抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

The Huisgen 1,3-dipolar cycloaddition reaction of organic azides and alkynes has gained considerable attention in recent years due to the introduction in 2001 of Cu(1) catalysis by Tornoe and Meldal, leading to a major improvement in both rate and regioselectivity of the reaction, as realized independently by the Meldal and the Sharpless laboratories. The great success of the Cu(1) catalyzed reaction is rooted in the fact that it is a virtually quantitative, very robust, insensitive, general, and orthogonal ligation reaction, suitable for even biomolecular ligation and in vivo tagging or as a polymerization reaction for synthesis of long linear polymers. The triazole formed is essentially chemically inert to reactive conditions, e.g. oxidation, reduction, and hydrolysis, and has an intermediate polarity with a dipolar moment of ∼5 D. The basis for the unique properties and rate enhancement for triazole formation under Cu(1) catalysis should be found in the high ∆G of the reaction in combination with the low character of polarity of the dipole of the noncatalyzed thermal reaction, which leads to a considerable activation barrier. In order to understand the reaction in detail, it therefore seems important to spend a moment to consider the structural and mechanistic aspects of the catalysis. The reaction is quite insensitive to reaction conditions as long as Cu(1) is present and may be performed in an aqueous or organic environment both in solution and on solid support.

Cu-catalyzed azide-alkyne cycloaddition.

3.7. Palladium Nanoparticles as Catalysts 888 3.8. Other Transition-Metal Complexes 888 3.9. Transition-Metal-Free Reactions 889 4. Applications 889 4.1. Alkynylation of Arenes 889 4.2. Alkynylation of Heterocycles 891 4.3. Synthesis of Enynes and Enediynes 894 4.4. Synthesis of Ynones 896 4.5. Synthesis of Carbocyclic Systems 897 4.6. Synthesis of Heterocyclic Systems 898 4.7. Synthesis of Natural Products 903 4.8. Synthesis of Electronic and Electrooptical Molecules 906

https://www.chem.ccu.edu.tw/~joyce/referance/ericyang/Chem.%20Rev/Chem.%20Rev.%202007,%20107,%20874-922.pdf

The Sonogashira Reaction: A Booming Methodology in Synthetic Organic Chemistry†

III. Foldamer Research 3910 A. Overview 3910 B. Motivation 3910 C. Methods 3910 D. General Scope 3912 IV. Peptidomimetic Foldamers 3912 A. The R-Peptide Family 3913 1. Peptoids 3913 2. N,N-Linked Oligoureas 3914 3. Oligopyrrolinones 3915 4. Oxazolidin-2-ones 3916 5. Azatides and Azapeptides 3916 B. The â-Peptide Family 3917 1. â-Peptide Foldamers 3917 2. R-Aminoxy Acids 3937 3. Sulfur-Containing â-Peptide Analogues 3937 4. Hydrazino Peptides 3938 C. The γ-Peptide Family 3938 1. γ-Peptide Foldamers 3938 2. Other Members of the γ-Peptide Family 3941 D. The δ-Peptide Family 3941 1. Alkene-Based δ-Amino Acids 3941 2. Carbopeptoids 3941 V. Single-Stranded Abiotic Foldamers 3944 A. Overview 3944 B. Backbones Utilizing Bipyridine Segments 3944 1. Pyridine−Pyrimidines 3944 2. Pyridine−Pyrimidines with Hydrazal Linkers 3945

A field guide to foldamers.

Since the discovery of organic azides by Peter Griess more than 140 years ago, numerous syntheses of these energy-rich molecules have been developed. In more recent times in particular, completely new perspectives have been developed for their use in peptide chemistry, combinatorial chemistry, and heterocyclic synthesis. Organic azides have assumed an important position at the interface between chemistry, biology, medicine, and materials science. In this Review, the fundamental characteristics of azide chemistry and current developments are presented. The focus will be placed on cycloadditions (Huisgen reaction), aza ylide chemistry, and the synthesis of heterocycles. Further reactions such as the aza-Wittig reaction, the Sundberg rearrangement, the Staudinger ligation, the Boyer and Boyer-Aube rearrangements, the Curtius rearrangement, the Schmidt rearrangement, and the Hemetsberger rearrangement bear witness to the versatility of modern azide chemistry.

