Undoped n‐InP and Zn‐doped p‐InP are grown by the SSD method. Hall measurements on wafers cut from the polycrystalline n‐InP ingots give values between 1015 and 1016 cm−3 for the carrier concentration averaged over the crystallites of the wafer. From the electron mobilities measured at 77 K on single crystalline samples (maximally 5.0 × 104 cm2/Vs) it can be concluded on the high purity and perfection of this material. Zn doping yields p‐InP with p = (3 to 4) × 1016 cm−3and μ = (113 to 140) cm2/Vs atroom temperature. The hole mobilities at 77 K(1700 to 2160 cm2/Vs) are the highest ones reported for InP up to now. By fitting of the p(T) curves between 30 and 500 K concentrations and activation energies for the shallow acceptor Zn and for a medium deep acceptor present beside Zn are determined.
Appendage of an amphiphilic chain by exploiting the nitrogen installed on the 6-aza-artemisinin imparted self-assembling properties. The fully synthetic 6-aza-artemisinin formed aggregates and exhibited increased in vitro anti-cancer activities.
To
achieve both structural changes and rapid synthesis of the tetracyclic
scaffold relevant to artemisinins, we explored two kinds of de novo synthetic approaches that generate both skeletally
diversified tetracyclic peroxides and 6-aza-artemisinins. The anti-malarial
activities of the tetracyclic peroxides with distinct skeletal arrays,
however, were moderate and far inferior to artemisinins. Given the
privileged scaffold of artemisinins, we next envisioned element implantation
at the C6 position with a nitrogen without the trimmings of substituents
and functional groups. This molecular design allowed the deep-seated
structural modification of the hitherto unexplored cyclohexane moiety
(C-ring) while keeping the three-dimensional structure of artemisinins.
Notably, this approach induced dramatic changes of retrosynthetic
transforms that allow an expeditious catalytic asymmetric synthesis
with generation of substitutional variations at three sites (N6, C9,
and C3) of the 6-aza-artemisinins. These de novo synthetic
approaches led to the lead discovery with substantial intensification
of the in vivo activities, which undermine the prevailing
notion that the C-ring of artemisinins appears to be merely a structural unit but to be a functional area
as the anti-malarial pharmacophore. Furthermore, we unexpectedly found
that racemic 6-aza-artemisinin (33) exerted exceedingly
potent in vivo efficacies superior to the chiral
one and the first-line drug, artesunate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.