Four new sesquiterpenoids from the soft coral Nephthea chabrollii

Chemical examination of the soft coral Nephthea chabrolii collected from the Mandapam coast in the Gulf of Mannar, afforded nine sesquiterpenoids of which four (1–4) are new. The structures of the new compounds (1–4) have been established by the interpretation of spectral data (UV, IR, 1H NMR, 13C NMR, 1H-1H COSY, NOESY and mass) and chemical methods.

A Novel Ceramide from the Indian Marine Sponge Fasciospongia Cavernosa

A new ceramide 1, has been isolated along with a known compound 3,6-diacetoxy-cholest-7-en-3β,5α,6β-triol (2) from a marine sponge Fasciospongia cavernosa collected off the Mandapam coast in the Gulf of Manner, India. The structures of 1 and 2 were determined by spectroscopic analysis.

Acid catalysed rearrangement of Δ9,15-africanene: A cytotoxic sesquiterpene

Acid catalysed rearrangements of Δ9,15-africanene, a cytotoxic sesquiterpene isolated from the soft corals of the genus Sinularia, have been studied for the first time and a marked difference was observed between the compositions of the conversion products with and without refluxing conditions.

Unusual Terpenoid Constituents of the Soft Coral Sinularia dissecta

Chemical examination of the soft coral Sinularia dissecta furnished six known terpenoids, along with a new sequiter-penoid seco-africanane (1) and a new norcembrane diterpene (2)

Bioactive Metabolites Produced by Pseudonocardia endophytica VUK-10 from Mangrove Sediments: Isolation, Chemical Structure Determination and Bioactivity

Chemical investigation of the actinobacterial isolate Pseudonocardia endophytica VUK-10 has led to the segregation of two known bioactive compounds, namely 4-(2-acetamidoethyl) phenyl acetate and 4-((1, 4-dioxooctahydropyrrolo [1, 2-a] pyrazin-3-yl) methyl) phenyl acetate. The strain was isolated from a sediment sample of the Nizampatnam mangrove ecosystem, south coastal Andhra Pradesh, India. The chemical structure of the active compounds was established on the basis of spectroscopic analysis, including (1)H NMR and (13)C NMR spectroscopies, FTIR, and EIMS. The antimicrobial and cytotoxic activities of the bioactive compounds produced by the strain were tested against opportunistic and pathogenic bacteria and fungi and on MDA-MB-231, OAW, HeLa, and MCF-7 cell lines. The compounds exhibited antimicrobial activities against gram-positive and gram-negative bacteria and fungi and also showed potent cytotoxic activity against MDA-MB-231, OAW, HeLa, and MCF-7 cell lines. This is the first example for this class of bioactive compounds isolated from Pseudonocardia of mangrove origin.

Toward synthesis of carbasugars (+)-gabosine C, (+)-COTC, (+)-pericosine B, and (+)-pericosine C

Asymmetric total synthesis of (+)-gabosine C, (+)-pericosine B, and (+)-pericosine C has been reported from readily available d-(-)-isoascorbic acid and d-ribose involving Grubbs ring closing metathesis, Morita-Baylis-Hillman (MBH) reaction, and Luche reduction.

Anti inflammatory potential of Decalepis hamiltonii (Wight and Arn) as evidenced by down regulation of pro inflammatory cytokines-TNF-alpha and IL-2

ETHNOPHARMACOLOGICAL RELEVANCE

Ancient tribes in the Western Ghats of India use the roots of Decalepis hamiltonii Wight and Arn (Asclepiadaceae) for several medicinal purposes particularly inflammation.

AIM

To investigate whether the pure compounds obtained from the Decalepis hamiltonii have anti inflammatory activity.

