A new flavonol glycoside from glandless cotton seeds

A new flavonol glycoside, namely quercetin 3-O-[α-d-apiofuranosyl(1–5)-β-d-apiofuranosyl(1–2)]-α-l-rhamnopyranosyl(1–6)-β-d-glucopyranoside (1), was isolated from glandless cotton seeds together with the known compounds quercetin 3-O-α-l-rhamnopyranosyl(1–2)-[α-l-rhamnopyranosyl(1–6)]-β-d-glucopyranoside (manghaslin, 2), kaempferol 3-O-β-d-apiofruranosyl(1–2)-β-d-glucopyranoside (3) and kaempferol 3-O-α-l-rhamnopyranosyl(1–6)-β-d-glucopyranoside (4). It is interesting that the tetrasaccharide fragment of 1 contained both a β-apiosyl and an unusual α-apiosyl group.     

A new meta-homoisoflavane from the fresh stems of dracaena cochinchinensis

A new meta-homoisoflavane, 10,11-dihydroxydracaenone C (1), together with 7,4′-dihydroxyflavone (2), 7,4′-dihydroxyflavane (3), 4,4′-dihydroxy-2-methoxychalcone (4), 4,4′-dihydroxy-2-methoxydihydrochalcone (5), 7,4′-dihydrohomoisoflavanone (6), 7,4′-homoisoflavane (7), lophenol (8), β-sitosterol (9), stigma-5, 22-diene-3-ol (10), 1-(4′-O-β-d-glucopyranosyl)benzyl-ethan-2-ol (11), 3,4-dihydoxy-1-allylbenezene-4-O-α-l-rhamnopyranosyl-(1 → 6)-O-β-d-glucopyranoside (12), 1-hydroxy-3,4,5-trimethoxybenzene-1-O-α-l-apiopyranosyl-(1 → 6)-O-β-d-glucopyranoside (13), and tachioside (14) have been isolated from the fresh stems of Dracaena cochinchinensis. Their structures have been established by spectroscopic analysis, especially by 2D NMR. This is the first time compounds 11, 13, 14 have been isolated from Dracaena.     

Microbial transformation of naringenin derivatives

Microbial transformations of (±)-7-O-prenylnaringenin (7-PN, 1) and (±)-7-O-allylnaringenin (7-AN, 2) have isolated four metabolites (3–6). Structures of these novel compounds were identified as 5,4′-dihydroxy-7-O-[(2E)-4-hydroxy-3-methyl-2-buten-1-yl]flavanone (3), 5,4′-dihydroxy-7-O-(2,3-dihdroxy-3-methylbutyl)flavanone (4), 5,4′-dihydroxy-7-O-(2,3-dihdroxypropyl)flavanone (5), and 5-O-β-D-glucopyranosyl-7-O-allyl-4′-hydroxyflavanone (6) based on spectroscopy. Compounds 1–6 were evaluated for their radical scavenging capacity using DPPH (2,2-diphenyl-1-picrylhydrazyl). The derivatives 3–6 exhibited more potent antioxidant activity than their corresponding substrates 1 and 2.     

C-glycosylflavones from the leaves of Iris tectorum Maxim.

A new C-glycosylflavone, 5-hydroxyl-4′,7-dimethoxyflavone-6-C-[O-(α-l-3′′′-acetylrhamnopyranosyl)-1→2-β-d-glucopyranoside] (1), along with five known C-glycosylflavones, 5-hydroxy-4′,7-dimethoxyflavone-6-C-[O-(α-l-2′′′-acetylrhamnopyranosyl)-1→2-β-d-glucopyranoside] (2), embinin (3), embigenin (4), swertisin (5) and swertiajaponin (6) were isolated from the leaves of Iris tectorum Maxim. Their structures were elucidated on the basis of extensive NMR experiments and spectral methods and their cytotoxic activities against A549 (lung cancer) human cell lines were determined.     

