Flavonoids of Guiera senegalensis J. F. GMEL. − Thin-layer Chromatography and Numerical Methods

The efficiency of seven thin-layer chromatographic systems for separating nine flavonoids isolated from Guiera senegalensis J. F. GMEL. (Combretaceae) was investigated. For this purpose, three mathematical techniques were applied. The first technique was the calculation of the information content derived from Shannon’s equation for each chromatographic system. In the second technique, the discriminating power of the systems was measured individually and in various combinations. The third technique classifies chromatographic systems according to clusters. The classification was carried out by the numerical taxonomy methods. The most suitable chromatographic systems for the separation of the investigated flavonoids are: ethyl acetate : ethylmethylketon : formic acid : water, 60:15:3:2, and ethyl acetate : formic acid : acetic acid : water, 100:11:11:27

Flavonoids of Guiera senegalensis J. F. GMEL. − thin-layer chromatography and numerical methods

The efficiency of seven thin-layer chromatographic systems for separating nine flavonoids isolated from Guiera senegalensis J. F. GMEL. (Combretaceae) was investigated. For this purpose, three mathematical techniques were applied. The first technique was the calculation of the information content derived from Shannon’s equation for each chromatographic system. In the second technique, the discriminating power of the systems was measured individually and in various combinations. The third technique classifies chromatographic systems according to clusters. The classification was carried out by the numerical taxonomy methods. The most suitable chromatographic systems for the separation of the investigated flavonoids are: ethyl acetate : ethylmethylketon : formic acid : water, 60:15:3:2, and ethyl acetate : formic acid : acetic acid : water, 100:11:11:27

Essential Oil of Portenschlagiella ramosissima from Croatia, a Rich Source of Myristicin

Isolation of the essential oil from the ripe fruits of Portenschlagiella ramosissima (Apiaceae) by hydrodistillation yielded 1.2 % (vol./w). By GC-FID and GC-MS analyses on fused silica capillaries with polar and non-polar stationary phases, respectively, 19 compounds representing 98.0 % of the total peak area could be identified. Major constituents were γ-terpinene (41.0 %) followed by myristicin (25.3 %, 257.2 ± 2.70 mg per gram of oil) and p-cymene (14.5 %). As a conclusion, in the sample of P. ramosissima collected in Middle Dalmatia a high content of myristicin could be detected which is in contradiction to previous investigations by Harborne et al.</p

Antimicrobial and Resistance Modulatory Activity of Alpinia katsumadai Seed Phenolic Extract, Essential Oil and Post-Distillation Extract

Antimikrobna otpornost patogenih mikroorganizama predstavlja ozbiljan problem u proizvodnji hrane, a naročito zbog rastućeg broja multirezistentnih sojeva. Sve je veća potreba za novim i efikasnim antimikrobnim agensima i modulatorima otpornosti radi prevladavanja ovog problema, pri čemu biljke predstavljaju bogat izvor takvih spojeva. U ovom je radu ispitan antimikrobni učinak fenolnog ekstrakta, eteričnog ulja i destilacijskog ekstrakta sjemenki biljke Alpinia katsumadai, te njihov utjecaj na modulaciju otpornosti sojeva Campylobacter jejuni i Staphylococcus aureus. Ekstrakt sjemenki i postdestilacijski ekstrakt imali su relativno snažan antimikrobni učinak na bakteriju C. jejuni, dok je bakterija S. aureus pokazala veću otpornost. Fenolni ekstrakt, eterično ulje i destilacijski ekstrakt A. katsumadai u kombinaciji sa svim ispitanim antimikrobnim agensima (ciprofloksacin, eritromicin, triklosan, soli žučne kiseline i etidijev bromid) uspješno su modulirali otpornost svih sojeva C. jejuni. Učinak je ekstrakata i eteričnog ulja na bakteriju S. aureus ovisio o bakterijskom soju i primjenjenom antimikrobnom agensu, ali je uspješno smanjena otpornost svih sojeva na soli žučne kiseline. Eterično je ulje sjemenki biljke A. katsumadai potaklo akumulaciju etidijevog bromida unutar bakterijskih stanica, čime je dokazano da se može upotrijebiti kao inhibitor efluksne pumpe bakterija C. jejuni i S. aureus.Antimicrobial resistance of food-related bacterial pathogens is becoming a serious problem, especially after the emergence of multidrug-resistant strains. To overcome this problem, new and effective antimicrobials or resistance modulators are highly needed and plant kingdom represents a valuable source of these compounds. We investigated antimicrobial and resistance modulatory activity of the phenolic extract, essential oil and post-distillation extract of Alpinia katsumadai seeds against Campylobacter jejuni and Staphylococcus aureus. Among the tested plant formulations, A. katsumadai seed phenolic extract and post-distillation extract showed moderate antimicrobial activity against C. jejuni, while S. aureus was more resistant. When evaluating resistance modulatory potential of A. katsumadai phenolic extract, essential oil and post-distillation extract in C. jejuni against ciprofloxacin, erythromycin, triclosan, bile salts and ethidium bromide, plant formulations exhibited modulatory activity in combination with all antimicrobials. Modulation of resistance was more strain- and antimicrobial-specific in S. aureus, but very efficient in the case of reduced resistance to bile salts. Essential oil from A. katsumadai seeds efficiently increased intracellular ethidium bromide accumulation and was thus confirmed as potential inhibitor of efflux pumps in C. jejuni and S. aureus

