Correction to: Extraction and bioactive profile of the compounds produced by sp. VLD-10.

[This corrects the article DOI: 10.1007/s13205-016-0576-6.].

Bioactive-guided fractionation of diols from Streptomyces sp. MSL.

An actinomycete strain with a great potential to produce bioactive compounds isolated from a laterite soil was identified as Streptomyces sp. MSL based on 16S rDNA sequence analysis. Secondary metabolites produced by the strain in optimized nutrient broth were extracted and analyzed by chromatographic and spectroscopic techniques.

Bioactive natural products from VUK-10.

Two proline containing cyclic dipeptides (CDPs), cyclo (L-Pro-L-Tyr) () and cyclo (L-Pro-L-Phe) () were isolated from the fermentation broth of VUK-10 originating from the Nizampatnam mangrove ecosystem on the south coast of Andhra Pradesh, India. The structures of the compounds were established by 1H NMR and 13C NMR spectroscopy, FTIR and EIMS. The antimicrobial and cytotoxic activities of the compounds were tested against a variety of medicinally and agriculturally important bacteria and fungi as well as on the MDA-MB-231, OAW-42, HeLa and MCF-7 human cell lines.

Extraction and bioactive profile of the compounds produced by Rhodococcus sp. VLD-10.

A potent actinobacterial strain isolated from the marine samples of Bheemunipatnam beach, Visakhapatnam, India, was identified as Rhodococcus sp. VLD-10 using the conventional and genomic (16S rRNA) approaches. Bioactive compounds responsible for the antimicrobial activity of the strain were elucidated by cultivating the strain VLD-10 in a modified yeast extract-malt extract-lactose broth followed by subsequent chromatographic and spectroscopic analyses.

Isolation and biological evaluation of N-(4-aminocyclooctyl)-3, 5-dinitrobenzamide, a new semisynthetic derivative from the Mangrove-associated actinomycete Pseudonocardia endophytica VUK-10.

The present study was aimed to isolate novel bioactive compounds from actinomycetes species isolated from mangrove habitats. With this connection, Pseudonocardia endophytica (VUK-10) was isolated using dilution plate technique and was examined for its secondary metabolite profiling. After successive purification and spectroscopic characterization viz.

Bioactive metabolites produced by Streptomyces Cheonanensis VUK-A from Coringa mangrove sediments: isolation, structure elucidation and bioactivity.

The strain VUK-A was isolated from a sediment sample of the Coringa mangrove ecosystem was identified as Streptomyces cheonanensis based on morphological, physiological, biochemical and molecular properties. Chemical investigation of the secondary metabolites of the strain Streptomyces cheonanensis VUK-A has led to the segregation of two bioactive compounds, namely 2-Methyl butyl propyl phthalate (1) and Diethyl phthalate (2) using column chromatography. The chemical structure of the active compounds was established on the basis of spectroscopic analysis, including H NMR and C NMR spectroscopies, FTIR and EIMS.

Direct Synthesis of Thioethers from Carboxylates and Thiols Catalyzed by FeCl3.

A new and efficient method has been developed for the synthesis of thioethers from carboxylates and thiols. The reaction proceeds via a Fe(III)-catalyzed direct displacement of carboxylates from benzylic or allylic esters by heterocyclic thiols. Short reaction times, good to excellent yields of products, and few side reactions are the significant features of the new protocol.

Isolation, structural assignment and synthesis of (SE)-2-methyloctyl 3-(4-methoxyphenyl) propenoate from the marine soft coral Sarcophyton ehrenbergi.

A new metabolite 1 has been isolated from the marine soft coral Sarcophyton ehrenbergi along with two known diterpenoids 2 and 3 and cholesterol 4. The structure of 1 was determined by means of detailed spectroscopic analysis and unambiguously confirmed to have the S configuration by the synthesis of both enantiomers using 4-benzyl-2-oxazolidinone auxiliaries. (S)- and (R)-1, 3 and some of the synthetic intermediates were evaluated for cytotoxic activity against human lung cancer (A549), prostate cancer (DU145), cervical cancer (HeLa) and breast cancer (MCF-7) cell lines in an in vitro bioassay.

Antioxidant properties of isolated compounds from banana rhizome.

Unlabelled: In this study, we attempted to explore banana rhizome (BR) as a source of natural bioactive compounds. Dried BR powder was subjected to sequential extraction using solvents with increasing polarity and studied for antioxidant activities. Chloroform and acetone extracts were selected for isolation and identification of bioactive compounds because of their high antioxidant properties.

Anti-cancer evaluation of carboxamides of furano-sesquiterpene carboxylic acids from the soft coral Sinularia kavarattiensis.

The chemical investigation of soft coral Sinularia kavarattiensis is described. It yielded furano-sesquiterpene carboxylic acids 1 and 2 and their methyl esters 3 and 4. Semi-synthesis of furano-sesquiterpene carboxylic acid 1 gave amide derivatives 5-12.

Purification and biological evaluation of the metabolites produced by Streptomyces sp. TK-VL_333.

An Actinobacterium strain isolated from laterite soils of the Guntur region was identified as Streptomyces sp. TK-VL_333 by 16S rRNA analysis. Cultural, morphological and physiological characteristics of the strain were recorded.

Chemical examination of the Sponge Phycopsis sp.