Four new antioxidant phenylpropanoid glycosides from Microlepia pilosissima

Four new phenylpropanoid glycosides, 9-O-[β-D-glucopyranosyl-(1→2)-α-L-rhamnopyranosyl]-3,4-dimethoxy-cinnamic acid (1), 9-O-[β-D-glucopyranosyl-(1→2)-α-L-rhamnopyranosyl]-4-methoxycinnamic acid (2), 9-O-α-L-rhamnopyranosyl-3,4-dimethoxy-cinnamic acid (3), and 9-O-[6-Oacetyl-β-D-glucopyranosyl]-4-methoxy-cinnamic acid (4), together with three known compounds 9-O-α-L-rhamnopyranosyl-4-hydroxy-cinnamic acid (5), 9-O-β-D-glucopyranosyl-4-methoxycinnamic acid (6), and 9-O-β-D-glucopyranosyl-3,4-dimethoxy-cinnamic acid (7) were isolated from the 70% EtOH extract of the dry fronds of Microlepia pilosissima. Their chemical structures were elucidated by spectroscopic analysis. Moreover, 1 and 2 exhibited comparable scavenging activities with (±)-α-tocopherol against DPPH radicals, while compounds 3–7 displayed moderate antioxidant activities.     

Phytochemical screening and evaluation of the antimicrobial and antioxidant activities of Ferula caspica M. Bieb. extracts

Chloroform, ethyl acetate and methanol extracts from the aerial parts of Ferula caspica M. Bieb. were tested for their antioxidant capacities by CUPRAC, ABTS, FRAP, Folin–Ciocalteu and aluminum chloride methods and for antimicrobial activities by the broth microdilution method. Chloroform and ethyl acetate extracts showed the highest antioxidant capacity and antimicrobial activity. Three known sesquiterpene derivatives; 1-(2′,4′-dihydroxyphenyl)-3,7,11-trimethyl-3-vinyl-6(E),10-dodecadien-1-one (1), 2,3-dihydro-7-hydroxy-2,3-dimethyl-2-[4′,8′-dimethyl-3′,7′-nonadienyl]-furo[3,2,c]coumarin (2), 2,3-dihydro-7-hydroxy-2,3-dimethyl-3-[4′,8′-dimethyl-3′,7′-nonadienyl]-furo[3,2,c]coumarin(3); phenylpropanoid; laserine/2-epilaserine (4/5) and steroid mixtures; stigmasterol and β-sitosterol (6/7) were isolated from chloroform extract; three known flavonoids; kaempferol-3-O-β-glucopyranoside (8), kaempferol-3-O-α-rhamnopyranoside (9), quercetin-3-O-β-glucopyranoside (10), and one benzoic acid derivative; 2,4-dihydroxybenzoic acid (11) were isolated from the ethyl acetate extract. The structures were elucidated by spectroscopic methods.     

Two new phenylpropane glycosides from <Emphasis Type="Italic">Allium tuberosum</Emphasis> Rottler

A phytochemical investigation of Allium tuberosum Rottler afforded two new phenylpropane glycosides, named tuberonoid A (1) and B (2), along with four known flavonoids, kaempferol 3-O-β-sophoroside (3), 3-O-β-d-(2-O-feruloyl)-glucosyl-7,4′-di-O-β-d-glucosylkaempferol (4), 3-O-β-sophorosyl-7-O-β-d-(2-O-feruloyl)glucosyl kaempferol (5), kaempferol 3,4′-di-O-β-d-glucoside (6). The identification and structural elucidation of the new compounds were carried out based on spectral data analyses (¹H and ¹³C NMR, ¹H–¹H COSY, HMQC) and HR-MS.     

Chalcone derivatives from the fern Cyclosorus parasiticus and their anti-proliferative activity

Three new chalcone derivatives, named parasiticins A–C (1–3), were isolated from the leaves of Cyclosorus parasiticus, together with four known chalcones, 5,7-dihydroxy-4-phenyl-8-(3-phenyl-trans-acryloyl)-3,4-dihydro-1-benzopyran-2-one (4), 2′-hydroxy-4′,6′-dimethoxychalcone (5), 2′,4′-dihydroxy-6′-methoxy-3′,5′-dimethylchalcone (6), 2′,4′-dihydroxy-6′-methoxy-3′-methylchalcone (7). The chemical structures of the new isolated compounds were elucidated unambiguously by spectroscopic data analysis. The cytotoxic activities of compounds 1–7 were evaluated against six human cancer cell lines in vitro. Compounds 3 and 6 exhibited substantial cytotoxicity against all six cell lines, especially toward HepG2 with the IC₅₀ values of 1.60 and 2.82 μM, respectively. Furthermore, we demonstrated that compounds 3 and 6 could induce apoptosis in the HepG2 cell line, which may contribute significantly to their cytotoxicity.     

