The development of boron agents with integrated functionality, including biocompatibility, high boron content, and cancer cell targeting, is desired to exploit the therapeutic efficacy of boron neutron capture therapy (BNCT)....

The prevalence of allergic disorders has increased worldwide in recent decades. Polyphenols, including resveratrol and curcumin, are posited to have potential as therapeutic agents for allergy; however, their use has been limited by poor water solubility. Accordingly, a highly concentrated, water dispersible, supramolecular complexes of polyphenols with polypeptides (poly‐L‐lysine, poly‐γ‐glutamic acid) and gelatin using high‐speed vibration milling are developed. The complex exhibits resistance to photobleaching and thermal radiation. Treatment of a rat basophilic leukemia cell line (RBL‐2H3) with polypeptide complexes containing resveratrol is suppressed allergic responses in vitro. Moreover, aerosolized administration of polypeptide complexes demonstrates excellent bioavailability and inhibition of immediate hypersensitivity reactions in ear tissue in vivo. Furthermore, the method avoids the use of organic solvent and therefore reduces undesirable biological responses.

A triple‐layered trisporphyrin molecule possessing two cleft cavities showed negative homotropic cooperativity in the host–guest complex. When an electron‐deficient guest molecule (yellow) was accommodated within one of the cleft cavities, the electronic structure of the porphyrin was altered, and the binding power of the remaining cavity was reduced. More information can be found in the Research Article by T. Haino and co‐workers (DOI: 10.1002/chem.202300107).

Invited for the cover of this issue is the group of Takeharu Haino at Hiroshima University. The image depicts the host–guest complex of a trisporphyrin double cleft with an electron‐deficient aromatic molecule, which shows negative cooperativity in guest binding. Read the full text of the article at 10.1002/chem.202300107.

The negative homotropic allostery of a triple‐layered trisporphyrin cleft with two guest binding sites is confirmed. The X‐ray crystal structures of the 1 : 2 host‐guest complexes showed that the trisporphyrin accommodated two guest molecules within the cleft through π–π stacking and donor‐acceptor interactions. In solution, 1H NMR and Job plots showed 1 : 2 host‐guest complexes. Isothermal titration calorimetry (ITC) and UV/vis absorption spectroscopy were employed to evaluate the binding constants and cooperativities. The guest binding of the trisporphyrin showed negative cooperativity and non‐cooperativity depending on the structures of the guest molecules. The correlations between the interaction parameters (α) and Hill constants were determined. ITC experiments showed that the host‐guest complexation of trisporphyrin with electron‐deficient guests incurred an enthalpy penalty in the successive guest binding process. DFT calculations revealed that binding of the first guest reduced the electron density of the central porphyrin plane, which led to an energetic penalty that weakened the successive binding process.