Triterpene glycosides from the sea cucumber Eupentacta fraudatrix. Structure and cytotoxic action of cucumariosides A2, A7, A9, A10, an, A13 and A14, seven new minor non-sulfated tetraosides and an aglycone with an uncommon 18-hydroxy group

Seven new minor triterpene glycosides, cucumariosides A2 (1), A7 (2), A9 (3), A10 (4), A11 (5), A13 (6) and A14 (7) have been isolated from the Far Eastern sea cucumber Eupentacta fraudatrix. Structures of the glycosides were elucidated by 2D NMR spectroscopy and MS. Glycosides 1-7 belong to the group of cucumariosides A, having linear tetrasaccharide carbohydrate moieties without any sulfate group and possessing 3-O-methyl-D-xylose as a terminal monosaccharide unit. Glycosides 1, 2, 5-7 differ from each other in side chain structures in aglycone moieties, while cucumarioside A10 (4) has a 23,24,25,26,27-pentanorlanostane aglycone with 18(16)-lactone. Cucumarioside A9 (3), having an uncommon 18-hydroxy group, is the second representative of the unique metabolically active glycosides that are regarded as intermediates of glycoside biosynthesis in sea cucumbers. Cytotoxic activities of glycosides 1-7 and cucumarioside A8 (8) against mouse spleen lymphocytes and the cells of the ascite form of mouse Ehrlich carcinoma, along with hemolytic activity against mouse erythrocytes and antifungal activity were studied. Cucumariosides A2 (1), A8 (8) and A13 (6) demonstrated high hemolytic activities. Glycosides 1, 4 and 6 showed moderate cytotoxic activity. Only cucumarioside A8 (8), having an 18-oxymethylene group and a 24(25)-double bond, was very active in all the tests.     

Triterpene glycosides from the sea cucumber Eupentacta fraudatrix. Structure and biological action of cucumariosides A1, A3, A4, A5, A6, A12 and A15, seven new minor non-sulfated tetraosides and unprecedented 25-keto, 27-norholostane aglycone

Seven new minor triterpene glycosides, cucumariosides A1 (1), A3 (2), A4 (3), A5 (4), A6 (5), A12 (6) and A15 (7) have been isolated from the Far Eastern sea cucumber Eupentacta fraudatrix. Structures of the glycosides were elucidated by 2D NMR spectroscopy and MS. Glycosides 1-7 belong to the group of cucumariosides A, having linear tetrasaccharide carbohydrate moieties without any sulfate group and possessing 3-O-methyl-D-xylose as a terminal monosaccharide unit. The latter peculiarity is rare in sea cucumber glycosides, but typical for the glycosides from E. fraudatrix. Glycosides 1-7 differ from each other by side chain structures in the aglycone moieties; three of them have unique structural features. The first is the presence of a 25-butoxy-group in the side chain of cucumarioside A3 (2), the second is a 23E,25-diene system in cucumarioside A6 (5) and the third is a 25-keto-27-nor-holostane aglycone in cucumarioside A12 (6); these were never previously found in sea cucumber glycosides. Cytotoxic activity of glycosides 1-7 against mouse spleen lymphocytes and the cells of the ascite form of mouse Ehrlich carcinoma, along with hemolytic activity against mouse erythrocytes and antifungal activity were studied. Glycosides 1 and 5 were the most active in all the tests.     

Structures and cytotoxic properties of cucumariosides H₂, H₃ and H₄ from the sea cucumber Eupentacta fraudatrix

New triterpene glycosides, cucumariosides H? (1), H? (2) and H? (3), have been isolated from the Far Eastern sea cucumber Eupentacta fraudatrix. The structures of 1-3 were elucidated using extensive NMR spectroscopy (1H- and 13C-NMR, DEPT, 1H-1H COSY, 1D TOCSY, H2BC, HMBC, heteronuclear single-quantum coherence, and NOESY) and ESI-MS. Glycosides 1-3 are monosulphated branched pentaosides having rare 3-O-methyl-D-xylose as a terminal monosaccharide. Glycosides 1 and 3 contain holostane aglycones, whereas 2 has a 23,24,25,26,27-pentanorlanostane aglycone with an 18(16)-lactone, which is also uncommon for the sea cucumbers. Glycoside 3 contains a very rare ethoxyl radical at C-25 of the aglycone side chain, and it is most probably an artefact that was formed during long storage of the ethanolic extract. Cytotoxic activities of 1-3 against mouse spleen lymphocytes, haemolytic activity against mouse erythrocytes and Ehrlich carcinoma cells have been studied. The presence of 25-hydroxy group in aglycone moiety significantly decreased the activities.     

