# Unusual Pharmacophores and New Tools for Cross-Coupling

> **NIH NIH R35** · SCRIPPS RESEARCH INSTITUTE, THE · 2020 · $70,912

## Abstract

Project Summary/ Abstract
 Bioassay-guided fractionation of cells often uncovers small molecules that bind
macromolecular targets in new and unexpected ways. Exploration of the chemical reactivity and
target selectivity of these metabolites has laid the chemical foundation for the development of
new biological tools and therapeutics. The molecular architecture of secondary metabolites is
challenging and different than the chemical space explored by most medicinal chemistry
campaigns: there is recognized `natural product-like' space and we lack the tools to explore it
with the same depth as `drug-like' space. Our lab has developed new tools to more easily
access natural products, and has focused our efforts on secondary metabolite families that
appear to covalently modify their targets as the basis for their phenotypic effects. Our chemical
syntheses are deliberately concise and easily-scaled to enable subsequent investigation into
reactivity and biological activity. The current application significantly advances these efforts,
provides compelling preliminary data as a foundation for the proposed work, and delves into
new areas of chemistry.
 In this proposal, two areas of research are described: 1. the identification and
investigation of covalently-reactive pharmacophores associated with the asmarine alkaloids,
Nuphar dimers and isocyanoterpenes; and 2. the development of cross-coupling technology to
access `natural product-space' more generally. In the first area, we disclose a preliminary
cellular target of the unusual N-hydroxydiazepine purine (HAP) pharmacophore of the asmarine
alkaloids and address unsolved problems posed by this motif. As part of a theme that runs
throughout our work, we show how the aims of chemistry and biology intersect in the study of
covalently reactive secondary metabolites. We also investigate the sulfur-electrophilicity of the
Nuphar dimers, a property recently demonstrated by our lab to operate in organic solvent and
cellular environments. We propose solutions to the challenging stereochemical problems posed
by the monohydroxy dimers and show how chemistry developed in our lab can generate a
combinatorial library of sulfur electrophiles. In a third area, we investigate the challenging
architecture and reactivity of the isocyanoterpenes, which we recently demonstrated can kill
Plasmodia by an alternative mechanism to the heme detoxification pathway often suggested.
We also propose a novel caging strategy to render the isonitriles systemically-viable. In part two,
we investigate a bimetallic catalytic cycle capable of solving long-standing problems in chemical
synthesis. The proposed methodology is supported by proof-of-principle examples and provides
chemists the reaction vehicles necessary to `escape from flatland.'

## Key facts

- **NIH application ID:** 10135614
- **Project number:** 3R35GM122606-04S1
- **Recipient organization:** SCRIPPS RESEARCH INSTITUTE, THE
- **Principal Investigator:** Ryan Ashok Shenvi
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $70,912
- **Award type:** 3
- **Project period:** 2017-04-01 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10135614

## Citation

> US National Institutes of Health, RePORTER application 10135614, Unusual Pharmacophores and New Tools for Cross-Coupling (3R35GM122606-04S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10135614. Licensed CC0.

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