Cytoskyrins and Cytosporones Produced by Cytospora sp. CR200: Taxonomy, Fermentation and Biological Activities

In screening endophytic fungi from Costa Rica for bioactivity, fungal culture CR200, isolated from a buttonwood tree, was found to contain compounds that initiate DNA damage in a test strain of E. coli (Biochemical Induction Assay, BIA) and inhibit growth of Gram-positive bacteria, including antibiotic-resistant strains. Two new bisanthraquinones (cytoskyrins A and B) and five new related octaketides (cytosporones A-E) were isolated from fermentation broths of this fungus. Cytoskyrin A exhibited potent in-vitro antibacterial (MICs against Gram-positive bacteria, 0.03 – 0.25 μg/mL) and DNA-damaging activities (10 ng/spot), whereas cytoskyrin B was inactive in these assays. Among the cytosporones, only D and E exhibited Gram-positive activity, but they were inactive in the BIA. Mechanistically, cytoskyrin A specifically inhibited DNA synthesis in E. coli imp at its MIC; however, it also moderately inhibited protein synthesis at 2x its MIC. Cytoskyrin A exhibited poor cytotoxicity against tumor cell lines (IC50 > 5 μg/mL) compared to known antitumor agents. The nuclear ribosomal internal transcribed spacer region of CR200 was found to share highest similarity (94–96%) with Cytospora spp. Micro- and macroscopic morphological observations of the conidia and conidiomata, respectively, also suggested this fungus to be a Cytospora sp

Correction: Singh, M.P., et al. Cytoskyrins and Cytosporones Produced by Cytospora sp. CR200: Taxonomy, Fermentation and Biological Activities

We found an error in Figure 1 in our paper published in the Marine Drugs [1]. The structure of Cytosporones A and B are corrected as follows: [..

Fluorometabolite biosynthesis : isotopically labelled glycerol incorporations into the antibiotic nucleocidin in Streptomyces calvus

Deuterium and carbon-13 labelled glycerols have been fed to Streptomyces calvus fermentations and isotope incorporation into the fluorine containing antibiotic nucleocidin have been evaluated by 19F-NMR. A single deuterium atom was incorporated from [2H5]- and (R)-[2H2]- glycerol into C-5’ of the antibiotic, suggesting that an oxidation occurs at this carbon after ribose ring assembly from glycerol (pentose phosphate pathway), during nucleocidin biosynthesis.PostprintPostprintPeer reviewe

Incorporation of [2H1]-(1R,2R)- and [2H1]-(1S,2R)-glycerols into the antibiotic nucleocidin in Streptomyces calvus

The authors thank the Chinese Scholarship Council for Ph.D Studentship support (to XF).Deuterium incorporations from [2H1]-(1R,2R) and [2H1]-(1S,2R) glycerols into the fluorine containing antibiotic nucleocidin, in Streptomyces calvus indicate that one deuterium atom is incorporated at the C-5′ site of nucleocidin from each of these isotopomers of glycerol. Two deuteriums become incorporated at C-5′ of nucleocidin after a feeding experiment with [2H5]-glycerol. These observations indicate that there is no obligate oxidation of the pro-R hydroxymethyl group of glycerol as it progresses through the pentose phosphate pathway and becomes incorporated into the fluorinated antibiotic.PostprintPeer reviewe

The marine actinomycete genus Salinispora: a model organism for secondary metabolite discovery

This review covers the initial discovery of the marine actinomycete genus Salinispora through its development as a model for natural product research. A focus is placed on the novel chemical structures reported with reference to their biological activities and the synthetic and biosynthetic studies they have inspired. The time line of discoveries progresses from more traditional bioassay-guided approaches through the application of genome mining and genetic engineering techniques that target the products of specific biosynthetic gene clusters. This overview exemplifies the extraordinary biosynthetic diversity that can emanate from a narrowly defined genus and supports future efforts to explore marine taxa in the search for novel natural products

ANALISIS KINERJA KEUANGAN PERUSAHAAN DENGAN MENGGUNAKAN METODE ECONOMIC VALUE ADDED (EVA) DAN MARKET VALUE ADDED (MVA) (Pada Industri Semen Indonesia Yang Tercatat di BEI)

