Lignans of the bark of Syringa volgaris

Two lignans have been isolated from the bark ofSyringa vulgaris and identified: (+)-lariciresinol 4--D-glucopyranoside (I) and -olivil 4--D-glucopyranoside (II). This is the first time that glycoside (9) has been described.All-Union Scientific-Research Institute of Medicinal Plants Scientific-Production Association, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 768–771, November–December, 1991.     

Some Pharmaceutical Properties of a New Branched Cyclodextrin, 6-O-α-(4-O- α-D-Glucuronyl)-D-glucosylβ-cyclodextrin

Some physicochemical and biological properties of a new branched cyclodextrin, 6-O--(4-O--d-glucuronyl)-d-glucosyl--cyclodextrin GUG--CyD) were investigated. Further, theinteraction of GUG--CyD with several drugs was studied by the solubility and spectroscopic methods, and compared with those of parent -CyD and 6-O--maltosyl--CyD(₂--CyD).The hemolytic activity of GUG--CyD on rabbit erythrocytes was lower than those of -CyD and ₂--CyD. GUG--CyD and ₂--CyD showed negligible cytotoxicity on Caco-2 cells up to at least 0.1 M. The inclusion ability of GUG--CyD to neutral and acidic drugs was comparable to or slightly smaller than those of -CyD and ₂--CyD, probably because of a steric hindrance of the branched sugar. On the other hand, GUG--CyD showed greater affinity for the basic drugs, compared with -CyD and ₂--CyD, owing to the electrostatic interaction of its carboxylate anion with positive charge of basic drugs. Thus GUG--CyD may be useful as a safe solubilizing agent particularly for basic drugs.     

Triterpene glycosides ofSalsola micranthera. I. Structures of salsolosides C and D

New triterpene glycosides — salsolosides C and D — have been isolated from the epigeal part ofSalsola micranthera Botsch. On the basis of chemical transformations and physicochemical measurements, salsoloside C has been assigned the structure of oleanolic acid 28-0--D-glucopyranoside 3-0-[0--D-xylopyranosyl-(1 4)--D-glucuropyranoside], and salsoloside D has the structure of hederagenin 28-0--D-glucopyranoside 3-0-[0--D-xylopyranosyl-(1 4)--D-glucuropyranoside].Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 727–732, November–December, 1983.     

Secondary metabolites of Astragalus danicus Retz. and A. inopinatus Boriss.

The chemical composition of the above-ground parts of Astragalus danicus and A. inopinatus collected in the Baikal region (Eastern Siberia) was studied for the first time. From A. danicus, pentacyclic triterpene saponins were isolated and identified, viz., 3-O-(-glucuronopyranosyl)-3,22,24-trihydroxyolean-12-ene, 3-O-[O-(-d-xylopyranosyl)-(12)-(-glucuronopyranosyl)]-3,22,24-trihydroxyolean-12-ene, 3-O-[O-(-d-glucopyranosyl)-(12)-(-glucuronopyranosyl)]-3,22,24-trihydroxyolean-12-ene, 3-O-[O-(-l-rhamnopyranosyl)-(12)-O-(-d-xylopyranosyl)-(12)-(-glucuronopyranosyl)]-3,22,24-trihydroxyolean-12-ene, 3-O-[O-(-l-rhamnopyranosyl)-(12)-O-(-d-glucopyranosyl)-(12)-(-glucuronopyranosyl)]-3,22,24-trihydroxyolean-12-ene, 3-O-methyl-d-chiro-inositol, and linolenic acid. In A. inopinatus, the same saponins were identified as well as tricosan-1-ol and tetracosan-1-ol, 5,7,4"-trihydroxyflavon (apigenin), and a tetracyclic triterpenoid, 20(R),24(S)-epoxycyclolanost-9(11)-ene-3,6,16,25-tetrol (cycloastragenol). All reported compounds from the both genus of Astragalus were isolated for the first time. Methanolic extracts of A. danicusand A. inopinatus exhibited low inhibitory activity with respect to the growth of HeLa cells. The chloroform fraction of A. danicus showed a strong antimicrobial activity against Staphylococcus aureus and a strong cytotoxic activity against HeLa cells.     

