucronata Royle. From leaves and stem oils fifty-one different constituents were identified through GC/MS examination. The antioxidant potential evaluated through DPPH free radical scavenging activity and %-inhibition of peroxidation in linoleic acid system. The stem's essential oil showed the good antioxidant activity as compared to leaves essential oil. Results of Antimicrobial activity revealed that both stem and leaves oils showed strong activity against Candida albicans with large inhibition zone (22.2 ± 0.01, 18.9 ± 0.20 mm) and lowest MIC values (0.98 ± 0.005, 2.44 ± 0.002 mg/mL) respectively. Leaves essential was also active against Escherichia coli with inhibition zone of 8.88 ± 0.01 mm and MIC values of 11.2 ± 0.40 mg/mL. These results suggested that the plant's essential oils would be a potential cradle for the natural product based antimicrobial as well as antioxidant agents.

CE-DAD Determination of Scutellarein and Caffeic Acid in Abelia triflora Crude Extract.

A precise, accurate, selective and sensitive capillary electrophoresis method using a diode array detector was developed for the first time for the determination of both scutellarein (SLN) and caffeic acid (CAA) in prepared Abelia triflora extract. Electrophoretic analysis was performed using a background electrolyte solution consisting of borax buffer (40 mM, pH 9.2) and a 200-nm detection wavelength. This method was fully validated according to The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. The method was linear in the concentration range 2.5-100 µg/mL and it allowed the determination of both compounds with high degree of recovery (%Er < 2%) and intra-day and inter-day precision (relative standard deviation values <2%) and method robustness was also assessed by the low values of %RSD < 2% obtained after small deliberate changes in the method parameters. The contents of SLN and CAA were calculated using both the external standard and standard addition methods. Analysis of the ethyl acetate fraction of A. triflora revealed that SLN and CAA were found in concentrations of 0.46 mg/g and 2.10 mg/g, respectively, in the ethyl acetate fraction and 0.29 and 1.32 mg%, respectively, in the dry plant leaves.

Trichosides A and B, new withanolide glucosides from Tricholepis eburnea.

Trichosides A (1) and B (2), new withanolide glucosides, have been isolated from the n-butanolic fraction of the 75% methanolic extract of aerial parts of Tricholepis eburnea. Their structures were elucidated through spectroscopic analysis including ESI-MS, 2D NMR and acid hydrolysis.

New antimicrobial flavonoids and chalcone from Colutea armata.

Colucins A (1) and B (2), new flavonoids and colucone (3), the new chalcone derivative, have been isolated from the CHCl3-soluble fraction of the whole plant of Colutea armata along with luteolin (4), luteolin 7-O-ß-D-glucoside (5), isoliquiritigenin (6), trans-caffeic acid (7) and stigmasterol (8) reported for the first time from this species. Their structures were elucidated by spectroscopic techniques including MS and 2D-NMR spectroscopy. Compounds 1 and 2 showed significant antimicrobial activity against two Gram positive and three Gram negative bacterial strains while 3 was moderately active.

Eburneolins A and B, new withanolide glucosides from Tricholepis eburnea.

Eburneolins A (1) and B (2), new withanolide glucosides, have been isolated from the n-butanolic fraction of the 75% methanolic extract of aerial parts of Tricholepis eburnea. Their structures were elucidated through spectroscopic analysis including ESI-MS, 2D NMR and acid hydrolysis.

Bioactive triterpenoids from Atriplex lasiantha.

Chromatographic purification of the ethyl acetate soluble fraction from the methanolic extract of Atriplex lasiantha yielded a new triterpenoid, 7ß,15α,16ß-trihydroxyolean-12-ene-28,30-dioic acid-3-O-ß-D-xylopyranoside (1), along with two known triterpenoids, rotundifolioside I (2) and corchorusin B (3). Structures of the compounds 1-3 were elucidated through sophisticated NMR studies and high resolution mass spectrometry. The three isolates (1-3) were evaluated for antibacterial, antioxidant, and antiurease activities. Compound 2 exhibited the best antibacterial activity against Escherichiacoli with IC50 value of 66.25 µg/ml, whereas, all the tested compounds exhibited antioxidant (IC50 values of 68.7-75.4 µg/ml) and antiurease (IC50 values of 25.5-49.3 µg/ml) activities, respectively.

Parvisides A and B, new glucosides from Galinsoga parviflora.

Phytochemical investigations of the n-butanol soluble sub-fraction of the methanolic extract of Galinsoga parviflora Cav. has led to the isolation of two new glucosides named as parvisides A (1) and B (2). Their structures have been assigned on the basis of their spectral analysis including 1D and 2D NMR techniques.