MATERIALS AND METHODS

The bioactive lead molecules from the roots of Decalepis hamiltonii were extracted into dichloromethane/methanol and purified by silica gel column chromatography. Structural elucidation of the purified compounds was performed with (1)H and (13)C NMR and mass spectrometry. The in vitro anti inflammatory activity of the pure compounds was studied in mitogen induced peripheral blood mononuclear cells (PBMCs) employing [(3)H] thymidine uptake assay and their effect on cytokine expression by reverse transcriptase polymerase chain reaction (RT-PCR). The inhibition of nuclear factor kappaB (NF-kappaB) activity in the presence of pure compounds was determined in J774 A.1 cells. The cytotoxicity of the compounds was tested using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay kit.

RESULTS AND DISCUSSION

Lupeol acetate (Compound 1) and (2S)-5,7,4'-trihydroxy flavanone 4'-O-beta-d-glucoside (Compound 2) isolated from Decalepis hamiltonii roots inhibited the proliferation of mitogen induced PBMCs with an IC(50) value of 8 and 0.5mug/ml respectively. MTT assay revealed the compounds to be non-cytotoxic. Though, both the compounds down regulated the synthesis of mRNA of the pro inflammatory cytokines, interleukin-2 (IL-2) and tumour necrosis factor-alpha (TNF-alpha), the anti inflammatory cytokine interleukin-10 (IL-10), was found to be up regulated. NF-kappaB activation in J774 A.1 cells were also inhibited by both the compounds.

CONCLUSION

Lupeol acetate and (2S)-5,7,4'-trihydroxy flavanone 4'-O-beta-d-glucoside isolated from Decalepis hamiltonii roots showed anti inflammatory activities by down regulating TNF-alpha and IL-2 specific mRNA, besides up regulating the synthesis of mRNA of IL-10.

Isolation, Characterization and Biological evaluation of secondary metabolite from Aspergillus funiculosus

Screening of Aspergillus funiculosus for bioactive secondary metabolites produced kojic acid, which is know to have wide range of biological properties. It is very active against Gram-negative bacteria, such as Pseudomonas aeruginosa and Escherichia coli, but moderately active against yeasts and Gram-positive bacteria except Staphylococcus epidermidis. Filamentous Fungi are more sensitive to kojic acid. When it exposed to larvicidal activity on Aedes aegypti third instar larvae are more sensitive than early fourth instar larvae.

Studies on removal of chromium (VI) from water using chitosan coated Cyperus pangorei

Environmental contamination by toxic heavy metals is a significant universal problem. The main objective of the study is to use a biodegradable materials like Cyperus pangorei and Chitosan as a composite biosorbent for the removal of Cr(VI) from water. The newly prepared biosorbent is characterized and the capacity of Cr(VI) removal of the biosorbent is carried out systematically by batch mode operations. The adsorption capacity of the biosorbent is examined by changing the parameters like biosorbent dose, varying the initial contact time, varying initial concentration of metal ion and pH of the metal ion solution to know the actual mechanism taking place during the initial sorption process. The experimental data obtained were fitted with the Freundlich, Langmuir and Redlich-Peterson isotherm models and the pseudo first order and the pseudo second order kinetic models. Equilibrium data were fitted very well to the Langmuir Isotherm model and pseudo second order kinetic model. Desorption of the metal ion is also carried out using different concentration of NaOH.

Furano-sesquiterpene from soft coral, Sinularia kavarittiensis: induces apoptosis via the mitochondrial-mediated caspase-dependent pathway in THP-1, leukemia cell line

Bioassay directed fractionation and purification led to the successful isolation of a furano sesquiterpene, Methyl 5-[(1E,5E)-2,6-Dimethyl octa-1,5,7-trienyl] furan-3-carboxylate (MDTFC), a bioactive component from a soft coral, Sinularia kavarittiensis. Its structure was determined by analyzing (1)H, (13)C NMR and FAB-MS. The results show that MDTFC could efficiently and selectively inhibit the proliferation of several human cancer cell lines. Among all the cell lines, THP-1 was found to be most sensitive (IC(50) 29.59 microM), whereas the peripheral blood mononuclear cells were least effected (IC(50) 464.16 microM). The molecular mechanism of MDTFC mediated apoptosis was investigated for the first time. Induction of apoptosis in THP-1 cells was characterized by cell membrane blebbing, chromatin condensation, DNA fragmentation, and decrease in level of pro-caspases 3, 9 and increase in Bax/Bcl-2 ratio. Our results were further strengthened through cleavage of poly (ADP-ribose) polymerase, reduction of mitochondrial membrane potential (Psim) and cytosolic release of cytochrome c, which are key events during apoptosis. Moreover, phosphatidyl serine exposure and appearance of sub-G1 peak also demonstrated cell death, when analyzed by flow cytometry. DNA fragmentation was prevented moderately when pretreated with caspase-9 inhibitor (Z-LEHD-FMK) and largely with caspase-3 inhibitor (Z-DEVD-FMK). In summary, MDTFC mediated apoptosis involves mitochondria-dependent pathway and the present compound of marine origin might have a therapeutic value against human cancer cell lines and especially on leukemia cells.

