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1.
Reactions of ω-diphenylphosphinofunctionalized alkyl phenyl sulfides Ph2P(CH2)nSPh (n = 1, 1a; 2, 2a; 3, 3a), sulfoxides Ph2P(CH2)nS(O)Ph (n = 1, 1b; 2, 2b; 3, 3b) and sulfones Ph2P(CH2)nS(O)2Ph (n = 1, 1c; 2, 2c; 3, 3c) with dinuclear chlorido bridged rhodium(I) complexes [(RhL2)2(μ-Cl)2] (L2 = cycloocta-1.5-diene, cod, 4; bis(diphenylphosphino)ethane, dppe, 5) afforded mononuclear Rh(I) complexes of the type [RhCl{Ph2P(CH2)nS(O)xPh-κP}(cod)]1 (n/x = 1/0, 6a; 1/1, 6b; 1/2, 6c; 2/0, 8a; 2/1, 8b; 2/2, 8c; 3/0, 10a; 3/1, 10b; 3/2, 10c) and [RhCl{Ph2P(CH2)nS(O)xPh-κP}(dppe)] (n/x = 1/0, 7a; 1/1, 7b; 1/2, 7c; 2/0, 9a; 2/1, 9b; 2/2, 9c; 3/0, 11a; 3/1, 11b; 3/2, 11c) having the P^S(O)x ligands κP coordinated. Addition of Ag[BF4] to complexes 6-11 in CH2Cl2 led with precipitation of AgCl to cationic rhodium complexes of the type [Rh{Ph2P(CH2)nS(O)xPh-κPS/O}L2][BF4] having bound the P^S(O)x ligands bidentately in a κPS (13a-18a, 15b-18b) or a κPO (13b, 14b, 13c-18c) coordination mode. Unexpectedly, the addition of Ag[BF4] to 6a in THF afforded the trinuclear cationic rhodium(I) complex [Rh3(μ-Cl)(μ-Ph2PCH2SPh-κPS)4][BF4]2·4THF (12·4THF) with a four-membered Rh3Cl ring as basic framework. Addition of sodium bis(trimethylsilyl)amide to complexes 6-11 led to a selective deprotonation of the carbon atom neighbored to the S(O)x group (α-C) yielding three different types of organorhodium complexes: a) Organorhodium intramolecular coordination compounds of the type [Rh{CH{S(O)xPh}CH2CH2PPh2CP}L2] (22a-c, 23a-c), b) zwitterionic complexes [Rh{Ph2PCHS(O)xPh-κPS/O}L2] having κPS (21a, 21b) and κPO (20b/c, 21c) coordinated anionic [Ph2PCHS(O)xPh] ligands, and c) the dinuclear rhodium(I) complex [{Rh{μ-CH(SPh)PPh2CP}(cod)}2] (19). All complexes were fully characterized spectroscopically and complexes 15b, 15c, 12·4THF and 19·THF additionally by X-ray diffraction analysis. DFT calculations of zwitterionic complexes gave insight into the coordination mode of the [Ph2PCHS(O)Ph] ligand (κPS versus κPO).  相似文献   

2.
Biotransformation of (+)-(1R,2S)-fenchol by the larvae of Spodoptera litura was carried out. Substrate was converted to three new terpenoids, (+)-(1R,2S)-10-hydroxyfenchol, (+)-(1R,2R,3S)-8-hydroxyfenchol and (−)-(1S,2S,6S)-6-exo-hydroxyfenchol, and one known terpenoid, (−)-(1R,2R,3R)-9-hydroxyfenchol. These structures were established by NMR, IR, specific rotation and mass spectral studies.  相似文献   

3.
Chemical investigation of the Red Sea soft coral Sarcophyton auritum led to the isolation and structure elucidation of two new diterpene cembranoids; 2-epi-sarcophine (2) and (1R,2E,4S,6E,8R,11R,12R)-2,6-cembradiene-4,8,11,12-tetrol (4), as well as two known diterpene cembranoids, reported for the first time from this species, namely sarcophine (1) and (+)-7α,8β-dihydroxydeepoxysarcophine (3). Structure elucidation was achieved using spectroscopic techniques, including 1D and 2D NMR and HRMS. The isolated cembranoids were found to display high cytotoxicity against HepG2 (liver cancer cell line) and MCF-7 (breast cancer cell line).  相似文献   

