bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metallkomplexe von biologisch wichtigen Liganden, CXXIX [1]. Palladium(II)-und Platin(II)-Komplexe von 4,4-disubstituierten Oxazolonen und C2-symmetrischen Bis(oxazolonen) Metal Complexes of Biologically Important Ligands, CXXIX [1]. Palladium(II) and Platinum(II) Complexes of 4,4-Disubstituted Oxazolones and of C2-Symmetric Bis(oxazolones)
Authors: Bauer Werner , Ponikwar Walter , Beck Wolfgang 
Published: February 2015

Abstract
4-Benzyl-4-methyl-2-phenyl-5(4H)-oxazolone (1) forms with the chloro bridged compounds [R3PMCl2]2 (M = Pt, Pd) the complexes Cl2Pt(PR3)(l) (R = Et, nBu) and Cl2Pd(PEt3)(l). The enantiomeric pure C2-symmetric CMe2 bridged bis(oxazolones) 5 and 6 have also been employed which give with PdCl2 the chelate complexes 13 and 14. The X-ray structural determination of Cl2P d[O-C (O)-CMe2-N=C-CMe2-C=N-CMe2-C (O)-O ] (10) shows that one of the methyl group of the CMe2 bridge is located near the palladium atom. This can also be detected in the 1H NMR spectrum.
Synthese und Komplexierung Phosphorylierter spacer-modifizierter Glucosederivate/ Synthesis and Complexation of Spacer Modified Phosphorylated Glucose Derivatives
Authors: Siedentop Tjark , Neda Ion , Schmutzler Reinhard 
Published: February 2015

Abstract
Treatment of the spacer modified glucose derivative 1 with diethylaminotrimethylsilane furnished the bis-silylated molecule 2. Reaction of 2 with two equivalents of the phosphorus compounds 3, 4, and 5 led to the spacer phosphorylated glucosyl derivatives 6, 7 and 8. Complexation of 6 with (COD)PtCl2 gave complex 9; the cis-conformation of 9 could be confirmed by 31P NMR investigations
Synthesis, Complex Formation and Spectral Investigation of New Tritopic Bis(Crown Ether) Compounds Containing Recognition Sites for Sodium and Nickel Guest Cations*
Authors: Hayvali Zeliha , Gündüz Necla , Kilic Zeynel , Weber Edwin 
Published: February 2015

Abstract
New bis(crown ether) ligands (1 - 3) of Schiff base type containing recognition sites for sodium and nickel guest cations have been synthesized by the condensation of two equivalents of 4′-formyl-5′-hydroxy(benzo-15-crown-5)with 1,5-diamino-3-azapentane, 1,8-diamino-3,6- diazaoctane or 1,8-diamino-3,6-dioxaoctane. Homonuclear ditopic crystalline 2:1 (Na+:ligand) complexes (1a - 3a) of the ligands with NaClO4 have been prepared. Heteronuclear tritopic crystalline 2:1:1 (Na⊕ : Ni2⊕ : ligand) complexes (2b and 3b) have also been synthesized from the reactions of the ditopic complexes (2a and 3a) with Ni(CH3COO)2 · 6H2O. The UV-VIS spectra of 1 - 3, their sodium complexes 1a - 3a and sodium-nickel complexes 2b and 3b have been recorded in polar and non-polar solvents as well as in acidic and basic media. In polar solvents and basic solutions, tautomeric equilibria (phenol-imine and keto-amine forms, O-H···N⇌O···H-N ) are present, depending on the hydrogen bonding. The results indicate that the concentrations of the keto forms of the compounds generally increase as the polarity of the solvent increases
N -Methoxyalkyl-Funktionalisierte α-Diketodiimide/ N -Methoxyalkyl Functionalized α-Diketodiimides
Authors: Kuhn Norbert , Steimann Manfred , Walker Isabel 
Published: February 2015

Abstract
The α-diketodiimides C10H20N2O2 (2a) and C12H24N2O 2 (2b) are prepared by reacting butane- 2,3-dione with the corresponding α,ϖ-amino- (methoxy)alkanes (1); the X-ray structure of 2a is reported
Characterization of the Inorganic/Organometallic Osmium(IV) Compound [Cp2 OsIVCl]2 [OsIVCl6] as Formed by the Reaction of OSCI3 with Pentamethylcyclopentadiene in Air
Authors: Sixta Torsten , Kaim Wolfgang , Preetz Wilhelm 
Published: February 2015

