Chemical constituents of Pseudopterogorgia species of the Indian ocean

A new ceramide, (2S,3R,4E)-1,3-dihydroxy-2-[(hexadecanoyl)amino]-nonadeca-4-ene (1), cholest-5-en-3β,7β,19-triol (2), identified as its, peracetyl derivative (3), and batyl alcohol (4) were isolated from Pseudopterogorgia species. 1 exhibited antibacterial activity against Gram-positive and Gram-negative bacteria.     

Screening of natural compounds for ligands to PfTrxR by ultrafiltration and LC-MS based binding assay

In our study, we have screened 133 structurally diverse natural compounds from the MEGx^® collection of AnalytiCon Discovery and three synthetic hispolone analogs for binding affinity to Plasmodium falciparum thioredoxin reductase (PfTrxR) using an ultrafiltration (UF) and liquid chromatography (LC/MS) based ligand-binding assay newly developed in our laboratory. PfTrxR catalyzes the reduction of thioredoxin (PfTrx) protein. In reduced form, PfTrx is essentially involved in the antioxidative defense and redox regulation of P. falciparum. Nine compounds (yohimbine (1), catharanthine (2), vobasine (3), gnetifolin E (4), quinidine N-oxide (5), 11-hydroxycoronaridine (6), hispolone (7), hispolone methyl ether (8), and hernagine (9)) displayed binding affinity for PfTrxR at 1 μM. The ranking order of compound's binding affinities for PfTrxR is 7 > 6 > 2 > 4 > 5 > 8 > 1 > 9 > 3. On the other hand, compounds 6, 7, 2 and 8 demonstrated specific binding to the active site of PfTrxR, when ligands were tested in an equimolar mixture of 1 μM.     

Quantitative analysis of anthocyanins in Euterpe oleracea (açaí) dietary supplement raw materials and capsules by Q-TOF liquid chromatography/mass spectrometry

Context: Euterpe oleracea Mart. (Arecaceae) fruits and their dietary supplements are gaining much popularity internationally. Anthocyanins and their aglycons are responsible for the dense color of a?aí fruit and are associated with a wide spectrum of health promoting effects. Objective: Quantitative analysis of anthocyanins in a?aí dietary supplement raw materials; processed a?aí powder (ADSR-1), organic a?aí powder (ADSR-2), and nonorganic a?aí powder (ADSR-3) by quadrupole-time-of-flight liquid chromatography/mass spectrometry (Q-TOF LC/MS) have been reported in this study. Materials and methods: The chromatographic separation for anthocyanins was achieved using a C-18 column with a gradient of 0.1% formic acid in water and 0.1% formic acid in methanol and acetonitrile (50:50, v/v). MS and MS/MS experiments were carried out on an electrospray ionization-Q-TOF LC/MS. Results: Except for ASDR-2, all the a?aí samples were found to have cyanidin 3-glucoside (1), cyanidin 3-sambubioside (2), cyanidin 3-rutinoside (3), and peonidin 3-rutinoside (4). ASDR-2 contained anthocyanins 1 and 3. Among the a?aí samples quantified, ADSR-3 showed higher concentration of anthocyanins compared to other raw materials and capsules tested in this study. Discussion and conclusion: The anthocyanins 1-4 present in ADSR-3 were 27.13?±?0.37, 1.76?±?0.04, 31.07?±?0.49, and 3.46?±?0.08?mg/100?g dry wt, respectively. The LOQ values for anthocyanins 1-4 were in the range of 2.44-9.76?ng/mL. Accuracy of the method was assessed by performing a recovery experiments. The intraday and interday variations (RSDs) were <10%. This is the first report on quantitation of anthocyanins in a?aí dietary supplement raw materials and capsules.     

In vitro propagation by asymbiotic seed germination and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity studies of tissue culture raised plants of three medicinally important species of dendrobium

A simple and efficient plant propagation system has been developed by asymbiotic germination of seeds in three medicinally important Dendrobium species, namely, Dendrobium tosaense, Dendrobium moniliforme, and Dendrobium linawianum. Plants obtained from natural habitats were grown in the greenhouse. The flowers were hand pollinated. Seeds of the capsules derived after 12 weeks of hand-pollination germinated asymbiotically (50-74%) on half strength Murashige and Skoog's (MS) basal medium with 3% sucrose and solidified with 0.9% Difco agar. Active growth in the germinated seedlings was achieved by re-culturing on full strength MS basal medium supplemented with 8% banana homogenate, 8% potato homogenate, 8% coconut water, 1.5% sucrose and 0.9% Difco agar. Healthy plantlets, transferred to plastic trays containing moss or moss and tree fern, successfully acclimatized (84-100%) in the greenhouse. A marked varied response was observed in the free radical scavenging activity of methanolic extracts of in vitro propagated plants, on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical using a UV spectrophotometer assay. Methanolic extracts were prepared by dissolving the powdered plant material, obtained from six months old in vitro propagated plants, each about 5 g, in boiling methanol. The percentage of scavenging effect of D. tosaense extract was 95.9% at 0.4 mg/ml concentration, whereas D. monoliforme, and D. linawianum extracts scavenged 83.4% and 92.3%, respectively, at a concentration of 0.4 mg/ml. All the extracts scavenged DPPH radical significantly in a concentration dependent manner.     

