Bioactive constituents from Chinese natural medicines. XXXII. aminopeptidase N and aldose reductase inhibitors from Sinocrassula indica: structures of sinocrassosides B(4), B(5), C(1), and D(1)-D(3)

From the methanolic extract of the whole plant of Sinocrassula indica (Crassulaceae), six new flavonol glycosides, sinocrassosides B(4) (1), B(5) (2), C(1) (3), D(1) (4), D(2) (5), and D(3) (6), were isolated together with 30 compounds. The structures of 1-6 were elucidated on the basis of chemical and physicochemical evidence. In addition, several constituents were found to show inhibitory effects on aminopeptidase N and aldose reductase.     

Bioactive constituents from chinese natural medicines. XXIX. Monoterpene and monoterpene glycosides from the roots of Rhodiola sachalinensis

A new monoterpene, sachalol, and three new monoterpene glycosides, sachalosides VI, VII, VIII, were isolated from Rhodiolae Radix, the roots of Rhodiola sachalinensis. The absolute stereostructures of new monoterpenes were elucidated on the basis of chemical and physicochemical evidence including the application of the modified Mosher's method.     

Bioactive constituents from Chinese natural medicines. XXIII. Absolute structures of new megastigmane glycosides, sedumosides A(4), A(5), A(6), H, and I, and hepatoprotective megastigmanes from Sedum sarmentosum

The methanol-eluted fraction of the hot water extract from the whole plant of Sedum sarmentosum (Crassulaceae) was found to show hepatoprotective effect on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes. From the active fraction, five new megastigmane glycosides, sedumosides A(4), A(5), A(6), H, and I, were isolated together with 22 megastigmane constituents. Their absolute stereostructures were elucidated on the basis of chemical and physicochemical evidence. Among them, sedumoside F(1) (IC(50)=47 microM), (3S,5R,6S,9R)-megastigmane-3,9-diol (61 microM), and myrsinionosides A (52 microM) and D (62 microM) were found to show the strong hepatoprotective activity.     

Bioactive constituents of chinese natural medicines. VI. Moutan cortex. (2): structures and radical scavenging effects of suffruticosides A, B, C, D, and E and galloyl-oxypaeoniflorin

Five paeonol glycosides, suffruticosides A, B, C, D, and E, and a monoterpene glucoside, galloyl-oxypaeoniflorin, were isolated from the glycosidic fraction of Chinese Moutan Cortex, the root cortex of Paeonia suffruticosa Andrews, together with paeonolide, apiopaeonoside, galloyl-paeoniflorin, oxypaeoniflorin, and paeoniflorin. The structures of five suffruticosides and galloyl-oxypaeoniflorin were elucidated on the basis of chemical and physicochemical evidence. Suffruticosides A, B, C, and D, galloyl-oxypaeoniflorin, and galloyl-paeoniflorin exhibited more potent radical scavenging effects than alpha-tocopherol.     

Bioactive constituents from Chinese natural medicines. XV. Inhibitory effect on aldose reductase and structures of Saussureosides A and B from Saussurea medusa

The 80% aqueous acetone extract from the whole plant of Saussurea medusa MAXIM. was found to inhibit rat lens aldose reductase (IC50=1.4 microg/ml). From this extract, flavonoids, lignans, and quinic acid derivatives were isolated together with two new ionone glycosides, saussureosides A and B. Their absolute stereostructures were elucidated on the basis of chemical and physicochemical evidence including the application of modified Mosher's method. In addition, some isolates were found to show an inhibitory effect on aldose reductase.     

Bioactive constituents from Chinese natural medicines. XXII. Absolute structures of new megastigmane glycosides, sedumosides E1, E2, E3, F1, F2, and G, from Sedum sarmentosum (Crassulaceae)

Six new megastigmane glycosides, sedumosides E1, E2, E3, F1, F2, and G, were isolated from the whole plant of Sedum sarmentosum (Crassulaceae). The structures of new constituents including the absolute configuration were elucidated on the basis of chemical and physicochemical evidence.     

Bioactive constituents of Chinese natural medicines. V. Radical scavenging effect of Moutan Cortex. (1): Absolute stereostructures of two monoterpenes, paeonisuffrone and paeonisuffral

The methanolic extract and the ethyl acetate-soluble and methanol-eluted fractions from Chinese Moutan Cortex, the roots of Paeonia suffruticosa ANDREWS, were found to exhibit scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radical and superoxide anion radical generated by the xanthine-xanthine oxidase system. Two monoterpenes called paeonisuffrone and paeonisuffral were isolated from the ethyl acetate-soluble fraction. Their absolute stereostructures were elucidated on the basis of chemical and physiochemical evidence, which included the application of a modified Mosher's method and lipase catalyzed debenzoylation reaction.     