Triterpene glycosides ofClimacoptera transoxana. III. The structures of copterosides E and F

New triterpene glycosides have been isolated from the epigeal part ofClimacoptera transoxana (Iljin) Botsch. — copterosides E and F. According to chemical transformations and physicochemical characteristics, copteroside E has the structure of oleanolic acid 28-O--D-glucopyranoside 3-O-{[O--D-xylopyranosyl-(12)]-[O--D-xylopyranosyl-(14)]--D-glucuronopyranoside} and copteroside F that that of hederagenin 28-O--D-glucopyranoside 3-O-{[O--D-xylopyranosyl-(12)]-[O--D-xylopyranosyl-(14)]--D-glucopyranoside}.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 596–601, September–October, 1983.     

Stereoselectivity of Reactions at the Glycoside Center of Carbohydrates: VII. Synthesis of Aryl α- and -β-D-Glucopyranosides by Helferich,Catalyzed by Boron Trifluoride Etherate

¹³C NMR spectroscopy was used to study the stereoselectivity of glycosylation of phenols with the and anomers of penta-O-acetyl-D-glucopyranose, penta-O-trifluoroacetyl-D-glucopyranose, and 2,3,4,6-tetra-O-acetyl-1-O-trifluoroacetyl-D-glucopyranose in the presence of boron trifluoride etherate at varied temperature, time, and catalyst amount. The boron trifluoride etherate-catalyzed reaction of penta-O-acetyl--D-glucopyranose and 2,3,4,6-tetra-O-acetyl-1-O-trifluoroacetyl--D-glucopyranose with phenols occurs with a high stereocontrol to give, depending on conditions, predominantly 1,2-cis- or 1,2-trans-arylglycosides. This reaction can be used for preparative synthesis of the - and -anomeric forms of glycosides of a wide range of phenols.     

Triterpene Glycosides of Fatsia japonica. VI. Structures of Glycosides D3a and D3b

Seeds of Fatsia japonica (Araliaceae) yielded the new glycosides of gypsogenin: 3-O--D-glucopyranosyl-(12)-O--D-glucopyranoside and 3-O--D-galactopyranosyl-(12)-O--D-glucopyranoside. The structures of these compounds were established by chemical methods and NMR spectroscopy.     

Triterpene glycosides from Pulsatilla chinensis

Four triterpene glycosides were isolated from the roots of Pulsatilla chinensis (Bunge) Regel (Ranunculaceae). Two new glycosides, chinensiosides A (1a) and B (2), were identified as 3-O-[-L-rhamnopyranosyl-(12)--L-arabinopyranosyl]-28-O-[-L-rhamnopyranosyl-(14)--D-glucopyranosyl-(16)--D-glucopyranosyl]-3,23-dihydroxylup-20(29)-en-28-oic acid and 3-O-{-L-rhamnopyranosyl-(12)-[-D-glucopyranosyl-(14)]--L-arabinopyranosyl}-28-O-[-L-rhamnopyranosyl-(14)--D-glucopyranosyl-(16)--D-glucopyranosyl]-3,23-dihydroxylup-20(29)-en-28-oic acid. The other two glycosides were identified as previously known hederasaponin C (3) from Hedera helix and glycoside III (4) from Pulsatilla cernua.     

Binding of vitamin A byβ-cyclodextrin and heptakis(2,6-O-dimethyl)-β-cyclodextrin

Inclusion complexation of all-trans-retinol, retinal and retinoic acid with -cyclodextrin (-CD) and heptakis(2,6-O-dimethyl)--cyclodextrin (DM--CD) were investigated by means of UV-vis spectroscopy. The association constants (K _a) obtained for vitamin A with DM--CD is greater than with -CD. On the other hand, for the same host compoundK _a values of retinol, retinal and retinoic acid are very close to each other.     