Antihepatotoxic, nephroprotective, and antioxidant activities of phenolic compounds from Satureja macrostema leaves against carbon tetrachloride-induced hepatic damage in mice

Satureja macrostema (SM) is used with culinary and medicinal purposes. Methanol extract from SM was investigated for its phenolic content, antioxidant, hepatoprotective, and kidney protective activities. Liver and kidney damage were induced in rats with CCl₄. Hepatoprotective efficacy was measured by the activity of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin, cholesterol, high density lipoprotein and total protein, and lipid peroxidation. Kidney function was evaluated by measuring plasma urea and creatinine. Antioxidant activity was evaluated by measuring blood glutathione content, superoxide dismutase and catalase activities, and malondialdehyde equivalent; their activity was comparable to that of silymarin, a well-known hepatoprotective agent. Methanol extracts of S. macrostema showed potent antioxidant, kidney protective, and hepatoprotective activities; in-depth chromatographic investigation resulted in the identification of six new flavonoid glycosides: 5-hydroxy-3,6,4′-trimethoxyflavonol-7-C-α-l-rhamnopyranosyl-(1 → 3)-β-d-glucopyranoside (2), 4′-methoxy-5,7,3′,5′-tetra-hydroxyflavanone-3-O-β-d-rhamnopyranosyl-(1 → 2)-β-d-rhamnopyranoside (3), 5,4′-dimethoxy-7,3′,5′-trihydroxyflavanone-3-O-β-d-rhamnopyranoside (4), 5,3′,4′,5′-tetrahydroxyflavanone-7-O-β-d-rhamnopyranoside (5), 5,3′,4′,5′-tetramethoxyflavanone-7-O-β-d-rhamnopyranoside (6), and 5,4′-dimethoxy-3′-hydroxyflavone-7-β-d-rhamnopyranoside (8) along with three known compounds: 5-hydroxy-7,4′-dimethoxyflavone (1), prunin (7), and diosmin (9) that were isolated. Structural elucidation of the new compounds was established based on the spectral data. The present study revealed that S. macrostema leaves have a significant radical scavenging and hepatoprotective activity.     

Phytochemical and biological studies of Solanum schimperianum Hochst

Chemical reinvestigation of the aerial parts of Solanum schimperianum Hochst led to the isolation of ten compounds, lupeol (1), β-sitosterol (2), β-sitosterol glucoside (3), oleanolic acid (4), teferidin (5), teferin (6), ferutinin (7), 5-hydroxy-3,7,4′-trimethoxyflavone (8), retusin (9) and kaempferol-3-O-β-d-glucopyranoside (10). Compounds 5–7 were isolated for the first time from Solanaceae and compounds 1–4 and 8–9 for the first time from Solanum schimperianum. The structure elucidation of the isolated compounds was based on careful inspection of spectral data including 1D (¹H and ¹³C NMR), 2D (¹H–H COSY, HMQC and HMBC, ROESY), UV, MS and IR, in addition to, comparison with literatures. The antimicrobial activity of the extracts as well as the isolated compounds was tested. Only hexane extract showed activity against Bacillus subtilus and Staphylococcus aureus.     

