Junipers of Various Origins as Potential Sources of the Anticancer Drug Precursor Podophyllotoxin.

Juniper representatives are natural sources of plenty of bioactive metabolites and have been used since ancient times as folk remedies against tapeworms, warts, cancer, etc. The antiproliferative activities of junipers are attributed to podophyllotoxin (PPT), which is a precursor for the synthesis of efficient anticancer drugs. However, the natural sources of PPT, Sinopodophyllum hexandrum (Royle) T. S. Ying and Podophyllum peltatum L., are already endangered species because of their intensive industrial exploitation. Therefore, identification of other sources of PPT is necessary. This study is a broad comparative investigation of junipers, for which original sources have been accessed from different continents of the world. The present research is aimed at the identification of species, producing PPT and other lignans at concentrations that are sufficient for the high antiproliferative activity of the corresponding extracts. Cytotoxic juniper leaf extracts demonstrated a broad spectrum of activity on a panel of cancer cell lines. The antiproliferative properties of junipers were attributed to the combined activity of great diversity of lignans (podophyllotoxin, deoxypodophyllotoxin, ß-peltatin, yatein, matairesinol, anhydropodorhizol, etc.), detected by UHPLC-HRMS and LC-ESI-MS/MS in the corresponding extracts. Several species of the genus Juniperus L. were outlined as perspective sources of drug precursors with potential pharmaceutical applications.

Neuroprotective, anti-α-glucosidase and prolipase active flavonoids from Good King Henry (Chenopodium bonus-henricus L.).

Nine glycosides of patuletin, 6-methoxykaempferol and spinacetin from Good King Henry (Chenopodium bonus-henricus L.) were investigated for neuroprotective, anti-α-glucosidase and lipase activities. All tested flavonoids (100 µM) showed statistically significant neuroprotective activities on isolated rat brain synaptosomes using 6-hydroxydopamine in vitro model. They preserved synaptosome viability as well as the reduced glutathione level. 6-Methoxykaempferol glycoside 9 possessed the most prominent neuroprotective and antioxidant effects, within the same range as silibinin (100 µM). Anti-α-glucosidase and lipase activities of the tested compounds were established by measuring the levels of the released 4-nitrophenol using LC-MS here for the first time. Patuletin glycosides 2 and 7 possessed similar activity to acarbose with IC50 210, 249 and 206 µM, respectively. All flavonoids exhibited prolipase activity and could be used in the treatment of cachexia. The most active were flavonoids, which contain esterified ferulic acid.

UHPLC-HRMS based flavonoid profiling of the aerial parts of Chenopodium foliosum Asch. (Amaranthaceae).

Chenopodium foliosum Asch. has been recognised by Bulgarian legislation as a medicinal plant. The decoction of its aerial parts has been used for treatment of cancer, as an immunostimulant and antioxidant drug. An UHPLC-HRMS profiling method was used for a comprehensive study of flavonoid composition of C. foliosum. Fourty flavonoid glycosides with nine aglycones (patuletin, gomphrenol, spinacetin, 6-methoxykaempferol, kaempferol, quercetin, isorhamnetin, 3,5,3',4'-tetrahydroxy-6,7-methylenedioxyflavone and 3,5,4'-trihydroxy-3'-methoxy-6,7-methylenedioxyflavone) were detected. Kaempferol, quercetin and isorhamnetin glycosides were identified as minor components. A pseudo MS3 experiment aided at discriminating 6-methoxykaempferol and isorhamnetin glycosides. Flavonoid composition dominated by di-, triglycosides and acylated flavonoids. Acid hydrolysis and GS-MS analysis confirmed the presence of D-glucose, D-apiose and L-rhamnose. Ten flavonoids were reported here for the first time.

Three new prenyloxy chromanones from aerial parts of Hypericum aucheri.

Three new prenyloxy chromanone derivatives, aucherine A-C (6, 7 and 9) as well as six known prenylated phloroglucinols (1-5 and 8) were isolated from the aerial parts of Hypericum aucheri Jaub. Et Spach. The structures of the isolated compounds were established by means of spectral techniques (HRESIMS, 1D and 2D NMR). The new compounds were tested on а panel of human tumor cell line using MTT assay. All tested compounds exerted moderate cytotoxicity with IC50 values ranging from 19.6 to 57.8 µM. The influence of the new compounds on some key signaling molecules (procaspase-9 and Bcl-xL), implicated in the regulation of programmed cell death was assessed by Western blot analysis.