Interactions with Charged Cyclodextrins and Chiral Recognition

Anionic N-acetylated -aminoacids (AcTrp^-, AcPhe^-, AcLeu^- and AcVal^-) are bound to protonatedheptakis(6-amino-6-deoxy)--cyclodextrin(per-NH₃ ⁺--CD) by a cooperative work of inclusion and Coulomb interactions.Such complexation occurs enantioselectively ((S)-selective)and is accompanied bypositive entropy changes. Similar (S)-selectivecomplexation occurs in the oppositelycharged system. Namely, cationic -aminoacid methyl esters are enantioselectivelybound to dissociatedheptakis(6-carboxymethylthio-6-deoxy)--cyclodextrin(per-COO^---CD). In order to obtain thegeneral mechanism for complexationof a charged host with an oppositely charged guest,we examined the ¹H NMR spectra oncomplexation of simple carboxylate anions suchas p-methylbenzoate anion andalkanoate anions with per-NH₃ ⁺--CD.Both Coulomb interactions andinclusion are essential to form stable complexesof these carboxylate anions. In allcases, positive entropy changes promote thecomplexation between the carboxylateanions and per-NH₃ ⁺--CD. Dehydrationfrom both charged host and guestis the origin of entropic gains. The mechanism forcomplexation of a charged host withan oppositely charged guest involving the cooperativework of inclusion and Coulombinteractions and positive entropy change due todehydration upon complexation isgenerally applied for related systems such asenantioselective complexation ofRu(phen)₃ ²⁺ with per-COO^---CDand of Ru(phen)₃ ²⁺with DNA.     

Triterpene glycosides of Astragalus and their genins XXXVII. Cycloaraloside F from Astragalus amarus and Astragalus villosissimus

The glycosides of the plantAstragalus villosissimus Bunge have been studied. Four glycosides have been isolated from the roots of this plant, and two of them have been identified as -sitosterol -D-glucopyranoside and cycloaraloside C. The most polar glycoside, which has also been isolated from the roots ofAstragalus amarus Pall., proved to be a new triterpene glycoside of the cycloartane series and has been called cycloaraloside F. It is a trioside of cyclosieversigenin containing two molecules of D-glucose and one molecule of D-apiose. On the basis of chemical transformations and spectral characteristics, the structure of cycloaraloside F has been established as 20R, 24S-epoxycycloartane-3,6,16,25-tetraol 3-0-[O-D-apio--D-furanosyl-(12)--D-glucopyranoside] 25-O--D-glucopyranoside.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 374–377, May–June, 1991.     

Triterpene glycosides ofSalsola micranthera. II. The strucutre of salsoloside E

A new triterpene glycoside — salsoloside E — has been isolated from the epigeal part of the plantSalsola micranthera Botsch. family Chenopodiaceae. On the basis of chemical transformations and physicochemical characteristics its structure has been established as oleanolic acid 28-0--D-glucopyranoside 3-0-{[0--D-glucopyranosyl-(1 2)][0--D-xylopyranosyl-(1 4)]--D-glucuronopyranoside}.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 65–69, January–February, 1964.     

Triterpene Glycosides from Astragalus. Structure of Cyclounifolioside B from Astragalus unifoliolatus

The previously known astrailienin A and the new cycloartane glycoside cyclounifolioside B with structure cyclosiversigenin 3-O-[-D-glucopyranosyl(1-2)]--D-glucopyranoside were isolated from Astragalus unifoliolatus Bunge. The structures of these compounds were established using chemical transformations and two-dimensional spectra (ROESY, HMBC, HSQC, TOCSY, COSY).     

Tripenoid glycosides of alfalfa. VII. Medicosides E and F

Two hederagenin glycosides — medicosides E and F — have been isolated from the roots ofMedicago sativa L. (Leguminosae). Medicoside E has the structure of hederagenin 28-O--D-glucopyranoside 3-O-[O--G-glucopyranosyl-(13)--D-xylopyranoside]. Medicoside F has the structure of hederagenin 28-O--D-glucopyranoside 3-O-[O--D-glucopyranosyl-(12)--L-arabinopyranoside].Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent. Institute of Organic Chemistry, Russian Academy of Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii. No. 5, pp. 701–705, September–October, 1993.     