Production of bioactive metabolites by Nocardia levis MK-VL_113

AIMS

To isolate and identify the bioactive compounds produced by Nocardia levis MK-VL_113.

METHODS AND RESULTS

Cultural characteristics of Noc. levis isolated from laterite soils of Guntur region were recorded on International Streptomyces Project media. Morphological studies of the strain through scanning electron microscopy revealed the clear pattern of its hyphal fragmentation into rod-shaped bacilli. Chemical examination of the secondary metabolites of the strain grown on sucrose-tryptone broth led to the isolation of three fractions active against Bacillus cereus. Further analysis of second fraction resulted in the isolation of two active subfractions. Two different phthalate esters, namely, bis-(2-ethylhexyl) phthalate and bis-(5-ethylheptyl) phthalate, were purified from the first active subfraction, and the structural elucidation of these compounds was confirmed on the basis of FT-IR, mass and NMR spectroscopy. The partially purified second subfraction subjected to Gas Chromatography-Mass spectroscopy contained nine components: decanedioic acid; 2,6-piperdione monooxime; 1-eicosanol; beta-1-arabinopyranoside, methyl; cyclopentaneundecanoic acid; hexadecanoic acid; silane, trichloro eicosyl; 1-hexacosanol; and 1,2-dodecanediol. The antimicrobial activity of the bioactive compounds produced by Noc. levis was expressed in terms of minimum inhibitory concentration.

CONCLUSIONS

The present study clearly revealed that the metabolites of Noc. levis act as bioactive compounds against gram-positive and gram-negative bacteria, yeast and filamentous fungi. It also supports the idea that there are a number of rare actinomycetes remained to be explored for new bioactive compounds.

SIGNIFICANCE AND IMPACT OF THE STUDY

Metabolites of Noc. levis exhibited antibacterial and antifungal activities. This is the first report of bis-(5-ethylheptyl) phthalate as well as the nine partially purified compounds from actinomycetes. In addition, this is also the first report of bis-(2-ethylhexyl) phthalate from the genus Nocardia.

Mild and Highly Efficient Stereoselective Synthesis of 2,3‐Unsaturated Glycopyranosides using La(NO3)3 · 6H2O as a Catalyst: Ferrier Rearrangement

A mild and highly efficient stereoselective reaction of 3,4,6-tri-O-acetyl-D-glucal with a variety of nucleophiles, viz. alcohols, phenols, thiols, thiophenols, and allyl trimethyl silane (TMS), in the presence of 5 mol% of lanthanum(III) nitrate hexahydrate under solvent-free conditions yielded the corresponding 2,3-unsaturated glycopyranosides (pseudoglycals) in excellent yields.

A mild and efficient synthesis of chloroesters by the cleavage of cyclic and acyclic ethers using Bi(NO3)3·5H2O as a catalyst under solvent-free conditions

A facile, efficient synthesis of chloroesters is described. The reaction of cyclic and acyclic ethers with acid chlorides in the presence of catalytic amounts of Bi(NO3)3·5H2O under solvent-free conditions yielded the corresponding chloroesters. Also, the catalyst can be recovered conveniently and reused efficiently for at least six times.Key words: Bismuth(III) nitrate pentahydrate, cyclic and acyclic ethers, chloroesters.