Abstract
Reaction of OsCl3, with pentamethylcyclopentadiene in ethanol in air yields the ionic osmium( IV) compound [Cp*2OsCl]2[OsCl6] which has been identified structurally and by vibrational spectroscopy. Under comparable conditions the RuCl3 homologue yields the ruthenium( III) compound [Cp*RuCl2]2, illustrating the more facile oxidation of the 5d element to the tetravalent state
Coordination Compounds of Lanthanide Nitrates with Dimorpholido-N-trichloroacetylphosphorylamide. The Structure of Di(dimorpholido-N-trichloroacetylphosphorylamide)- diaqua Neodymium(III)trinitrate
Authors: Ovchynnikov Vladimir A. , Timoshenko Taras P. , Amirkhanov Vladimir M. , Sieler Joachim , Skopenko Viktor V. 
Published: February 2015

Abstract
Lanthanide, Carbacylamidophosphate The coordination compounds of the general formula Ln(NO3)3(HL)2(H2O)2 H2O , where Ln = La, Ce -Nd, Sm -Dy, HL = CCl3C(O)NHP(O)[N(CH2CH2)2O]2, dimorpholido-N-tri-chloroacetylphosphorylamide, have been synthesized. The complexes were studied by IR, 1H and 31P NMR and UV-VIS absorption spectroscopies. X-ray diffraction analyses indicate that all synthesized compounds are isostructural. The crystal structure of Nd(NO3)3(HL)2(H2O)2 H2O was solved (monoclinic, a = 11.0467(3), b = 15.9080(5), c = 24.1921(7) Å, β = 96.4080(10)°, space group P21/n, V = 4224.7(2) Å3, Z = 4, R = 0.049, wR = 0.0915). The complex has a molecular structure. The monodentate neutral phosphorictriamide ligands are coordinated to the metal atom via the phosphoryl oxygen atom. The coordination polyhedron of Nd is a sphenocorona; C.N. = 10(60[NO3
-], 20[HL], 20[H2O]).
It was shown that these compounds in methanol solution are 1:1 electrolytes, and in acetone solution weak electrolytes. According to NMR data in acetone solution the complexes of the lanthanides with the ligand {HL} have axial symmetry.
A Novel Convenient Synthesis of Mixed-Valence TiIII/TiIV Double Phosphates Starting with Titanium Nitride TiN
Authors: Zatovsky Igor V. , Slobodyanik Nikolay S. , Stratiychuk Denis A. , Domasevitch Konstantin V. , Sieler Joachim , Rusanov Eduard B. 
Published: February 2015

Abstract
A new synthetic approach for the low- and mixed-valence double titanium phosphates starting with titanium nitride, TiN, and based on the controlled oxidation of a low-valent metal in the phosphate melt is presented. The reaction of the system MI
2O - P2O5 - TiN (MI = Na, K) in air (800-1050 °C) leads to loss of nitrogen, N2, and results in the formation of a number of double phosphates: KTiP2O7, K2TiniTiIV(PO4)3, KTiOPO4, NaTiP2O7, NaTi2(PO4)3 and a new mixed-valent diphosphate, NaTiIIITiIV(P2O7)2. The mixed-valent species K2TiIIITiIV(PO4)3 and NaTiIIITiIV(P2O7)2 were characterized by single crystal X-ray diffraction. The described synthetic procedure is proposed as a simple and convenient method for the preparation of lowand mixed-valent phosphate materials
β-Enaminonitriles in Heterocyclic Synthesis: Synthesis of New 1,4-Dihydropyridine, PyrazoIo[1,5-a]pyrimidine, Aminothiophene and Pyridine Derivatives
Authors: Hafiz Ibrahim S. A. 
Published: February 2015

Abstract
Utility of 3-aminocinnamonitrile (1) in the synthesis of new 1,4-dihydropyridine, pyrazolo- [1,5-a]pyrimidine, aminothiophene and pyridine derivatives is reported
A Major Saponin from Leaves Extract of Acer velutinum
Authors: Glénsk Michał , Włodarczyk Maciej , Bassarello Carla , Pizza Cosimo , Stefanowicz Piotr , Świtalska Marta 
Published: February 2015