4.
Syntheses and solid-state structures of zinc and tin(II) compounds, containing the N-silyl-amide ligands (OtBu)(NR)SiMe2, R = tBu (LtBu), or R = p-tolyl (LpTol), are reported. The N-silyl amines were synthesized by modified published procedures from commercially available Me2SiCl2, tBuOH, and tBuNH2, or p-Me-C6H4NH2, respectively. Treatment of SnCl2 with LiLpTol furnished Sn(LpTol)2, which was X-ray structurally characterized and shown to contain two covalent Sn-N bonds and two asymmetrical O → Sn donor bonds. The single-crystal X-ray structure of Sn(LtBu)2 revealed a much more symmetrically-coordinated, pseudo-trigonal-bipyramidal tin atom. Aminolysis of diethylzinc with HLpTol produced [EtZn(LpTol)]2, which crystallized as a centrosymmetric dimer, containing four-coordinate zinc atoms connected by bridging amides. Zinc dichloride, by contrast, reacted with two equivalents of LiLtBu to produce the homoleptic, pseudo-spirocyclic Zn(LtBu)2.  相似文献   

5.
A new polyhydroxylated macrolide, named mangiferaelactone (1) was isolated from a solid culture of the endophytic fungus Pestalotiopsis manguiferae, together with ten known compounds [(6S,1′S)-LL-P880α; (6S,1′S,2′R)-LL-P880β; (1′S,2′R)-LL-880γ; (1′R)-dehydropestalotin; (−)-5-carboxylmellein; (−)-5-methylmellein; (−)-5-hydroxylmethylmellein; arabenoic acid; 5,6-dihydro-4-methoxy-2H-pyran-2-one; and the (−)-2-hexylidene-3-methylsuccinic acid]. P. manguiferae was isolated from Hyptis dilatata, a small shrub common in the central region of Panama. The structure of compound 1 was elucidated by a combination of spectroscopic methods (IR, MS, optical rotation, 1D and 2D NMR spectroscopy). The absolute configuration of 1 was established as 4R,7R,8R,9S by application of vibrational circular dichroism (VCD). Compound 1 showed a minimum inhibitory concentration (MIC) of 1.6863 mg/mL against Listeria monocytogenes, and 0.5529 mg/mL against Bacillus cereus. No activity was observed for compound 1 against Plasmodium falciparum or Trypanosoma cruzi; likewise, no cytotoxic activity was observed against A2058 and H522-T1 cells.  相似文献   

6.
Treatment of the chloro-bridged dinuclear complex [Pd{3,4-(MeO)2C6H2C(H)N(Cy)-C6,N}(μ-Cl)]2 (1) with homobidentate [P,P], [As,As], [N,N], and heterobidentate [P,As], [P,N] ligands in a 1:1 molar ratio gave the dinuclear complexes [{Pd[3,4-(MeO)2C6H2C(H)N(Cy)-C6,N](Cl)}2{μ-L}] (L = Ph2PC4H6(NH)CH2PPh2 (2); Ph2As(CH2)2AsPh2 (3); 1,3-(NH2CH2)2C6H4 (4); Ph2P(CH2)2AsPh2 (5); Ph2P(CH2)2NH2 (6)), with the bidentate ligands bridging the two cyclometallated fragments.The reaction with the homobidentate ligands in a 1:2 molar ratio in the presence of NaClO4 afforded the mononuclear compounds [[Pd{3,4-(MeO)2C6H2C(H)N(Cy)-C6,N}{L-P,P}][ClO4] (L = Ph2PC4H6(NH)CH2PPh2 (7); (o-Tol)2P(CH2)2P(o-Tol)2 (8)), [Pd{3,4-(MeO)2C6H2C(H)N(Cy)-C6,N}{Ph2As(CH2)2AsPh2-As,As}][ClO4] (9) and [Pd{3,4-(MeO)2C6H2C(H)N(Cy)-C6,N}{L-N,N}][ClO4] (L = NH2(CH2)3NH2 (10); NH2(C6H8)CH2(C6H8)NH2 (11); 1,3-(NH2CH2)2C6H4 (12); 1,3-(NH2)2C5H3N (13); NH2(C6H4)O(C6H4)NH2 (14); NMe2(CH2)2NMe2 (15)), in which the chloro ligands are absent and the bidentate ligands are chelated to the palladium atom.Reaction of 1 with Ph2P(CH2)2AsPh2 in 1:2 molar ratio in acetone in the presence of NH4PF6 afforded the analogous mononuclear compound [Pd{3,4-(MeO)2C6H2C(H)N(Cy)-C6,N}{Ph2P(CH2)2AsPh2-P,As}][PF6] (16); whereas reaction with Ph2P(CH2)3NH2 gave [Pd{3,4-(MeO)2C6H2C(H)N(Cy)-C6,N}{Ph2P(CH2)3N(CMe2)-P,N}][PF6] (17), derived from intermolecular condensation between the aminophosphine and acetone. Condensation of the NH2 group was precluded by change of solvent, using dichloromethane.Iminophoshines also reacted with 1 in 1:2 molar ratio in acetone to give a new series of mononuclear cyclometallated complexes: [Pd{3,4-(MeO)2C6H2C(H)N(Cy)-C6,N}{L-P,N}][ClO4] (L = Ph2PC6H4C(H)NCy (20); Ph2PC6H4C(H)NC(CH3)3 (21); Ph2PC6H4C(H)NNMe2 (22); Ph2PC6H4C(H)NNHMe (23); Ph2PC6H4C(H)NNHPh (24)). Analogous complexes with a stable P,O-chelate were obtained using bidentate [P,O] donor ligands: [Pd{3,4-(MeO)2C6H2C(H)N(Cy)-C6,N}{L-P,O}][Cl] (L = 2-(Ph2P)C6H4CHO (25); Ph2PN(Me)C(O)Me (26)).The crystal structures of compounds 1, 5, 15, 16, 18, 20 have been determined by X-ray crystallography.  相似文献   

