Bioorganic & Medicinal Chemistry Letters
Antimicrobial evaluation and action mechanism of pyridinium-
decorated 1,4-pentadien-3-one derivatives
a
a
b
a,b,
Jian Zhou a, Qing-Qing Tao a, Pei-Yi Wang a, , Wu-Bin Shao , Zhi-Bing Wu , Zhong Li , Song Yang
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a State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of
Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang 550025, China
b College of Pharmacy, East China University of Science & Technology, Shanghai 550025, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 8 February 2018
Revised 5 April 2018
Accepted 13 April 2018
Available online 16 April 2018
A type of pyridinium-decorated 1,4-pentadien-3-one derivatives possessing flexible alkyls were designed
and synthesized by integrating the key scaffolds of pyridinium cations and 1,4-pentadien-3-one skeleton
in a single molecular architecture. Antimicrobial bioassays indicated that some of the target molecules
exerted considerable bioactivities against six phytopathogenic strains, especially for Xanthomonas oryzae
pv. oryzae, the minimal EC50 value can reach to 0.504 mg/mL. A plausible action mechanism for this kind of
compounds was proposed and confirmed by employing fluorescent spectroscopy, fluorescence micro-
scopy, and scanning electron microscopy. We anticipated that this finding can promote high-efficient
lead compounds discovery in the research of antimicrobial chemotherapy.
Keywords:
Pyridinium
1,4-Pentadien-3-one
Synthesis
Ó 2018 Elsevier Ltd. All rights reserved.
Action mechanism
Antimicrobial
Microbial infection has become one of the world’s largest agri-
cultural issues, not only due to the significant threats they impose
on agricultural products, but also the potential risks associated
with human health.1–3 To address this issue, antimicrobial drugs
have been extensively developed and widely used to treat infec-
tious diseases and reduce the infection and spread of pathogenic
microorganism, such as bismerthiazol (BT), thiodiazole copper
(TC), and streptomycin. However, long-term and abuse of
traditional antimicrobial agents had induced the emergence of
resistance in the pathogenic microorganism,4,5 resulting in poor
treatment efficacy and even large economic losses, which gives
us great challenges to manage this new circumstance. Therefore,
developing alternative drugs or rational treatment methods to
attack pathogenic microorganism through unique mechanisms or
render them unable to resist the treatment is an important
research topic for chemists.
of bioactive molecules based on naturally occurring products have
aroused extensive interest by scientists owing to their privileged
performances including inartificial structural features, good
physicochemical property, superior biocompatibility, low mam-
malian toxicity, environmental friendliness, specificity for the tar-
get species, and unique modes of action.10–14 1,4-Pentadien-3-one
derivatives and analogues, derived from plant metabolic products
curcumin, were discovered with an impressive array of pharmaco-
logical activities such as anticancer, antiviral, and anti-inflamma-
tory.15–20 Because 1,4-pentadien-3-one moiety performs a key
role in the determination of the final bioactivity of target
compounds, continuous efforts and repeatedly numerous studies
on this functional scaffold opened a new avenue for the discovery
of novel, high-efficient bioactive substrates, especially in the
anticancer and antiviral fields.21–25 However, few studies were per-
formed via using this kind of compounds in growth suppression of
plant pathogenic microorganism.
Considerable efforts and investment are being devoted to the
exploration and development of novel, high-efficient antimicrobial
substances, leading to an array of designed compounds with
admirable pharmacological activities.6–9 Particularly, fabrication
As another stimulating key fragment in the exploration and
development of novel antimicrobial candidates, pyridinium
scaffold has been extensively investigated for the crucial role in
reforming the bioactivity of final target compounds due to the pos-
itive charge can promote their specificity for the target species.26–
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29
Corresponding authors at: State Key Laboratory Breeding Base of Green
Herein, an array of pyridinium-decorated 1,4-pentadien-3-one
Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and
Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chem-
icals of Guizhou University, Guiyang 550025, China.
derivatives were constructed via coupling a key fragment of
pyridinium scaffold into 1,4-pentadien-3-one structures linked
by flexible alkyls of different lengths (Fig. 1A). The alkyl chains
(S. Yang).
0960-894X/Ó 2018 Elsevier Ltd. All rights reserved.