Two new compounds 7alpha,8alpha-epoxy theonellin isothiocyanate (1) and 5alpha,8alpha-epidioxyergosta-6Z,22Z,25-trien-3beta-ol (2) along with two known compounds, theonellin isothiocyanate (3) and theonellin formamide (4) have been isolated from the sponge Phycopsis sp. Compound 2 showed cytotoxic activity against HL-60 and U937 human cancer cell lines with IC(50) values of 5.96+/-0.

Isolation, characterization and biological evaluation of bioactive metabolites from Nocardia levis MK-VL_113.

An Actinomycete isolate found to be prominent in the laterite soils of Acharya Nagarjuna University (ANU) Campus, Guntur was identified as Nocardia levis MK-VL_113 by 16S rRNA analysis. Cultural, morphological and physiological characteristics of the strain were recorded. Screening of secondary metabolites obtained from 4-day old culture broth of the strain led to the isolation of two fractions active against a wide variety of Gram-positive, Gram-negative bacteria and fungi.

Study on bioactive compounds from Streptomyces sp. ANU 6277.

An attempt was made to study the bioactive compounds from a terrestrial Streptomyces sp. ANU 6277 isolated from laterite soil. Four active fractions were recovered from the solvent extracts obtained from the culture broth of five day-old strain.

Biological activity of phenylpropionic acid isolated from a terrestrial Streptomycetes.

The strain ANU 6277 was isolated from laterite soil and identified as Streptomyces sp. closely related to Streptomyces albidoflavus cluster by 16S rRNA analysis. The cultural, morphological and physiological characters of the strain were recorded.

A high dimensional QSAR study on the aldose reductase inhibitory activity of some flavones: topological descriptors in modeling the activity.

The quantitative structure-activity relationships (QSAR) of the Aldose Reductase (AR) inhibitory activity of 48 flavones were studied using Free-Wilson, Combinatorial Protocol in Multiple Linear Regression (CP-MLR), and Partial Least Squares (PLS) procedures. For the latter two procedures 152 Molconn-Z parameters and six indicators corresponding to the hydroxyls of flavones were used as molecular descriptors. Independently, all procedures suggested the significance of hydroxyls in modulating the activity of these compounds.

New acylated iridoid glucosides from Vitex altissima.

Six new iridoid glucosides, 6'-O-trans-feruloylnegundoside (1), 6'-O-trans-caffeoylnegundoside (2), 2'-O-p-hydroxybenzoyl-6'-O-trans-caffeoylgardoside (3), 2'-O-p-hydroxybenzoyl-6'-O-trans-caffeoyl-8-epiloganic acid (4), 2'-O-p-hydroxybenzoyl gardoside (5), and 2'-O-p-hydroxybenzoyl-8-epiloganic acid (6), along with two known iridoids, agnuside and negundoside, have been isolated from the ethyl acetate extractive of the leaves of Vitex altissima. The structures of these compounds were elucidated on the basis of spectral data interpretation. These isolates did not exhibit significant 5-lipoxygenase enzyme inhibitory activity, but compounds 2-4 showed potent antioxidant activity by both the superoxide (NBT riboflavin photoreduction) free-radical-scavenging and DPPH-radical-scavenging methods.

Anti-HIV active petrosins from the marine sponge Petrosia similis.

A marine sponge Petrosia similis afforded two compounds which belongs to bis-quinolizidine alkaloids namely, petrosin (1) and petrosin-A (2), respectively. Petrosin (1) and petrosin-A (2) showed anti-HIV inhibition with IC(50) values of 41.3 and 52.

Two new macrocyclic diaryl ether heptanoids from Boswellia ovalifoliolata.

The stems of Boswellia ovalifoliolata BAL. & HENRY (Burseraceae) afforded two new macrocyclic diaryl ether heptanoids, ovalifoliolatin A (1) and B (2) together with three known compounds; acerogenin C (3), 3 alpha-hydroxyurs-12-ene (4), and sitost-4-en-3-one (5). The structures were established by means of spectroscopic analysis and compounds 1, 3-5 were evaluated for their antibacterial activity.

Two new bromotyrosine-derived metabolites from the sponge Psammaplysilla purpurea.

Two new bromotyrosine-derived metabolites (1, 2) have been isolated along with the known compounds 3,5-dibromo-4-methoxyphenylacetonitrile, 3-bromo-4-methoxyphenylacetonitrile, 3-bromo-4-hydroxyphenylacetonitrile, 1-hydroxyuracil, 1-methoxyhemibastadin 2, purpuramine H and a steroid 5alpha,8alpha-epidioxycholest-6-en-3beta-ol from the sponge Psammaplysilla purpurea. Compounds 1 and 2 were characterized by interpretation of their spectral data. The antibacterial activity of these compounds is summarized.

Three new ingol diterpenes from Euphorbia nivulia: evaluation of cytotoxic activity.

The latex of Euphorbia nivulia afforded three new ingol diterpenes, 3-acetyl-8-methoxyl-7-angolyl-12-hydroxylingol (7), 3,12-diacetyl-7-hydroxy-8-methoxylingol (8), and 3,12-diacetyl-7-angolyl-8-hydroxylingol (9) along with five known ingol diterpenes 2-6 and a known triterpene cyclonivulinol (1). Their structures were established by means of spectroscopic analysis. Diterpenes 2-9 were evaluated for their cytotoxic activity.