7.
N,N,N′,N′-Tetramethylmethanediamine (1a), N,N,N′,N′-tetramethylethanediamine (1b), N,N,N′,N′-tetramethyl-1,3-propanediamine (1c), and N,N,N′,N′-tetramethyl-1,6-hexanediamine (1d) were reacted at 25 °C with 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (2a), 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedione (2b), 2-thenoyltrifluoroacetone (2c), and 4,4,4-trifluoro-1-(2-furyl)-1,3-butanedione (2d) to form the ionic adducts 3-18. 1,4,7,10-Tetraazacyclododecane (1e) reacted at 25 °C with β-diketones (2a-d) and 1,1,1-trifluoro-2,4-pentanedione (2e) to give ionic solids 19-23 in good yields. Some of the products are liquid at 25 °C and are thermally stable over long liquid ranges as determined by thermal gravimetric analyses. Single-crystal X-ray structure determinations show that compounds 9 and 21 crystallize in the monoclinic space groups P2(1)/c and P2(1)/n, respectively. All the new compounds were characterized by 1H, 19F and 13C NMR, electrospray MS and/or elemental analyses.  相似文献   

8.
As part of our research on 2-aza analogues of pentalongin, the active principle of Pentas longiflora Oliv., the first synthesis of 2,3-disubstituted benzo[g]isoquinoline-1,5,10(2H)-triones via 3,4-disubstituted 6-hydroxybenzo[g]furo[4,3,2-de]isoquinoline-2,5(4H)-diones as the key intermediates is reported. The latter compounds have been prepared by treating 2-methoxycarbonyl-1,4-naphthoquinone with N-substituted enaminoesters under acidic conditions. These reagents are easily accessible from readily available 1,4-dihydroxy-2-naphthoic acid, β-ketoesters and primary amines. Finally, a short synthesis of substituted benzo[g]isoquinoline-1,5,10(2H)-triones is achieved by an oxidative addition of N-substituted enaminoesters onto methyl 1,4-dihydroxynaphthalene-2-carboxylate.  相似文献   

9.
We prepared a novel fluorous deoxy-fluorination reagent N,N-diethyl-α,α-difluoro-[3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzyl]amine (1b) from 3,5-diiodobenzoic acid (3b) via N,N-diethyl-3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzamide (2b) in four steps and used it for the fluorination of alcohols and diols. After the fluorination reactions, the isolation of the products and recovery of 2b was performed by extraction with a fluorous/organic solvent system.  相似文献   

