Four new stilbenes and one new flavonoid with potential antibacterial and anti-SARS-CoV-2 activity from Cajanus cajan.

Four new stilbenes (1-4) and one new flavonoid (5), named cajanines D-H, together with three known stilbenes (6-8) were isolated from the leaves of Cajanus cajan (L.) Millsp. (pigeon pea). The structures of these compounds were elucidated unambiguously on the basis of IR, 1D, and 2D NMR, as well as HRESIMS data. Structurally, stilbenes 1-4 bore an isopentyl side chain, and further hydroxylation of compounds 1-3 generated a greater variety of structural forms. Compound 5 was a flavonoid owning an isopentyl side chain. Besides, antibacterial activity of the isolated compounds against Staphylococcus aureus, Bacillus cereus, and Escherichia coli was studied in vitro. Compounds 1-8 were endowed with profound antibacterial activity. Among them, the MIC values of compounds 4, 6, and 7 against S. aureus were 1.56, 0.78, and 0.78 µg/mL, respectively, among which 6 and 7 had better antibacterial activity than the positive control Vancomycin with the MIC values of 1.56 µg/mL. Additionally, the anti-SARS-CoV-2 main protease activity of all the isolated compounds was evaluated, and it was worth mentioning that the IC50 values of compounds 5-7 were 8.27, 4.65, and 8.30 µM, respectively, being comparable to the positive control Ebselen. Our findings may provide valuable guidance for the application of stilbenes as lead compounds in the future for the development of drugs with antibacterial or anti-COVID-19 activity.

Four new eudesmane-type and one new eremophilane-type sesquiterpenes from the whole plant of Carpesium abrotanoides L.

The extract of the whole plant of Carpesium abrotanoides L. yielded five new sesquiterpenes including four eudesmanes (1-4) and one eremophilane (5). The new compounds were characterized by spectroscopic analysis especially 1D and 2D NMR spectroscopy and HRESIMS data. Structurally, both compounds 1 and 2 were sesquiterpene epoxides and 2 owned an epoxy group at C-4/C-15 position to form a spiro skeleton. Compounds 4 and 5 were two sesquiterpenes without lactones and 5 possessed a carboxy group in the molecule. Additionally, all the isolated compounds were preliminarily evaluated for the inhibitory activity against SARS-CoV-2 main protease. As a result, compound 2 showed moderate activity with an IC50 value of 18.79 µM, while other compounds were devoid of noticeable activity (IC50 > 50 µM).

Nanohollow Titanium Oxide Structures on Ti/FTO Glass Formed by Step-Bias Anodic Oxidation for Photoelectrochemical Enhancement.

In this study, a new anodic oxidation with a step-bias increment is proposed to evaluate oxidized titanium (Ti) nanostructures on transparent fluorine-doped tin oxide (FTO) on glass. The optimal Ti thickness was determined to be 130 nm. Compared to the use of a conventional constant bias of 25 V, a bias ranging from 5 V to 20 V with a step size of 5 V for 3 min per period can be used to prepare a titanium oxide (TiOx) layer with nanohollows that shows a large increase in current of 142% under UV illumination provided by a 365 nm LED at a power of 83 mW. Based on AFM and SEM, the TiOx grains formed in the step-bias anodic oxidation were found to lead to nanohollow generation. Results obtained from EDS mapping, HR-TEM and XPS all verified the TiOx composition and supported nanohollow formation. The nanohollows formed in a thin TiOx layer can lead to a high surface roughness and photon absorbance for photocurrent generation. With this step-bias anodic oxidation methodology, TiOx with nanohollows can be obtained easily without any extra cost for realizing a high current under photoelectrochemical measurements that shows potential for electrochemical-based sensing applications.

[Implantation of phakic anterior chamber intraocular lens for high myopia]

OBJECTIVE: To investigate the efficacy and safety of the implantation of phakic anterior chamber intraocular lens for high myopia. METHODS: A consecutive group of 29 eyes in 16 patients with (-7.00 to -30.00) D of myopia were implanted. RESULTS: All of the 29 eyes were implanted successfully and followed-up 3 approximate, equals 6 months. The mean best corrected visual acuity was 0.50+/-0.26 pre-operatively and 0.73+/-0.263 months post-operatively, there was no significant difference t=2.043, P=0.051 . The mean refractive diopter was -18.03+/-5.54 D pre-operatively and -0.82+/-1.54 D post-operatively t=30.899 P=0.000 ; The mean intraocular pressure was 2.091+/-0.380 kPa pre-operatively and (1.734+/-0.572)kPa post-operatively t=1.98 P=0.07 ; The mean counts of endothelial cells was (2704+/-390 /mm2 pre-operatively and (2 519+/-278)/mm2 post-operatively (t=1.16 P=0.26). CONCLUSION: The implantation of phakic anterior chamber intraocular lens for high myopia is predictable, reversible and controllable with simple manipulation. Long- time following-up is still required.