Structural elucidation and antimicrobial activity of a diketopiperazine isolated from a sp. associated with the marine sponge .

A diketopiperazine (3, 6)-3,6-diisobutylpiperazine-2,5-dione was isolated from a sponge-associated microbe for the first time and characterized by FTIR, HRESI-MS, H, C NMR and 2D NMR. The source is novel for this compound. Single crystal XRD of this diketopiperazine obtained as a natural product was analysed for the first time and its melting point was determined to be 262 °C.

Characterization and Inception of a Triterpenoid Astrakurkurol, as a Cytotoxic Molecule on Human Hepatocellular Carcinoma Cells, Hep3B.

Mushrooms are customary influential sources of pharmaceutically active metabolites. Usually lanostane-type triterpenoids from mushrooms had prospective for cancer disease treatments. Recently, a triterpenoid, astrakurkurol obtained from the fresh basidiocarps of the edible mushroom , drew attention as a new cytotoxic therapeutic.

Astrakurkurone, a sesquiterpenoid from wild edible mushroom, targets liver cancer cells by modulating Bcl-2 family proteins.

Induction of apoptosis is the target of choice for modern chemotherapeutic treatment of cancer, where lack of potent "target-specific" drugs has led to extensive research on anticancer compounds from natural sources. In our study, we have used astrakurkurone, a triterpene isolated from wild edible mushroom, Astraeus hygrometricus. We have discussed the structure and stability of astrakurkurone employing single-crystal X-ray crystallography and studied its potential apoptogenicity in hepatocellular carcinoma (HCC) cells.

Examination of postures and frequency of musculoskeletal disorders among manual workers in Calcutta, India.

Background: Manual material handling (MMH) activities require workers to adopt various awkward postures leading to the development of musculoskeletal disorders (MSD).

Objectives: To investigate the postures adopted during heavy load handling and the frequency of MSDs among MMH workers in Calcutta, India.

Methods: We conducted a cross-sectional study with 100 MMH workers.

A novel triterpene from Astraeus hygrometricus induces reactive oxygen species leading to death in Leishmania donovani.

Aim: The effect of astrakurkurone, a novel triterpene, isolated from Indian mushroom Astraeus hygrometricus has been investigated to elucidate the mechanisms involved in selective cell death of Leishmania donovani.

Materials & Methods: The hypotheses were investigated using flow-cytometry, scanning electron microscopy and confocal microscopy.

Results: The time dependent elevation of astrakurkurone-induced reactive oxygen species (ROS) was found intimately associated with apoptosis.

Leishmanicidal and anticandidal activity of constituents of Indian edible mushroom Astraeus hygrometricus.

Two new lanostane-type triterpenes, 1 and 2, were isolated from Astraeus hygrometricus. The structures were established by IR, (1)H- and (13)C-NMR, MS, and X-ray crystallographic experiments. The triterpenes exhibited excellent in vitro toxicities against Candida albicans, comparable to standard antifungal antibiotics.

Breathers in a discrete nonlinear Schrödinger-type model: Exact stability results.

Following our earlier work [Phys. Rev. Lett.

Traveling kinks in discrete media: exact solution in a piecewise linear model.

We present an exact integral representation of a traveling kink solution in a reaction-diffusion equation with a piecewise linear reaction function, complementing existence proofs and numerical observations of such solutions in discrete excitable media. The kink speed is determined through a matching condition, and is worked out explicitly in two limiting situations: the pinning limit, and the opposite limit of infinitely fast kink. Results on the pinning limit agree with those in a recent paper by Fath [Physica D 116, 176 (1998)].

Discrete breathers: exact solutions in piecewise linear models.

Exact breather solutions are constructed in piecewise linear (PWL) versions of the discrete nonlinear Schrodinger and Klein-Gordon equations. These solutions correspond to intersections of stable and unstable manifolds of relevant fixed points in associated 2D mappings, an exact construction of which is possible due to the PWL nature of the models. Such exact solutions give us insight into several aspects of breather properties.