10.
A convenient and rapid synthesis of hitherto unknown 3-aroyl-4-aryl-2-phenylamino-4H-benzo[g]chromene-5,10-diones in high yield from β-aroyl-thioacetanilide, aromatic aldehyde, and 2-hydroxy-1,4-naphthoquinone via InCl3 catalyzed one-pot three-component tandem Knoevenagel condensation–Michael addition–intramolecular cyclization–elimination reaction sequence is disclosed for the first time. This domino protocol has been used to obtain highly substituted pyrano[3,2-c]chromen-5(4H)-ones and 7,7-dimethyl-7,8-dihydro-4H-chromen-5(6H)-ones from N,3-diaryl-3-oxo-propanethioamide, aromatic aldehyde, and 4-hydroxycoumarine or dimedone under mild reaction conditions. A plausible reaction mechanism is proposed. The 4H-pyrano[3,2-c]chromen-5-one and 7,7-dimethyl-7,8-dihydro-4H-chromen-5(6H)-one derivatives possessing 3-(2-chlorobenzoyl)-2-phenylamino-substituents further cyclized under basic conditions to yield penta-cyclic 7,13-diaryl-5,14-dioxa-13-aza-benzo[a]naphthacen-6,8(7H,13H)-dione and tetra-cyclic 6,12-diaryl-3,3-dimethyl-3,4-dihydro-2H-chromeno[2,3-b]quinolin-1,11(6H,12H)-dione, respectively.  相似文献   

11.
Aihua Zhou 《Tetrahedron》2006,62(17):4093-4102
2-Alkyloxazolines and 2-alkylthiazolines react with 2-halobenzoyl chlorides to form N-(2-halobenzoyl)-cyclic ketene-N,O-acetals and N-(2-halobenzoyl)-cyclic ketene-N,S-acetals in excellent yields, respectively. These ketene acetals readily undergo stereocontrolled aryl radical cyclizations to afford the central six-membered rings of substituted-2,3,10,10α-tetrahydrooxazolo[3,2-b]isoquinolin-5-ones and their 2,3,10,10α-tetrahydrothiazolo[3,2-b]isoquinolin-5-one analogs. The tertiary N,O- and N,S-radicals formed upon aryl radical reaction at the ketene-N,X(X=O, S)-acetal double bond appear to have reasonable stability. The stereoselectivity in hydrogen abstractions by these intermediate radicals from both Bu3SnH and (Me3Si)3SiH was investigated. The N,S-heterocyclic fused ring products may have potential medical value.  相似文献   

12.
Two novel polynuclear complexes with methanoate anions and 3-hydroxypyridine ligands [Cu(μ-HCO2)2(3-pyOH)]n (1) and [Cu2(μ-HCO2)2(μ-3-pyOH)2(3-pyOH)2(HCO2)2]n (2), respectively, were synthesized and characterized. The central copper atom in 1 is surrounded by four methanoates and a 3-pyOH molecule, forming a square-pyramidal CuO3NO chromophore. All the methanoates are bidentate and serve as bridges between the adjacent copper ions via syn-anti and anti–anti coordination. The basal square coordination axes are formed by O(syn), N(3-pyOH) (1.974(2), 2.016(2) Å) and O(anti), O(anti) (1.945(2), 1.960(2) Å), while the third O(anti) (2.247(2) Å) is on the top of the pyramid. A ferromagnetic transition with an exchange constant 2J/kB = 9.2 cm−1 is found for 1 below 20 K. This interaction probably takes place through two syn-anti methanoates extended in a chain through the 2D structure. On the other hand, two monoatomic Cu–O–Cu intra-dinuclear asymmetric (1.986(2), 2.415(2) Å) bridges of two methanoates in [Cu2(HCO2)4(3-pyOH)4] (2) are present. An elongated distorted octahedral coordination sphere around each copper(II) atom is completed by an additional monodentate terminal methanoate (1.975(2) Å), two N-coordinated 3-pyOH (2.005(2), 2.002(2) Å) and the third weakly O-coordinated 3-pyOH (2.732(2) Å). Although a shorter Cu?Cu distance is noticed in 2 than in 1 (4.690(1) Å 1, 3.442(1) Å 2), much weaker ferromagnetism is found in 2.  相似文献   