A new indole glycoside from the seeds of <Emphasis Type="Italic">Raphanus sativus</Emphasis>

A new indole glycoside, β-d-glucopyranosyl 2-(methylthio)-1H-indole-3-carboxylate, named raphanuside A (1), as well as eight known compounds, β-d-fructofuranosyl-(2 → 1)-(6-O-sinapoyl)-α-d-glucopyranoside (2), (3-O-sinapoyl)-β-d-fructofuranosyl-(2 → 1)-α-d-glucopyranoside (3), (3-O-sinapoyl)-β-d-fructofuranosyl-(2 → 1)-(6-O-sinapoyl)-α-d-glucopyranoside (4), (3,4-O-disinapoyl)-β-d-fructofuranosyl-(2 → 1)-(6-O-sinapoyl)-α-d-glucopyranoside (5), isorhamnetin 3,4′-di-O-β-d-glucoside (6), isorhamnetin 3-O-β-d-glucoside-7-O-α-l-rhamnoside (7), isorhamnetin 3-O-β-d-glucoside (8) and 3'-O-methyl-(?)-epicatechin 7-O-β-d-glucoside (9) were isolated from the seeds of Raphanus sativus. Furthermore, compounds 1–3 and 6–9, were isolated from this plant for the first time. The structures of compounds 1–9 were identified using 1D and 2D NMR, including ¹H–¹H COSY, HSQC, HMBC and NOESY spectroscopic analyses. The inhibitory activity of these isolated compounds against interleukin-6 (IL-6) production in TNF-α stimulated MG-63 cells was also examined.     

New flavonol glycosides and new xanthone from Polygala japonica

Three new flavonol glycosides and a new xanthone were isolated from Polygala japonica HOUTT. with eight known compounds. Their structures were identified as 1,7-dihydroxy-3,4-dimethoxy-xanthone (1), kaempferol-7,4′-dimethyl ether (2), physcion (3), guazijinxanthone (4), rhamnetin (5), polygalin A (6), 3,5,7-trihydroxy-4′-methoxy-flavone-3-O-β-d-galactopyranoside (7), 3,5,3′-trihydoxy-7,4′-dimethoxy-flavone-3-O-β-d-galactopyranoside (8), 3,5,3′,4′-tetrahydroxy-7-methoxy-flavone-3-O-β-d-galactopyranoside (9), 3,5,3′,4′-tetrahydroxy-7-methoxy-flavone-3-O-β-d-glucopyranoside (10), polygalin B (11), polygalin C (12). Among them, compound 4 is a new xanthone, and 6, 11 and 12 are new flavonol glycosides. Compounds 1, 4, 7 and 8 were tested for cytotoxic activity with MTT assays on five human tumor cell lines, K562, A549, PC-3M, HCT-8 and SHG-44. Compound 4 showed cytotoxic activity against all the five cell lines.     

C<Subscript>21</Subscript> steroid derivatives from the Dai herbal medicine Dai-Bai-Jie,the dried roots of <Emphasis Type="Italic">Marsdenia tenacissima</Emphasis>, and their screening for anti-HIV activity

Twenty-three new C₂₁ steroidal glycosides, marstenacissides C1–C10 (1–10), D1–D7 (11–17) and E1–E6 (18–23), and four new C₂₁ steroids, 11α,12β-O-ditigloyl-tenacigenin C (24), 11α-O-benzoyl-12β-O-tigloyl-tenacigenin C (25), 11α-O-tigloyl-12β-O-benzoyl-tenacigenin C (26) and 11α-O-tigloyl-12β-O-benzoyl-marsdenin (27), were isolated from the Dai herbal medicine Dai-Bai-Jie, derived from the roots of Marsdenia tenacissima. The chemical structures of all compounds were established by spectroscopic techniques, including high-resolution mass spectrometry and NMR spectroscopy, as well as by comparison with reported spectral data. The anti-HIV activities of these compounds were screened, and the compounds obtained displayed inhibitory effects against HIV-1 with inhibition rates of 36.4–81.3% at 30 μM.     

Phenylethanoid and flavone glycosides from Ruellia tuberosa L.

A new phenylethanoid glycoside, isocassifolioside (8), and two new flavone glycosides, hispidulin 7-O-α-l-rhamnopyranosyl-(1′″ → 2″)-O-β-d-glucuronopyranoside (11) and pectolinaringenin 7-O-α-l-rhamnopyranosyl-(1′″ → 2″)-O-β-d-glucuronopyranoside (12) were isolated from the aerial portions of Ruellia tuberosa L., together with verbascoside (1), isoverbascoside (2), nuomioside (3), isonuomioside (4), forsythoside B (5), paucifloside (6), cassifolioside (7), hispidulin 7-O-β-d-glucuronopyranoside (9) and comanthoside B (10). The structure elucidations were based on analyses of chemical and spectroscopic data including 1D- and 2D-NMR. The isolated compounds 1–12 exhibited radical scavenging activity using ORAC assay.     

