Nanobiotechnology and nanomedicine: small change brings big difference

正The physicist Richard Feynman put forward the concept of nanotechnology in his famous speech,"There’s Plenty of Room at the Bottom,"at the annual meeting of the American Physical Society on December 29,1959.He began with a"bottom up"approach and proposed assembling from a single molecule or even an atom to meet the requirements of the design.He indicated that the laws of physics do not rule out the possibility of making an object by atom stack and     

Callicarpanes A–L,Twelve New Clerodane Diterpenoids with NLRP3 Inflammasome Inhibitory Activity from Callicarpa integerrima

Twelve new clerodane diterpenoids named callicarpanes A–L ( 1 – 12 ), together with eight known compounds ( 13 – 20 ), were isolated from Callicarpa integerrima. Their structures were determined by comprehensive spectroscopic data. The calculated chemical shifts were used to identify relative configurations using DP4+ analysis. The absolute configurations (AC) were assigned based on quantum chemical calculations and X-ray single-crystal diffraction methods. Compounds 1 , 3 , 5 , 9 , 10 , 12 , 15 , 16 , and 19 showed significant inhibitory activity for NLRP3 inflammasome activation, with the IC₅₀ against lactate dehydrogenase (LDH) release ranging from 0.08 to 4.78 μM. Further study revealed that compound 10 repressed IL-1β secretion and caspase-1 maturation in J774A.1 cell as well as blocked macrophage pyroptosis.     

Chemical Constituents of the Branches and Leaves of Picrasma chinensis P.Y. Chen and Tyrosinase Inhibiting Activity

One new alkaloid, picrasine A, two new quassinoids, picralactones A−B, together with eleven known compounds were isolated from Picrasma chinensis P.Y. Chen. The structures of these compounds were determined using 1D and 2D NMR, HR-ESI-MS, and IR spectroscopic data, and by comparison with published data. Some compounds were tested for tyrosinase inhibiting activity, however, none of them exhibited strong inhibitory effects.     

Structural modifications of 5,6-dihydroxypyrimidines with anti-HIV activity

A series of 5,6-dihydroxypyrimidine analogs were synthesized and evaluated for their anti-HIV activity in vitro. Among all of the analogs, several compounds exhibited significant anti-HIV activity, especially 1b and 1e, which showed the most potent anti-HIV activity with EC₅₀ values of 0.14 and 0.15 μM, and TI (therapeutic index) values of >300 and >900, respectively. Further docking studies revealed that the representative compounds 1e and 3a could meet the HIV-1 integrase inhibition minimal requirements of a chelating domain (two metal ions) and an aromatic domain (π–π stacking interactions).