Immunomodulatory action of monosulfated triterpene glycosides from the sea cucumber Cucumaria okhotensis: stimulation of activity of mouse peritoneal macrophages

Six monosulfated triterpene glycosides, frondoside A1 (1), okhotoside B1 (2), okhotoside A1-1 (3), frondoside A (4), okhotoside A2-1 (5) and cucumarioside A2-5 (6), isolated from Cucumaria okhotensis Levin et Stepanov, stimulate spreading and lysosomal activity of mouse macrophages and ROS-formation in the macrophages. The highest macrophage spreading and stimulation of their lysosomal activity was induced by glycosides 1, 4 and 6. All glycosides similarly stimulate ROS formation in macrophages, but glycoside 2 caused minimal stimulation.     

Structures of 1-(arylseleninyl)naphthalenes: O, G, and Y dependences in 8-G-1-[p-YC6H4Se(O)]C10H6

Structures of 8-G-1-[p-YC6H4Se(O)]C10H6 [1 (G = H), 2 (G = F), 3 (G = Cl), and 4 (G = Br): Y = H, OMe, OCH2Ph, t-Bu, Me, Cl, and NO2] and (1-C10H7)2SeO (5) are investigated by the X-ray crystallographic analysis. Structures of 1 are all A with regard to the naphthyl group (1 (A)), where the Se-C(Ar) and Se-O bonds are perpendicular to and parallel to the naphthyl plane, respectively. Those of 2-4 are also A. Since structures of 8-G-1-(p-YC6H4Se)C10H6 [7 (G = F), 8 (G = Cl), and 9 (G = Br)] are all B, the results exhibit that B of 7-9 change dramatically to A of 2-4 with the introduction of O atoms. The factor to determine the A structures of 1-4 by O is called O dependence. The origin of the O dependence is the nonbonded np(O)- - -pi(Nap) interaction, which results in CT from np(O) to pi(Nap) since O in 1-4 is highly electron rich due to the polar Se+=O- bond and pi(Nap) acts as an acceptor. There are two types of np(O)'s, npy(O) and npz(O), if the directions of the Se-O bond and the p-orbitals of pi(Nap) are taken in the x- and z-axes, respectively. Double but independent np(O)- - -pi(Nap) interactions in 5 lead to 5 (AA). The conformation of the p-YC6H4Se group in 1 changes depending on Y (Y dependence), although the effect is not strong. The Y dependence is explained on the basis of the magnitude of CT of the np(O)-->pi(Ar) type in 1, in addition to the np(O)- - -pi(Nap) interaction. The structure around the Se=O group in 1 is close to that of 5 (AA), if the accepting ability of the p-YC6H4Se group is similar to that of the naphthyl group. A of 2-4 are further stabilized by the np(G)- - -sigma(Se-O) 3c-4e interactions, which are called G dependence. QC calculations performed on the methyl analogues of 1-4 (11-14, respectively) reproduced the observed structures, supported the above discussion, and revealed the energy profiles. The energy-lowering effect of the O dependence would be close to the G dependence of the nonbonded n(Br)- - -sigma(Se-O) 3c-4e interaction in 14 if the steric repulsion between Br and Se is contained in the G dependence. The value is roughly predicted as 20 kJ mol(-1). The structures of 1-5 are well explained by O, G, and Y dependences.     

Triterpene glycosides from Antarctic sea cucumbers III. Structures of liouvillosides A(4) and A(5), two minor disulphated tetraosides containing 3-O-methylquinovose as terminal monosaccharide units from the sea cucumber Staurocucumis liouvillei (Vaney)

Two new minor triterpene glycosides, liouvillosides A(4) (1) and A(5) (2) have been isolated from the sea cucumber Staurocucumis liouvillei living in Antarctic and Sub-Antarctic waters. The structures of the new glycosides were elucidated using extensive nuclear magnetic resonance (NMR) spectroscopy ((1)H- and (13)C-NMR spectroscopy, (1)H-(1)H COSY, 1D-TOCSY, HMBC, HSQC and NOESY), ESI-MS and MALDI TOF MS. The glycosides 1 and 2 are disulphated tetraosides having very rare 3-O-methylquinovose as terminal monosaccharide.     

