A Novel 4H-Chromen-4-One Derivative from Marine Streptomyces ovatisporus S4702T as Potential Antibacterial and Anti-Cancer Agent.

BACKGROUND: Marine actinomycetes are among indispensable sources of natural bioactive compounds with unique antimicrobial and anti-cancer activities. OBJECTIVE: Herein, it was aimed to elucidate the bioactive potential of a marine-derived Streptomyces ovatisporus S4702T, isolated previously. METHODS: Streptomyces ovatisporus S4702T was cultured in N-Z Amine broth, and extraction was carried out using different organic solvents. Bioassay-guided purification was followed by chemical characterization using NMR and LC-MS/MS. The compound was then evaluated for its antibacterial, antioxidant and cytotoxic activities. RESULTS: Etyl acetate extracts gave the highest antibacterial activity, and chemical characterization of this extract indicated the formula as C15H29O5N3 and the corresponding possible molecular structure as 4H-chromen-4-one derivative. It was found highly potent against Bacillus subtilis ATCC 6633 (MIC: 0.25 µg ml-1) and Micrococcus luteus ATCC 9341 (MBC: 0.5 µg ml-1). It has no remarkable antioxidant activity, but a higher EC50 value and less cytotoxicity against normal cells. The EC50 values of this chromen derivative were found as 9.68 µg ml-1 for human colon carcinoma, 9.93 µg ml-1 for human prostate adenocarcinoma and 25.5 µg ml-1 for human embryonic kidney cells. CONCLUSION: Overall, the presented 4H-chromen-4-one derivative is a remarkable bioactive compound with potent antibacterial and cytotoxic activity. With its high bioactive potential, it is proposed as a good candidate in medicine.

Hemodynamics of the temporal and nasal short posterior ciliary arteries in pseudoexfoliation syndrome.

PURPOSE: The aim of this study was to investigate blood flow changes in the temporal and nasal short posterior ciliary arteries (SPCAs) in pseudoexfoliation syndrome using color Doppler ultrasonography. METHODS: This prospective clinical study included 67 eyes of 53 patients scheduled for cataract surgery. Pseudophakic eyes, eyes with traumatic cataract, were excluded. The demographic characteristic of the patients were recorded. Ocular blood flow was measured using 6-10 MHz Doppler ultrasound. Peak systolic velocity (PSV), end-diastolic velocity (EDV), mean flow velocity (Vm), and resistive index (RI) in the temporal and nasal SPCAs were determined for 39 eyes of 30 patients with pseudoexfoliation syndrome and cataract and a control group comprising 28 eyes of 23 patients with senile cataract. RESULTS: Compared to the control group, patients with pseudoexfoliation syndrome had significantly lower PSV (8.85 ± 2.88 cm/s), EDV (3.21 ± 1.12 cm/s), and Vm (5.27 ± 1.98 cm/s) in the temporal SPCA (PSV P = .001; EDV P = .002; Vm P = .001). There was no difference in velocities in the nasal SPCA. RI of both the temporal and nasal SPCA did not differ statistically between the groups (temporal SPCA P = .517, nasal SPCA P = .752) CONCLUSION: There were significant decreases in temporal SPCA hemodynamic parameters in patients with pseudoexfoliation syndrome. These findings suggest that temporal SPCA ocular blood flow measurements have greater diagnostic value than those of the nasal SPCA.