Natural Products as Antibacterial Agents — Antibacterial Potential and Safety of Post-distillation and Waste Material from Thymus vulgaris L., Lamiaceae

Medicinal plants have a long tradition of use in folk and conventional medicine. In recent years numerous studies confirm various bioactivities of natural products, among them antibacterial activity. Natural antibacterial agents such are essential oils and isolated compounds now represent a notable source for pharmaceutical and food industry and are widely used in cosmetology. They meet standards of \u27green consumerism\u27 together with excellent antibacterial activity. Aromatic plants such is Thymus vulgaris L. are the major sources of essential oils. Thyme essential oil, as well as dominant compounds thymol and carvacrol are generally recognised as safe and have been registered by European Commission for use as flavouring agents in foodstuffs. However, essential oil is present in very low amount (0,8-2,6%) in thyme leaves. Thus, the majority of plant material remains unused after the isolation. Nowadays, the biological potential of various plant waste materials are in focus of numerous studies. These investigations also include the antimicrobial activity considering the fact that waste material extracts represent the valuable source of different phenolic compounds. Regarding all this, the aim of the present study was to determine antibacterial potential of chemically characterised extracts obtained from waste material remaining after the preparation of drug (stems) and isolation of thyme essential oil (deodorised leaves, postdistillation decoction) on selected bacterial strains. Also, in order to determine safety of waste extracts their cytotoxicity was investigated. All extracts were prepared with maceration using 45% or 75% ethanol (EtOH) for 24 h at room temperature (1:10 w/v). Total phenolic compounds and flavonoids were determined spectrophotometrically. Extracts were chemically characterized by HPLC/DAD analysis. Antibacerial testing was done with broth dilution method against several bacterial strains (Staphylococcus aureus, Bacillus cereus, Salmonella infantis, Escherichia coli and Campylobacter jejuni). Cytotoxicity and cytoprotection studies were performed by XTT assay. Result of HPLC analysis showed that investigated extracts, especially those obtained from deodorised leaves represent a valuable source of rosmarinic acid and luteolin 7-O-glucuronide. Antibacterial testing indicated that all waste material extracts, except the extract T2, possess similar or even stronger bacteriostatic activity than T1. No cytotoxicity nor cytoprotection were determined. In conclusion, results of this study confirmed antibacterial potential investigated thyme extracts. High concentrations of rosmarinic acid and luteolin 7-O-glucuronide, which both have numerous pharmacological activities, were determined. This indicates that thyme postdistillation waste material extracts could be used for isolation of dominant compounds or as addities in pharmaceutical and food industry

Diterpenes and Phenolic Compounds from Salvia brachyodon Vandas

Salvia brachyodon, the short-tooth sage, is one of the rarest plant species and endemic in the Adriatic area of the Balkan Peninsula. As aside from its essential oil, only limited information on its phytochemical composition is known, a more detailed study of the leaves was undertaken. From its leaves two diterpenes, agastanol (2), and a new natural compound 1, i.e., 3-methyl-4-methylen-11,12,14-trihydroxy-8,11,13-abietatrien-7-one, were isolated and identified by NMR spectroscopy and mass spectrometry. In addition, caffeic acid, isoquercitrin, luteolin 7-O-glucoside and rosmarinic acid were identfied by comparison with reference compounds. The fraction containg the diterpenes as well as the isolated compound 1 showed significant antimycobacterial activity against Mycobacterium smegmatis. The diterpenes of S. brachyodon represent promising antimycobacterial substances for further evaluation. Due to the endangered nature of the plant, the wide use of S. brachyodon and its bioactive compounds could be achieved by growing the plants in culture

Identification and characterization of [6]-shogaol from ginger as inhibitor of vascular smooth muscle cell proliferation