Compositional studies and Biological activities of Perovskia abrotanoides Kar. oils.

BACKGROUND: Current study has been designed to evaluate the chemical composition of essential and fixed oils from stem and leaves of Perovskia abrotanoides and antioxidant and antimicrobial activities of these oils. RESULTS: GC-MS analysis of essential oil identified 19 compounds with (E)-9-dodecenal being the major component in stem and hexadecanoic acid in leaves. In contrast, GC-MS analysis of fixed oil showed 40 constituents with α-amyrin the major component in stem and α-copaene in leaves. The antioxidant activity showed the highest value of 76.7% in essential oil from leaves in comparison with fixed oil from stem (45.9%) through inhibition of peroxidation in linoleic acid system. The antimicrobial assay tested on different microorganisms (e.g. E. coli, S. aureus, B. cereus, Nitrospira, S. epidermis, A. niger, A. flavus and C. albicans) showed the higher inhibition zone at essential oil from leaves (15.2 mm on B. cereus) as compared to fixed oil from stem (8.34 mm on S. aureus) and leaves (11.2 mm on S. aureus). CONCLUSIONS: The present study revealed the fact that essential oil analyzed from Perovskia abrotanoides stem and leaves could be a promising source of natural products with potential antioxidant and antimicrobial activities, as compared to fixed oil.

Absolute configuration of oplopanone derivatives from Serphidium stenocephalum: ECD spectra of acyclic ketones with front-octant contributions.

The electronic circular dichroism (ECD) spectra of two sesquiterpenoids (1 and 2) related to oplopanone, obtained from a methanolic extract of the plant Serphidium stenocephalum (Artemisia stenocephala), were measured and reproduced by means of time-dependent density functional theory (TDDFT) calculations, establishing their absolute configuration. The application of ketone octant rule for carbonyl n-π* ECD band to compounds 1 and 2, which include an acyclic carbonyl group, was critically assessed. The peculiar oplopanone skeleton makes a straightforward application of the octant rule impossible, because of the uncertainty related to the shape of the so-called third nodal surface separating front and back octants. The various group contributions to the carbonyl n-π* ECD band were estimated with TDDFT calculations on selected molecular models obtained by consecutive dissections from 1.

Compositional studies and Biological activities of Perovskia abrotanoides Kar. oils

BACKGROUND: Current study has been designed to evaluate the chemical composition of essential and fixed oils from stem and leaves of Perovskia abrotanoides and antioxidant and antimicrobial activities of these oils. RESULTS: GC-MS analysis of essential oil identified 19 compounds with (E)-9-dodecenal being the major component in stem and hexadecanoic acid in leaves. In contrast, GC-MS analysis of fixed oil showed 40 constituents with α-amyrin the major component in stem and α-copaene in leaves. The antioxidant activity showed the highest value of 76.7% in essential oil from leaves in comparison with fixed oil from stem (45.9%) through inhibition of peroxidation in linoleic acid system. The antimicrobial assay tested on different microorganisms (e.g. E. coli, S. aureus, B. cereus, Nitrospira, S. epidermis, A. niger, A. flavus and C. albicans) showed the higher inhibition zone at essential oil from leaves (15.2 mm on B. cereus) as compared to fixed oil from stem (8.34 mm onS. aureus) and leaves (11.2 mm on S. aureus). CONCLUSIONS: The present study revealed the fact that essential oil analyzed from Perovskia abrotanoides stem and leaves could be a promising source of natural products with potential antioxidant and antimicrobial activities, as compared to fixed oil.

Isolation of natural compounds from Phlomis stewartii showing α-glucosidase inhibitory activity.

Stewartiiside (1), a phenylethanoid glycoside and three 28-nortriterpenoids: stewertiisins A-C [(17R)-19(18→17)-abeo-3α,18ß,23,24-tetrahydroxy-28-norolean-12-ene, 2; (17R)-19(18→17)-abeo-2α,16ß,18ß,23,24-pentahydroxy-28-norolean-12-en-3-one, 3; (17R)-19(18→17)-abeo-2α,3α,23,24-tetrahydroxy-28-noroleane-11,13-diene, 4] together with eight known compounds: lunariifolioside (5), notohamosin A (6), phlomispentanol (7), isorhamnetin 3-(6-p-coumaroyl)-ß-D-glucopyranoside (8), tiliroside (9), caffeic acid (10), p-hydrxybenzoic acid (11) and oleanolic acid (12) were isolated from the ethyl acetate soluble fraction of the methanolic extract of whole plant of Phlomis stewartii. The structures of these isolates (1-12) were elucidated by the combination of 1D ((1)H and (13)C NMR), 2D (HMQC, HMBC COSY, NOESY) NMR spectroscopy and mass spectrometry (EIMS, HREIMS, FABMS, HRFABMS) and in comparison with literature data of related compounds. All the isolates (1-12) showed α-glucosidase inhibitory activity with IC50 values ranging between 14.5 and 355.4 µM, whereas, compounds 1, 5, 9 and 10 showed promising α-glucosidase inhibitory activity with IC50 values below 30 µM.

