Cyclolanostane triterpene glycosides from Souliea vaginata

Five new cyclolanostane triterpene glycosides, 12-deacetyloxy-15alpha-hydroxy-23-epi-26-deoxyactein, 12-deacetyloxy-23-epi-26-deoxyactein, 24-O-acetyldahurinol-3-O-beta-D-xylopyranoside, 12beta-hydroxycimigenol-3-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranoside, 25-anhydrocimicigenol-3-O-beta-D-(2'-O-acetyl)xylopyranoside, were isolated from the rhizome of Souliea vaginata collected in China. Their structures were elucidated by spectroscopic techniques, including 2D NMR spectra, and in the case of 5, by chemical correlation.     

Trojanosides I-K: new cycloartane-type glycosides from the aerial parts of Astragalus trojanus.

Three new cycloartane-type triterpene glycosides have been isolated from the aerial parts of Astragalus trojanus. The structures were established mainly by a combination of one- and two-dimensional NMR techniques [1H-1H-correlation spectroscopy (COSY), 1H-13C-heteronuclear multiple quantum correlation spectroscopy (HMQC), and 1H-13C-heteronuclear multiple-bond correlation spectroscopy (HMBC)] and high resolution electrospray ionization mass spectrometry (HR-ESI-MS) as 3-O-beta-(2',3'-di-O-acetyl)-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-16-O- acetoxy-20(R),24(S)-epoxycycloartane-3beta,6alpha,16beta,25-tetrol, 3-0-[alpha-L-rhamnopyranosyl-(1-->2)-beta-(3',4'-di-O-acetyl)-D-xylopyranosyll-6-O-beta-D-xylopyranosyl-20(R),24(S)-epoxycycloartane-3p,6alpha,16beta,25-tetrol, 3-O-beta-D-xylopyranosyl-6,16-di-O-beta-D-glucopyranosyl-20(R)24(S)-epoxycycloartane-3beta,6alpha,16beta,25-tetrol.     

Flavonol triglycosides from the leaves of Hammada scoparia (POMEL) ILJIN

A new flavonol triglycoside, isorhamnetin 3-O-beta-D-xylopyranosyl-(1"-->3)-alpha-L-rhamnopyranosyl-(1'-->6")-beta-D-galactopyranoside, has been isolated from the leaves of Hammada scoparia together with two known compounds, isorhamnetin 3-O-beta-D-apiofuranosyl-(1'-->2")[alpha-L-rhamnopyranosyl-(1"-->6")]-beta-D-galactopyranoside and isorhamnetin 3-O-alpha-L-rhamnopyranosyl-(1'-->2")[alpha-L-rhamnopyranosyl-(1"-->6")]-beta-D-galactopyranoside. The structures were determined by spectroscopic methods.     

Phenolic glycosides from Lindera fruticosa root and their inhibitory activity on osteoclast differentiation

Two new compounds were found in the phenolic glycosides isolated from the roots of Lindera fruticosa: 5-O-[beta-D-apiofuranosyl-(1'-->2')-O-beta-D-xylopyranosyl]gentisic acid-7,5'-ester (3), named linderofruticoside A; and 5-O-[beta-D-apiofuranosyl-(1'-->3')-O-beta-D-xylopyranosyl]gentisic acid methyl ester (4), linderofruticoside B. Two previously known phenolic glycosides were also identified: beta-D-(3,4-disinapoyl)fructofuranosyl-alpha-D-(6-sinapoyl)glucopyranoside (1) and beta-D-(3-sinapoyl)fructofuranosyl-alpha-D-(6-sinapoyl)glucopyranoside (2). Compounds 1 and 2 inhibited osteoclast differentiation in a dose-dependent manner at concentrations higher than 1.04 microM and 0.132 microM, respectively.     

Studies on the constituents of Luffa acutangula Roxb. I. Structures of acutosides A--G, oleanane-type triterpene saponins isolated from the herb.