A major triterpenoid saponin was isolated from the leaves extract of Acer velutinum. This compound was characterized as 21β ,22α-O-diangeloylprotoaescigenin 3-O-[β -D-glucopyranosyl- (1→2)][β -D-glucopyranosyl-(1→4)]-β -D-glucuronopyranosyl acid.
Its structure was elucidated by 1H, gCOSY, ROESY, gHSQC, gHMBC NMR as well as ESI-MS experiments. Isolated saponin exhibited in vitro cytotoxicity against HL-60, B16-F0 and BALB/3T3 cell lines.
Secondary Metabolites from a Streptomyces Strain Isolated from Livingston Island, Antarctica
Authors: Ivanova Veneta , Oriol Monica , Montes Maria-Jesus , García Angela , Guinea Jesus 
Published: February 2015

Abstract
The producing strain Streptomyces sp. 1010 was isolated from a shallow sea sediment from the region of Livingston Island, Antarctica. From the culture broth of this strain naturally active secondary metabolites were isolated identical to phthalic acid diethylester (C12H1404, MW.222); 1, 3-bis (3-phenoxyphenoxy)benzene (C30H22O4 , MW.446); hexaned ioic acidd ioctylester (C22H42O4 , MW.370) and the new substance 2-amino-9, 13 -dimethylheptad ecanoic acid (C19H39NO2 , MW.313). These compounds represent diverse classes of chemical struc­tures and provideevidence for the untapped biosynthetic potential of marine bacteria from Antarctica.
Neodictyoprolenol and Dictyoprolenol, the Possible Biosynthetic Intermediates of Dictyopterenes, in the Japanese Brown Algae Dictyopteris
Authors: Yamamoto Yuuko , Akakabe Yoshihiko , M atsui Kenji , Shimizu Hiroshi , Kajiwara Tadahiko 
Published: February 2015

Abstract
Neodictyoprolenol [(-)-(3 S )-(1,5 Z, 8Z)-undecatrien-3-ol] and dictyoprolenol [ (-) - ( 3 S ) - (1,5 Z , 8Z )-undecadien-3-ol]), which had been proposed as possible biosynthetic intermediates of the sex pheromones of marine brown algae such as dictyopterene B [(-)-trans-1- ((1'E,3' Z )-hexadienyl)-2-vinylcyclopropane], D ' [(+ )-6 -((1' Z )-butenyl)-1,4 -cycloheptadiene] and C' [(+ )-6-butyl-1,4-cycloheptadiene], were again identified in the essential oils from Dictyopteris prolifera, D. latiscula, and in D. undulata, together with the C11-related volatile compounds such as neodictyoprolene, dictyoprolene and dictyopterenes. Incubation of D. prolifela preparation with racemic neodictyoprolenol and dictyoprolenol as substrates showed (S)-enantioselective decreases of the added substrates and increases in dictyopterenes. From these results, a possible pathway to form dictyopterenes is discussed.
New Semisynthetic Antimicrobial Labdane-Type Diterpenoids Derived from the Resin “Ladano” of Cistus creticus
Authors: Kalpoutzaki Eleftherios , Aligiannis Nektarios , Mitaku Sofia , Harvala Catherine , Skaltsounis Alexios-Leandros 
Published: February 2015

Abstract
The antimicrobial activity of fifteen semisynthetic labdane-type diterpenes derived from the two major natural compounds 3 and 4 of the resin "ladano" of Cistus creticus is reported. The chloroethyl carbamidic esters 15 and 20 showed the strongest antimicrobial activity against Gram (+), Gram (-) bacteria and pathogenic fungi.
Phase Response Curve for the Ultradian Rhythm of the Lateral Leaflets of Desmodium gyrans Using DC Current Pulses
Authors: Sharma Vijay Kumar , Jensen Christer , Johnsson Anders 
Published: February 2015

Abstract
In the present study the leaf movement rhythm was perturbed by the application of DC current pulses 15 μA, 10 seconds, voltage applied: 10 V) to the upper part of the pulvinus, passing through the pulvinus and its stalk. The pulses were applied at four different positions of the leaflets: when the leaves were at the lowermost position, when moving up, at the uppermost position and when moving down. The pre-perturbed and the post-perturbed rhythms were compared. We found that the rhythms were shifted in phase and the phase shifts observed at the four different positions of the leaflets were significantly different in magnitude as well as direction. Furthermore, we could also observe phase advances, which is in contrast to an earlier finding. A phase response curve (PRC) was constructed to illustrate the sensitivity of the oscillating leaflet system to DC pulses. Substantial delays of about 50 s (as compared to the period of about 200 s) were obtained when pulses were administered at the lowermost position and when leaflet were moving upwards, while advances or no phase shifts were recorded in the uppermost position and when leaflet were moving down respectively.
Influence of Food and Larval Age on the Defensive Chemistry of Satumia pyri
Authors: Deml Reinhold 
Published: February 2015