13.
Layered zirconium benzylamino-N,N-dimethylphosphonate phosphate (ZBMPA) was prepared by the reaction of zirconyl chloride with benzylamino-N,N-dimethylphosphonic acid (H2BMPA) and phosphoric acid in the presence of hydrofluoric acid. The intercalation of n-alkylamines (n-butylamine, n-heptylamine and n-decylamine) into ZBMPA was primarily investigated at room temperature. These materials were characterized by elemental analysis, ICP, XRD, SEM, FT-IR, Raman spectra, TG and DSC. The composition of ZBMPA is Zr(HPO4)(C6H5CH2N(CH2PO3)2)0.5 · 2.0H2O. The interlayer distance of ZBMPA, n-butylamine, n-heptylamine and n-decylamine intercalation compounds is 2.03, 2.58, 2.52 and 3.17 nm, respectively. ZBMPA and the n-alkylamine intercalation compounds are different in the morphology and vibration spectra. Thermogravimetries of all materials obtained reveal three step mass losses at temperatures of up to 1000 °C. These results indicate that n-alkylamines are intercalated into the galleries of host ZBMPA.  相似文献   

14.
Hydroxy-amino-diphosphonates HO-Cn-NH2, with 2 ? n ? 11, have been successfully synthesized via the Kabachnick-Field reaction at 70 °C with high yields. These hydroxy compounds are then reacted with methacryloyl chloride to lead to novel amino-diphosphonate methacrylates MACnNP2 (with 2 ? n ? 11). These highly pure methacrylate monomers were obtained with yields higher than 75%. Radical copolymerizations of MACnNP2 (with 2 ? n ? 11) with MMA have been conducted and the r1 values (related to MACnNP2) are in the range of 1.1-1.3, and r2 values (related to MMA) about 0.8; this shows that the diphosphonate groups are statistically bonded to the methacrylic backbone.  相似文献   

15.
16.
Sebastien Meiries 《Tetrahedron》2009,65(15):2951-2958
The divergent syntheses of the trichloroacetamide derivatives of (2S,3R,8R,9R,4E,6E)-3-amino-9-methoxy-2,6,8-trimethyl-10-phenyl-decadenoic acid (enantio-iso-ADDA), and (2R,3R,8R,9R,4E,6E)-3-amino-9-methoxy-2,6,8-trimethyl-10-phenyl-decadenoic acid (enantio-ADDA), have been achieved. Our approach takes advantage of highly efficient non-aldol aldol, palladium catalysed aza-Claisen and cross-metathesis methodologies.  相似文献   

17.
The complexes [Rh(CO)(PPh3){Ph2PNP(O)Ph2-P,O}] (3), [Rh(CO)2{Ph2P(Se)NP(Se)Ph2-Se,Se′}] (5), and [Rh(CO)(PPh3){Ph2P(Se)NP(Se)Ph2-Se,Se′}] (6), were synthesised by stepwise reactions of CO and PPh3 with [Rh(cod){Ph2PNP(O)Ph2-P,O}] (2) and [Rh(cod){Ph2P(Se)NP(Se)Ph2-Se,Se′}] (4), respectively. The complexes 3, 5 and 6 have been studied by IR, as well as 1H and 31P NMR spectroscopy. The ν(CO) bands of complexes 3 and 6 appear at approximately 1960 cm−1, indicating high electron density at the RhI centre. The structure of complexes 3 and 6 has been determined by X-ray crystallography, and the 31P NMR chemical shifts have been resolved via low temperature NMR experiments. Both complexes exhibit square planar geometry around the metal centre, with the five-membered ring of complex 3 being almost planar, and the six-membered ring of complex 6 adopting a slightly distorted boat conformation. The C-O bond of the carbonyl ligand is relatively weak in both complexes, due to strong π-back donation from the electron rich RhI centre. The catalytic activity of the complexes 2, 3 and 6 in the hydroformylation of styrene has been investigated. Complexes 2 and 3 showed satisfactory catalytic properties, whereas complex 6 had effectively no catalytic activity.  相似文献   