Phenolic compounds isolated from Pilea microphylla prevent radiation-induced cellular DNA damage

Six phenolic compounds namely, quercetin-3-O-rutinoside (1), 3-O-caffeoylquinic acid (2), luteolin-7-O-glucoside (3), apigenin-7-O-rutinoside (4), apigenin-7-O-β-d-glucopyranoside (5) and quercetin (6) were isolated from the whole plant of Pilea microphylla using conventional open-silica gel column chromatography and preparative HPLC. Further, these compounds were characterized by 1D, 2D NMR techniques and high-resolution LC–MS. Compounds 1–3 and 6 exhibited significant antioxidant potential in scavenging free radicals such as DPPH, ABTS and SOD with IC₅₀ of 3.3–20.4 μmol/L. The same compounds also prevented lipid peroxidation with IC₅₀ of 10.4–32.2 μmol/L. The compounds also significantly prevented the Fenton reagent-induced calf thymus DNA damage. Pre-treatment with compounds 1–3 and 6 in V79 cells attenuated radiation-induced formation of reactive oxygen species, lipid peroxidation, cytotoxicity and DNA damage, correlating the antioxidant activity of polyphenols with their radioprotective effects. Compounds 1, 3 and 6 significantly inhibited lipid peroxidation, presumably due to 3′,4′-catechol ortho-dihydroxy moiety in the B-ring, which has a strong affinity for phospholipid membranes. Oxidation of flavonoids, with catechol structure on B-ring, yields a fairly stable ortho-semiquinone radical by facilitating electron delocalization, which is involved in antioxidant mechanism. Hence, the flavonoid structure, number and location of hydroxyl groups together determine the antioxidant and radioprotection mechanism.     

Transport and killing mechanism of a novel camptothecin-deoxycholic acid derivate on hepatocellular carcinoma cells

Abstract

Camptothecin-20(s)-O-glycine ester-[N-(3′α, 12′α-dihydroxy-24′-carbonyl-5′β-cholan)] (A2), 10-(3′α,12′α-dihydroxy-5′β-cholan-24′-carboxyl)-(20?s)-camptothecin (C2), and 10-O-(3-O-(3′α, 12′α-dihydroxy-24′-carbonyl-5′β-cholan)-propyl)-(20S)-camptothecin (D2) are novel camptothecin-deoxycholic acid analogues. MTT assays were performed to assess the anticancer activity of these compounds against hepatocellular carcinoma SMMC-7721, breast carcinoma MCF-7, and colorectal carcinoma HCT-116 cells. A2 had a high killing ability on SMMC-7721 cells selectively, but C2 and D2 did not exhibit selectivity with regard to SMMC-7721 killing. Uptake assays were performed in an effort to elucidate the transport mechanisms of A2 into SMMC-7721 cells. A2 increased the mRNA expression of OATP1B3 (an organic anion-transporting polypeptide) and uptake of A2 was inhibited by rifampin (inhibitor of OATP1B3), which indicated that the transporter-mediated transport of A2 was mediated by OATP1B3. In addition, according to the western blot and apoptosis assays, we found that A2 killed SMMC-7721 cells by inducing cell apoptosis mainly via an AIF (apoptosis-inducing factor) pathway and a caspase-dependent mitochondria apoptosis pathway.     

