Band 69, Heft 3-4

1 A new and rare ergostane triterpenoid, 4α-methyl-3α,4β-dihydroxy-ergost-8,24(28)-dien-7,11- dion-25-al (), was isolated from cultures of the basidiomycete Inocybe lilacina, and its structure established on the basis of spectral methods (MS, IR, 1D and 2D NMR).

Phytochemical investigation of the cytotoxic fractions of fresh bulbs of Pancratium maritimum L. led to the isolation and structure identification of two new compounds, pancricin (1) and pancrichromone (4), together with four known compounds, including 2,4-dihydroxy-6- methoxy-3-methyl acetophenone (2), 5-formylfurfuryl acetate (3), 7-β-D-glucosyloxy-5-hydroxy-2- methylchromone (5), and ethyl-b-D-glucopyranoside (6). Their structures were established on the basis of 1D and 2D NMR spectroscopy ( 1 H, 13 C, COSY, HSQC, and HMBC), as well as HR mass spectral analyses. The compounds were evaluated for their antimigratory and antiproliferative activities against the highly metastatic human prostate cancer cell line (PC-3M). Compound 5 was the most active compound displaying good activity in the proliferation assay comparable to that of the positive control 4-hydroxyphenylmethylene hydantoin, while it displayed only weak antimigratory activity compared to the positive control 4-ethylmercaptophenylmethylene hydantoin.

Chemotherapy is one of the main strategies for reducing the rate of cancer progression or, in some cases, curing the tumour. Since a great number of chemotherapeutic agents are cytotoxic compounds, i. e. similarly affect normal and neoplastic cells, application of antitumour drugs is preferred in cancer management and therapy. In this study, the cytotoxicity of diversin was evaluated in 5637 cells, a transitional cell carcinoma (TCC) subline (bladder carcinoma), and normal human fibroblast cells using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Chromatin condensation and DNA damage induced by diversin were also determined by means of 4’,6-diamidino-2- phenylindole (DAPI) staining and the comet assay, respectively. In addition, the mechanism of action of diversin was studied in more detail by the caspase 3 colourimetric assay and flow cytometry-based cell-cycle analyses (PI staining). Our results revealed that diversin has considerable cytotoxic effects in 5637 cells, but not on HFF3 (human foreskin fibroblast) and HDF1 (human dermal fibroblast) cells. Further studies showed that diversin exerts its cytotoxicity via induction of chromatin condensation, DNA damage, and activation of caspase 3 in 5637 cells. In addition, flow cytometric analyses revealed that 5637 cells are mostly arrested at the G2 phase of the cell cycle in the presence of diversin.

The antileishmanial activity of extracts and phytoconstituents of Moringa oleifera Lam: was investigated in vitro against promastigotes of Leishmania donavani. The 70%ethanolic extract of roots and the methanolic extract of leaves showed moderate inhibitory activity with IC 50 values of 83:0 μg/ml and 47:5 μg/ml, respectively. Antileishmanial activity of the methanolic extract of leaves increased upon fractionation, as its ethyl acetate fraction was found to be more active with an IC 50 value of 27:5 mg=ml. The most active antileishmanial compound niazinin, a thiocarbamate glycoside isolated from this fraction, showed an IC 50 value of 5:25 mM. Results presented in this study indicate that extracts from M. oleifera may be developed as an adjuvant therapy for the treatment of leishmaniasis.

Two new polyacetylenes, callyspongenol-D (1) and callyspongendiol (2), the known polyacetylene dehydrosiphonochalynol (3), and the known triterpenoid sipholenol-A (4) were isolated from the Red Sea sponge Siphonochalina siphonella. Their chemical structures were elucidated on the basis of spectroscopic analyses. The cytotoxicity of the isolated compounds towards the human mammary carcinoma cell line MCF-7 was determined by the lactate dehydrogenase (LDH) assay, and compounds 4 and 1 were found to be the most toxic of the four, with IC 50 values of 8.8 and 11:7 mM, respectively.

Leucaena leucocephala is a nitrogen-fixing tropical leguminous tree that produces two pyridine alkaloids, i. e. mimosine [β-(3-hydroxy-4-pyridon-1-yl)-L-alanine] and trigonelline (1- methylpyridinium-3-carboxylate). Mimosine has been detected in leaves, flowers, pods, seeds, and roots, and it is one of the principal non-protein amino acids that occurs in all organs. Asparagine was the most abundant amino acid in flowers. The mimosine content varied from 3.3 μmol/g fresh weight (FW) in developing flowers to 171 μmol/g FW in mature seeds. Trigonelline was also detected in leaves, flowers, pods, and seeds, but not roots. The trigonelline content was lower than that of mimosine in all organs. It varied from 0.12 μmol/g FW in developing seeds to 2.6 μmol/g FW in mature seeds. [2- 14 C]Nicotinic acid supplied to the developing seeds was incorporated into trigonelline but not mimosine. This indicates that the pyridine and dihydroxypyridine structures of these two alkaloids are derived from distinct precursors. The physiological functions of mimosine and trigonelline are discussed briefly.

