Triterpenoid saponins and acylated prosapogenins from Harpullia austro-caledonica

Three new triterpenoid saponins have been isolated from the stem bark of Harpullia austro-caledonica and identified as 24-O-[alpha-L-rhamnopyranosyl-(1->2)-beta-D-glucopyranosyl]-28-O-[beta-D-glucopyranosyl-(1->2)-beta-D-glucopyranosyl]-protoaescigenin, 24-O-[alpha-L-rhamnopyranosyl-(1->2)-beta-D-glucopyranosyl]-28-O-[beta-D-glucopyranosyl-(1->2)-beta-D-glucopyranosyl]-16-desoxyprotoaescigenin, 24-O-[alpha-L-rhamnopyranosyl-(1->2)-beta-D-glucopyranosyl]-28-O-[beta-D-glucopyranosyl-(1->2)-beta-D-glucopyranosyl]-24-oxo-camelliagenin D. The 21,22-di-O-angeloate esters of protoaescigenin and barringtogenol C were isolated in the acid hydrolysate of the saponin extract together with a new prosapogenin identified as 21beta,22alpha-di-O-angeloyl camelliagenin D. The structures were established using one- and two- dimensional NMR and mass spectrometry.     

Pendulaosides A and B. Two acylated triterpenoid saponins from Harpullia pendula seed extract

Two new acylated triterpenoid saponins named pendulaosides A and B as well as the known phenolic compounds methyl gallate, gallic acid, 1,2,3,6-tera-O-galloyl-β-d-glucose and 1,2,3,4,6-penta-O-galloyl-β-d-glucose, were isolated from the seeds of Harpullia pendula. The structures of pendulaosides A and B were determined using extensive 1D and 2D NMR analysis and mass spectrometry as well as acid hydrolysis, as 3-O-β-d-glucopyranosyl-(1→2)-[α-L-arabinofuranosyl-(1→3)]-β-d-glucuronopyranosyl-22-O-angeloyl-3β,16α,22α,24β,28-pentahydroxylolean-12-ene and 3-O-β-d-glucopyranosyl-(1→2)-[α-L-arabinofuranosyl-(1→3)]-β-d-glucuronopyranosyl-16-O-(2-methylbutyroyl)-3β,16α,22α,24β,28-pentahydroxylolean-12-ene, respectively. To the best of our knowledge the two triterpene parts 22-O-angeloyl-3β,16α,22α,24β,28-pentahydroxylolean-12-ene and16-O-(2-methylbutyroyl)-3β,16α,22α,24β,28-pentahydroxylolean-12-ene have never been characterized before. The two isolated saponins were assayed for their in-vitro cytotoxic activity against the three human tumor cell lines HepG2, MCF7 and PC3. The results showed that pendulaoside A exhibited moderate activity on PC3 cell line with IC50value equal to 13.0 μM and weak activity on HepG2 cell line with IC50 value equal to 41.0 μM. Pendulaoside B proved to be inactive against the three used cell lines.     

Saponins and acylated saponins from Dizygotheca kerchoveana

Four new triterpenoid saponins were isolated from the leaves and stem of branches of Dizygotheca kerchoveana along with seven known ones. The new saponins were respectively characterized as 3-O-[beta-D-glucopyranosyl-(1-->3)]-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl echinocystic acid, 3-O-[beta-D-glucopyranosyl-(1-->3)]-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl echinocystic acid 28-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl] ester, 3-O-[beta-D-3-O-trans-p-coumaroyl-glucopyranosyl-(1-->3)]-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl echinocystic acid 28-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl] ester and 3-O-[beta-d-3-O-cis-p-coumaroyl-glucopyranosyl-(1-->3)]-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl echinocystic acid 28-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl] ester. Their structures were elucidated by 1D and 2D NMR experiments, FAB-MS as well as chemical means.     

Cytotoxic triterpenoid saponins acylated with monoterpenic acids from fruits of Gleditsia caspica Desf.

