Records of Natural Products Articles

A new apiofuranoside, named flavifloside A (1), together with two known hydroquinone diglycoside acyl ester, seguinoside E (2), seguinoside K (3) and a new natural product, 6'-O-(3, 4-dimethoxycinnamoyl)-arbutin (4), were isolated from the rattan of Piper flaviflorum. All these compounds were reported from this plant for the first time. Their structures were elucidated by detailed analyses of NMR, IR and MS data. In the mean time, all the compounds have been tested against A549, HCT116, MDA-MB-231 and CCRF-CEM cancer cell lines. Only flavifloside A showed moderate cytotoxicity against CCRF-CEM cancer cell line and none of them showed significant cytotoxicity against the other tested cell lines.

Phytochemical investigation of the root extract of Terminalia glaucescens afforded three known compounds, ellagic acid 1, arjungenin 2, hypatic acid 3 and and a new triterpenoid named glaucescic acid, 2α,3α,6α,23-tetrahydroxyolean-12-en-28-oic acid 4. The structure and relative configuration of this new compound was elucidated on the basis of spectroscopic data, especially 2D NMR techniques.

From the aerial parts of Astragalus armatus, a new acylated flavonol triglycoside, isorhamnetin-3-O-(5'''-p-hydroxybenzoyl)-β-apiofuranosyl-(1→2)[ α -rhamnopyranosyl-(1→6)]- β -galactopyranoside (1) which we named astrarmatuside, has been isolated and structurally elucidated together with seven known flavonol glycosides: tamarixetin-3-O- α -apiofuranosyl-(1→2)[ α -rhamnopyranosyl-(1→6)]- β -galactopyranoside (2) (m illettias p ec oside D) , isorhamnetin-3-O-β-apiofuranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-galacto-pyranoside (3), kaempferol-3-O-α-rhamnopyranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-glucopyranoside (4), kaempferol-3-O-α-rhamnopyranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-galactopyranoside (mauritianin) (5), isorhamnetin-3-O-α-rhamnopyranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-galactopyranoside (6), kaempferol-3-O-α-rhamnopyranosyl-(1→6)]-β-glucopyranoside (nikotiflorin) (7) and isorhamnetin-3-O-α-rhamnopyranosyl-(1→6)]-β-glucopyranoside (narcissin) (8) . The structures of the isolated compounds were established by means of 2D NMR experiments, HPLC-DADMS, HR-MS and UV spectral analyses. Pivotal role in the structure elucidation and in particular in the determination of sugar sequence, played HSQC-TOCSY and ROESY experiments whereas those of the known compounds (2–8) were established by spectral comparison with those published in the literature.

In search for antioxidant constituents, a new triterpenoid (1) along with three known compounds (2-4) were isolated from Sorbus lanata . LCMS, HR-ESIMS, and advanced NMR (1D & 2D) data were used for the determination of structures and spectral assignments. The isolated compounds were also tested for their antioxidant activities in the diphenylpicrylhydrazyl (DPPH) radical scavenging assay.

Two n ew saccharide fatty acid esters (1) and (2), and six other compounds were isolated from the fruit of Morinda citrifolia L. (Rubiaceae) The structures were established as (2E)-oct-2-enoate-2-O-β-D - glucopyranosyl-β-D-glucopyranoside(1), (2E)-2,6-dimethyl -6-hydroxyl-oct-2,7-dienoate-2-O-β-D-glucopyranosyl-β-D-glucopyranoside(2), saccharumoside C(3), O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranosides of 3-methyl-2-butenol(4), 3-methyl-but-2-en-1-yl β-D-glucopyranosyl (1→6)-β-D-glucopyranoside(5), benzyl - glucopyranoside(6), Hexyl-O-β-D-glucopyranoside(7), and caproic acid(8). Compound 1 and 2 showed moderate activity against ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonate)) radical in concentration of 0.1-3.2 mg/mL.

