Komal Anjum

A new curvularin glycoside and its cytotoxic and antibacterial analogues from marine actinomycete Pseudonocardia sp. HS7

Five curvularin macrolides (1–5) were isolated from the cultured broth of marine actinomycete Pseudonocardia sp. HS7 that was obtained from the cloacal aperture of sea cucumber Holothuria moebii. The structures of these isolates were characterized as (11S,15R)-11-hydroxycurvularin (1), (11R,15R)-11-hydroxycurvularin (2), curvularin-7-O-α-D-glucopyranoside (3), trans-dehydrocurvularin (4) and curvularin (5) based on their NMR and HRESIMS data as well as chemical degradation. Compound 3 is a new macrolide with a rare α-D-glucopyranose substituent. Compounds 1–4, 5a and 5c (the acyl products of 5), suppressed the proliferation of all six tested cancer cell lines and 4 is the most active compound with IC50 values ranging from 0.59 to 3.39 μM. The 11-hydroxycurvularins 1 and 2 also showed antibacterial activity inhibiting the growth of Escherichia coli.

Bioactive Polycyclic Quinones from Marine Streptomyces sp. 182SMLY.

Chemical investigation of the cultures of marine Streptomyces sp. 182SMLY led to the discovery of two new polycyclic anthraquinones, which were elucidated as N-acetyl-N-demethylmayamycin (1) and streptoanthraquinone A (2) based on the extensive spectroscopic analysis including 2D NMR, HRESIMS, and an electronic circular dichroism (ECD) calculation. Both anthraquinones remarkably suppressed the proliferation of four different glioma cell lines with IC50 values in a range from 0.5 to 7.3 μM and induced apoptosis in the glioma cells. The ratios of IC50 for normal human astrocytes to IC50 for glioma cells were 6.4–53 for 1 and >14–31 for 2. N-acetyl-N-demethylmayamycin (1) also inhibited the growth of methicillin-resistant Staphylococcus aureus with MIC 20.0 μM.

Marine Sponges as a Drug Treasure

Marine sponges have been considered as a drug treasure house with respect to great potential regarding their secondary metabolites. Most of the studies have been conducted on sponge’s derived compounds to examine its pharmacological properties. Such compounds proved to have antibacterial, antiviral, antifungal, antimalarial, antitumor, immunosuppressive, and cardiovascular activity. Although, the mode of action of many compounds by which they interfere with human pathogenesis have not been clear till now, in this review not only the capability of the medicinal substances have been examined in vitro and in vivo against serious pathogenic microbes but, the mode of actions of medicinal compounds were explained with diagrammatic illustrations. This knowledge is one of the basic components to be known especially for transforming medicinal molecules to medicines. Sponges produce a different kind of chemical substances with numerous carbon skeletons, which have been found to be the main component interfering with human pathogenesis at different sites. The fact that different diseases have the capability to fight at different sites inside the body can increase the chances to produce targeted medicines.

Current status and future therapeutic perspectives of glioblastoma multiforme (GBM) therapy: A review

Glioblastoma multiforme (GBM) is the deadliest form of heterogeneous brain cancer. It affects an enormous number of patients every year and the survival is approximately 8 to 15 months. GBM has driven by complex signaling pathways and considered as a most challenging to treat. Standard treatment of GBM includes surgery, radiation therapy, chemotherapy and also the combined treatment. This review article described inter and intra- tumor heterogeneity of GMB. In addition, recent chemotherapeutic agents, with their mechanism of action have been defined. FDA-approved drugs also been focused over here and most importantly highlighting some natural and synthetic and novel anti- glioma agents, that are the main focus of researchers nowadays.

Synthesis and bioactivity of tripolinolate A from Tripolium vulgare and its analogs

A new coniferol derivative, named as tripolinolate A (1), and 11 known compounds (2-12) were isolated from whole plants of Tripolium vulgare Nees. The structure of this new compound was determined as 4-(2S-methylbutyryl)-9-acetyl-coniferol based on its NMR and HRESIMS spectral analyses. A simple and efficient method was designed to prepare tripolinolate A and its 19 analogs including nine new chemical entities for bioactive assay. Tripolinolate A and its analog 4,9-diacetyl-coniferol were found to be the two most active compounds that significantly inhibited the proliferation of different cancer cell lines with IC50 values ranging from 0.36 to 12.9μM and induced apoptosis in tumor cells. Structure-activity relationship analysis suggested that the molecular size of acyl moieties at C-4 and C-9 position might have an effect on the activity of this type of coniferol derivatives.