Alkyl phenols,alkenyl cyclohexenones and other phytochemical constituents from <Emphasis Type="Italic">Lannea rivae</Emphasis> (chiov) Sacleux (Anacardiaceae) and their bioactivity

Six novel compounds, 3-nonadec-14′-(Z)-enyl phenol (1a); 4,5-dihydroxy-4,2′-epoxy-5-[16′-Z-18′-E-heneicosenyldiene]-cyclohex-2-enone (2), 2,4,5-trihydroxy-2-[16′-Z-heneicosenyl]-cyclohexanone (3); 4S,6R-dihydroxy-6-[12′-Z-heptadecenyl]-cyclohex-2-enone (4a); 4S,6R-dihydroxy-6-[14′-Z-nonadecenyl]-cyclohex-2-enone (4b); and 1,2,4-trihydroxy-4-[16′-Z-heneicosenyl]-cyclohexane (5) were identified from the roots and stems of Lannea rivae in addition to the known cardanols, 3-heptadec-12′-Z-enyl phenol (1b), 3-pentadec-10′-Z-enyl phenol (1c) and 3-pentadecyl phenol (1d), sitosterol (6), sitosterol glucoside (7), taraxerone (8), taraxerol (9), E-lutein (10), myricetin (11), myricetin-3-O-α-rhamnopyranoside (12), myricetin-3-O-β-galactopyranoside (13) and (-)-epicatechin-3-O-gallate (14). The ketones 4a and 4b were isolated as a mixture and were qualitatively separated and identified by GCMS. Myricetin (11) and epicatechin gallate (14) displayed over 90 % DPPH radical-scavenging activity at 50 μg mL^?1, while its glycosides (12 and 13) showed percentages of over 70 % in the same assay. The same compounds 11 and 14 showed antibacterial activity similar to erythromycin and vancomycin against Gram-positive bacteria and were also active against Gram-negative bacteria, but not as much as the cefuroxime, ciprofloxacin and nalidixic acid standards. Compounds 1a–d, 4a–b and 5 were all relatively non-toxic, while 2 (the epoxy cyclohex-2-enone) and 3 (the trihydroxy cyclohexanone) showed more toxicity than the others. These two toxic compounds, 2 and 3 also showed antiplasmodial activity with IC₅₀ values between 0.48 and 2.05 μg mL^?1. The mixture of dihydroxy cyclohex-2-enones 4a and 4b, which was far less toxic than 2 and 3, also showed promising antiplasmodial activity and may be a possible lead for further investigation as an antiplasmodial drug.     

Flavonoids from silkworm droppings and their promotional activities on heme oxygenase-1

A new flavane glucoside, 7,2′-dihydroxy-8-hydroxyethyl-4′-methoxyflavane-2′-O-β-d-glucopyranoside (3), along with three known flavonoids, 7,2′-dihydroxy-8-prenyl-4′-methoxyflavane (1), euchrenone a₇ (2), and 7,2′-dihydroxy-8-prenyl-4′-methoxy-2′-O-β-d-glucopyranosylflavane (4), was isolated from silkworm droppings. The structures of the compounds were elucidated on the basis of 1D and 2D NMR spectroscopic analyses and optical rotational characteristics. The compounds isolated from silkworm droppings were evaluated for their effects on heme oxygenase-1 (HO-1) activity. Compounds 1 and 3 increased the expression of HO-1 in HepG2 cells. HO-1 is an antioxidant enzyme that catabolizes heme to carbon monoxide, free iron, and biliverdin, all of which are involved in the suppression of inflammatory mediators.     

Three new isoflavone glycosides from Tongmai granules

Three new isoflavone glycosides, 3′-methoxydaidzein-7,4′-di-O-β-d-glucopyranoside (1), biochanin A-8-C-β-d-apiofuranosyl-(1 → 6)-O-β-d-glucopyranoside (2), daidzein-7-O-β-d-glucopyranosyl-(1 → 4)-O-β-d-glucopyranoside (3), and a new natural isoflavone glycoside, daidzein-7-O-α-d-glucopyranosyl-(1 → 4)-O-β-d-glucopyranoside (4) were isolated along with 18 known isoflavones from the EtOAc and n-BuOH fractions of the aqueous extraction of Tongmai granules. All the isoflavones were obtained and determined for the first time from Tongmai granules. The structures of these compounds were elucidated by spectral methods. It was confirmed that the compounds 1–4 were originally from Puerariae Lobatae Radix based on HPLC-DAD analysis of the crude drug extract. The isoflavones isolated were tested for their antioxidative activities by measuring the capacities of scavenging the 2,2′-diphenyl-1-picrylhydrazyl radical.