Four bisdesmosidic triterpenoid saponins named caspicaosides A-D, were isolated from the fruits of Gleditsia caspica Desf. Their structures were determined by NMR spectroscopy including HOHAHA, ¹H-¹H COSY, ROE, HMQC, HMBC experiments and HRFAB-MS as well as acid hydrolysis. The four 3,28-O-bisdesmosidic triterpenoid saponins comprised echinocystic acid as the aglycone and common oligosaccharide moieties at C3 and C28. The saccharide moiety at C-3 was identified as β-d-xylopyranosyl-(1 → 2)-α-l-arabinopyranosyl-(1 → 6)-β-d-glucopyranosyl while that at C-28 was determined as β-d-xylopyranosyl-(1 → 3)-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 6)-]β-d-glucopyranosyl. The pentasaccharide moiety linked to C-28 was acylated with monoterpenic acid and or monoterpene-arabinoside moieties at C-2 or C-2 and C-3 of the terminal rhamnose unit. The isolated saponins were assayed for their in vitro cytotoxicities against the three human tumor cell lines HepG2, A549 and HT29 using MTT method. The results showed that caspicaosides B and C bearing two and three monoterpene units, respectively, exhibited significant cytotoxic activities against the used cell lines with IC₅₀ values 1.5-6.5 μM. Caspicaosides A and D with one monoterpene unit exhibited significant cytotoxic activities on HepG2 cell line with IC₅₀ values equal to 4.5 and 5.4 μM, respectively, and IC₅₀ values >10 μM against the other two cell lines. The number of monoterpene units seems to play a main role in determining the activity.     

Cytotoxic triterpenoid saponins from the stem bark of Antonia ovata

Phytochemical investigation of the MeOH extract of the stem bark of Antonia ovata led to the isolation of four triterpenoid saponins, along with eleven known compounds. Their structures were established by extensive 1D and 2D NMR, as well as HR-MS analysis and acid hydrolysis. All isolated saponins contained the same tetrasaccharide chain O-β-d-xylopyranosyl-(1 → 2)-O-β-d-glucopyranosyl-(1 → 3)-O-[β-d-glucopyranosyl-(1 → 2)]-β-d-glucuropyranoside linked to C-3 of esterified derivatives of R₁-barrigenol, A₁-barrigenol, barringtogenol C, or camelliagenin. Biological evaluation of the compounds against KB cell line revealed a potent cytotoxic activity with IC₅₀ values ranging from 3.1 to 6.6 μM. The known compounds were found to be inactive at 10 μg/ml concentration.     

Triterpenoid saponins from the fruits and galls of Sapindus mukorossi

Six saponins, sapinmusaponin K (1) [hederagenin-3-O-(3-O-acetyl-alpha-L-arabinopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside], sapinmusaponin L (2) [hederagenin-3-O-(4-O-acetyl-alpha-L-arabinopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabino-pyranoside], sapinmusaponin M (3) [hederagenin-3-O-(2,3-O-diacetyl-beta-D-xylopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside], sapinmusaponin N (4) [hederagenin-3-O-(2,4-O-diacetyl-beta-D-xylopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside], sapinmusaponin O (5) [3,7,20(S)-trihydroxydammar-24-ene-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside], and sapinmusaponin P (6) [3,7,20(R)-trihydroxydammar-24-ene-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-d-glucopyranoside], along with seven known saponins (7-13), were isolated from fruits and the galls of Sapindus mukorossi. Their structures were elucidated by 1D and 2D NMR spectroscopic techniques and acid hydrolysis. Biological evaluation indicated that saponins 1-4 and 7-13 showed moderate cytotoxicity against several human tumor cell lines.     

Oleanolic glycosides from Pometia ridleyi

Six triterpenoid saponins were isolated from the stem bark of Pometia ridleyi along with two known saponins, acutoside A and calenduloside C. Their structures were established using one- and two-dimensional NMR and mass spectrometry as 3-O-beta-D-apiofuranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucopyranosyl-, 3-O-beta-D-apiofuranosyl-(1-->3)-alpha-L-arabinopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucopyranosyl-, 3-O-beta-D-apiofuranosyl-(1-->3)-beta-D-galactopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucopyranosyl-, 3-O-alpha-L-arabinopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl-, 3-O-beta-D-galactopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl-, 3-O-beta-D-apiofuranosyl-(1-->3)-beta-D-galactopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl-oleanolic acid. The EtOH and EtOAc extracts of the stem bark showed no cytotoxic activity. At a concentration of 23 microg/ml, the saponin mixture showed haemolytic activity and caused 50% haemolysis of a 10% suspension of sheep erythrocytes.     