Emerging biopharmaceuticals from marine actinobacteria.

Actinobacteria are quotidian microorganisms in the marine world, playing a crucial ecological role in the recycling of refractory biomaterials and producing novel secondary metabolites with pharmaceutical applications. Actinobacteria have been isolated from the huge area of marine organisms including sponges, tunicates, corals, mollusks, crabs, mangroves and seaweeds. Natural products investigation of the marine actinobacteria revealed that they can synthesize numerous natural products including alkaloids, polyketides, peptides, isoprenoids, phenazines, sterols, and others. These natural products have a potential to provide future drugs against crucial diseases like cancer, HIV, microbial and protozoal infections and severe inflammations. Therefore, marine actinobacteria portray as a pivotal resource for marine drugs. It is an upcoming field of research to probe a novel and pharmaceutically important secondary metabolites from marine actinobacteria. In this review, we attempt to summarize the present knowledge on the diversity, chemistry and mechanism of action of marine actinobacteria-derived secondary metabolites from 2007 to 2016.

Emerging biopharmaceuticals from bioactive peptides derived from marine organisms.

Biologically active natural products are spontaneous medicinal entrants, which encourage synthetic access for enhancing and supporting drug discovery and development. Marine bioactive peptides are considered as a rich source of natural products that may provide long‐term health, in addition to many prophylactic and curative medicinal drug treatments. The large literature concerning marine peptides has been collected, which shows high potential of nutraceutical and therapeutic efficacy encompassing wide spectra of bioactivities against a number of infection‐causing agents. Their antimicrobial, antimalarial, antitumor, antiviral, and cardioprotective actions have achieved the attention of the pharmaceutical industry toward new design of drug formulations, for treatment and prevention of several infections. However, the mechanism of action of many peptide molecules has been still untapped. So in this regard, this paper reviews several peptide compounds by which they interfere with human pathogenesis. This knowledge is one of the key tools to be understood especially for the biotransformation of biomolecules into targeted medicines. The fact that different diseases have the capability to fight at different sites inside the body can lead to a new wave of increasing the chances to produce targeted medicines.

Antiglioma pseurotin A from marine Bacillus sp. FS8D regulating tumour metabolic enzymes

Abstract Pseurotin A was isolated from a culture of marine Bacillus sp. FS8D and showed to be active against the proliferation of four different glioma cells with IC50 values of 0.51–29.3 μM. It has been found that pseurotin A downregulated the expression of tumour glycolytic enzymes pyruvate kinase M2 (PKM2) and lactate dehydrogenase 5 (LDH5) and upregulated the expression of pyruvate dehydrogenase beta (PDHB), adenosine triphosphate synthase beta (ATPB) and cytochrome C (Cyto-C), the important regulators for tricarboxylic acid cycle and oxidative phosphorylation. The data suggested that targeting multiple metabolic enzymes might be one of the antiglioma mechanisms of pseurotin A.

Bioactive Bafilomycins and a New N-Arylpyrazinone Derivative from Marine-derived Streptomyces sp. HZP-2216E

A MeOH extract prepared from culture of an actinomycete Streptomyces sp. HZP-2216E isolated from marine green algae Ulva pertusa was found to significantly inhibit proliferation of human glioma cells. Two different media were applied to culture this marine actinomycete, which produced two new compounds of 23-O-butyrylbafilomycin D and streptoarylpyrazinone A, together with known bafilomycin D, 9-hydroxybafilomycin D, and bafilomycin A1. Structures of new compounds were determined by extensive NMR spectroscopic analyses and HRESIMS data. Bioactive assay indicated that all isolated bafilomycins significantly inhibited the proliferation of different glioma cell lines and the growth of methicillin-resistant Staphylococcus aureus with 23-O-butyrylbafilomycin D as the most active compound. Streptoarylpyrazinone A is a new N-arylpyrazinone derivative existing as a zwitterion, and this type of compounds was rarely found from natural resources.

New streptophenazines from marine Streptomyces sp. 182SMLY

Abstract Six phenazines including three new ones were isolated from the culture of a marine actinomycete Streptomyces sp. 182SMLY. Based on the analyses of NMR, HRESIMS, optical rotation value, and CD data, the structures of these isolated compounds were determined as new phenazines of (-)-streptophenazines M–O and known phenazines of 1-carbomethoxyphenazine and (-)-streptophenazines A and B. (-)-Streptophenazine B showed activity in suppressing the growth of methicillin-resistant Staphylococcus aureus with MIC value of 4.2 μg/mL.