Organic Azides: An Exploding Diversity of a Unique Class of Compounds

We have studied hybridisation affinities and fluorescence behaviour of intercalator-modified oligonucleotides. The phosphoramidite of (S)-1-O-(4, 4'-dimethoxytriphenylmethyl)-3-O-(1-pyrenylmethyl)glycerol, an intercalating pseudo-nucleotide (IPN), was synthesised and by standard methods inserted into 7mer and 13mer oligodeoxyribonucleotides (ODNs) to generate intercalating nucleic acids (INAs). INAs showed greatly increased affinity for complementary single-stranded DNA (ssDNA), as determined by a thermal stabilisation of the formed DNA/INA duplex of up to 10.9 degrees C per modification when the IPN was added as a dangling end and up to 6.7 degrees C per modification when the IPN was inserted as a bulge. There was a positive stabilisation effect of the formed DNA/INA duplex on introducing a second IPN in the INA strand, when the two IPNs were separated by at least 1 bp. The effect is more pronounced the larger the separation of the two IPNs. Contrary to the enhanced affinity for ssDNA, the IPNs lower the affinity for complementary single-stranded RNA (ssRNA), giving rise to a difference in melting temperature of up to 25.8 degrees C for two IPN insertions in an RNA/INA duplex when compared with the corresponding DNA/INA duplex. In this way INA is able to discriminate ssDNA over ssRNA with identical sequences. Fluorescence measurements show a stronger interaction of the pyrene moiety with DNA than with RNA, indicating intercalation as the stabilising factor in DNA/INA duplexes.

/pdf/intercalating-nucleic-acids-containing-insertions-of-1-o-1-3iexl5bsrg.pdf

Intercalating nucleic acids containing insertions of 1-O-(1-pyrenylmethyl)glycerol: stabilisation of dsDNA and discrimination of DNA over RNA

Compounds having the general formula trans-M II (py) 4 X 2 (M II =V, Mn, Fe, Co, Ni, Ru; X=NCS, Cl, Br, I) have been synthesized, and the vanadium(II) and manganse(II) compounds have been characterized by ESR spectroscopy using the iron, cobalt, nickel, and ruthenium compounds as solid solvents. Furthermore, all compounds prepared have been characterized by means of X-ray powder diffraction and thereby space groups and unit cell parameters have been obtained in most cases

ESR characterization of trans-diacidatotetrakis(pyridine)vanadium and -manganese trans-VII(py)4X2 and trans-MnII(py)4X2 (X = NCS, Cl, Br, I; py = pyridine)

Appropriately substituted 2,3-dihydro-7H-thiazolo[3,2-a]pyrimidin-7-ones 9−12 and 18 were considered as annulated analogues of HEPT (1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine), and some of these compounds were also found active against HIV-1, the most active one being 2,3-dihydro-5-[(3,5-dimethylphenyl)methyl]-3-ethoxy-6-ethyl-7H-thiazolo[3,2-a]pyrimidin-7-one (10b). S-Alkylation of 5-alkyl-6-(arylmethyl)-2-thiouracils 1−4 was performed with 2-bromoacetaldehyde acetals to furnish the S-[bis(alkoxy)ethyl] derivatives 5−8 and with allyl bromide to furnish S-allyl derivatives 17. The target compounds 9−12 were obtained by an N1 regioselective intramolecular cyclization reaction of silylated 5−8 using trimethylsilyl trifluoromethanesulfonate (TMS triflate) as the catalyst. Treatment of the S-allyl derivatives 17 with bromine in dry methylene chloride afforded the 3-(bromomethyl) derivatives 18.

Synthesis and Anti-HIV-1 Activity of Novel 2,3-Dihydro-7H-thiazolo[3,2-a]pyrimidin-7-ones

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are promising drugs for the treatment of HIV when used in combination with other anti-HIV drugs such as nucleoside reverse transcriptase (RT) inhibitors and protease inhibitors. The first generation of NNRTIs have, however, suffered from the rapid development of resistance. This review discusses the properties of the FDA-approved NNRTI drugs and focuses on the recent efforts being made to produce second generation inhibitors that circumvent this resistance problem.

https://journals.sagepub.com/doi/pdf/10.1177/095632029901000601

Non-nucleoside reverse transcriptase inhibitors: the NNRTI boom.

S-Glycosylation took place on reaction of 5-alkylidene- and 5-arylidene-3-aryl-2-thiohydantoins with glycosyl halides under alkaline conditions. Bisglucosylation also took place when N-3 unsubstituted hydantoins were reacted. The bisglucosylated hydantoins produced N-3 glucosylated hydantoins on treatment with ammonia in methanol. In antiviral studies the most active compounds against both HSV-1 and HSV-2 were 5-(2-thienylmethylene)-3-phenyl-2-(2,3,4,6- tetra-O-acetyl-beta-D-glucopyranosyl)-2-thiohydantoin and 5-(2-thienylmethylene)-3-(4-chlorophenyl)-2-(2,3,4,6-tetra-O-acety l-beta-D- glucopyranosyl)-2-thiohydantoin.

Erik B. Pedersen

Papers

Intercalating nucleic acids containing insertions of 1-O-(1-pyrenylmethyl)glycerol: stabilisation of dsDNA and discrimination of DNA over RNA

ESR characterization of trans-diacidatotetrakis(pyridine)vanadium and -manganese trans-VII(py)4X2 and trans-MnII(py)4X2 (X = NCS, Cl, Br, I; py = pyridine)

Synthesis and Anti-HIV-1 Activity of Novel 2,3-Dihydro-7H-thiazolo[3,2-a]pyrimidin-7-ones

Non-nucleoside reverse transcriptase inhibitors: the NNRTI boom.

S-Glucosylated hydantoins as new antiviral agents