Status of lipid peroxidation and antioxidant enzymes in malignant (bronchogenic carcinoma) and non-malignant pleural effusions

Eighty patients from Chennai Medical College (patients with bronchogenic carcinoma) and from Tambaram Tuberculosis Hospital (patients with non-malignant pulmonary diseases mainly tuberculosis) in whom the etiologic diagnosis of their pleural effusions are confirmed were included in the study. Lipid peroxidation (LPO) and activities of antioxidant enzymes were estimated in pleural exudates of the two groups. Lipid peroxidation was found to be increased and the status of antioxidants were found to be decreased in lung malignant pleural exudates when compared to those of non-malignant effusions. The possible reasons for the observed results discussed.     

Identification of oleamide in Guatteria recurvisepala by LC/MS-based Plasmodium falciparum thioredoxin reductase ligand binding method

Our current research on applications of mass spectrometry to natural product drug discovery against malaria aims to screen plant extracts for new ligands to Plasmodium falciparum thioredoxin reductase (PfTrxR) followed by their identification and structure elucidation. PfTrxR is involved in the antioxidant defense and redox regulation of the parasite and is validated as a promising target for therapeutic intervention against malaria. In the present study, detannified methanol extracts from Guatteria recurvisepala, Licania kallunkiae, and Topobea watsonii were screened for ligands to PfTrxR using ultrafiltration and liquid chromatography/mass spectrometry-based binding experiments. The PfTrxR ligand identified in the extract of Guatteria recurvisepala displayed a relative binding affinity of 3.5-fold when incubated with 1 μM PfTrxR. The ligand corresponding to the protonated molecule m/z 282.2792 [M+ H]+ was eluted at a retention time of 17.95 min in a 20-min gradient of 95% B consisting of (A) 0.1%formic acid in 95% H?O-5% ACN, and (B) 0.1% formic acid in 95% ACN-5% H?O in an LC-QTOF-MS.Tandem MS of the protonated molecule m/z 282.2792 [M + H]+, C??H??NO (DBE: 2; error: 1.13 ppm) resulted in two daughter ions m/z 265.2516[M + H-NH?]+ (DBE: 3; error: 0.35 ppm) and m/z 247.2405 [M + H-NH?-H?O] +, (DBE: 4; error:2.26 ppm). The PfTrxR ligand was identified as oleamide and confirmed by comparison of the retention time, molecular formula, accurate mass,and double bond equivalence with the standard oleamide. This is the first report on the identification of oleamide as a PfTrxR ligand from Guatteria recurvisepala R. E. Fr. and the corresponding in vitro activity against P. falciparum strain K1 (IC?? 4.29 μg/mL).     

Withanolide sulfoxide from Aswagandha roots inhibits nuclear transcription factor‐kappa‐B,cyclooxygenase and tumor cell proliferation

Investigation of the methanol extract of Aswagandha (Withania somnifera) roots for bioactive constituents yielded a novel withanolide sulfoxide compound (1) along with a known withanolide dimer ashwagandhanolide (2) with an S‐linkage. The structure of compound 1 was established by extensive NMR and MS experiments. Compound 1 was highly selective in inhibiting cyclooxygenase‐2 (COX‐2) enzyme by 60% at 100 µm with no activity against COX‐1 enzyme. The IC₅₀ values of compound 1 against human gastric (AGS), breast (MCF‐7), central nervous system (SF‐268) and colon (HCT‐116) cancer cell lines were in the range 0.74–3.63 µm. Both S‐containing dimeric withanolides, 1 and 2, completely suppressed TNF‐induced NF‐κB activation when tested at 100 µm. The isolation of a withanolide sulfoxide from W. somnifera roots and its ability to inhibit COX‐2 enzyme and to suppress human tumor cell proliferation are reported here for the first time. In addition, this is the first report on the abrogation of TNF‐induced NF‐κB activation for compounds 1 and 2. Copyright © 2009 John Wiley & Sons, Ltd.     

Ashwagandhanolide, a bioactive dimeric thiowithanolide isolated from the roots of Withania somnifera

A new dimeric withanolide, ashwagandhanolide (1), was isolated from the roots of an Ayurvedic medicinal herb, Withania somnifera. A detailed spectroscopic evaluation revealed its identity as a dimer with an unusual thioether linkage. Compound 1 displayed growth inhibition against human gastric (AGS), breast (MCF-7), central nervous system (SF-268), colon (HCT-116), and lung (NCI H460) cancer cell lines, with IC50 values in the range 0.43-1.48 microg/mL. In addition, it inhibited lipid peroxidation and the activity of the enzyme cyclooxygenase-2 in vitro.     

Chemical Constituents of Pseudopterogorgia Species of the Indian Ocean

Abstract

A new ceramide, (2S,3R,4E)-1,3-dihydroxy-2-[(hexadecanoyl)amino]-nonadeca-4-ene (1), cholest-5-en-3β,7β,19-triol (2), identified as its, peracetyl derivative (3), and batyl alcohol (4) were isolated from Pseudopterogorgia species. 1 exhibited antibacterial activity against Gram-positive and Gram-negative bacteria.