Hepatoprotective activity of a purified methanol extract and saponins from the roots of Chenopodium bonus-henricus L.

An ultra-high-performance liquid chromatography-high-resolution mass spectrometry based profiling of a purified MeOH extract (PME) from the roots of Chenopodium bonus-henricus L. (Amaranthaceae) tentatively identified 15 saponins of six sapogenins. The PME exerts hepatoprotective and antioxidant activities comparable to those of flavonoid complex silymarin in in vitro (1 and 10 µg/mL) and in vivo (200 mg/kg/daily for 7 days) models of hepatotoxicity, induced by CCl4. The main constituents of PME, respectively saponins bonushenricoside A (1), 3-O-ß-D-glucuronopyranosyl-bayogenin-28-O-ß-D-glucopyranosyl ester (2), 3-O-ß-D-glucuronopyranosyl-medicagenic acid-28-O-ß-D-xylopyranosyl (1→4)-α-L-rhamnopyranosyl(1→2)-α-L-arabinopyranosyl ester (3), 3-O-ß-D-glucuronopyranosyl-2ß-hydroxygypsogenin-28-O-ß-D-glucopyranosyl ester (4), 3-O-α-L-rabinopyranosyl-bayogenin-28-O-ß-D-glucopyranosyl ester (6) and bonushenricoside B (8) (3 µg/mL each), compared to silymarin (5 and 50 µg/mL), significantly reduced the cellular damage caused by CCl4 in rat hepatocytes, preserved cell viability and glutathione level, decreased lactate dehydrogenase leakage and reduced lipid damage. The experimental data suggest that the glycosides of phytolaccagenin, bayogenin, medicagenic acid, 2ß-hydroxygypsogenin, 2ß-hydroxyoleanoic acid and oleanoic acid are a promising and safe class of hepatoprotective agents.

Saponins from the roots of Chenopodium bonus-henricus L.

Two new glycosides of phytolaccagenin and 2ß-hydroxyoleanoic acid, namely bonushenricoside A (3) and bonushenricoside B (5) together with four known saponins, respectively compounds 3-O-L-α-arabinopyranosyl-bayogenin-28-O-ß-glucopyranosyl ester (1), 3-O-ß-glucuronopyranosyl-2ß-hydroxygypsogenin-28-O-ß-glucopyranosyl ester (2), 3-O-ß-glucuronopyranosyl-bayogenin-28-O-ß-glucopyranosyl ester (4) and 3-O-ß-glucuronopyranosyl-medicagenic acid-28-ß-xylopyranosyl(1→4)-α-rhamnopyranosyl(1→2)-α-arabinopyranosyl ester (6) were isolated from the roots of Chenopodium bonus-henricus L. The structures of the compounds were determined by means of spectroscopic methods (1D and 2D NMR, IR and HRMS). The MeOH extract and compounds were tested for cytotoxic activity on five leukemic cell lines (HL-60, SKW-3, Jurkat E6-1, BV-173 and K-562). In addition, the ability of metanolic extract and saponins to modulate the interleukin-2 production in PHA/PMA stimulated Jurkat E6-1 cells was investigated as well.

Cytotoxic prenylated acylphloroglucinols from Hypericum annulatum.

A phytochemical investigation of the aerial parts of Hypericum annulatum Moris led to the isolation of five new prenylated acylphloroglucinol derivatives hyperannulatins A-E (1-3, 5 and 7) in addition to the known hypercalyxone A (4) and 3-geranyl-1-(2'-methylpropanoyl)phloroglucinol (6). The structures were determined by 1D and 2D NMR and MS spectroscopic techniques. Compounds 1 and 2 have in their structure evgenyl group, a rare hydrocarbon side chain. The cytotoxicity of isolated compounds was established on a panel of tumor cell lines (HL-60, HL-60/DOX, MDA-MB, SKW-3 and K-562) and was determined using MTT based assays. The compounds 1 and 2 showed to be the most potent cytotoxic agents, whose IC50 values against the chemosensitive cell lines ranged 3.42-5.87 µM and 1.48-8.21 µM, respectively. Noteworthy, albeit all tested compounds were less potent than podophyllotoxin their IC50 values were comparable to that of the other reference drug etoposide. In some of the cell lines compounds 1 and 2 even outclassed the cytotoxicity of etoposide.

Chenopodium bonus-henricus L. - A source of hepatoprotective flavonoids.