Oligosaccharide polyester and triterpenoid saponins from the roots of Polygala japonica

An oligosaccharide polyester, 1-O-(E)-p-coumaroyl-(3-O-benzoyl)-beta-D-fructofuranosyl-(2-->1)-[6-O-(E)-feruloyl-beta-D-glucopyranosyl-(1-->2)]-[6-O-acetyl-beta-D-glucopyranosyl-(1-->3)-(4-O-acetyl)-beta-D-glucopyranosyl-(1-->3)]-4-O-[4-O-alpha-L-rhamnopyranosyl-(E)-p-coumaroyl]-alpha-D-glucopyranoside (polygalajaponicose I), and four triterpenoid saponins, 3beta, 23, 27-trihydroxy-29-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-olean-12-en-28-oic acid (polygalasaponin XLVII), 3-O-beta-D-glucopyranosyl presenegenin 28-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranosyl ester (polygalasaponin XLVIII), 3-O-beta-D-glucopyranosyl presenegenin 28-O-beta-D-galactopyranosyl-(1-->5)-beta-D-apiofuranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl ester (polygalasaponin XLIX) and 2beta, 27-dihydroxy-3-O-beta-D-glucopyranosyl 11-oxo-olean-12-en-23, 28-dioic acid 28-O-beta-D-galactopyranosyl-(1-->5)-beta-D-apiofuranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranosyl ester (polygalasaponin L), in addition to five known compounds have been isolated from the roots of Polygala japonica.     

New triterpenoid saponins from Patrinia scabiosaefolia

Phytochemical investigation of the methanol extract from the whole plants of Patrinia scabiosaefolia Fisch. resulted in the isolation of four new triterpenoid saponins (1–4) along with six known compounds (5–10). On the basis of spectroscopic and chemical methods, the structures of the new compounds were established as 3-O-β-d-xylopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-β-d-xylopyranosyl-12β,30-dihydroxy-olean-28,13β-olide (1), 3-O-α-l-rhamnopyranosyl-(1→2)-β-d-xylopyranosyl-12β,30-dihydroxy-olean-28,13β-olide (2), 3-O-β-d-xylopyranosyl-(1→2)-β-d-glucopyranosyl-12β, 30-dihydroxy-olean-28,13β-olide (3), and 3-O-β-d-glucopyranosyl-(1→4)-β-d-xylopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-β-d-xylopyranosyl-oleanolic acid 28-O-β-d-glucopyranoside (4), respectively. Compounds 1–3 possess a novel 12β,30-dihydroxy-olean-28,13β-lactone aglycone and a 12β-hydroxy substituent that is rarely found in this kind of triterpenoid saponin.     

Acetylated glucuronide triterpene bidesmosidic saponins from Symplocos glomerata

Nine new bidesmosidic 3-O-glucuronide oleanane triterpenoid saponins were isolated from the stem bark of Symplocos glomerata King along with two known saponins, salsoloside C and copteroside E, and two major lignans, (-)-pinoresinol and (-)-pinoresinol-4'-O-beta-D-glucopyranoside. The structures of the new saponins were established using one- and two-dimensional NMR spectroscopy and mass spectrometry as, 3-O-[beta-D-xylopyranosyl(1-->4)-[2-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[beta-D-xylopyranosyl(1-->4)-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[beta-D-xylopyranosyl (1-->4)-[2,3-O-diacetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[alpha-L-arabinopyranosyl(1-->4)-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[alpha-L-arabinopyranosyl (1-->4)-[2-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[[beta-D-xylopyranosyl (1-->2)]-[beta-D-xylopyranosyl (1-->4)]-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[[beta-D-glucopyranosyl (1-->2)]-[beta-D-xylopyranosyl (1-->4)]-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, 3-O-[[beta-D-glucopyranosyl (1-->2)]-[alpha-L-arabinofuranosyl (1-->4)]-[3-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-oleanolic acid, and 3beta-O-[beta-D-xylopyranosyl(1-->4)-[2-O-acetyl]-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-morolic acid. The EtOH and EtOAc extracts of the stem bark showed no cytotoxic activity. At a concentration of 370 microg/ml, the saponin mixture showed haemolytic activity and caused 50% haemolysis of a 10% suspension of sheep erythrocytes.     

New triterpenoid saponins from the roots of Gypsophila pacifica Kom.

Six new triterpenoid saponins (1-6) have been isolated from the roots of Gypsophila pacifica Kom. Their structures were established on the basis of extensive NMR (¹H, ¹³C, TOCSY, HSQC, and HMBC) and ESIMS studies.     