Abstract
Scolus secretions and hemolymph of caterpillars of Satumia pyri fed with two different foodplants (Crataegus monogyna, Prunus spinosa) were chemically analyzed and their chemical similarities determined. The secondary-compound patterns obtained for the two body fluids showed no significant differences when compared between the two groups of alterna­ tively fed last-instar larvae. Thus, the composition of these fluids of full-grown caterpillars is not influenced by the larval diet. However, younger larvae on P. spinosa revealed a diversity of compounds differing significantly from that of larger caterpillars fed with either C. mono­gyna (both body fluids) or P. spinosa (hemolymph only). This indicates that, on the one hand, the hemolymph composition is adapted to the changing physiological requirements of the given instars whereas, on the other hand, the defensive mixtures remain unaltered in the late larval instars due to a constant spectrum of potential enemies.
Phenolic Acids and Depsides from Some Species of the Erodium Genera
Authors: Fecka Izabela , Kowalczyk Adam , Cisowski Wojciech 
Published: February 2015

Abstract
Six natural polyphenolic compounds, brevifolin carboxylic acid, brevifolin, ellagic acid, methyl gallate, gallic acid and protocatechuic acid have been isolated from the methanol extract of the whole plant of Erodium cicutarium (L.) L.’Herit. (Geraniaceae). Structures were determined by conventional methods of analysis and confirmed by MS and NMR spectral analysis. The distribution of these compounds in the other species of the Erodium genera (E. botrys, E. chium, E. ciconium, E. cicutarium, E. glutinosum subsp. dunense, E. gruinum, E. manescavi, E. pelargoniiflorum, E. petraeum ) were examined by HPLC with a RP-18 column, and MGD-TLC methods on unmodified silica gel and silica gel chemically modified with polar and nonpolar groups (HPTLC-Si 60 LiChrospher, HPTLC-NH2, HPTLC-DIOL, HPTLC RP-18W).
Chemistry of New Zealand Apiaceae: A Rare Phenylpropanoid and Three New Germacrane Derivatives from Anisotome lyallii
Authors: Zidorn Christian , Perry Nigel B. 
Published: February 2015

Abstract
A phytochemical investigation of the New Zealand endemic Apiaceae species Anisotome lyallii Hook.f. yielded (+)-α-angeloyloxylatifolone (1), 6-0-angeloyl-8-0-tigloyl-6β,8α,11-trihydroxygermacra- 1(10)E,4E-diene (2), 6-O-tigloyl-8-O-tigloyl-6β,8α,11-trihydroxygermacral( 10)E,4E-diene (3) and 6-O-tigloyl-8-O-tigloyl-la,6β,8α,11-tetrahydroxygermacra-4E,10- (14)diene (4). The structures were elucidated by HR mass spectrometry and 1D- and 2DNMR spectroscopy. A chemosystematic survey for compounds 1 - 3 in other New Zealand Apiaceae by HPLC-MS revealed that 1 - 3 were confined to A. haastii Cockayne & Laing and A. lyallii, and that some minor compounds in other species of Anisotome were isomers of 2 and 3.
Sesquiterpenoids and Phenolics from Crepis conyzifolia
Authors: Kisiel Wanda , Michalska Klaudia 
Published: February 2015

Abstract
From the roots of Crepis conyzifolia, two new and two known guaianolides were isolated together with three known phenylpropanoids. Structures of the new compounds were estab­lished as 8β-hydroxy-4β, 15-dihydrozaluzanin C and 4β, 15, 11β, 13-tetrahydrozaluzanin C-3-O-β-glucopyranoside by spectral methods. The identity of 8 -epiisolippidiol and dentalactone was also discussed.
Chromene Chalcones from Tephrosia carrollii and the Revised Structure of Oaxacacin
Authors: Gómez-Garibay Federico , Arciniega Minarda De La O , Céspedes Carlos L. , Taboada Javier , Calderón José S. 
Published: February 2015

