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.     

Formulation and Preliminary in vivo Testing of Rufloxacin-Cyclodextrin Ophthalmic Solutions

Aim of the present work was to investigate the effect of somecyclodextrins (CDs) on the solubility and ocular bioavailability of rufloxacin base (RUF), with theultimate goal of developing an ophthalmic formulation. Phase solubility studies of RUF inpH 7.4 buffer were carried out in the presence of -cyclodextrin (-CD),hydroxypropyl--cyclodextrin (HP--CD) and -cyclodextrin(-CD). The effect of hydroxypropyl methylcellulose (HPMC) on RUF solubility was evaluated after heating the solutionscontaining HP--CD at 120 °C.A significant enhancement of RUF solubility was achieved by associatingthe drug with CDs, particularly HP--CD. This CD formed with RUF a less stablecomplex than that formed by -CD, but did not suffer the solubility limitations ofthe parent CD, and showed a higher solubilizing capacity than -CD. Addition of 0.25%(w/v) HPMC to solutions containing HP--CD increased the solubilizing effect of this CD,thus allowing reduction of the amount necessary for solubilization of 0.3% (w/v) RUF.Preliminary pharmacokinetic data in rabbits indicated that theocular bioavailability of 0.3% (w/v) RUF solubilized by HP--CD was higher when compared witha 0.3% (w/v) RUF suspension used as reference.     

Steroid saponins X. Glycosides of Allium narcissiflorum the structure of glycosides A and B

Summary FromAllium narcissiflorum Wells have been isolated for the first time trillin and a glycoside B, which proved to be 3-O-[-O-D-glucopyranosyl-(1 3)-O--D-glucopyranosyl-(1 6)-O--D-glucopyranosyl-(1 ]-26-O-[-D-glucopyranosyl-(1 ]-25R-furost-5-ene-3,22 , 26-triol.Institute of Chemistry, Academy of Sciences of the Moldavian SSR, Kishinev. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 55–58, January–February, 1976.     

Steroid saponins and sapogenins ofAllium IX. The structure of aginoside

Summary From a methanolic extract of the skins of the bulbs ofAllium giganteum Rgl, a new steroid glycoside has been isolated — aginoside, which is (25R)-5-spirostan-2, 3, 6-triol 3-0-{[0--D-xylopyranosyl-(13)-]-[0--D-glucopyranosyl-(12)]-0--D-glucopyranosyl-(14)-0--D-galactopyranoside}.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 480–486, July–August, 1976.     

Reduction of photohemolytic activity of benoxaprofen byβ-cyclodextrin complexations

Inclusion complexations of benoxaprofen (BXP) with-cyclodextrin (-CyD) and heptakis (2,6-di-O-methyl)--CyD (DM--CyD) were studied by the solubility method and CD and¹H-NMR spectroscopy. Both -CyDs decelerated the photodecarboxylation of BXP, and suppressed the BXP-photosensitized hemolysis, where the inhibitory effect of DM--CyD was larger than that of -CyD. This order was well correlated with the magnitude of the stability constants of BXP--CyD complexes. The peroxidation of lipid components in erythrocyte ghosts induced by BXP was also suppressed particularly by DM--CyD. The protective effect of -CyDs on the BXP-induced photohemolysis seems to be due to the suppression in the photochemical reactions of BXP yielding toxic transient species, together with the inhibition in attacks of the transient species to the membrane, through inclusion complexation.     

Trriterpene glycosides ofAstragalus and their genins LIX. Structure of cyclocanthoside F

The structure of a new cycloartane glycoside, cyclocanthoside F, has been established on the basis of spectral characteristics as 20R,25-epoxy-24S-cycloartane-3,6,16,24-tetraol 3-O-[O--D-glucopyranosyl-(12)--D-xylopyranoside] 6-O--D-glucopyranoside. The possibility in principle of using the -effects of glycosylation and¹³C NMR spectroscopy for determining a glycosyl substituent at C-6 of a cycloartane has been demonstrated.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (371) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 348–353, May–June, 1999.     

Triterpene glycosides of alfalfa VIII. Medinoside E from the leaves

From the leaves ofMedicago sativa L. (Leguminosae) we have isolated the glycoside soyasapogenol B — medinoside E. Medinoside E has the structure of olean-12-ene-3,22,24-triol 3-O-[O--L-rhamnopyranosyl-(12)-O--D-galactopyranosyl-(12)-O--D-glucopyranosyl-(12)--D-glucopyranuronoside].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. 705–710, September–October, 1993.     