Loasins A and B, new flavonoids from Eremostachys loasifolia.

Loasins A (1) and B (2), new flavonoids, have been isolated from the ethyl acetate soluble sub-fraction of the ethanolic extract of Eremostachys loasifolia along with apuleisin (3) and apuleidin (4), isolated for the first time from this species. Their structures were assigned on the basis of their spectral data including 1D and 2D NMR.

Bioactive phenolics from Seriphidium stenocephalum.

Chromatographic separation of the ethyl acetate soluble part of the methanolic extract from Seriphidium stenocephalum yielded three new compounds: stenocepflavone (1), stenocepflavan (2), and stenocephol (3), together with cirsimaritin (4), 5,7,5'-trihydroxy-3',4',6-trimethoxyflavone (5), 5,6,7,5'-tetrahydroxy-4'-methoxyflavone (6), and axillaroside (7). All isolates were characterized with the help of spectroscopic data including 1D, 2D NMR, and high resolution mass spectrometry and/or in comparison with the related compounds in literature. All compounds were tested for in vitro enzyme inhibitory activities against acetylcholinesterase, butyrylcholinesterase, and lipoxygenase. Compounds 1 and 4-7 exhibited significant activity against all the tested enzymes, whereas compounds 2 and 3 were found inactive.

Chemical analysis and calcium channel blocking activity of the essential oil of Perovskia abrotanoides.

The aim of this study was to investigate the chemical composition and provide a pharmacological base for the medicinal use of the essential oil of Perovskia abrotanoides (Pa.Oil) in gastrointestinal disorders, such as colic. The chemical investigation resulted in the identification of 26 compounds, of which tricyclene, beta-trans-ocimene, terpinene-4-acetate, terpinen-4-ol, caran-3beta-ol, linalyl acetate, beta-caryophyllene oxide and alpha-elemene had not previously been reported from P. abrotanoides. Major constituents were 1,8-cineol and delta-3-carene, which constituting 50% of the oil. In the isolated rabbit jejunum preparation Pa.Oil caused inhibition of spontaneous and high K+ (80 mM)-induced contractions, with respective EC50 values of 0.13 (0.08-0.20; n = 4) and 0.90 mg/mL (0.50-1.60; n = 5), thus showing that spasmolytic activity is mediated possibly through calcium channel blockade (CCB). The CCB activity was confirmed when pre-treatment of the tissue with Pa.Oil (0.03-0.1 mg/mL) caused a rightward shift in the Ca++ concentration-response curves, similar to that caused by verapamil, a standard calcium channel blocker. These data indicate that the essential oil of P. abrotanoides possesses spasmolytic activity mediated possibly through inhibition of voltage-dependent calcium channels, which may explain its medicinal use in colic and possibly diarrhea.

Spiraeamide, new sphingolipid from Spiraea brahuica.

Spiraeamide, a new sphingolipid, has been isolated from the ethyl acetate-soluble fraction of the methanolic extract of the whole plant of Spiraea brahuica, along with marrubiin, 19-acetylmarrubenol, and 6-acetylmarruenol. Their structures were elucidated by ¹H and ¹³C NMR spectra, and COSY, NOESY, HMQC, HMBC, EI-MS, and FAB-MS experiments.

Two new triterpenoids from Zygophyllum eurypterum.

Two new triterpenoids trivially named as atriplicoide A and B were isolated from the n-BuOH extract of the whole plant of Zygophyllum eurypterum. Based on EI-MS, IR, 1H- and 13C-NMR, and 2D-NMR (HMQC, HMBC, COSY and NOESY) data, the structures of the new compounds were determined as 30-carboxy-3beta,24-dihydroxy-urs-28,13beta-lactam-N-acetate (1) and 3beta,24-dihydroxyursan-28,13beta-olide (2).

Loasifolin, a new flavonoid from Eremostachys loasifolia.

Loasifolin (1), a new highly oxygenated flavonoid, has been isolated from Eremostachys loasifolia and its structure is assigned on the basis of spectroscopic data including 1D and 2D NMR techniques. 6,7-Dihydroxycoumarin (2) and luteolin 4'-O-beta-d-glucopyranoside (3) have also been isolated for the first time from the genus Eremostachys.