Steroid glycosides of the leaves of Yucca aloifolia

Two new steroid glycosides have been isolated from the leaves of aloe yucca and their structures have been established. Glycosides B and C are tigogenin penta-and hexaosides. Glycoside B, which we have called yuccaloeside B is (25R)-5α-spirostan-3β-ol 3-{[O-β-D-glucopyranosyl-(1→2)]-[O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→3)]-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside}, and glycoside C, which we have called yuccaloeside C is (25R)-5α-spirostan-3β-ol 3-{[(O-β-D-glucopyranosyl-(1→3)-O-β-D-glucopyranosyl-(1→2)]-[O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→3)]-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside}.     

Syntheses, Spectroscopic Properties and Crystal Structures of （2-Cl-C6H4CH2）3SnS2CN（C5H10） and （2-Cl-C6H4CH2）3SnS2CN（C4H9N）

1 INTRODUCTION The chemistry of organotin(IV) complexes was extensively studied due to their biological activity and coordination chemistry[1～7]. More recently, phar- maceutical properties of alkyltin(IV) complexes with dithiocarbamate ligands have bee…     

Synthesis and antibacterial activity of the metabolites of 9-fluoro-6,7-dihydro-8-(4-hydroxy-1-piperidyl)-5-methyl-1-oxo-1H,5H- benzo[i,j]quinolizine-2-carboxylic acid (OPC-7251)

The metabolites of 9-fluoro-6,7-dihydro-8-(4-hydroxy-1-piperidyl)-5-methyl-1-oxo-1H,5H- benzo[i,j]quinolizine-2-carboxylic acid (OPC-7251) (1), which has a potent antibacterial activity against gram-positive bacteria, characteristically Propionibacterium acnes, were synthesized to confirm their structures and to examine their antibacterial activity. The structures of three major metabolites (2, 3a and 4) were identified by means of comparison with the synthetic compounds. The antibacterial activity of the metabolites (2, 3a and 4) was found to be lower than that of 1.     

Two new steroidal saponins, hylodoside A and novaeguinoside Y, from the starfish Leptasterias hylodes reticulata and Culcita novaeguineae (juvenile)

New steroid glycosides, hylodoside A (1) and novaeguinoside Y (2), along with previously known polyhydroxylated steroids (3-7) were isolated from the ethanolic extracts of the starfish Leptasterias hylodes reticulata and Culcita novaeguineae (juvenile). The structures have been elucidated using 1D and 2D NMR spectra (1H, 13C, DEPT, COSY-45, 1D-TOCSY, HSQCGP, ROESY, HSQC and HMBCGP) and mass spectrometry. Compound 3 was shown to inhibit the growth of Staphylococcus aureus up to 10% from the control at a concentration of 1 mg/mL. Steroids 1, 2 and 5 showed moderate hemolytic activity in the mouse erythrocytes assay. Compounds 3, 4 and 6 displayed pH-depended hemolytic properties.     

新型6-氯-4(3H)-喹唑啉酮类Schiff碱的合成及其抑菌活性

以6-氯邻氨基苯甲酸为起始原料,与醋酐酰化关环制得6-氯-2-甲基噁嗪-4-酮(1);1在80%水合肼中回流反应制得6-氯-2-甲基-3-氨基-4(3H)-喹唑啉酮(2);2与羟基芳醛反应合成了4种新型的6-氯-4(3H)-喹唑啉酮类Schiff碱(4a~4d),其结构经1H NMR,13C NMR,IR和元素分析表征。采用琼脂扩散法研究了4a~4d对金黄色葡萄球菌(A)、大肠杆菌(B)和枯草杆菌(C)的抑制活性。结果表明:用药浓度为300 mg·m L~(-1)时,4a~4d对A~C均有一定的抑制活性,其中6-氯-2-甲基-3-(5-甲基-2-羟基苯亚甲氨基)-4(3H)-喹唑啉酮(4c)抑菌活性最强,对A~C的抑菌圈直径分别为8.8 mm,11.9 mm和9.6 mm。     