18.
Treatment of the chloro-bridged dinuclear compounds [{Pd[RC6H3C(H)NCy-C2,N]}(μ-Cl)]2 (R = 4-(COH), 1; R = 5-(COH), 2) with bidentate phosphorus or arsenic diphosphines or diarsine ligands in 1:1 molar ratio gave the dinuclear complexes [{Pd[RC6H3C(H)NCy-C2,N](Cl)}2{μ-(o-Tol)2P(CH2)2P(o-Tol)2}] (R = 4-(COH), 3; R = 5-(COH), 4), [{Pd[RC6H3C(H)NCy-C2,N](Cl)}2{μ-Ph2PC4H2(NH)CH2PPh2}] (R = 4-(COH), 5; R = 5-(COH), 6) and [{Pd[RC6H3C(H)NCy-C2,N](Cl)}2{μ-Ph2As(CH2)2AsPh2}] (R = 4-(COH), 7; R = 5-(COH), 8) with the homobidentate [P,P] and [As,As] ligands in a bridging mode. Treatment of 1 and 2 with the aminophosphine Ph2P(CH2)2NH2 yields the dinuclear complexes [{Pd[RC6H3C(H)NCy-C2,N](Cl)}2{μ-Ph2P(CH2)2NH2}] (R = 4-(COH), 9; R = 5-(COH), 10). The analogous reactions carried out in a 1:2 molar ratio, in the presence of NH4PF6 or NaClO4, gave the mononuclear compounds [Pd{RC6H3C(H)NCy-C2,N}{(o-Tol)2P(CH2)2P(o-Tol)2-P,P}][PF6] (R = 4-(COH), 11; R = 5-(COH), 12), [Pd{RC6H3C(H)NCy-C2,N}{Ph2PC4H2(NH)CH2PPh2-P,P}][ClO4] (R = 4-(COH), 13; R = 5-(COH), 14) and [Pd{RC6H3C(H)NCy-C2,N}{Ph2As(CH2)2AsPh2-As,As}][ClO4](R = 4-(COH), 15; R = 5-(COH), 16), with the [P,P] and [As,As] ligands chelated to the palladium atom.Treatment of 2 with Ph2P(CH2)3NH2 in a 1:2 molar ratio in acetone in the presence of NH4PF6 afforded the mononuclear compound [Pd{5-(COH)C6H3C(H)NCy-C2,N}{Ph2P(CH2)3N(Me2)-P,N}][PF6], 17, via intermolecular condensation between the aminophosphine and the solvent. Condensation was precluded using toluene as solvent to give [Pd{RC6H3C(H)NCy-C2,N}{Ph2P(CH2)nNH2-P,N}][PF6], (n = 3, R = 5-(COH), 18; n = 2, R = 4-(COH), 19; n = 2, R = 5-(COH), 20). Treatment of 1 and 2 with Ph2P(C6H4)CHO in a 1:2 molar ratio in the presence of NH4PF6 gave the mononuclear complexes [Pd{RC6H3C(H)NCy-C2,N}{2-(Ph2P)C6H4CHO-P,O}][PF6] (R = 4-(COH), 21; R = 5-(COH), 22) with the palladium atom bonded to four different atoms (C, N, P, O) and a chelating [P,O] ligand. The crystal structures of compounds 7, 11, 15 and 21 have been determined by X-ray crystallography.  相似文献   

19.
An investigation was conducted to identify the structures and bioactive properties of five compounds isolated from the Halichondrida sponges Amorphinopsis foetida and Axinyssa aplysinoides. All compounds possessed the spiro-axane sesquiterpene core and all were substituted at C-2 with nitrogen containing functionality. The stereochemistry of one known compound has been revised to (2R,5R,10S)-2-formamido-6-axene (3). It exhibited mild selective solid tumor and mild antibacterial activity and was found from Axinyssa. A second known substance whose stereochemistry has also been revised, (2R,5R,10S)-2-isothiocyanato-6-axene (4) plus its undescribed diastereomer (5) were isolated from Amorphinopsis. Both sponges were the source of two new N-phenethyl-2-formamido-6-axene diastereomeric compounds 6 and 7. No solid tumor or antibacterial activity was found for 4-7.  相似文献   

20.
A Pseudomonas sp. was cultured which was associated with the Japanese seaweed Diginea sp. Crude extracts prepared from this bacterial culture were found to inhibit the growth of other marine bacterial strains. From this bacterial culture, two new peptides cyclo-[phenylalanyl-prolyl-leucyl-prolyl] (3) and cyclo-[isoleucyl-prolyl-leucyl-alanyl] (4) have been isolated together with two known peptides (1) and (2). The crude extract from a culture of Pseudoalteromonas sp. associated with the Thai sponge Halisarca ectofibrosa was found to inhibit the growth of Bacillus subtilis and Vibrio anguillarum. Isolation studies yielded a fraction containing two peptides that were identified as cyclo-[phenylalanyl-leucyl]2 (5) and cyclo-[leucyl-isoleucyl]2 (6) by means of LC-MS and 2D NMR data. Absolute stereochemistry was confirmed by the synthesis of cyclo-[l-phenylalanyl-l-leucyl]2. Peptides (1)-(3) were also isolated from this bacterial strain. None of the individual peptides isolated in this study showed antibiotic activity.  相似文献   

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