Scope Vascular smooth muscle cell (VSMC) proliferation is involved in the pathogenesis of cardiovascular disease, making the identification of new counteracting agents and their mechanisms of action relevant. Ginger and its constituents have been reported to improve cardiovascular health, but no studies exist addressing a potential interference with VSMC proliferation. Methods and results The dichloromethane extract of ginger inhibited VSMC proliferation when monitored by resazurin metabolic conversion (IC50 = 2.5 μg/mL). The examination of major constituents from ginger yielded [6]-shogaol as the most active compound (IC50 = 2.7 μM). In the tested concentration range [6]-shogaol did not exhibit cytotoxicity toward VSMC and did not interfere with endothelial cell proliferation. [6]-shogaol inhibited DNA synthesis and induced accumulation of the VSMC in the G0/G1 cell-cycle phase accompanied with activation of the nuclear factor-erythroid 2-related factor 2 (Nrf2)/HO-1 pathway. Since [6]-shogaol lost its antiproliferative activity in the presence of the heme oxygenase-1 (HO-1) inhibitor tin protoporphyrin IX, HO-1 induction appears to contribute to the antiproliferative effect. Conclusion This study demonstrates for the first time inhibitory potential of ginger constituents on VSMC proliferation. The presented data suggest that [6]-shogaol exerts its antiproliferative effect through accumulation of cells in the G0/G1 cell-cycle phase associated with activation of the Nrf2/HO-1 pathway

Synthesis and Antibacterial Evaluation of a New Series of N-Alkyl-2-alkynyl/(E)-alkenyl-4-(1H)-quinolones

To gain further insight into the structural requirements of the aliphatic group at position 2 for their antimycobacterial activity, some N-alkyl-4-(1H)-quinolones bearing position 2 alkynyls with various chain length and triple bond positions were prepared and tested for in vitro antibacterial activity against rapidly-growing strains of mycobacteria, the vaccine strain Mycobacterium bovis BCG, and methicillin-resistant Staphylococcus aureus strains, EMRSA-15 and -16. The compounds were also evaluated for inhibition of ATP-dependent MurE ligase of Mycobacterium tuberculosis. The lowest MIC value of 0.5 mg/L (1.2–1.5 µM) was found against M. fortuitum and M. smegmatis. These compounds displayed no or only weak toxicity to the human lung fibroblast cell line MRC-5 at 100 µM concentration. The quinolone derivatives exhibited pronounced activity against the epidemic MRSA strains (EMRSA-15 and -16) with MIC values of 2–128 mg/L (5.3–364.7 µM), and M. bovis BCG with an MIC value of 25 mg/L (66.0–77.4 µM). In addition, the compounds inhibited the MurE ligase of M. tuberculosis with moderate to weak activity showing IC50 values of 200–774 µM. The increased selectivity towards mycobacterial bacilli with reference to MRC-5 cells observed for 2-alkynyl quinolones compared to their corresponding 2-alkenyl analogues serves to highlight the mycobacterial specific effect of the triple bond. Exploration of a terminal bromine atom at the side chain of N-alkyl-2-(E)-alkenyl-4-(1H)-quinolones showed improved antimycobacterial activity whereas a cyclopropyl residue at N-1 was suggested to be detrimental to antibacterial activity

Dvojni lijekovi primakina i nesteroidnih protuupalnih lijekova: Sinteza, hvatanje slobodnih radikala, antioksidativno djelovanje i keliranje Fe2+ iona

Novel primaquine conjugates with non-steroidal anti-inflammatory drugs (PQ-NSAIDs, 4a-h) were prepared, fully chemically characterized and screened for radical scavenging and antioxidant activities. The synthetic procedure leading to twin drugs 4a-h involved two steps: i) preparation of NSAID benzotriazolides 3a-h from the corresponding NSAID (ibuprofen, ketoprofen, fenoprofen, ketoprofen hydroxy and methylene analogues, diclofenac or indomethacin) and benzotriazole carboxylic acid chloride (BtCOCl, 1), ii) reaction of intermediates 3a-h with PQ. The prepared PQ-NSAIDs exerted moderate activities in the DPPH free radical test and -carotene-linoleic acid assay. Moreover, ketoprofen derivatives 4d and 4b demonstrated a notable Fe2+ chelating ability as well. On the other hand, negligible antiproliferative and antituberculotic effects of conjugates 4a-h were observed.U radu je opisana sinteza novih konjugata primakina s nesteroidnim protuupalnim lijekovima (PQ-NSAIDs, 4a-h), njihova potpuna karakterizacija te testiranje sposobnosti hvatanja slobodnih radikala i antioksidativnog djelovanja. Sintetski postupak za pripravu dvojnih lijekova 4a-h uključuje dva koraka: i) pripravu NSAID-benzotriazolida 3a-h iz odgovarajućih nesteroidnih protuupalnih lijekova (ibuprofena, ketoprofena, fenoprofena, hidroksi i metilenskih analoga ketoprofena, diklofenaka i indometacina) i klorida 1-benzotriazol karboksilne kiseline (BtCOCl, 1), ii) reakciju intermedijera 3a-h s primakinom. Novi PQ-NSAID konjugati pokazuju umjerenu sposobnost hvatanja slobodnih radikala u DPPH testu te umjereno antioksidativno djelovanje u pokusu s -karotenom i linoleinskom kiselinom. Osim toga, derivati ketoprofena 4d i 4b imaju primjetnu sposobnost keliranja Fe2+ iona. Svi konjugati 4a-h pokazuju vrlo slabo antiproliferativno i antituberkulotsko djelovanje