Phenolic compounds and rare polyhydroxylated triterpenoid saponins from Eryngium yuccifolium

Phytochemical investigation on the whole plant of Eryngium yuccifolium resulted in the isolation and identification of three phenolic compounds (1-3) and 12 polyhydroxylated triterpenoid saponins, named eryngiosides A-L (4-15), together with four known compounds kaempferol-3-O-(2,6-di-O-trans-p-coumaroyl)-β-d-glucopyranoside (16), caffeic acid (17), 21β-angeloyloxy-3β-[β-d-glucopyranosyl-(1→2)]-[β-d-xylopyranosyl-(1→3)]-β-d-glucuronopyranosyloxyolean-12-ene-15α,16α,22α,28-tetrol (18), and saniculasaponin III (19). This study reports the isolation of these compounds and their structural elucidation by extensive spectroscopic analyses and chemical degradation.     

Triterpenoid saponins from Pteleopsis suberosa stem bark

Thirteen oleanane saponins (1-13), four of which were new compounds (1-4), were isolated from Pteleopsis suberosa Engl. et Diels stem bark (Combretaceae). Their structures were determined by 1D and 2D NMR spectroscopy and ESI-MS spectrometry. The compounds were identified as 2alpha,3beta,19alpha,23,24-pentahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester (1), 2alpha,3beta,19beta,23,24-pentahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester (2), 2alpha,3beta,19alpha,23-tetrahydroxy-11-oxo-olean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester (3), and 2alpha,3beta,6beta,19alpha,24-pentahydroxy-11-oxo-olean-12- en-28-oic acid 28-O-beta-D-glucopyranosyl ester (4). The presence of alpha,beta-unsaturated carbonyl function was not common in the oleanane class and the aglycons of these compounds were not found previously in the literature. Moreover, the isolated compounds were tested against Helicobacter pylori standard and vacA, and cagA clinical virulence genotypes. Results showed that compound 6 has an anti-H. pylori activity against three metronidazole-resistant strains (Ci 1 cagA, Ci 2 vacA, and Ci 3).     

Hopane-type saponins from Glinus lotoides Linn

Seven hopane-type saponins were isolated from the methanol extract of Glinus lotoides. Six of them were identified as novel compounds and designated as lotoideside A [3-O-beta-D-xylopyranosyl (1-->2)-alpha-L-rhamnopyranosyl-6 alpha-O-beta-D-xylopyranosyl-22-beta-O-beta-D-glucopyranosyl-16 beta-hydroxy hopane (1)], lotoideside B [3-O-beta-D-xylopyranosyl (1-->2)-alpha-L-rhamnopyranosyl-22-beta-O-beta-D-glucopyranosyl-6 alpha,16 beta-dihydroxyhopane (2)], lotoideside C [3-OD-xylopyranosyl-6 alpha-O-beta-D-xylopyranosyl-16 beta-O-beta-D-xylopyranosyl-22 beta-hydroxyhopane (3)], lotoideside D [3-O-beta-D-xylopyranosyl-16 beta-O-alpha-L-arabinopyranosyl-6 alpha,22-beta-dihydroxyhopane (4)], lotoideside E [3-O-beta-D-xylopyranosyl-6 alpha-O-beta-D-xylopyranosyl-16 beta,22-beta-dihydroxyhopane (5)], and lotoideside F [3-O-beta-D-xylopyranosyl-22-beta-O-beta-D-glucopyranosyl-16 beta-hydroxyhopan-6-one (6)]. The known compound succulentoside B (7) was also encountered. Their structures were elucidated on the basis of one-and two-dimensional NMR spectroscopic techniques, ESIMS and chemical evidences.     

A triterpenoid saponin possessing antileishmanial activity from the leaves of Careya arborea

Bioguided-fractionation of the methanol extract of the leaves of Careya arborea led to isolation of a triterpenoid saponin, designated arborenin, and characterized as 3-O-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl-2 alpha,3beta-dihydroxy-taraxast-20-en-28-oic acid (1), together with desacylescin III (2). The structures were determined on the basis of extensive 2D NMR spectroscopic analysis. The saponin showed in vitro antileishmanial activity against Leishmania donovani (strain AG 83).     

Pentacyclic triterpenoid and saponins from Gambeya boukokoensis

Chemical studies of the EtOAc extract of Gambeya boukokoensis Aubr. et Pellegr. stem bark led to the isolation of eight compounds. Three of them were elucidated as new compounds and designated as: gamboukokoensein A, 1alpha,2alpha,3beta,19alpha,23-pentahydroxyurs-12-en-28-oic acid; gamboukokoenside A, 2beta,3beta,6beta,28-tetrahydroxyolean-12-en-23-oic acid 23-O-alpha-L-arabinopyranosyl ester and gamboukokoenside B, 6beta,28-dihydroxy-3-oxoolean-12-en-23-oic acid 23-O-alpha-L-arabinopyranosyl ester. The other five compounds were known and identified as myrianthic acid, protobassic acid, oleanolic acid, erythrodiol and chondrillasterol. Their structures were elucidated on the basis of one and two dimensional NMR spectroscopic techniques, FABMS, ESMS and chemical evidence.     