From the herb of Luffa acutangula ROXB. (Cucurbitaceae), seven oleanane-type triterpene saponins, acutosides A--G, were isolated and their structures were determined. Acutoside A is oleanolic acid 3-O-beta-D-glucopyranosyl-(1----2)-beta-D-glucopyranoside. Acutosides B, D, E, F and G have a common prosapogenin structure, acutoside A, and only differ in the structures of the ester-linked sugar moieties. Acutoside B is a 28-O-[O-beta-D-xylopyranosyl-(1----4)-O-alpha-L-rhamnopyranosyl-(1----2) -alpha-L-arabinopyranosyl] ester, D is a 28-O-[O-beta-D-xylopyranosyl-(1----3)-O-beta-D-xylopyranosyl-(1----4)-O- alpha-L-rhamnopyranosyl-(1----2)-alpha-L-arabinopyranosyl] ester, E is a 28-O-[O-alpha-L-arabinopyranosyl-(1----3)-O-beta-D-xylopyranosyl-( 1----4)-O-alpha-L-rhamnopyranosyl-(1----2)-alpha-L-arabinopyranosyl] ester, F is a 28-O-[O-beta-D-xylopyranosyl-(1----3)-[O-beta-D-xylopyranosyl-(1----4)-O -alpha-L-rhamnopyranosyl-(1----2)-alpha-L-arabinopyranosyl] ester, and G is a 28-O-beta-D-xylopyranosyl-(1----3)-[O-alpha-L-arabinopyranosyl-(1- ---3)-O-beta-D-xylopyranosyl-(1----4)]-O-alpha-L- rhamnopyranosyl-(1----2)-alpha-L-arabinopyranosyl] ester. Acutoside C is a machaelinic acid (=21 beta-hydroxyoleanolic acid) saponin having the same sugar moiety as that of acutoside B.     

Chemical constituents of two sages with free radical scavenging activity

From the aerial parts of Salvia trichoclada Bentham and S. verticillata L. one new and two known phenolic acids, 3-(3',4'-dihydroxyphenyl)-2-hydroxymethyl propionic acid (1), 3-(3',4'-dihydroxyphenyl) lactic acid (2), and rosmarinic acid (3); two flavonoids, apigenin 4'-methyl ether 7-O-glucuronide (4), and luteolin 7-O-beta glucuronide (5); two lupan type triterpene aglycones, lupeol (6), and 30-hydroxylup-20 (29)-en-3-on (7); an oleanane-type triterpene acid, oleanolic acid (8); and an ursan-type triterpene acid, ursolic acid (9) were isolated. The structures of the compounds were elucidated by spectroscopic analysis. Different extracts of the plants were examined for their free radical scavenging activities by DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay. Some of the polar extracts showed high free radical scavenging activity.     

The pK(a) of the internucleotidic 2'-hydroxyl group in diribonucleoside (3'-->5') monophosphates

Ionization of the internucleotidic 2'-hydroxyl group in RNA facilitates transesterification reactions in Group I and II introns (splicing), hammerhead and hairpin ribozymes, self-cleavage in lariat-RNA, and leadzymes and tRNA processing by RNase P RNA, as well as in some RNA cleavage reactions promoted by ribonucleases. Earlier, the pK(a) of 2'-OH in mono- and diribonucleoside (3'-->5') monophosphates had been measured under various nonuniform conditions, which make their comparison difficult. This work overcomes this limitation by measuring the pK(a) values for internucleotidic 2'-OH of eight different diribonucleoside (3'-->5') monophosphates under a set of uniform noninvasive conditions by 1H NMR. Thus the pK(a) is 12.31 (+/-0.02) for ApG and 12.41 (+/-0.04) for ApA, 12.73 (+/-0.04) for GpG and 12.71 (+/-0.08) for GpA, 12.77 (+/-0.03) for CpG and 12.88 (+/-0.02) for CpA, and 12.76 (+/-0.03) for UpG and 12.70 (+/-0.03) for UpA. By comparing the pK(a)s of the respective 2'-OH of monomeric nucleoside 3'-ethyl phosphates with that of internucleotidic 2'-OH in corresponding diribonucleoside (3'-->5') monophosphates, it has been confirmed that the aglycons have no significant effect on the pK(a) values of their 2'-OH under our measurement condition, except for the internucleotidic 2'-OH of 9-adeninyl nucleotide at the 5'-end (ApA and ApG), which is more acidic by 0.3-0.4 pK(a) units.     

A new unsaturated glycoglycerolipid from a cultured marine dinoflagellate Amphidinium carterae

From the cultured marine dinoflagellate Amphidinium carterae, a new unsaturated glycoglycerolipid (2S)-1,2-O-6,9,12,15-dioctadecatetraenoyl-3-O-[alpha-D-galactopyranosyl-(1'-->6')-O-beta-D-galactopyranosyl]-glycerol (1), has been isolated together with two known saturated ones, (2S)-1,2-distearoyl-3-O-(6-sulpho-alpha-D-quinovopyranosyl)-glycerol (2) and (2S)-1-stearoyl-3-O-(6-sulpho-alpha-D-quinovopyranosyl)-glycerol (3). Their structures were elucidated on the basis of chemical and spectral data.     