In vitro nitrosation of ephedrine in the presence of cyclodextrins

-, and -cyclodextrin and heptakis-2,6-di-O-methyl--cyclodextrin enhance the nitrosation rate of l-ephedrine if the nitrosation assay procedure (NAP test) is applied. During this reaction with -cyclodextrin a solid inclusion compound of -cyclodextrin andN-nitrosoephedrine precipitates. Solubilities and stabilities of inclusion compounds of the cyclodextrins with ephedrine and nitrosoephedrine, respectively, explain especially the catalytic effects of some cyclodextrins on ephedrine.Part of the PhD thesis of V. Wedelich, Freie Universität Berlin, 1985.     

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.     

Astragalus triterpene glycosides and their genins. I. Structures of cycloalpigenin and cycloalpioside

Another two methylsteroids of the cycloartane series have been isolated from the epigeal part ofAstragalus alopecurus. The structures of the compounds isolated, cycloalpigenin and cycloalpioside, have been established as (20R,24R)-16,24:20, 24-diepoxycycloartane-3,7,25-triol and (20R,24R)-16, 24:20,24-diepoxycycloartane-3,7, 25-triol 3-O--D-xylopyranoside, respectively, on the basis of chemical transformations and spectral characteristics. The structure of cycloalpigenin has been confirmed by chemical correlation with that of cycloalpigenin D.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 700–708, September–October, 1995. Original article submitted February 1, 1995.     

Mixed polynitroorthocarbonates

The reaction of-nitro- and-fluoro--nitrodichloroformals with -nitroalcohols in the presence of ferric chloride gave mixed 22-polynitroorthocarbonates.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 198–200, January, 1991.     

New cardenolides from the seeds ofCoronilla hyrcana

Summary Four substances have been isolated from the seeds ofCoronilla hyrcana: hyrcanoside, deglucohyrcanoside, hyrcanogenin, and substance E.It has been established that hyrcanoside (I) has the structure 3-(O--D-xylopyranosyl- <4 1 > -O--D-glycopyranosyl)-14-hydroxy-19-oxocard-4, 20 (22)-dienolide; deglucohyrcanoside (VII) is 3-(O--D-xylopyranosyl)-14-hydroxy-19-oxocard-4, 20 (22)-dienolide; and hyrcanogenin (V) is 3, 14-dihydroxy-19-oxocard-4, 20 (22)-dienolide. Both the aglycone hycanogenin (V) and its glycosides (I) and (VII) are new compounds.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 4, pp. 251–257, 1966     

Triterpene Glycosides from Tragacantha stipulosa and Their Genins. Structure of Cyclostipuloside E

The known compound trojanoside A (1) and a new cycloartane glycoside cyclostipuloside E (2) were isolated from the aerial parts of Tragacantha stipulosa Boriss. The structure of cyclostipuloside E was proposed as 24R-cycloartan-3,6,16,24,25-pentaol 6,16,25-tri-O--D-glucopyranoside 3-O--D-xylopyranoside based.     

Acid chlorides of unsaturated phosphonous acids

Summary The dichloride of -ethoxyvinyl-, -isooctyloxyvinyl-, and 2-chloro-3-methylbut-3-enylphosphonous acids have been synthesized and characterized for the first time. The diethyl ester of -ethoxyvinylphosphonous acid has been-obtained from the dichloride of -ethoxyvinylphosphonous acid.     

Syntheses based on strophanthidin

Summary With strophanthidin as starting material, 3, 5, 10, l4-tetrahydroxy-19-norandrostan-17-one has been obtained by a five-stage synthesis.     

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.     

Steroid polyols from the Far-Eastern starfish Henricia sanguinolenta

A new polyhydroxylated steroid (20R,24S)-5-cholestane-3,6,15,24-tetraol and a known glycoside, laeviuscoloside G, was isolated from the Far-Eastern starfish Henricia sanguinolenta, collected in the sea of Okhotsk, and characterized.     

Steroid compounds from the Pacific starfish Lysastrosoma anthosticta

Two new steroid compounds, 3,6-dihydroxy-5-cholesta-9(11),24-dien-23-one 3-sulfate and 3,6-dihydroxy-5-cholest-9(11)-en-23-one 3-sulfate, were isolated from the Pacific starfish Lysastrosoma anthosticta as the corresponding sodium salts and identified. Two previously known glycosides of 24(S)-5-cholestane-3,6,8,15,24-pentol were also isolated and identified as sodium 24-O--d-glucopyranoside 6"-sulfate (pycnopodioside C) and sodium 24-O--d-xylopyranoside 4"-sulfate (luridoside A).     

Synthesis of the β isomers of 2,4,6-trisubstituted 1,3,5-trithianes

The condensation of bis(-hydroxy-,,-trichloroethyl) sulfide with aldehydes under acid catalysis conditions gives 2,4,6-trisubstituted 1,3,5-trithianes. The latter are realized only in the thermodynamically more favorable forms.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1625–1626, December, 1976.