Isolation and characterization of phenolic compounds from the leaves of Salix matsudana

A bioassay-guided in vitro screen has revealed that a 70% methanol extract of the leaves of Salix matsudana shows considerable inhibitory activity against cyclooxygenases (COX-1 and COX-2). A subsequent phytochemical study led to the isolation of a new flavonoid, matsudone A (1), together with five known flavonoids--luteolin (2), isoquercitrin (3), 7-methoxyflavone (4), luteolin 7-O-glucoside (5), 4',7-dihydroxyflavone (6)--and two phenolic glycosides, leonuriside A (7) and piceoside (8). Their structures were elucidated on the basis of extensive 1D- and 2D-NMR studies, high resolution ESI mass spectroscopic analyses and comparisons with literature data. The isolated compounds 1-8 were tested for their inhibitory activities against COX-1 and COX-2. Compounds 1, 5 and 6 were found to have potent inhibitory effect on COX-2 and compounds 3-5 exhibited moderate inhibition against COX-1.     

Preparations, structures, and magnetic properties of a series of novel copper(II)-lanthanide(III) coordination polymers via hydrothermal reaction

The hydrothermal reaction of Ln2O3 (Ln = Er, Gd, and Sm), pyridine-2,5-dicarboxylic acid (H2pydc), and Cu(II) reagents (CuO, Cu(OAc)2-2H2O, or CuCl2-2H2O) with a mole ratio of 1:2:4 resulted in the formation of six polymeric Cu(II)-Ln(III) complexes, [(Ln2Cu3(pydc)6(H2O)12)-4H2O]n (Ln = Er (1); Ln = Gd (2)), [(Ln4Cu2(pydc)8(H2O)12)-4H2O]n (Ln = Sm (3); Ln = Gd (4); Ln = Er (5)), and [(Gd2Cu2(pydc)4(H2O)8)-Cu(pydc)2-12H2O]n (6). 1 and 2 are isomorphous and crystallize in triclinic space group Ponebar. Compounds 3-5 are isomorphous and crystallize in monoclinic space group P2(1)/c. Compound 6 crystallizes in triclinic space group Ponebar. Complexes 1 and 2 have one-dimensional zigzag chain structures and compounds 3-5 display three-dimensional wavelike polymeric structures, while 6 has an infinite sandwich-type structure. The different structures of the complexes are induced by the different forms of Cu(II) reagents; the reactions of Cu(OAc)2-2H2O yield high Cu/Ln ratio products 1, 2, and 6, while the reactions of CuO or CuCl2-2H2O/2,2'-bipyridine results in low Cu/Ln ratio compounds 3-5. Temperature-dependent magnetic susceptibilities for 2, 4, and 5 were studied, and the thermal stabilities of complexes 2 and 4 were examined.     

Structures of four new triterpene glycosides from the holothurian Cucumaria japonica

Four new triterpene glycosides of the holostane series have been isolated from an alcoholic extract of the economically important Pacific Ocean holothurianCucumaria japonica: cucumariosides A₁-2 (I), A₂-3 (II), A₂-4 (III), and A₄-2 (IV). The structures of these substances have been established by the methods of carbohydrate chemistry and¹³C NMR spectroscopy. Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 787–793, November–December, 1990.     

Diphosphacarbollide analogues of the C5H5- anion: isolation of the nido-di- and triphosphacarboranes 7,8,9-P2CB8H10, [7,8,9-P2CB8H9]-, [7,8,10-P2CB8H9]-, and 7,8,9,10-P3CB7H8