Cholestane glycosides from Solanum abutiloides. III

Four new cholestane glycosides, named abutilosides D (1), E (2), F (3) and G (4), were isolated from the fresh roots of Solanum abutiloides. By chemical and spectroscopic evidence, their structures were elucidated as 26-O-beta-D-glucopyranosyl 3beta,16alpha,26-trihydroxy-5alpha-cholestan-22-one 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->4)-beta-D- glucopyranoside and its desxylosyl compound (1 and 3, respectively), 26-O-beta-D-glucopyranosyl 3beta,16alpha,26-trihydroxycholest-5-en-22-one 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->4)-beta-D- glucopyranoside and its desxylosyl compound (2 and 4, respectively). These compounds were regarded as precursors of a dormantinone type compound on a hypothetical pathway of steroid biogenesis.     

Mass spectrometric study of dirhenium biscarboxylate:purine dinucleotide complexes

Dirhenium adducts of purine dinucleotides were identified by mass spectrometry. In consecutive studies, Re(2)(O(2)C(2)H(3))(2)Cl(4) . 2H(2)O was reacted with 2'-deoxyguanylyl(3'-->5')-2'-deoxyguanosine (dGpG) and 2'-deoxyadenylyl(3'-->5')-2'-deoxyguanosine (dApG) in H(2)O or D(2)O. These reactions were monitored to identify novel dinuclear rhenium:dinucleotide complexes as confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), electrospray ionization mass spectrometry (ESI-MS) and collision-induced dissociation tandem mass spectrometry (CID MS/MS) experiments. However, the most abundant adducts detected by ES-MS were dirhenium:nucleotide species. Of these, guanine-containing ions were observed with highest ion counts suggesting a preference for guanine coordination. Dimetal adducts showed coordination of the purine bases and common metalated fragments were observed for both dGpG and dApG reactions.     

Triterpene and coumarins from Skimmia laureola

In the course of our studies on the chemical constituents of the leaves of Skimmia laureola, a new triterpene O-methyl cyclolaudenol (1) and a new coumarin, (+)-7-methoxy-6-(2'R-methoxy-3'-hydroxy-3'-methyl butyl) coumarin (2) were isolated. In addition five known coumarins, isogospherol (3), heraclenol (4), 5,8-dimethoxy coumarin-2H-1-benzopyran-2-one (5), 7-methoxy-6[2'-oxo-3'-methyl butyl] coumarin (6), and (+)-ulopterol (7) were also isolated for the first time from this plant. The structures were identified by spectroscopic studies and the stereochemistry at C-2' in compounds 3 and 4 were established by Horeau's procedure.     

Studies on the constituents of Swertia japonica MAKINO I. On the structures of new secoiridoid diglycosides

Eight new secoiridoid diglycosides, 6'-O-alpha-L-arabinopyranosylswertiamarin (1), 3'-O-beta-D-glucopyranosylswertiamarin (2), 4'-O-beta-D-glucopyranosylswertiamarin (3), 3'-O-beta-D-galactopyranosylswertiamarin (4), 6'-O-alpha-D-galactopyranosylswertiamarin (5), 6'-O-alpha-D-mannopyranosylswertiamarin (6), 6'-O-beta-D-fructofuranosylswertiamarin (7) and 5'-O-beta-D-glucopyranosylamaroswerin (12), were isolated, together with five known compounds from the whole plants of Swertia japonica MAKINO. The structures of the new compounds were elucidated on the basis of chemical and spectroscopic evidence. Compounds 6 and 7 are the first naturally occuring iridoid diglycosides having an alpha-D-mannopyranosyl unit and beta-D-fructofuranosyl unit, respectively.     

Medicinal flowers. XI. Structures of new dammarane-type triterpene diglycosides with hydroperoxide group from flower buds of Panax ginseng

Six new dammarane-type triterpene diglycosides with a hydroperoxide group, floralginsenosides A, B, C, D, E, and F, were isolated from ginseng flower, the flower buds of Panax ginseng C. A. MEYER, together with seven known dammarane-type triterpene oligoglycosides. The structures of new floralginsenosides were elucidated on the basis of chemical and physicochemical evidence.     

Three cycloartane glycosides from Cimicifuga rhizome and their immunosuppressive activities in mouse allogeneic mixed lymphocyte reaction

One known (1) and two new cycloartane triglycosides, 20S,22R,23S,24R-16beta,23;22,25-diepoxy-cycloartane-3beta,23,24-triol 3-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->2)-beta-D-xylopyranoside (2) and 20S,22R,23S,24R-16beta,23;22,25-diepoxy-cycloartane-3beta,23,24-triol 3-O-(6-O-trans-isoferuloyl-beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranosyl-(1-->2)-beta-D-xylopyranoside (3), were isolated from a commercial Cimicifuga Rhizome. Their structures were determined by two dimensional (2D) NMR spectroscopic analysis and chemical evidence. These compounds suppressed the proliferation of lymphocytes in mouse allogeneic mixed lymphocyte reaction.     

