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Picrotoxinin (1), a stable natural neurotoxin containing a highly oxygenated polycyclic rigid compound, was first isolated from berries of Anamirta cocculus (L.) Wight & Arn. (formerly known as Menispermum cocculus). The present work was aimed to study the modification of the complex polycyclic structure of picrotoxinin (1) by using microbial transformation. Initially various fungi, such as Macrophomina phaseolina, Cunninghamella blakesleeana, Aspergillus flavus, Aspergillus niger, Cephalosporium aphidicola, and Fusarium lini were screened for their ability to modify the structure of 1. Only one fungus Macrophomina phaseolina was able to catalyze the structural modification of picrotoxinin (1). The subsequent whole cell catalysis produced an intramolecular trans-esterified product 2. The structure of the transformed product was deduced by spectroscopic, and single-crystal X-ray diffraction analyses. A comparative study on convulsant activity of picrotoxinin (1) and its metabolite 2 was conducted in mice. Interestingly, metabolite 2 showed a delayed convulsant activity, as compared to the compound 1.

Zingiber officinale Roscoe (Ginger) is a widely used traditional medicinal plant (for different ailments such as arthritis, constipation, and hypertension). This article describes the isolation and characterization of a so far unknown protein from ginger rhizomes applying ion exchange, affinity, size-exclusion chromatography, small angle X-ray scattering (SAXS), and mass spectrometry techniques. One-dimensional Coomassie-stained SDS-PAGE was performed under non-reducing conditions, showing one band corresponding to approx. 27 kDa. Dynamic light scattering (DLS) analysis of the protein solution revealed monodispersity and a monomeric state of the purified protein. Circular dichroism (CD) spectroscopy strongly indicated a β-sheet-rich protein, and disordered regions. MALDI-TOF-MS, and LC-MS/MS analysis resulted in the identification of 27.29 kDa protein, having 32.13% and 25.34% sequence coverage with Zingipain-1 and 2, respectively. The monomeric state and molecular weight were verified by small angle X-ray scattering (SAXS) studies. An elongated ab-initio model was calculated based on the scattering intensity distribution.

Oilseeds of the plant family Brassicaceae are important for providing both lipid and protein contents to human nutrition. Cruciferins (12S globulins) are seed storage proteins, which are getting attention due to their allergenic and pathogenicity related nature. This study describes the purification and characterization of a trimeric (∼190 kDa) cruciferin protein from the seeds of Brassica nigra (L.). Cruciferin was first partially purified by ammonium sulfate precipitation (30% saturation constant) and further purified by size exclusion chromatography. The N-terminal amino-acid sequence analysis showed 82% sequence homology with cruciferin from Arabidopsis thaliana. The 50–55 kDa monomeric cruciferin produced multiple bands of two major molecular weight ranges (α-polypeptides of 28–32 kDa and β-polypeptides of 17–20 kDa) under reduced conditions of SDS-PAGE. The 2D gel electrophoretic analysis showed the further separation of the bands into their isoforms with major pI ranges between 5.7 and 8.0 (α-polypeptides) and 5.5–8.5 (β-polypeptides). The Dynamic Light Scattering (DLS) showed the monodisperse nature of the cruciferin with hydrodynamic radius of 5.8 ± 0.1 nm confirming the trimeric nature of the protein. The Circular Dichroism (CD) spectra showed both α-helices and β-sheets in the native conformation of the trimeric protein. The pure cruciferin protein (40 mg/ml) was successfully crystallized; however, the crystals diffracted only to low resolution data (8 A). Small-angle x-ray scattering (SAXS) was applied to gain insights into the three-dimensional structure in solution. SAXS showed that the radius of gyration is 4.24 ± 0.25 nm and confirmed the nearly globular shape. The SAXS based ab initio dummy model of B. nigra cruciferin was compared with 11S globulins (PDB ID: 3KGL ) of B. napus which further confirmed a highly similar molecular weight and globular shape indicating a conserved trimerization of B. nigra cruciferin. The comparison of the scattering patterns of both proteins showed a minimized χ2-value of 1.337 confirming a similar molecular structure. This is the first report describing the purification and characterization of a cruciferin protein from seeds of B. nigra.

The development of new and more effective antibiotic agents is necessary for human health. Herein, we have prepared the series of azo-derivatives of 1,3-indandion and metal complexes (Cu2+, Zn2+, Ni2+ and Mn2+) with these azo derivatives like 3-hydroxy-2-[phenyldiazenyl]-1H-inden-1-one (HPDIO), 3-hydroxy-2-[2-methylphenyldiazenyl]-1H-inden-1-one (HMPDIO),3-hydroxy-2-[2-nitrophenyldiazenyl]-1H-inden-1-one (HNPDIO) and 3-hydroxy2-[2-chlorophenyldiazenyl]-1H-inden-1-one (HCPDIO) have been successfully synthesized and screened against some bacteria. The appearance of –N N- peak at 1400-1500 cm−1 with disappearance of NH2 peak at 3500 cm−1 in FTIR spectra and chemical shift at 4.07–4.05 ppm and appearance of multiplet at 8.0–7.5 ppm for phenyl protons confirmed the synthesis of new azo derivatives. The appearance of, C–N sharp peak at 102 ppm, aromatic carbon peak in the range of 115–135 ppm, C–OH sharp peak at 192 ppm and C O peaks at 160–187 ppm and appearance of molecular ion peaks at 250 m/z, 264 m/z, 295 m/z and 284 m/z respectively further gives strong indication for the synthesis of proposed azo derivatives. Further, the XRD analysis of azo derivatives confirmed that these derivatives have cubic geometry. A relationship between anti-bacterial activities and structure of synthesized compounds have been established, the addition of electron donating group (for example methyl group) on the compound (HMPDIO) showed remarkable results which were equal to standard drug ciproxin against B. subtilis. Furthermore, the metal complexes of HCPDIO with Zn(II) and HNPDIO with Cu(II) showed more anti-bacterial activity against E.coli, P.aeruginose, B.subtilis and S.aureus than other metal complexes and azo derivatives. The compounds also screened against antioxidant as well as chymotrypsin activity and HCPDIO gives maximum inhibition against antioxidant activity than standard drug (BHA). All the ligands give good inhibition results against chymotrypsin activity except HCPDIO.