Medicinal foodstuffs. XIX. Absolute stereostructures of canavalioside, a new Ent-kaurane-type diterpene glycoside, and gladiatosides A1, A2, A3, B1, B2, B3, C1, and C2, new acylated flavonol glycosides, from sword bean, the seeds of Canavalia gladiata

A new ent-kaurane-type glycoside, canavalioside, and eight new acylated flavonol glycosides, gladiatosides A1, A2, A3, B1, B2, B3, C1, and C2, were isolated from the seed of Canavalia gladiata together with robinin, kaempferol 3-O-beta-D-galactopyranosyl-7-O-alpha-L-rhamnopyranoside, and kaikasaponin III. The absolute stereostructures of canavalioside and gladiatosides A1, A2, B1, B2, B3, C1, and C2 were elucidated on the basis of chemical and physicochemical evidence.     

The 1 (2)A(1), 1 (2)B(2), and 1 (2)A(2) states of the SO(2) (+) ion studied using multiconfiguration second-order perturbation theory

The 1 (2)A(1), 1 (2)B(2), and 1 (2)A(2) electronic states of the SO(2) (+) ion have been studied using multiconfiguration second-order perturbation theory (CASPT2) and two contracted atomic natural orbital basis sets, S[6s4p3d1f]/O[5s3p2d1f] (ANO-L) and S[4s3p2d]/O[3s2p1d] (ANO-S), and the three states were considered to correspond to the observed X, B, and A states, respectively, in the previous experimental and theoretical studies. Based on the CASPT2/ANO-L adiabatic excitation energy calculations, the X, A, and B states of SO(2) (+) are assigned to 1 (2)A(1), 1 (2)B(2), and 1 (2)A(2), respectively, and our assignments of the A and B states are contrary to the previous assignments (A to (2)A(2) and B to (2)B(2)). The CASPT2/ANO-L energetic calculations also indicate that the 1 (2)A(1), 1 (2)B(2), and 1 (2)A(2) states are, respectively, the ground, first excited, and second excited states at the ground-state (1 (2)A(1)) geometry of the ion and at the geometry of the ground-state SO(2) molecule. Based on the CASPT2/ANO-L results for the geometries, we realize that the experimental geometries (determined by assuming the bond lengths to be the same as the neutral ground state of SO(2)) were not accurate. The CASPT2/ANO-S calculations for the potential energy curves as functions of the OSO angle confirm that the 1 (2)B(2) and 1 (2)A(2) states are the results of the Renner-Teller effect in the degenerate (2)Pi(g) state at the linear geometry, and it is clearly shown that the 1 (2)B(2) curve, as the lower component of the Renner splitting, lies below the 1 (2)A(2) curve. The UB3LYP/cc-pVTZ adiabatic excitation energy calculations support the assignments (A to (2)B(2) and B to (2)A(2)) based on the CASPT2/ANO-L calculations.     

Combined quantum chemical and RRKM modeling of the main fragmentation pathways of protonated GGG. II. Formation of b(2), y(1), and y(2) ions

Quantum chemical and RRKM calculations were performed on protonated GGG in order to determine the atomic details of the main fragmentation pathways leading to formation of b(2),y(1), and y(2) ions. Formation of y(1) ions on the "diketopiperazine" pathway is initiated from relatively high-energy C-terminal amide nitrogen protonated species for which the N-terminal amide bond is in the cis isomerization state. The reaction goes through a transition structure which is only slightly less favored than the reactive configuration itself. RRKM calculations indicate that this reaction is extremely fast as soon as the fragmenting species have more internal energy than the reaction threshold. The calculated energetics suggests that y(1) ions are formed on the "diketopiperazine" pathway with a non-negligible (6-10 kcal/mol) reverse activation barrier. Investigation of species occurring during the formation of b(2) ions having an oxazolone structure indicates that y(1) ions can be formed also from intermediates previously thought to result in only b(2) ions. As the first step of the "b(x)-y(z)" pathway proposed here the extra proton must reach the nitrogen of the C-terminal amide bond. Attack of the N-terminal amide oxygen on the carbon center of the C-terminal amide bond results in formation of the oxazolone ring while the detaching G leaves the precursor ion. Under low-energy collision conditions the complex of protonated 2-aminomethyl-5-oxazolone and G can rearrange to form a proton-bonded dimer of these species. In such circumstances the extra proton is shared by the two monomers and dissociation of the dimer will be determined by the thermochemistry involved. Based on the "b(x)-y(z)" pathway one can easily explain the linear relationship between the logarithm of the y(1)/b(2) ion abundance ratio and the proton affinity of the C-terminal amino acid substituent for the series of H-Gly-Gly-Xxx-OH tripeptides where Xxx was varied (Morgan DG, Bursey MM. Org. Mass. Spectrom. 1994; 29: 354). The calculated energetics indicates that both y(1) and b(2) ions are formed with no reverse activation barrier on the "b(x)-y(z)" pathway.     

