Kyung Ran Kim

Synthesis of novel L-N-MCd4T as a potent anti-HIV agent

L-N-MCd4T (1) has been synthesized as a potent anti-HIV agent starting from (R)-epichlorohydrin using tandem alkylation, chemoselective reduction of ester in the presence of lactone functional group, RCM reaction and Mitsunobu reaction as key steps and was found to be a very potent anti-HIV-1 (EC50 = 6.76 microg mL(-1)) agent without cytotoxicity up to 100 microg mL(-1), indicating that the anti-HIV-1 activity found is similar to that of ddI (EC50 = 4.95 microg mL(-1)), which is used clinically for the treatment of AIDS patients.

Design, synthesis, and biological evaluation of novel iso-D-2',3'-dideoxy-3'-fluorothianucleoside derivatives.

Abstract Novel iso-d-2′,3′-dideoxythianucleoside derivatives 1–4 were designed and asymmetrically synthesized as a bioisostere of lamivudine to search for new anti-HIV agents. The information about using sulfur participation occurred on DAST fluorination and Mitsunobu reaction will be of great help in synthesizing sulfur-containing compounds. Final compounds 1–4 were evaluated against HIV-1 and 2, HSV-1 and 2, EMCV, Cox. B3, VSV, FluA (Taiwan), FluA (Johan.), FCV, and FIP. Only cytosine analogue 3 showed a potent anti-VSV activity (EC50 =9.43μg/mL). This result implies that iso-2′,3′-dideoxy sugar templates might play a role of a sugar surrogate of nucleosides for the development of anti-RNA virus agent.

STEREOSELECTIVE SYNTHESIS OF CONFORMATIONALLY RIGID APIO CARBANUCLEOSIDES AS POTENTIAL ANTIVIRAL AGENTS

Apio north-methanocarbocyclic nucleosides 1–3 with bicyclo[3.1.0]hexane template were first synthesized. Introduction of hydroxymethyl substituent was efficiently and stereoselectively accomplished by aldol and retro-aldol reaction and fixed conformation was achieved from a modified Simmons-Smith cyclopropanation on a cyclopentane ring.

Synthesis of enantiopure pseudo-L-vinylcyclopropyl nucleosides bearing quaternary carbon as potential anti-herpesvirus agent.

Pseudo-l-vinylcyclopropyl adenine and guanine nucleosides 11 and 12 were designed and enantiopurely synthesized starting from (S)-epichlorohydrin using tandem alkylation, regioselective oxirane-ring opening, and chemoselective reduction as key steps.

Asymmetric synthesis and biological activity of L-bicyclocarba-d4T.

Novel l-bicyclocarba-d4T (1), an enantiomer of d-N-MCd4T has been enantiopurely synthesized as a potent anti-HIV agent starting from (R)-epichlorohydrin using tandem alkylation, chemoselective reduction of ester in the presence of lactone functional group, Grignard reaction, RCM reaction, and Mitsunobu reaction as key steps. l-N-MCd4T (1) was found to be very potent anti-HIV-1 (EC50 = 6.76 μg/mL) agent with no cytotoxicity.

Design, Enantiopure Synthesis, and Biological Evaluation of Novel ISO-D-2′,3′-Dideoxy-3′-Fluorothianucleoside Derivatives as a bioisostere of Lamivudine

Novel iso D-2′,3′-dideoxythianucleoside derivatives 1–3 were designed and asymmetrically synthesized to search for new anti-HIV agents. Final compounds 1–3 were evaluated against a variety of viruses including HIV-1 and 2. Only cytosine analog 3 showed a potent anti-VSV activity (EC 50 = 9.43 μ g/mL). This result implies that iso 2′,3′-dideoxy sugar templates might play a role of a sugar surrogate of nucleosides for the development of anti-RNA virus agent.

Asymmetric Synthesis of Apio Fluoroneplanocin a Analogs as Potential AdoHcy Hydrolase Inhibitor

Apio fluoroneplanocin A (apio F-NPA, 3) and its uracil analogue 4 have been designed and asymmetrically synthesized starting from D-ribose. Introduction of fluoro group into vinylic position of 5 was accomplished successfully over 5 steps employing key reactions such as iodination according to an addition-elimination reaction mechanism, stereo- and regioselective reduction of α,β -unsaturated ketone, and electrophilic fluorination. This methodology can be adapted to the synthesis of fluoro compounds extensively.

Asymmetric Synthesis of Novel Pseudo-d-Vinylcyclopropyl Nucleosides Bearing Quaternary Carbon as Potential Anti-Herpesvirus Agent

Pseudo-d-vinylcyclopropyl nucleosides 10–12 bearing a quaternary carbon were designed and synthesized starting from (R)-epichlorohydrin using a tandem reaction of double alkylation and lactonization via oxirane-ring opening reaction, a Wittig reaction, and chemoselective reduction as potential anti-herpesvirus agent.