There is accumulating evidence that the renin-angiotensin system (RAS) is involved in hepatic inflammation and fibrogenesis. Garlic was found to lower the activity of the angiotensin converting enzyme (ACE) in the serum of rats in a diabetic model. We examined the effect of an aqueous garlic extract (AGE) on the ACE activity, cholestasis-induced liver fibrosis, and associated renal dysfunction in comparison with the effect of the standard drug enalapril. Both AGE and enalapril were administered orally for six weeks starting from the third day after bile duct ligation (BDL). BDL significantly increased the serum activities of liver enzymes, serum lactate dehydrogenase (LDH) activity, an indicator of liver cell death, serum total bilirubin (TB) level, liver myeloperoxidase (MPO) activity, and liver malondialdehyde (MDA) content. BDL was associated with elevation of serum urea and creatinine levels indicating renal dysfunction. BDL also caused an increase in the transcript levels of the genes coding for tumour necrosis factor alpha (TNF-a), transforming growth factor beta-1 (TGF-b1), and matrix metalloproteinase-13 (MMP-13), a collagenase, in liver tissues. A significant decrease in hepatic reduced glutathione (GSH) was observed in BDL rats, while serum ACE activity was increased. Both AGE and enalapril counteracted all these deleterious changes, with the exception that only AGE reduced the MPO activity. These findings suggest that AGE possesses hepato- and renoprotective properties, similar to enalapril, probably by modulating the levels of proteins such as TNF-α, TGF-β1 and MMP-13, and involving a reduction of ACE and of oxidative stress.

Aquaporin proteins (AQPs) have been shown to be involved in abiotic stress responses. However, the precise role of AQPs, especially in response to cold stress, is not understood in wheat (Triticum aestivum). In the present study, quantitative real time polymerase chain reaction (qRT-PCR) analysis revealed that TaAQP7 expression increased in leaves, but decreased in roots after cold treatment. Expression of TaAQP7 in tobacco plants resulted in increased root elongation and better growth compared with wild-type (WT) plants under cold stress. Moreover, after cold treatment, the transgenic tobacco lines exhibited higher chlorophyll contents, lower levels of malondialdehyde (MDA), and less ion leakage (IL) than WT plants. Thus, expression of TaAQP7 enhanced cold stress tolerance in transgenic tobacco. Taken together, our results suggest that TaAQP7 confers cold stress tolerance by relieving membrane damage in the transgenic plants.

The lipoxygenase LOX Psa 1 of Pleurotus sapidus, originally investigated because of its ability to oxidize (+)-valencene to the valuable grapefruit aroma (+)-nootkatone, was isolated from the peptidase-rich lyophilisate using a three-step purification scheme including preparative isoelectric focusing and chromatographic techniques. Nano-liquid chromatography electrospray ionization tandem mass spectrometry (nLC-ESI-MS=MS) of the purified enzyme and peptide mass fingerprint analysis gave 38 peptides of the lipoxygenase from P. sapidus. Nearly 50% of the 643 amino acids long sequence encoded by the cDNA was covered. Both terminal peptides of the native LOX Psa 1 were identified by de novo sequencing, and the postulated molecular mass of 72:5 kDa was confirmed. With linoleic acid as the substrate, the LOXPsa1 showed a specific activity of 113 U mg -1 and maximal activity at pH 7.0 and 30 °C, respectively.

The atonal genes are an evolutionarily conserved group of genes encoding regulatory basic helixloop- helix (bHLH) transcription factors. These transcription factors have a critical antioncogenic function in the retina, and are necessary for cell fate determination through the regulation of the cell signal pathway. In this study, the atonal gene was cloned from Bombyx mori, and the transcription factor was named BmAtonal. Sequence analysis showed that the BmAtonal protein shares extensive homology with other invertebrate Atonal proteins with the bHLH motif. Reverse transcriptionpolymerase chain reaction (RT-PCR) and Western blot analyses revealed that BmAtonal was expressed in all developmental stages of B. mori and various larval tissues. The BmAtonal protein was expressed in Escherichia coli, and polyclonal antibodies were raised against the purified protein. By immunofluorescence, the BmAtonal protein was localized to both the nucleus and cytoplasm of BmN cells. After knocking out nuclear localization signals (NLS), the BmAtonal protein was only detected in the cytoplasm. In addition, using the B. mori nuclear polyhedrosis virus (BmNPV) baculovirus expression system, the recombinant BmAtonal protein was successfully expressed in the B. mori cell line BmN. This work lays the foundation for exploring the biological functions of the BmAtonal protein, such as identifying its potential binding partners and understanding the molecular control of the formation of sensory organs.

The total antioxidant capacities (TAC) of feces of mammalian herbivores and carnivores were compared. TAC were estimated using three different methods: 2,2’-azino-bis(3-ethylbenzothiazoline- 6-sulfonic acid) radical (ABTS·) reduction, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) reduction, and ferric reducing antioxidant power (FRAP). TAC of 18 herbivorous species were generally higher with respect to 16 carnivorous species [(14:21±6:72) vs. (9:45±7:32) mmol Trolox equivalents/kg feces; P < 0:05] in the FRAP assay. The ABTS· reduction assay indicated that the TAC originating from “fast” reacting antioxidants were higher in the herbivores than in carnivores [(17:92±7:18) vs. (12:22±8:5) mmol Trolox equivalents/kg feces; P < 0:05], while a reverse trend was observed for TAC originating from “slowly” reacting antioxidants [(20:68±4:85) vs. (24:68±6:87) mmol Trolox equivalents/kg feces].

Porcine pancreas lipase type II (PPL II) exhibited unnatural catalytic activity in direct asymmetric aldol reactions between cyclic ketones and aromatic or heteroaromatic aldehydes in acetonitrile in the presence of phosphate buffer. A wide range of substrates was accepted by the enzyme to afford the corresponding aldol products in low to high yields (10 - 98%), with moderate to excellent enantioselectivities (53 - 94% ee, for anti-isomers) and low to moderate diastereoselectivities (48/52 - 87/13 dr, anti/syn). This methodology expands the application of PPL II, and it might be developed into a potentially valuable method for sustainable organic synthesis.