Phenolic Compounds of Salix acutifolia Bark

Column chromatography over silica gel and polyamide was used to isolate 14 phenolic substances from bark of sharp-leaved willow (Salix acutifolia Willd.). These included naringenin, prunin, (-)-salipurposide, (+)-catechin, isosalipurposide, 6-coumarylisosalipurposide, isosalipurpol (flavonoids), triandrin, syringin (phenylpropanoids), and salicyl alcohol (saligenin) and its derivatives acylsaligenin, salicin, salicortin, and tremulacin. Nine of these were isolated for the first time from this species. They were identified using UV, IR, NMR, and mass spectra, chemical transformations, and comparison with authentic samples.     

Flavonoids ofPhellodendron sachalinense andPh. amurense

Summary 1. About ten substances of a flavonoid nature have been found in the leaves ofPhellodendron sachalinense (F. Schm.) Sarg. andPh. amurense Rupr.2. The two species of cork tree each contain two new flavonoids, which have been called phelloside and dihydrophelloside. The results of chemical and spectroscopic studies have permitted phelloside to be characterized as the 7,-di-O--D-glucopyranoside of noricaritin and dihydrophelloside as the 7,-di-O--D-glucopyranoside of dihydronoricaritin, the base of which contains kaempferol and aromadendrin.3. Amurensin (the 7--D-glucopyranoside of noricaritin) and icariside-1 (the -O--D-glucopyranoside of noricaritin) have been isolated as intermediates in the stepwise hydrolysis of phelloside; the latter has not been previously found in the Amur and Japanese cork trees.Khimiya Prirodnykh Soedinenii, Vol. 4, No. 2, pp. 77–82, 1968     

Trans-cis Photoisomerization of 1-Methyl-4-(4′-hydroxystyryl)pyridinium in inclusion complexes ofβ-cyclodextrin and its derivatives

The effects of -cyclodextrin (-CyD), heptakis(2,6-di-O-methyl)--cyclodextrin (DMCyD) and heptakis(2,3,6-tri-O-methyl)--cyclodextrin (TMCyD) ontrans-cis photoisomerization of 1-ethyl-4-(4-hydroxystyryl)pyridinium (POH) have been studied in aqueous solutions. The ratio of [cis]/[trans] for POH in the photostationary state at pH 8.54 was remarkably reduced by the presence of CyD or DMCyD. The reduction of the [cis]/[trans] ratio in the photostationary state was explained in terms of the shift of the equilibrium of POH ₊ ^trans PO _trans + H^– toward PO _trans formation. The binding constants of CyD and DMCyD for PO _trans were 2.00- and 1.36-fold larger than those for POH ₊ ^trans , respectively. The binding constants of TMCyD for both species are much smaller than those of CyD and DMCyD. This result indicates that PO _trans , which has a betain structure, forms stable complexes with CyD and DMCyD with its hydrophobic parts inside and the charged parts outside the CyD cavities.     

Triterpene glycosides ofSilphium perfoliatum. III. Structure of silphioside E

A new triterpene glycoside — silphioside E — has been isolated from the epigeal part ofSilphium perfoliatum L. and its structure has been established on the basis of chemical transformations and spectral characteristics as oleanolic acid 28-0--D-glycopyranoside 3-0-[0--D-glycopyranosyl-(1 2)--D-glucopyranoside].Pyatigorsk Pharmaceutical Institute. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnikh Soedinenii, No. 6, pp. 750–753, November–December, 1984.     

Synthesis of glycosides of gypsogenin and of gypsogenic acid by the orthoester method

Summary 1. Gypsogenin 3--D-glucopyranoside has been obtained for the first time.2. The natural 3-(-D-xylopyranoside) of gypsogenic acid (saponaroside) has been synthesized.Institute of Organic and Physical Chemistry, Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 373–377, May–June, 1975.