The genus Echinops belonging to the Asteraceae family comprises 130 species. The dried leaves and seeds of Echinops orientalis Trauv. were extracted separately with methanol. Apigenin-7-O-(6"-trans-p-coumaroyl- b -D-glucopyranoside 1, and Apigenin-7-O- b -D glucoside 2 were isolated from leaves and 1-methoxycarbonylindole 3 and beta-sitositerol 4 were isolated from seeds. The compounds were isolated by chromatographic techniques, based on column chromatography, preparative TLC and identified by spectroscopic methods including 1D-, 2D-NMR, UV, IR, HPLC-QTOF/MS. Isolated compounds and extracts were applied to antioxidant activity tests. While s eeds and leaves extracts have high DPPH and moderate ABTS radical scavenging activities, the isolated flavones exhibited high cation radical scavenging activities.

An investigation of MeOH extract of Embelia schimperi stem led to the isolation of a new resorcinol derivative, 5-(7’Z-pentadecenyl)resorcinol (1), along with the known compounds lupeol (2) and β-sitosterol glucoside (3). The structures of isolated compounds were elucidated using spectroscopic methods. Compound 1 exhibited moderate in vitro cytotoxic activity against human Hela cell line.

Phytochemical studies on the leaves of the Philippine endemic Annonaceae plant, Goniothalamus gitingensis enabled the isolation and identification of four secondary metabolites corresponding to three styryllactones, isoaltholactone (1), altholactone (2) and goniopypyrone (3), and the alkaloid liriodenine (4). Structure identification was facilitated through various spectroscopic experiments such as NMR ( 1H, 13C, COSY, HSQC, HMBC and NOESY), LR-EIMS, X-ray and through comparison with literature values. Our study accounts the first report of all compounds in this plant species. The extracts together with the isolated compounds (1-4) were tested for antituberculosis activity using MABA and cytotoxic activity using the CellTiter-Blue1 assay. The majority of the samples tested indicated good inhibitory activity against Mycobacterium tuberculosis H 37Rv (MIC up to 16 m g/mL). Liriodenine (4) showed the most excellent antimycobacterial activity (MIC=16 m g/mL) followed by 1 and the 5:4 mixture of 1 and 2. Their cytotoxicity against three human cancer cell lines, human umbilical vein endothelial cell line (HUVEC), human leukemia cell line (K-562) and HeLa cells were also assessed. The crude extract, alkaloid extract, petroleum ether sub-extract and EtOAc sub-extract showed moderate cytotoxicity against the cancer cell-lines. In addition, the results showed that compounds 1, 4 and the mixture of 1 and 2 exhibited highest cytotoxicity against HUVEC, K-562 and HeLa cell lines with GI 50 values up to 4 μg/mL (vs. HUVEC and/or K-562) and CC 50 values up to 25.1 μg/mL (vs. HeLa).

The present study was aimed to investigate the chemical constituents of Curcuma elata Roxb. (Zingiberaceae) rhizomes originating in Thailand. Ten sesquiterpenes, germacrone (1), curzerenone (2), isofuranodienone (3), furanodienone (4), curdione (5), neocurdione (6), zederone (7), curcumenone (8), 13- hydroxygermacrone (9) and zedoarondiol (10), and four diarylheptanoids, 3-hydroxy- 5-platyphyllone (11), (3S)-1,7-bis(4-hydroxyphenyl)-(6E)-6-hepten-3-ol (12), centrolobol (13) and (3 S )- 1- (3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-(6E)-6-hepten-3-ol (14) were isolated for the first time from the rhizomes of this plant. The structures of the isolated compounds were identified by comparison of the spectroscopic and physical data with those of the reported values and the stereochemistry at the asymmetric carbon was determined by the modified Mosher’s method and, in some cases, was confirmed by comparison of optical rotation data with literature. Compounds 12 and 13 exhibited strong cytotoxic activity against KB cell line, whereas compounds 4, 9and 12-14 showed strong cytoxicity against NCI-H187 cell line.