Triterpene glycosides of Thalictrum squarrosum. IV. Structures of squarrosides A1, A2, B1, and B2

Four new cycloartane glycosides have been isolated from a methanolic extract ofThalictrum squarrosum Stephan ex Willd.: squarroside A1 (I) — (21R, 22S, 23R)-3-(-D-glucopyranosyloxy)-21-methoxy-21,23-epoxycycloart-24-ene-22,30-diol, C₃₀H₆₀O₁₀; squarroside A2 (II) — the (21S)-epimer of compound (I); squarroside B1 (III) (21R, 22S, 23R)-3gb-[O--L-rhamnopyranosyl-(1 6)--D-glucopyranosyloxy]-21-methoxy-21,23-epoxycycloart-24-ene-22,30-diol, C₄₃H₇₀O₁₄; and squarroside B2 (IV) — the (21S)-epimer of compound (III). The proposed structures were determined on the basis of¹H and¹³C NMR spectroscopy, FAB mass spectrometry, and chemical transformations.Irkutsk Institute of Organic Chemistry, Siberian Branch, USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 516–523, July–August, 1989.     

New triterpene constituents, foliasalacins A(1)-A(4), B(1)-B(3), and C, from the leaves of Salacia chinensis

Four dammarane-type, three lupane-type, and an oleanane-type triterpenes named foliasalacins A(1) (1), A(2) (2), A(3) (3), A(4) (4), B(1) (5), B(2) (6), B(3) (7), and C (8) were isolated from the leaves of Salacia chinensis LINN. collected in Thailand. The structures of new triterpene constituents (1-8) were characterized on the basis of chemical and physiochemical evidence.     

Bioactive constituents of Chinese natural medicines. VII. Inhibitors of degranulation in RBL-2H3 cells and absolute stereostructures of three new diarylheptanoid glycosides from the bark of Myrica rubra

Three new diarylheptanoid glycosides, named (+)-S-myricanol 5-0-beta-D-glucopyranoside, myricanene A 5-O-alpha-L-arabinofuranosyl(1-->6)-beta-D-glucopyranoside, and myricanene B 5-0-alpha-L-arabinofuranosyl(1-->6)-beta-D-glucopyranoside, were isolated from the bark of Chinese Myrica rubra, together with twenty known compounds. The absolute stereostructures of the new diarylheptanoid glycosides were elucidated on the basis of chemical and physicochemical evidence, including the application of the modified Mosher's method. The inhibitory effects of isolated constituents on the release of beta-hexosaminidase from RBL-2H3 cells were examined, and several diarylheptanoids, myricanol, (+)-S-myricanol, myricanone, and myricanenes A and B, and a flavonol, myricetin, were found to show the inhibitory activity.     

Low frequency Raman spectra of barium borate glasses in the system (BaCl2)y[(BaO)x(B2O3)1-y-x]1-y for various x and y

Low frequency Raman spectra of glasses of the types (BaO)_x·(B₂O₃)_1−x and (BaCl₂)_y·[(BaO)_x·(B₂O₃)₁-_y-_x]₁-_y have been reported. The temperature reduced Raman spectra show peaks at 67, 116 and 140 cm⁻¹ for the binary glass. The bands at 116 and 140 cm⁻¹ are ascribed to the librational motions of the borate groups and the 67 cm⁻¹ band arises because of the limited structural correlation range (SCR) of the glass network, causing a maximum of the frequency dependent Raman coupling coefficient. Due to addition of BaO in v-B₂O₃, the oxygen are mostly incorporated in the formation of BO₄ units; however large Ba²⁺ ions also enhance the number of non-bridging oxygen at higher concentrations of dopant. These barium ions as well as chlorine ions are accomodated in the interstitial vacancies of the glass network which leads to an expansion of the network structure.     