Steroidal oligoglycosides from Solanum nigrum

Two new steroidal saponins, named nigrumnins I and II, together with two known saponins were obtained from the whole plant of Solanum nigrum L. On the basis of spectroscopic analysis (1H-NMR, 13C-NMR, 1H-1H COSY, TOCSY, HMQC, HMBC and FAB-MS), nigrumnin I was established as (25R)-5alpha-spirostan-3beta-ol 3-O-betaD-xylopyranosyl-(1-->3)-[alpha-L-arabinopyranosyl-(1 -->2)]-beta-D- glucopyranosyl-(1-->4)-[alpha-L-rhamnopyranosyl(1-->2)]-beta-D- galactopyranoside (1), and nigrumnin II was elucidated as (25R)-3beta,17alpha-dihydroxy-5alpha-spirostan-1 2-one 3-O-beta-D-xylopyranosyl-(1-->3)-[alpha-L-arabinopyranosyl-(1--> 2)]-beta-D-glucopyranosyl-(1-->4)-[alpha-L-rhamnopyra- nosyl-(1-->2)l-beta-D-galactopyranoside (2).     

Two new triterpene glycosides with monomethyl malonate groups from the rhizome of Cimifuga foetida L

Two new 9,19-cycloartane triterpene glycosides 1-2, together with four known compounds--26-deoxyactein (3), actein (4), 7,8-didehydro-26-deoxyactein (5) and cimiaceroside B (6)--were isolated from the rhizome of Cimicifuga foetida. The new triterpene glycosides were identified as 23-O-methyl-24-deoxy-2'-O-(3'-methylmalonyl)-cimiaceroside B (1) and 2'-O-(3'-methylmalonyl)actein (2) based on analysis of their spectral data and chemical reactions.     

Triterpenoid saponins from the fruits of Akebiae quinata

Three new triterpenoid saponins together with eight known compounds have been isolated from the fruits of Akebiae quinata. On the basis of the spectroscopic and physiochemical evidence, the new compounds were elucidated as 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl gypsogenin, 3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl gypsogenin and 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl gypsogenin.     

Triterpenes and lignans from Artemisia caruifolia and their cytotoxic effects on meth-A and LLC tumor cell lines

One new triterpene, 3beta-hydroxy-29-norcycloart-24-one (1), and four new lignans, caruilignans (2-5), together with six known compounds were isolated from the aerial part of Artemisia caruifolia BUCH.-HAM. ex TOXB. Their structures were determined by various spectroscopic means. Most of the isolated lignans were moderately cytotoxic to Meth-A cells with ED50 values of 5-10 microg/ml, but not to Lowis lung carcinoma (LLC) cells. An oxime derivative of 1 showed more potent cytotoxic activity against Meth-A and LLC cells than the original triterpene 1.     

Fargosides A-E, triterpenoid saponins from Holboellia fargesii

Five new triterpenoid saponins, fargosides A, B, C, D, and E, were isolated from the roots of Holboellia fargesii. The structures of fargosides A-E were elucidated on the basis of chemical and physicochemical evidence and found to be 3beta,20alpha-dihydroxy-29-norolean-12-en-28-oic acid 3-O-beta-D-xylopyranosyl-(1-->2)-beta-D-glucopyranoside (1), 3beta,20alpha,24-trihydroxy-29-norolean-12-en-28-oic acid 23-O-beta-D-fucopyranosyl-(1-->2)-[alpha-L-arabinopyranosyl-(1-->3)]-beta-D-glucopyranoside (2), 3beta,23-dihydroxy-30-norolean-2,20(29)-dien-28-oic acid 3-O-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-glucopyranosyluronic acid-(1-->3)]-alpha-L-arabinopyranoside (3), 3beta,23-dihydroxy-30-norolean-12,20(29)-dien-28-oic acid 3-O-methyl beta-D-glucopyranosyluronate-(1-->3)-alpha-L-arabinopyranoside (4), and 3beta,23-dihydroxy-olean-12-en-28-oic acid 3-O-methyl beta-D-glucopyranosyluronate-(1-->3)-alpha-L-arabinopyranoside (5), respectively.     

Base-pairing systems related to TNA: alpha-threofuranosyl oligonucleotides containing phosphoramidate linkages

(3'NH)- and (2'NH)-TNA, two isomeric phosphoramidate analogues of TNA (alpha-threofuranosyl-(3'-->2') oligonucleotides), are shown to be efficient Watson-Crick base-pairing systems and to undergo intersystem cross-pairing with TNA, RNA, and DNA. [reaction: see text]