 n -Hexane, EtOAc, and BuOH fractions obtained from methanol extract of leaves of Cordia rothii Roem and Schult, yielded 1-octacosanol (1), β-sitosterol (2), stigmast-5-en-3-O-β- D -glucoside (3), (2S,1′S,2′S,3′R,7′Z)-N-1′-(O-β- D -glucopyranosyl)methyl-2′,3′-dihydroxy-heptadec-7′-enyl-2-hydroxytetracosane-amide (4), methyl 2-hydroxy-3-(4′-hydroxy)-phenyl propionate (5), (2R)-(4-hydroxyphenyl)lactic acid (6), syringaresinol mono-β- D -glucoside (7), 6-hydroxy-3-oxo-α-ionol 9-O-β- D -glucopyranoside (8), staphylionoside D (9), and 3-(3′,5′-dimethoxy-4′-O-β- D -glucopyranosyl-phenyl)-prop-2E-en-1-ol (10). To the best of our knowledge, all compounds except 2 are reported for the first time from this source. Norterpenoid, lignan, cerebroside, and megastigmane are also reported for the first time. Immunomodulatory activity was evaluated using oxidative burst; phytohaemagglutinin (PHA) stimulated T-cell proliferation and nitric oxide (NO) assays. EtOAc fraction exhibited significant inhibitory activity against ROS with IC 50 value of 29.4 ± 2.8 µg/mL.
n-Hexane fraction exhibited very strong suppressive effect on PHA stimulated T-cell proliferation with IC 50 value of <3.12 µg/mL. Some of the sub-fractions also affected the adaptive immune system with >85% inhibition. Compound 7 exhibited significant inhibitory activity (IC 50 = 11.3 and 18.0 on PMN and whole blood respectively) on zymosan activated ROS generation. Eight sub-fractions showed potent inhibitory activity on the NO with >60% inhibition. These results suggest that compounds from C. rothii could be potential inhibitor for the mediators involved in innate and adaptive immune responses, and potential anti-inflammatory agents.

This study is to investigate the effect of the geographic variation on the composition of needle oils of Abies bornmuelleriana endemic to Turkey. Samples were taken from the stands distanced up to 500 km from each other. By means of GC-MS/FID analyses, it was found that main compounds making up about 90 percent of the needle essential oils exhibit notable systematic variation depending on the longitude where the trees grow. Among most occurring monoterpenes, the percentages of a -pinene and camphene tend to increase in west–east direction. To compensate these increments a decrease was observed in mainly the three monoterpenes, β-pinene, β-phellandrene and limonene.

The way of drying the fresh herbal material influences the chemical content and the biological activities of their essential oils. The influence of the different drying methods of the herb Mentha longifolia (L.) Hudson on the antioxidant and antimicrobial activity of the extracted essential oils has been analyzed in this study. Drying has been carried out in three ways: in the natural way, in the laboratory oven (45°C) and in the absorptional low-temperature condensational drier (35°C). The antioxidant activity of the essential oil has been estimated by FRAP and DPPH assays, while the antimicrobial activity has been estimated by the diffusible and micro-delusional method, testing on the nine types of bacteria and two types of fungi. The essential oil obtained from the herb dried in the natural way has shown the highest antioxidant activity and the lowest from the herb dried in the laboratory oven. Bacillus subtilis , Micrococcus luteus and Enterococcus faecalis have shown the highest sensitivity on the three samples. The oil obtained from the herb dried in the absorptional low-temperature drier has shown the strongest antimicrobial effect.

Aqueous extract and two flavanone glycosides named 5,7-dihydroxy-4’-methoxy flavanone-5-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside (1) and 5,5’-dihydroxy-4’,7-dimethoxyflavanone-5,5’-di-O-β-D-glucopyranoside (2) obtained from the flowers of Butea monosperma were studied for evaluate their dyeing properties on cotton fibers. The stem bark of Myrica esculenta was used as natural mordant whereas SnCl 2 and FeCl 3 as synthetic mordants. The combination of dye with mordants showed interesting shades with excellent washing and light fastness properties.