Browsing by Author "Das, Anindya"

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Design and synthesis of 1,2,3-triazole-containing N-acyl zanamivir analogs as potent neuraminidase inhibitors
(2016-11-10)
Das, Anindya
;
Adak, Avijit K.
;
Ponnapalli, Kalyankumar
;
Lin, Chien-Hung
;
Hsu, Kai-Cheng
The design of potent metabolically stable neuraminidase (NA) inhibitors represents an attractive approach for treating influenza virus infection. In this study, we describe the exploitation of the 150-cavity in the active site of group 1 NA for the design, synthesis, and in vitro evaluation of new triazole-containing N-acyl derivatives related to Zanamivir. Inhibition studies with influenza virus NAs of group 1 (H1N1) and group 2 (H3N2) revealed that several of them are good inhibitors, with IC50 values in the low nanomolar (2.3 nM-31 nM) range. Substituents that form stable van der Waals interaction with the 150-cavity residues play crucial roles in NA inhibition as demonstrated by the potency of 6a (H1N1 IC50 = 23 nM, and H3N2 IC50 = 2.9 nM). Docking studies indicated that the cyclohexane-substituted triazole ring extended toward the hydrophobic region in the active site of group 1 NA in open form. The high potency observed for inhibitor 6a may be attributable to the highly favorable hydrophobic interactions in this region. (C) 2016 Elsevier Masson SAS. All rights reserved.
Stereoselective synthesis of a 9-O-sulfo Neu5Gc-capped O-linked oligosaccharide found on the sea urchin egg receptor
(2019-01-07)
Das, Anindya
;
Li, Pei-Jhen
;
Adak, Avijit K.
;
Wu, Hsin-Ru
;
Anwar, Mohammad Tarique
A straightforward synthesis of the (25)-linked 9-O-sulfated Neu5Gc-capped O-linked tetrasaccharide (1) identified in the egg cell surface glycoproteins of the sea urchin Strongylocentrotus purpuratus receptor for sperm is reported. The construction of the (25)Neu5Gc trimer by the formation of an amide linkage rather than a glycosidic bond avoids the requirement for -stereoselective glycosylation. To highlight this amide bond formation strategy as a relatively facile method for synthesizing oligo-Neu5Gc containing O-linked glycans, its versatility is demonstrated by application to the coupling of SO3H-9Neu5Gc(25)Neu5Gc glycolic acid and a sialyl-Tn-derived amine for achieving the target tetrasaccharide. This synthetic strategy may be implemented in the generation of other structurally similar O-sulfo Neu5Gc-capped 25-O-glycolyl-linked oligo-Neu5Gc chains, enabling additional biological and chemical investigations.
Synthesis of acylguanidine zanamivir derivatives as neuraminidase inhibitors and the evaluation of their bio-activities
(2013)
Lin, Chien-Hung
;
Chang, Tsung-Che
;
Das, Anindya
;
Fang, Ming-Yu
;
Hung, Hui-Chen
A series of acylguanidine-modified zanamivir analogs were synthesized and their inhibitory activities against the NAs of avian influenza viruses (H1N1 and H3N2) were evaluated. In particular, zanamivir derivative 3j, with a hydrophobic naphthalene substituent, exhibits the best inhibitory activity against group-1 NA with an IC50 of 20 nM.
trans-Stilbene C-Glycosides: Synthesis by a Microwave-Assisted Heck Reaction and Evaluation of the SGLT-2 Inhibitory Activity
(2017-09-01)
Ponnapalli, Kalyana Kumar
;
Adak, Avijit Kumar
;
Das, Anindya
;
Song, Jen-Shin
;
Wu, Szu-Huei
A protocol for the microwave-assisted Heck coupling reaction of C-aryl glycosides and styrenes has been developed for the synthesis of mono-and bis(C-glycoside) stilbenes. This method exclusively provides C-glycoside trans-stilbenes in good yields. The Pd-catalyzed Heck coupling re-action was successfully applied to various functionalized C-glycosyl aryl iodides and various substituted styrenes to deliver several C-glycoside trans-stilbenes with high selectivity. The obtained C-glycosyl trans-stilbenes were also examined for human SGLT-2 inhibitory activity.