Suatu perusahaan harus memiliki acuan untuk menilai kinerja, agar dapat mengetahui seberapa besar laba yang diperoleh dan tingkat kerugian yang akan didapat nanti.pengukuran kinerjaberdasarkan rasio keuangan tidak dapat dikatakan sebagai pembantu penentuan perencanaan tindakan untuk masa depan sepenuhnya. Economic Value Added (EVA) dan Market Value Added (MVA) menjadi relevan untuk mengukur kinerja yang berdasarkan nilai ( value).Permasalahan yang dikaji dalam penelitian ini adalah bagaimana kinerja keuangan PT. Semen Indonesia Tbk., PT. Indocement Tunggal Prakarsa Tbk. dan PT. Holcim Indonesia Tbk. diukur dengan menggunakan metode Economic Value Added dan Market Value Added pada tahun 2010-2012. EVAmerupakan estimasi laba ekonomi usaha yang sebenarnya untuk tahun tertentu. EVA menunjukan sisa laba setelah biaya modal, sedangkan MVA (Merket Value Added) adalah perbedaan antara nilai pasar saham suatu perusahaan dengan jumlah ekuitas modal investor yang telah diberikan, MVA merupakan ukuran kumulatif kinerja keuangan yang menunjukan seberapa besar nilai tambah terhadap modal yang ditanam investor selama perusahaan berdiri. Penelitian ini merupakan penelitian deskriptif kuantitatif, yang bertujuan untuk memberikan gambaran kinerja keuangan perusahaan. penelitian ini semata- mata bersifat deskriptif dan tidak bermaksud mencari penjelasan, hipotesis, ataupun membuat prediksi. Metode pengumpulan data yang digunakan dalam penelitian ini adalah metode dokumentasi. Sampel dalam penelitian ini adalah industri semen di Indonesia yang tercatat di BEI. Alat analisis yang digunakan Economic Value Added (EVA) dan Market Value Added (MVA). Hasil penelitian mennunjukan bahwa berdasarkan analisis kinerja keuangan perusahaan dengan menggunakan metode EVA pada PT. Semen Indonesia Tbk. tahun 2010 sampai dengan 2012 menunjukan kinerja keuangan yang baik dengan memperoleh EVA yang positif dan telah menciptakan nilai tambah ekonomis bagi perusahaan. untuk PT. Indocement Tunggal Prakarsa Tbk. tahun 2010 sampai dengan 2012 menunjukan kinerja yang baik dengan memperoleh nilai EVA yang Positif, dimana perusahaan telah mampu menciptakan nilai tambah ekonomi. Sedangkan PT. Holcim Indonesia Tbk. menunjukan nilai EVA yang negatif pada tahun 2010, sehingga bisa dikatakan kinerja keuangan PT. Holcim Indonesia Tbk. pada tahun 2010 kurang baik, namun pada tahun 2011 dan 2012 PT. Holcim Indonesia Tbk. mampu memperoleh nilai EVA yang positif, sehingga bisa dikatakan perusahaan telah memperbaiki kinerjanya dan telah mampu menciptakan nilai tambah ekonomi bagi perusahaan. Hasil analsis kinerja keuangan perusahaan dengan MVA. Pada PT. Semen Indonesia Tbk. pada tahun 2010 sampai dengan tahun 2012 memperoleh hasil yang positif, berarti pihak manajemen menunjukan kinerja yang baik dan telah mampu menciptakan atau menambah kekayaan untuk pemegang saham dan perusahaan. untuk PT. Indocement Tunggal Prakarsa Tbk. tahun 2010 sampai dengan 2012 menunjukan kinerja keuangan yang baik dengan memperoleh nilai MVA yang Positif, dimana pihak manajemen telah mampu menciptakan atau menambah kekayaan bagi pemegang saham dan perusahaan. kemudian PT. Holcim Indonesia Tbk. pada tahun 2010 sampai dengan 2012, memperoleh nilai MVA yang positif, yang berarti pihak manajemen telah mampu menciptakan nilai tambah atau kekayaan bagi pemegang saham dan perusahaan. Kesimpulan dari penelitian ini menyatakan bahwa kinerja keuangan perusahaan industri semen di Indonesia yang tercatat di BEI secara keseluruhan dari tahun 2010 sampai dengan 2012 menunjukan hasil yang baik. Dimana PT. Semen Indonesia Tbk., PT. Indocement Tunggal Prakarsa Tbk. dan PT. Holcim indonesia mampu menciptakan nilai tambah bagi perusahaan

A medical clinical skills laboratory: towards a safer future for medical education

Ring! Ring! It is early morning and a final year medical student rushes over to the nurses’ station to answer the phone. Yes. Immediately. Bed four? Reaching the bed, she sees her patient, Stan. Respiratory distress. 25 breaths per minute. A cursory glance at the ECG – Narrow QRS complex. Tachycardia. Supraventricular tachycardia? – and the stethoscope is whisked off its position around the neck. Crackles. With no nurses to help her she rushes off to the treatment room to get supplies to give her patient a dose of adenosine. After finally finding a sharps container, the distraught medical student quickly swipes the antecubital fossa and searches for a vein. Found it! Needle in, push the drug and a wave of relief floods through the medical student. The patient seems to be quieter and sleeping now. Only then does the medical student look at the ECG again: oddly, it’s a flat line. Thankfully, episodes such as this are not common, but fears of making a fatal mistake as a young intern are commonplace. This entire scenario, however, is false. False, in that it took place in a clinical skills laboratory with no risk to any real patients: ‘Stan’ is a patient simulator.</p

RCSIsmj Ethics Challenge winner 2009

The RCSIsmj Ethics Challenge 2009 presented the case of a rural GP in Ireland who has diagnosed one of his patients, Richard, as HIV positive. Given a troublesome marriage in which Richard and his wife Sheila have stopped any form of intimacy, the GP is threatened with litigation should Richard’s HIV status become known to Sheila. The age-old notion of patient confidentiality is, clearly, at the centre of this ethical dilemma. This article aims to identify the ethical issues raised by the case, to address these academically and to suggest how the situation might be addressed in a satisfactory manner. Throughout the article weaknesses of the arguments are also identified. The underlying question that is posed is of interest to medical students who will encounter ethical dilemmas throughout their careers: how is it possible for a GP to reconcile his professional duty of confidentiality with protecting the welfare and health of another patient and of society in general?</p