Treatment of a solution of excess PCl(3) and PS (PS = "proton sponge" = 1,8-dimethylamino naphthalene) with arachno-4-CB(8)H(14) (1) in CH(2)Cl(2), followed by hydrolysis of the reaction mixture, resulted in the isolation of the eleven-vertex diphosphacarbaborane nido-7,8,9-P(2)CB(8)H(10) (2) (yield 34%) as the main product. Other products isolated from this reaction were the phosphacarboranes nido-7,8,9,10-P(3)CB(7)H(8) (3) (yield 5%) and closo-2,1-PCB(8)H(9) (4) (yield 15%). Compound 2 can be deprotonated by PS in CH(2)Cl(2) or NaH in diethyl ether to give the [nido-7,8,9-P(2)CB(8)H(9)](-) (2(-)()) anion, which gives back the original compound, 2, upon re-protonation. Thermal rearrangement of anion 2(-) (Na(+) salt) at 350 degrees C for 2 h produced the isomeric [nido-7,8,10-P(2)CB(8)H(9)](-) (5(-)()) anion, which was isolated as a PPh(4)(+) salt (yield 86%). Multinuclear ((1)H, (11)B, (31)P, and (13)C), two-dimensional [(11)B-(11)B] COSY, (1)H{(11)B(selective)}, (1)H{(31)P(selective)}, and gradient-enhanced ([(1)H-(13)C] HSQC) magnetic resonance measurements led to complete assignments of all resonances which are in excellent agreement with the structures proposed. Coupling constants, (1)J((31)P,(13)C), (2)J((31)P,C,(1)H), and (1)J((31)P,(31)P), were calculated using the DFT method B3LYP/6-311+G(d,p). The molecular geometries of all compounds were optimized ab initio at a correlated level of theory (RMP2(fc)) using the 6-31G basis set, and their correctness was assessed by comparison of the experimental (11)B and (13)C chemical shifts with those calculated by the GIAO-SCF/II//RMP2(fc)/6-31G method. The computations also include the structures and chemical shieldings of the still unknown isomers [nido-7,10,8-P(2)CB(8)H(9)](-) (6(-)) and [nido-7,9,8-P(2)CB(8)H(9)](-) (7(-)).     

New chemistry of 1,2-closo-P2B10H10 and 1,2-closo-As2B10H10; in silico and gas electron diffraction structures, and new metalladiphospha- and metalladiarsaboranes

The molecular structures of 1,2-closo-P(2)B(10)H(10) (1) and 1,2-closo-As(2)B(10)H(10) (2) have been determined by gas electron diffraction and the results obtained compared with those from computation at the MP2/6-31G** level of theory. The level of agreement is good for 2 (root-mean-square [rms] misfit for As and B atoms 0.0297 ?) and very good for 1 (rms misfit for P and B atoms 0.0082 ?). In comparing the structures of 1 and 2 with that of 1,2-closo-C(2)B(10)H(12) (I) it is evident that expansion of the polyhedron from I to 1 to 2 is restricted only to the heteroatom vertices and the B(6) face to which these are bound. Following deboronation (at B3) and subsequent metallation, compounds 1 and 2 have been converted into the new metalladiheteroboranes 3-(η-C(9)H(7))-3,1,2-closo-CoAs(2)B(9)H(9) (4), 3-(η-C(10)H(14))-3,1,2-closo-RuAs(2)B(9)H(9) (5), 3-(η-C(5)H(5))-3,1,2-closo-CoP(2)B(9)H(9) (6), 3-(η-C(9)H(7))-3,1,2-closo-CoP(2)B(9)H(9) (7) and 3-(η-C(10)H(14))-3,1,2-closo-RuP(2)B(9)H(9) (8), the last three constituting the first examples of metalladiphosphaboranes. Together with the known compound 3-(η-C(5)H(5))-3,1,2-closo-CoAs(2)B(9)H(9) (3), compounds 4-8 have been analysed by NMR spectroscopy and (except for 8) single-crystal X-ray diffraction. The (11)B NMR spectra of analogous pairs of metalladiphosphaborane and metalladiarsaborane (6 and 3, 7 and 4, 8 and 5) reveal a consistently narrower (9-10 ppm) chemical shift range for the metalladiarsaboranes, the combined result of a deshielding of the lowest frequency resonance (B6) and an increased shielding of the highest frequency resonance (B8) via an antipodal effect. In crystallographic studies, compounds 3 and 5B (one of two crystallographically-independent molecules) suffer As/B disorder, but in both cases it was possible to refine distinct, ordered, components of the disorder, the first time this has been reported for metalladiarsaboranes. Moreover, whilst the Cp compounds 6 and 3 are disordered, their indenyl analogues 7 and 4 are either ordered or significantly less disordered, a consequence of both the reduced symmetry of an indenyl ligand compared to a Cp ligand and the preference of the former for a distinct conformation relative to the cage heteroatoms. Unexpectedly, whilst this conformation in the cobaltadiphosphaborane 7 is cis-staggered (similar to that previously established for the analogous cobaltadicarborane), in the cobaltadiarsaborane 4 the conformation is close to cis-eclipsed.     