Steroidal saponins from the aerial parts of Tribulus alatus Del

Six steroidal glycosides (1-6) were isolated from the aerial parts of Tribulus alatus Del. (Zygophyllaceae), together with one known cholestane, one spirostane, and six flavonol glycosides. Among them, 1 and 2 possess a furostane-type aglycone, 3 and 6 a cholestane structure, and 4 and 5 a spirostane skeleton. Their structural elucidation was accomplished by extensive spectroscopic methods including 1D ((1)H, (13)C, (13)C DEPT, TOCSY, ROESY) and 2D NMR experiments (DQF-COSY, HSQC, HMBC) as well as ESI-MS analysis.     

Triterpene saponins from Silphium radula

Nine triterpene saponins (1-9) were isolated from leaves and stems of Silphium radula Nutt. (Asteraceae). Their structures were determined by extensive 1D ((13)C, (1)H, DEPT, TOCSY) and 2D NMR (NOESY, HSQC, HMBC) and ESI-MS studies. The compounds were identified as 3beta,6beta,16beta-trihydroxyolean-12-en-23-al-3-O-beta-glucopyranosyl-16-O-beta-glucopyranoside (1), urs-12-ene-3beta,6beta,16beta-triol-3-O-beta-galactopyranosyl-(1-->2)-beta-glucopyranoside (2), 3beta,6beta,16beta-trihydroxyolean-12-en-23-oic acid-3-O-beta-glucopyranosyl-16-O-beta-glucopyranoside (3), urs-12-ene-3beta,6beta,16beta,21beta-tetraol-3-O-beta-glucopyranoside (4), olean-12-ene-3beta,6beta,16beta,21beta-tetraol-3-O-beta-glucopyranoside (5), olean-12-ene-3beta,6beta,16beta,21beta,23-pentaol-3-O-beta-glucopyranosyl-16-O-beta-glucopyranoside (6), olean-12-ene-3beta,6beta,16beta-triol-3-O-beta-glucopyranosyl-16-O-alpha-arabinopyranosyl-(1-->2)-beta-glucopyranoside (7), olean-12-ene-3beta,6beta,16beta,23-tetraol-3-O-beta-glucopyranosyl-16-O-alpha-arabinopyranosyl-(1-->2)-beta-glucopyranoside (8), 3beta,6beta,16beta,21beta-tetrahydroxyolean-12-en-23-al-3-O-beta-glucopyranoside (9). The presence of a 6beta-hydroxyl function was not common in the oleanene or ursene class and the aglycones of these compounds were not found previously in the literature. Moreover, the cytotoxic activities of the isolated compounds were tested against human breast cancer cell line MDA-MB-231. Results showed that compound 2 decreased cell proliferation in a statistically significant manner at 25 microg/ml.     

Steroidal saponins from Asparagus acutifolius

Six new steroidal saponins (1-6) were isolated from the roots of A. acutifolius L., together with a known spirostanol glycoside (7). Their structures were elucidated mainly by extensive spectroscopic analysis (1D and 2D NMR, FABMS and HRESIMS). Compounds 4-7 demonstrated antifungal activity against the human pathogenic yeasts C. albicans, C. glabrata and C. tropicalis with MICs values between 12.5 and 100 microg/ml.     

Three acylated flavone glycosides from Sideritis ozturkii Aytac & Aksoy

From the aerial parts of Sideritis ozturkii, three new flavonoids, chrysoeriol 7-O-[2'-O-caffeoyl-O-acetyl-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside], chrysoeriol 7-O[2'-O-caffeoyl-beta-D-glucopyranosyl-(1 -->2)-beta-D-glucopyranoside] and chrysoeriol 7-O[2'-O-p-coumaroyl-6'-beta-O-acetyl-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside] named as ozturkosides A, B and C, respectively, were isolated, along with three known phenylethanoid glycosides, verbascoside, leucoseptoside A, martynoside and five known diterpenoids, 7-epicandicandiol, linearol, sidol, sideroxol, epoxyisolinearol. The structures were elucidated mainly by spectroscopic methods.