Isolation of a new quinic acid derivative and its antibacterial modulating activity.

BACKGROUND AND THE PURPOSE OF THE STUDY: The species Hymenocrater calycinus, belongs to the plant family Lamiaceae and grows wildly in the north-east of Iran. Previously, the antimicrobial activity of the plant extracts was reported. In the present study, the bioactivity-guided fractionation of the methanol extract of H. calycinus and the combination effects of the isolated compound with cell wall active agents against S. aureus and E. coli was investigated. METHODS: Column and thin layer chromatographic methods were used for isolation and purification and spectroscopic data (MS, (1)H- and (13)C-NMR, HMQC, HMBC and (1)H-(1)H COSY) were employed for identification of the compound isolated from the extract. A disk diffusion method was used to determine the antibacterial activity of the isolated compound against S. aureus and E. coli in comparison with 7 different antibiotics. RESULTS: The isolated compound 1 was identified as 3-(3, 4- dihydroxyphenyl) lactic acid 2-O-quinic acid. Compound 1 (500 µg/disc) enhanced antibacterial effect of ampicillin, ciprofloxacin, vancomycin and cefepime against S. aureus and activated the effects of ampicillin and vancomycin against E. coli. CONCLUSION: Results showed that the compound 1 was not active against both tested strains at any concentration below 1 mg/disk, and as a result the enhancing effect of the compound could be due its association with antibiotics.

Free radical scavenging and lipid peroxidation activity of the Shahani black grape.

The present study was designed to evaluate antioxidant activity of different parts of Shahani black grape berries. The antioxidant activity of grape berry juice, seed and skin extracts were measured by the inhibition of lipid peroxidation (Ferric Ammonium Thiocyanate) and free radical scavenging activity (2, 2-diphenyl-l-picrylhydrazyl) methods. Vitamin E and Butylated Hydroxy Toluene (BHT) were used as reference values. The free radical scavenging capacity of grape extracts followed this order: seed methanol extract> skin extract> grape juice> seed hexane extract. Meanwhile, inhibitions of lipid peroxidation of seed methanol and hexane extracts were the highest, grape skin extract activity was intermediate and that of grape juice was the lowest. It seems that the antioxidant activity of samples from grape seed and skin extracts to be mainly based on inhibition of lipid peroxidation, whereas the Antioxidant Activity of grape juice is based on free radical scavenging activity. The results indicate that Shahani black grape has potent antioxidant activity specially on lipid peroxidation and has beneficial effects on human health and help to prevent disease which are caused by free radicals.

New pyrrolizidine alkaloids from Heliotropium crassifolium.

Heliotropium crassifolium Boiss, (Boraginaceae) from a population of Ilam, western region of Iran was studied for pyrrolizidine alklaoids (PAs). Four alkaloids have been identified: europine 1, europine N-oxide 2 and a new pyrrolizidine alkaloids ilamine 3 and its N-oxide 4, respectively. Their structures were elucidated by IR, 1H-NMR and EIMS data.

Precision surgery with an electromagnetically induced current convergence probe application in aneurysm treatment, angioplasty, and brain tumor resection in in vivo and in vitro models.

A hand-held probe, or one introduced through a catheter, rapidly produces an extremely high, tissue-vaporizing temperature in a precisely defined manner enabling surgeons or interventional radiologists to perform angioplasty, thrombose aneurysms, and vaporize tumors. The probe is operated in a near field of an inductive coil, and the current induced in the biologic tissue is converged maximally at the tip of the probe at the resonance frequency of both the inductor and the probe, producing a maximum temperature in excess of 1400 degrees C. Radio-frequency power controls the probe-tip temperature. The operation of the probe is comparable to that of a CO2 or YAG laser and is complementary to laser-surgical techniques. The low cost relative to lasers and simplicity of the device including its disposable components make the prospect of commercialization of this device promising.