Systematic investigation of lanthanide phosphonatoethanesulfonate framework structures by high-throughput methods, Ln(O3P-C2H4-SO3)(H2O) (Ln=La-Dy)

Following the strategy of using polyfunctional phosphonic acids for the synthesis of new metal phosphonates, the flexible organic linker molecule 2-phosphonoethanesulfonic acid, H2O3P-C2H4-SO3H (H3L), was used in a high-throughput (HT) investigation of lanthanide phosphonatoethanesulfonates. Two HT experiments comprising 96 individual hydrothermal reactions were performed to systematically investigate the influence of pH, rare earth ion, molar ratio of Ln3+:H3L, and the counterion in the system LnX3/H3L/NaOH/H2O with X=NO3-, Cl-, and CH3COO-. Whereas under basic conditions Ln(OH)3 is formed, acidic reaction conditions lead to nine isotypic compounds Ln(O3P-C2H4-SO3)(H2O) with Ln=La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8), and Dy (9). The crystal size of the compounds is strongly dependent on the ionic radius of the lanthanides and the pH. No significant influence of the counterions of the rare earth salts is observed. For compounds 1, 2, 4, and 5 the crystal structures could be determined from single-crystal X-ray diffraction. The structures are built up from chains of edge-sharing LnO8 polyhedra that are connected by the phosphonate and sulfonate groups to layers. These layers are linked by the -CH2CH2- group to a three-dimensional framework. The compounds 6 and 8 display luminescence in the visible range (intensity maximum 612 and 544 nm, respectively). Thermogravimetric investigations and temperature-dependent X-ray powder diffraction demonstrate the stability of the crystal structure up to 270 degrees C. Furthermore IR, Raman, and solid-state MAS NMR spectra of 1 and magnetic property measurements of 7 are also presented.     

Syntheses and structural characterizations of endo-eta(1)-, exo-eta(1)-, eta(4)-, eta(5)-, and eta(6)-metallaphosphamonocarbaborane complexes derived from a versatile new polyborane ligand: exo-6-R-arachno-6,7-PCB(8)H(12)

Deprotonation of the phosphamonocarbaborane, exo-6-R-arachno-6,7-PCB(8)H(12) (R = Ph 1a or Me 1b), yields exo-6-R-arachno-6,7-PCB(8)H(11)(-), which when reacted with appropriate transition-metal reagents affords new metallaphosphamonocarbaborane complexes in which the metals adopt endo-eta(1), exo-eta(1), eta(4), eta(5), or eta(6) coordination geometries bonded to the formal R-arachno-PCB(8)H(11)(-), R-arachno-PCB(8)H(10)(2-), R-arachno-PCB(8)H(9)(3-), or R-nido-PCB(8)H(9)(-) ligands. The reaction of exo-6-(C(6)H(5))-arachno-6,7-PCB(8)H(11)(-) (1a-) with Mn(CO)(5)Br generated the eta(1)-sigma product exo-6-[Mn(CO)(5)]-endo-6-(C(6)H(5))-arachno-6,7-PCB(8)H(11) (2) having the [Mn(CO)(5)] fragment in the thermodynamically favored exo position at the P6 cage atom. On the other hand, reaction of 1a- with (eta(5)-C(5)H(5))Fe(CO)(2)I resulted in the formation of two products, an eta(1)-sigma complex endo-6-[(eta(5)-C(5)H(5))Fe(CO)(2)]-exo-6-(C(6)H(5))-arachno-6,7-PCB(8)H(11) (3) having the (eta(5)-C(5)H(5))Fe(CO)(2) fragment attached at the endo-P6 position and an eta(6)-closo complex, 1-(eta(5)-C(5)H(5))-2-(C(6)H(5))-closo-1,2,3-FePCB(8)H(9) (4a). Rearrangement of the endo-compound 3 to its exo-isomer 5 was observed upon photolysis of 3. Synthesis of the methyl analogue of 4a, 1-(eta(5)-C(5)H(5))-2-CH(3)-closo-1,2,3-FePCB(8)H(9) (4b), along with a double-insertion product, 1-CH(3)-2,3-(eta(5)-C(5)H(5))(2)-2,3,1,7-Fe(2)PCB(8)H(9) (6), containing two iron atoms eta(5)-coordinated to a formal R-arachno-PCB(8)H(9)(3-), was achieved by reaction of exo-6-CH(3)-arachno-6,7-PCB(8)H(11)(-) (1b-) with FeCl(2) and Na(+)C(5)H(5)(-). Complexes 4a and 4b can be considered ferrocene analogues, in which an Fe(II) is sandwiched between C(5)H(5)(-) and 6-R-nido-6,9-PCB(8)H(9)(-) anions. Reaction of exo-6-(C(6)H(5))-arachno-6,7-PCB(8)H(11)(-) (1a-) with cis-dichlorobis(triphenylphosphine)platinum (II) afforded two compounds, an eta(1)-sigma complex with the metal fragment again in the endo-P6 position, endo-6-[cis-(Ph(3)P)(2)PtCl]-exo-6-(C(6)H(5))-arachno-6,7-PCB(8)H(11) (7) and an eta(4)-complex, 7-(C(6)H(5))-11-(Ph(3)P)(2)-nido-11,7,8-PtPCB(8)H(10) (8) containing the formal R-arachno-PCB(8)H(10)(2)(-) anion. The structures of compounds 2, 3, 4a, 4b, 6, 7, and 8 were crystallographically confirmed.     

