Band 70, Heft 7-8

Phytochemical investigation of the stem bark extract of Crossopteryx febrifuga resulted in the isolation of epimeric mixtures of 3 β -urs-12,20(30)-diene-27,28-dioic acid and 18-epi-3 β -urs-12,20(30)-diene-27,28-dioic acid ( 1 ), as well as: 3 β -D-glucopyranosylurs-12,20(30)-diene-27,28-dioic acid and 18-epi-3 β -D-glucopyranosylurs-12,20(30)-diene-27,28-dioic acid ( 2 ), together with some known compounds such as the monoglyceride of palmitic acid, as well as β -sitosterol and its glucoside. The structures of the isolated compounds were determined by application of spectroscopic methods. The MeOH extract and compounds 1 and 2 were examined for antimicrobial activity in in vitro assays against bacteria ( Enterobacter aerogenes ATCC13048, Escherichia coli ATCC8739, Klebsiella pneumoniae ATCC11296, Staphylococcus aureus ) and fungi ( Candida parapsilosis , Candida albicans ATCC 9002 and Cryptococcus neoformans IP 90526). The tested samples showed selective activities. The antibacterial and antifungal activities of compound 2 (MIC=8–64 μg/mL) were in some cases equal to or even higher than those of the respective reference drugs chloramphenicol (MIC=16– 64 μg/mL) and nystatin (MIC=128–256 μg/mL).

Oxidative/nitrosative stress, inflammation, and apoptosis play a crucial role in the pathogenesis of arsenic-induced testicular injury. Telmisartan, the angiotensin II-receptor antagonist, possesses antioxidant and anti-inflammatory activities. The protective effect of telmisartan against arsenic-induced testicular damage was investigated in rats. Testicular damage was induced by sodium arsenite (10 mg kg –1 /day, p.o., for 2 consecutive days). Telmisartan (10 mg kg –1 /day, i.p.) was given for 3 consecutive days, starting 1 day before sodium arsenite administration. Telmisartan significantly attenuated the arsenic-induced decrease in the levels of serum testosterone and testicular reduced glutathione, and significantly decreased the elevation of the levels of testicular malondialdehyde, nitric oxide, and arsenic levels, as well as myeloperoxidase activity resulting from sodium arsenite administration. Histopathological and immunohistochemical examination revealed that telmisartan markedly attenuated testicular tissue changes, and decreased the arsenic-induced expression of vascular endothelial growth factor, inducible nitric oxide synthase, tumor necrosis factor-α, cyclooxygenase-2, nuclear factor-κB, and caspase-3. Telmisartan, via its antioxidant and/or anti-inflammatory effects, may represent a potential candidate to protect against the deleterious effects of arsenic on testicular tissue.

Twenty-seven previously reported chalcones and their pyrazoline and hydrazone derivatives as well as two further chalcones have been screened for their antimicrobial, antifungal and antimycobacterial activities against standard microbial strains and drug resistant isolates. The minimum inhibitory concentration (MIC) value of each compound was determined by a two-fold serial microdilution technique. The compounds were found to possess a broad spectrum of antimicrobial activities with MIC values of 8–128 μg/mL. One compound [( E )-1-(4-hydroxyphenyl)-3- p -tolylprop-2-en-1-one] had equal activity with gentamycin (8 μg/mL) against Enterococcus faecalis . Chalcones were found to be more active than their hydrazone and 2-pyrazoline derivatives against Staphylococcus aureus ATCC 29213 and E. faecalis ATCC 29212.

A reliable and statistically valid classification of biomineralization peptides is herein presented. 27 biomineralization peptides (BMPep) were randomly selected as representative samples to establish the classification system using k -means method. These biomineralization peptides were either discovered through isolation from various organisms or via phage display. Our findings show that there are two types of biomineralization peptides based on their length, molecular weight, heterogeneity, and aliphatic residues. Type-1 BMPeps are more commonly found and exhibit higher values for these significant clustering variables. In contrast are the type-2 BMPeps, which have lower values for these parameters and are less common. Through our clustering analysis, a more efficient and systematic approach in BMPep selection is possible since previous methods of BMPep classification are unreliable.

Proteins and proteolytic activities in the contents of the salivary gland (SGc), digestive tract (DTc) and excretory-secretory products (ESP) from larvae of the camel nasal botfly Cephalopina titillator were separated electrophoretically, and characterized. The protein profiles of the different samples were qualitatively quite similar in the larval stages L2 and L3. Zymogram analysis of proteases in the samples indicated that the digestive tract contained a greater variety of proteases than the salivary gland or the excretory-secretory products. They are mainly serine proteases. Proteases of ESP and DTc (especially of 3 rd instar) contain trypsin- and chymotrypsin-like serine proteases, while the serine proteases of SGc are not of the trypsin- or chemotrypsin-type.

A series of androstane derivatives 2–16 were synthesized from 3β-hydroxyandrostan-17-one derivatives ( 1a–e ). Compounds ( 1a,b ) were treated with ethyl cyanoacetate, cyanoacetamide, or malononitrile and gave the corresponding derivatives 2–7 , respectively. Additionally, compounds ( 1a–e ) were condensed with cyanothioacetamide, urea, or guanidine hydrochloride afforded the corresponding derivatives 8–12 , which then by Moffat oxidation gave the oxidized derivatives 9, 11 and 13 , respectively. Finally, compound ( 1 ) condensed with acetyl acetone or ethyl acetoacetate gave cyclohexene derivatives ( 14a–c ) and ( 15a,b ), respectively. Compound 15 was oxidized with a Moffat oxidizing agent and afforded the corresponding oxidized compound 16 . The newly synthesized compounds activated the tumor suppressor p53 in cancer cells through inhibition of the p53-specific ubiquitin E3 ligase HDM2.

Volatile oils from the leaves, flowers and rhizomes of Dietes bicolor (Steud.) Sweet ex Klatt (Iridaceae) were analyzed using GLC/FID and GLC/MS. A total of 84 compounds were identified accounting for 94.65, 95.63 and 87.09% in the hydrodistilled oils from flowers, leaves and rhizomes, respectively. Spathulenol (48.44%) represented the major component in the leaf oil, followed by dihydro-edulan I (6.25%), cubenol (6.00%) and τ -cadinol (5.90%). For the flower and rhizome oils, fatty acids, their esters, aliphatic hydrocarbons and their derivatives predominate. The antimicrobial activity of both leaf and flower oils was investigated against four bacteria in addition to four fungi using the micro-broth dilution method. The leaf oil showed a more potent antimicrobial activity as compared to the flower oil against most of the assessed bacteria and fungi, with higher activities against Gram- positive organisms showing MIC values of 115 and 460 μg/ml for Bacillus subtilis and Streptococcus pneumonia , respectively. Gram-negative bacteria were generally less susceptible (MIC > 2 mg/ml for both oils against Escherichia coli ) and being completely ineffective against Pseudomonas aeruginosa . A relevant antifungal potency of the leaf oil against Geotrichum candidum and Syncephalastrum racemosum was also observed with MIC values of 115 and 920 μg/ml, respectively.