Abstract
The aerial parts of Tephrosia carrollii afforded two chromene chalcones. Their structures and stereochemistry were established by spectroscopic methods. The structure of oaxacacin was revised and confirmed by X-ray diffraction. In this paper, we describe the isolation of the chalcone known as "oaxacacin" and the new chalcone named epoxyobovatachalcone. The compound der. oaxacacin was found to be identical with obovatachalcone based on spectroscopic evidence and X-ray diffraction.
Limnantheoside C (20-Hydroxyecdysone 3-O-β-ᴅ-glucopyranosyl- [1→3]-β-ᴅ-xylopyranoside), a Phytoecdysteroid from Seeds of Limnanthes alba (Limnanthaceae)
Authors: Meng Yanhui , Whiting Pensri , Šik Vladimir , Rees Huw H. , Dinan Laurence 
Published: February 2015

Abstract
A new ecdysteroid glycoside, lim nantheoside C (20-hydroxyecdysone 3-O-β-ᴅ-glucopyra-nosyl-[→3]-β-ᴅ-xylopyranoside [1]), together with limnantheoside A (20-hydroxyecdysone 3-O-β-ᴅ-xylopyranoside [2]) and 20-hydroxyecdysone (3) have been isolated by bioassay/RIA-directed HPLC analyses of a methanol extract of the seedmeal of Limnanthes alba Hartw. ex Benth. The structure of the novel ecdysteroid glycoside (1) was determined unambigu­ously by UV, LSIMS and a combination of ID -and 2D-NMR experiments. These three compounds are isolated from Limnanthes alba for the first time.
Chemical Composition and Biological Activities of the Black Sea Algae Polysiphonia denudata (Dillw.) Kutz. and Polysiphonia denudata f. fragilis (Sperk) Woronich
Authors: Rosa Salvatore De , Kamenarska Zornitsa , Bankova Vassya , Stefanov Kamen , Dimitrova-Konaklieva Stefka , Najdenski Hristo , Tzevtkova Iva , Popov Simeon 
Published: February 2015

Abstract
The two investigated algae had almost identical sterol composition, but there were signifi­cant differences in the com position of the polar components and especially in the composi­tion of the volatiles. P. denudata f. fragilis extracts possessed a stronger biological activity (antibacterial, antifungal and toxicity against Artemia salina). Despite the minute morpholog­ical differences between the two algae, we recommend P. denudata f. fragilis to be regarded as P. denudata subsp. fragilis.
Properties of Chlorophyllase from Capsicum annuum L. Fruits
Authors: Hornero-Méndez Dámaso , Mínguez-Mosquera María Isabel 
Published: February 2015

Abstract
The in vitro properties of semi-purified chlorophyllase (chlorophyll-chlorophyllido hy­drolase, EC 3.1.1.14) from Capsicum annuum fruits have been studied. The enzym e showed an optimum of activity at pH 8.5 and 50 °C. Substrate specificity was studied for chlorophyll (Chi) a, Chi b, pheophytin (Phe) a and Phe b, with Km values of 10.70, 4.04, 2.67 and 6.37 μᴍ respectively. Substrate inhibition was found for Phe b at concentrations higher than 5 μᴍ. Chlorophyllase action on Chi a' and Chi b' was also studied but no hydrolysis was observed, suggesting that the mechanism of action depends on the configuration at C-132 in the chloro­ phyll molecule, with the enzyme acting only on compounds with R132 stereochemistry. The effect of various metals (Mg2+, Hg2+, Cu2+, Zn2+, Co , Fe2+ and Fe3+) was also investigated, and a general inhibitory effect was found, this being more marked for Hg2+ and Fe2+. Func­tional groups such as -SH and -S-S-seem ed to participate in the formation o f the enzyme-substrate complex. Chelating ion and the carbonyl group at C3 appeared to be important in substrate recognition by the enzyme. The method for measuring Chlase activity, including HPLC separation of substrate and product, has been optimized.
Production and Properties of a Bacterial Thermostable Exo-inulinase
Authors: Uzunova Kristina , Vassileva Anna , Kambourova Margarita , Ivanova Viara , Spasova Dimitrina , Mandeva Rositza , Derekova Anna , Tonkova Alexandra 
Published: February 2015