Bioactive saponins and glycosides. XIV. Structure elucidation and immunological adjuvant activity of novel protojujubogenin type triterpene bisdesmosides, protojujubosides A, B, and B1, from the seeds of Zizyphus jujuba var. spinosa (Zizyphi Spinosi Semen)

Following the elucidation of jujubosides A1 and C and acetyljujuboside B, novel protojujubogenin type triterpene bisdesmosides, protojujubosides A, B, and B1, were isolated from Zizyphi Spinosi Semen, the seeds of Zizyphus jujuba Mill. var. spinosa Hu. The structures of protojujubosides A, B, and B1 were determined on the basis of chemical and physicochemical evidence, which included the conversion of protojujubosides to known jujubosides using enzymatic hydrolysis. Protojujubosides A and jujubosides A, B, and C were found to show potent immunological adjuvant activity.     

Bioactive saponins and glycosides. XV. Saponin constituents with gastroprotective effect from the seeds of tea plant, Camellia sinensis L. var. assamica Pierre, cultivated in Sri Lanka: structures of assamsaponins A, B, C, D, and E

The saponin fraction from the seeds of the tea plant, Camellia sinensis L. var. assamica Pierre cultivated in Sri Lanka, was found to show a potent protective effect on gastric mucosal lesions induced by ethanol in rats. Nine new acylated polyhydroxyoleanene-type triterpene oligoglycosides called assamsaponins A-I were isolated from the active saponin fraction together with three known saponins, theasaponin E1 and E2 and camelliasaponin B1. The structures of assamsaponins A-E were elucidated on the basis of chemical and physicochemical evidence. Theasaponin E1 exhibited potent gastroprotective activity.     

Bioactive constituents from Chinese natural medicines. XI. inhibitors on NO production and degranulation in RBL-2H3 from Rubia yunnanensis: structures of rubianosides II,III, and IV,rubianol-g,and rubianthraquinone

Three new arborinane-type triterpene glycosides, rubianosides II, III, and IV, a new arborinane-type triterpene, rubianol-g, and a new anthraquinone, rubianthraquinone, were isolated from a Chinese natural medicine, the roots of Rubia yunnanensis. The structures of the new constituents including their absolute configurations were determined on the basis of chemical and physicochemical evidence. The inhibitory effects of the isolated constituents on nitric oxide production in lipopolysaccharide-activated macrophages were examined. Among them, a cyclic peptide constituent, RA-XII and its aglycon, RA-V (deoxybouvadin), potently inhibited overproduction of nitric oxide and induction of inducible nitric oxide synthase. In addition, an anthraquinone constituent, 2-methyl-1,3,6-trihydroxy-9,10-anthraquinone, was found to show inhibitory effects on the release of beta-hexosaminidase in RBL-2H3 cells.     

N'-(5-芳基-1,3,4(口恶)二唑-2-基)-N-(邻苯磺酰甲酰亚胺乙酰基)硫脲的合成及抑菌活性

将邻苯甲酰磺酰亚胺、1.3,4-(口恶)二唑2个杂环同时引入到酰基硫脲中,合成了12种新的N'-(5-芳基-1,3,4.(口恶)二唑-2-基)-N-(邻苯磺酰甲酰亚胺乙酰基)硫脲化合物,化合物的结构均经元素分析、1H NMR和IR 等测试技术得以确证.抑菌法生物活性测试结果表明,大部分化合物对黄瓜灰霉病菌、油菜菌核病菌抑制效果很好,特别是化合物5b和5l对5种病菌抑制率均在87%以上,有的病菌抑制率达到100%.     

Crossed molecular beam study on the reaction of boron atoms, B(2Pj), with allene, H2CCCH2(X1A1)

The reaction of ground state boron atoms, 11B(2Pj), with allene, H2CCCH2(X1A1), was studied under single collision conditions at a collision energy of 21.5 kJ mol(-1) utilizing the crossed molecular beam technique; the experimental data were combined with electronic structure calculations on the 11BC3H4 potential energy surface. The chemical dynamics were found to be indirect and initiated by an addition of the boron atom to the pi-electron density of the allene molecule leading ultimately to a cyclic reaction intermediate. The latter underwent ring-opening to yield an acyclic intermediate H2CCBCH2. As derived from the center-of-mass functions, this structure was long-lived with respect to its rotational period and decomposed via an atomic hydrogen loss through a tight exit transition state to form the closed shell, C2v symmetric H-C is equivalent C-B=CH2 molecule. A brief comparison of the product isomers formed in the reaction of boron atoms with methylacetylene is also presented.