A domain-specific language framework for farm management information systems in precision agriculture

Precision Agriculture - Farm management information system (FMIS) is an important element of precision agriculture to support the decision making process in the agricultural business. Developing...     

Biologically active secondary metabolites from Ginkgo biloba

Three new compounds, (7E)-2beta,3alpha-dihydroxy-megastigm-7-en-9-one (1), 3-[5,7-dihydroxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-8-yl]-4-methoxybenzoic acid (2), and 4'-O-methyl myricetin 3-O-(6-O-alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside (3), were isolated from Ginkgo biloba, together with 27 known compounds. The structures of the new compounds were determined primarily from 1D- and 2D-NMR analysis. The 4-O-methylbenzoic acid structural feature at C-8 in 2 is encountered for the first time. The antioxidant activities of 29 compounds isolated from Ginkgo biloba were evaluated on intracellular reactive oxygen species in HL-60 cells. It was found that quercetin, kampferol, and tamarixetin had antioxidant activity that was approximately 3-fold greater than that of their respective glycosides and also approximately 3-fold greater than that of a standard ascorbic acid with an IC(50) at maximum effectiveness.     

Inhibitory Effects of Rosemary Extracts, Carnosic Acid and Rosmarinic Acid on the Growth of Various Human Cancer Cell Lines

The leaves of Rosmarinus officinalis harvested from three different locations of Turkey were extracted by both methanolic and supercritical CO₂ extraction. Subsequently, six extracts and the active compounds, carnosic acid, and rosmarinic acid were applied to various human cancer cell lines including NCI-H82 (human, small cell lung, carcinoma), DU-145 (human, prostate, carcinoma), Hep-3B (human, black, liver, carcinoma, hepatocellular), K-562 (human chronic myeloid leukemia), MCF-7 (human, breast, adenocarcinoma), PC-3 (human, prostate, adenocarcinoma) and MDA-MB-231 (human, breast, adenocarcinoma) by MTT assay. Supercritical CO₂ extracts had superior antiproliferative effect compared to the soxhlet extracts. Although the extracts exhibited various cytotoxic effects against different cell lines, comparatively low IC₅₀ values ranging between 12.50 and 47.55 μg/ml were attained against K-562, being the most sensitive cell line. Moreover, carnosic acid caused the lowest cell viability with values ranging from 13 to 30 % at a concentration of 19 μM after 48 h of treatments, resulting in superior antiproliferative effect. Rosemary extract is a potential candidate to be included in the anti-cancer diet with pre-determined doses avoiding toxicity.     

Antifungal clerodane diterpenes from Macaranga monandra (L) Muell. et Arg. (Euphorbiaceae)

Hexane and ethyl acetate phases of the methanol extract of Macaranga monandra showed fungal growth inhibition of Colletotrichum acutatum, C. fragariae and C. gloeosporioides, Fusarium oxysporum, Botrytis cinerea, Phomopsis obscurans, and P. viticola. Bioassay-guided fractionation led to the isolation of two active clerodane-type diterpenes that were elucidated by spectroscopic methods (1D-, 2D-NMR, and MS) as kolavenic acid and 2-oxo-kolavenic acid. A 96-well microbioassay revealed that kolavenic acid and 2-oxo-kolavenic acid produced moderate growth inhibition in Phomopsis viticola and Botrytis cinerea.     

Diversity and antibiotic-producing potential of cultivable marine-derived actinomycetes from coastal sediments of Turkey

Purpose

Marine environments, especially sediments, are rich sources of actinomycetes that provide many bioactive compounds, primarily antibiotics. The goal of this study was to investigate the diversity of cultivable actinomycetes and their potential to produce antibiotics from sediments collected from the coastal zones of Turkey.

Materials and methods

Thirty sediment samples were collected from nine different coastal sites in three seas surrounding the Anatolian Peninsula of Turkey. Of the samples, 6 were collected from one site in the Black Sea, 18 from seven sites in the Aegean Sea, and 6 from one site in the Mediterranean Sea. Strains of pure actinomycetes were isolated by modified actinomycetes isolation agar (MAIA), M1 agar, M6 agar, and modified R2A agar. Ethyl acetate extracts and fermentation broths were used for the evaluation of antimicrobial activity against antibiotic resistant test microorganisms. The identification of the isolates was undertaken by 16S rRNA gene sequencing.

Results and discussion

A total of 261 strains of actinomycetes were isolated, of which 66 (25 %) were active against at least one antibiotic-resistant microorganism. Sixty-five of the actinomycetes isolates with antimicrobial activity were Streptomyces spp. and one was Nocardia sp., which implied that genus Streptomyces was predominant. Whereas MAIA agar was the best medium to recover actinomycetes, M6 agar was superior to others for the isolation of antibiotic-producing strains.

Conclusions

Extensive screening of the extracts from the 261 isolates for antimicrobial activities revealed considerable potential to produce antibiotics. These findings imply that actinomycetes from marine sediments of the Anatolian Peninsula coasts have potential for the discovery of novel bioactive compounds.