Abstract
Enzyme production of newly isolated thermophilic inulin-degrading Bacillus sp. 11 strain was studied by batch cultivation in a fermentor. The achieved inulinase and invertase activi­ ties after a short growth time (4.25 h) were similar or higher compared to those reported for other mesophilic aerobic or anaerobic thermophilic bacterial producers and yeasts. The investigated enzyme belonged to the exo-type inulinases and splitted-off inulin, sucrose and raffinose. It could be used at temperatures above 65 °C and pH range 5.5-7.5. The obtained crude enzyme preparation possessed high thermostability. The residual inulinase and inver­ tase activities were 92-98% after pretreatment at 65 °C for 60 min in the presence of substrate inulin.
Photosynthetic Pigments, Photosynthesis and Plastid Ultrastructure in RbcS Antisense DNA Mutants of Tobacco {Nicotiana tabacum)
Authors: Sehoefs Benoît , Darko Eva , Rodermel Steve 
Published: February 2015

Abstract
RbcS antisense DNA mutants of tobacco have reduced amounts of ribulose bisphosphate carboxylase oxygenase (Rubisco). We found that carotenoid and chlorophyll contents decrease in parallel as Rubisco is decreased, however, pigment levels are not significantly altered until Rubisco levels are reduced sharply. The mutants have normal Chi a /Chi b ratios and normal plastid ultrastructures, suggesting that reductions in Rubisco do not dramatically alter the composition of the thylakoid membranes. Nevertheless, chlorophyll fluorescence measurements, in which developmentally homogenous leaves were sampled, showed that there is reduced photosynthetic capacity of PSII and an enhanced photosensitivity in the mutants, especially in transgenics with severe reductions in Rubisco content. Support for this conclusion comes from several observations; 1) light saturation occurs at a lower light inten­ sity in the mutants, resulting in an earlier closure of PS II (lower photochemical quenching); 2) the mutants have reduced photosynthetic efficiency (lower ΔF/Fm'); and 3) the mutants have a slower recovery of Fv/Fm. We found that acclimation to increasing light intensies in the mutants appears to involve an enhanced inactivation of PSII reaction centers as well as an increased activation of photoprotective mechanisms, notably an engagement of the xanthophyll cycle at lower than normal light intensities. We conclude that the photosensitivity of the antisense mutants is due, in part, to a limitation in Rubisco activation state.
Relaxation of Water Protons in Highly Concentrated Aqueous Protein Systems Studied by NMR Spectroscopy
Authors: Szuminska Katarzyna , Gutsze Aleksander , Kowalczyk Andrzej 
Published: February 2015

Abstract
In this paper we present proton spin-lattice ( T1) and spin-spin ( T2) relaxation times measured vs. concentration, temperature, pulse interval (τCPMG) as well as 1H NMR spectral measurements in a wide range of concentrations of bovine serum albumin (B SA ) solutions. The anomalous relaxation behaviour of the water protons, similar to that observed in mammalian lenses, was found in the two most concentrated solutions (44% and 46% ). The functional dependence of the spin-spin relaxation time vs. τCPMG pulse interval and the values of the motional activation parameters obtained from the temperature dependencies of spinlattice relaxation times suggest that the water molecule mobility is reduced in these systems. The slow exchange process on the T2 time scale is proposed to explain the obtained data. The proton spectral measurements support the hypothesis of a slow exchange mechanism in the highest concentrated solutions. From the analysis of the shape of the proton spectra the mean exchange times between bound and bulk water proton groups (τex) have been estimated for the range of the highest concentrations (30% - 46% ). The obtained values are of the order of milliseconds assuring that the slow exchange condition is fulfilled in the most concentrated samples.
The First Glycosides Isolated from Propolis: Diterpene Rhamnosides
Authors: Popova Milena , Bankova Vassya , Tsvetkova Iva , Naydenski Christo , Silva Mario Vides 
Published: February 2015

Abstract
Two diterpene glycosides, ent8(17)-labden-15-O-α-ʟ-rhamnoside and ent-8(17)-labden-15-O-(3′-O-acetyl)-α-ʟ-rhamnoside (new natural compounds) were isolated from propolis from El Salvador. The compounds showed significant antibacterial activity and moderate toxicity to Artemia salina nauplii. These are the first glycosides reported in bee glue.