Structures of four new triterpene glycosides from the holothurian Cucumaria japonica

Four new triterpene glycosides of the holostane series have been isolated from an alcoholic extract of the economically important Pacific Ocean holothurianCucumaria japonica: cucumariosides A₁-2 (I), A₂-3 (II), A₂-4 (III), and A₄-2 (IV). The structures of these substances have been established by the methods of carbohydrate chemistry and¹³C NMR spectroscopy.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 787–793, November–December, 1990.     

Preparation and properties of cyclopentadienyl- and pentamethylcyclopentadienyl-titanium(IV) complexes with the C8H4S8 ligand, electrical conductivities of their oxidized species, and X-ray crystal structure of Ti(C5Me5)2(C8H4S8)

Ti(C5H5)2(C8H4S8) (1), Ti(C5Me5)2(C8H4S8) (2), [NMe4][Ti(C5H5)(C8H4S8)2] (3), and [NMe4][Ti(C5Me5)(C8H4S8)2] (4) [C8H4S8(2-) = 2-(4,5-ethylenedithio)-1,3-dithiole-2-ylidene)-1,3-dithiole-4,5- dithiolate(2-)] were prepared by reaction of Ti(C5H5)2Cl2, Ti(C5Me5)2Cl2, Ti(C5H5)Cl3, or Ti(C5Me5)Cl3 with Li2C8H4S8 or [NMe4]2[C8H4S8] in THF. They were oxidized by iodine, the ferrocenium cation, or TCNQ (7,7,8,8-tetracyano-p-quinodimethane) in CH2Cl2 or in acetone to afford one-electron-oxidized and over-one-electron-oxidized species, [Ti(C5H5)2(C8H4S8)].I3, [Ti(C5H5)2(C8H4S8)][PF6], [Ti(C5Me5)2(C8H4S8)].I3, [Ti(C5Me5)2(C8H4S8)][PF6], [Ti(C5H5)(C8H4S8)2].I0.9, [Ti(C5H5)(C8H4S8)2][TCNQ]0.3, [Ti(C5Me5)(C8H4S8)2].I2.4, and [Ti(C5Me5)(C8H4S8)2][TCNQ]0.3, with the C8H4S8 ligand-centered oxidation. They exhibited electrical conductivities of 1.6 x 10(-1) to 7.6 x 10(-4) S cm-1 measured for compacted pellets at room temperature. The crystal structure of 2 was clarified to consist of isolated dimerized units of the molecules through some sulfur-sulfur nonbonded contacts: monoclinic, P2(1)/c, a = 9.534(2) A, b = 18.227(2) A, c = 17.775(2) A, beta = 94.39(1) degrees, Z = 4.