Three new flavonoid glycosides (7-9) named patuletin-3-O-(5″'-О-Е-feruloyl)-ß-d-apiofuranosyl(1→2)[ß-d-glucopyranosyl (1→6)]-ß-d-glucopyranoside (7), spinacetin-3-O-(5″'-О-Е-feruloyl)-ß-d-apiofuranosyl (1→2)[ß-d-glucopyranosyl(1→6)]-ß-d-glucopyranoside (8) and 6-methoxykaempferol-3-O-(5″'-О-Е-feruloyl)-ß-d-apiofuranosyl(1→2)[ß-d-glucopyranosyl (1→6)]-ß-d-glucopyranoside (9) together with six known flavonoid glycosides of patuletin, spinacetin and 6-methoxykaempferol (1-6) were isolated from the aerial parts of C. bonus-henricus and identified with spectroscopic methods (1D and 2D NMR, UV, IR, HRESIMS). The MeOH extract exerts hepatoprotective and antioxidant activities comparable to those of flavonoid complex silymarin in in vitro (60µg/mL) and in vivo (100mg/kg/daily for 7days) models of hepatotoxicity, induced by CCl4. Flavonoids (1-9) (100µM), compared to silybin, significantly reduced the cellular damage caused by CCl4 in rat hepatocytes, preserved cell viability and GSH level, decreased LDH leakage and reduced lipid damage. High concentrations of compounds (1-9) showed marginal or no cytotoxicity on HepG2 cell line. The experiment data suggest that the glycosides of 6-methoxykaempferol, spinacetin and patuletin are a promising and safe class of hepatoprotective agents.

Polyprenylated Phloroglucinols from Hypericum maculatum.

A detailed phytochemical investigation of the dichloromethane extract of the aerial parts of Hypericum maculatum Crantz. led to the isolation of four new (2-5) and six known (1a/b, 6-10) polyprenylated phloroglucinol derivatives. The new compounds were identified by means of spectral methods (MS, NMR, IR, UV) as (E)-4-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-2-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl isobutyrate (2), (E)-2-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-4-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl isobutyrate (3), (E)-4-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-2-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl 2-methylbutanoate (4) and (E)-2-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-4-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl 2-methylbutanoate (5). The known compounds have been identified as hyperpolyphyllirin/hyperibine J (1a/b), erectquione A (6), (E)-1-(3-(3,7-dimethylocta-2,6-dien--yl)-2,4,6-trihydroxyphenyl)-2-methylpropan-1-one (7), (E)-1-(3-(3,7-dimethylocta-2,6-dien-1-yl)- 2,4,6-trihydroxyphenyl)-2-methylbutan-1-one (8), 1-(5,7-dihydroxy-2-methyl-2-(4-methylpent-3-en-1-yl)chroman-8-yl)-2-methylpropan-1-one (9) and 1-(6,8-dihydroxy-1,1,4a-trimethyl-2,3,4,4a,9,9a-hexahydro-1H-xanthen-5-yl)-2-methylpropan-1-one (10). The stereochemistry of 1a is described for the first time. The cytotoxicity of 1-6 on SKW-3, BV-173 and K-562 tumor cell lines was determined using MTT based assays.

30-normedicagenic acid glycosides from Chenopodium foliosum.

Two new glycosides of 30-normedicagenic acid, namely 3-O-[beta-D-glucuronopyranosyl methyl ester]-2beta,3beta-dihydroxy-30-noroleane-12,20(29)-diene-23,28-dioic acid 28-O-beta-D-glucopyranosyl ester, and 3-O-beta-D-glucopyranosyl-2beta,3beta-dihydroxy-30-noroleane- 12,20(29)-diene-23,28-dioic acid, together with the known 3-O-beta-glucopyranosyl-2beta,3beta-dihydroxy-30-noroleane-12,20(29)-diene-23 ,28-dioic acid 28-O-beta-glucopyranosyl ester, and 3-O-beta-glucuronopyranosyl-2beta,3beta-dihydroxy-30-noroleane-12,20(29)-diene-23,28-dioic acid 28-O-beta-glucopyranosyl ester were isolated from the aerial parts of Chenopodium foliosum Asch. The structures of the compounds were determined by means of spectroscopic methods (1D and 2D NMR, UV, IR) and HRMS-ESI. The compounds were tested for cytotoxicity on three leukemic cell lines (BV-173, SKW-3, HL-60). In addition, the saponins showed moderate stimulatory effects on interleukin-2 production in PHA/PMA stimulated Jurkat E6.1 cells.