Synthesis and biological evaluation of novel bile acid-nucleoside conjugates

published results and work in progress

Maria Luisa NAVACCHIA

CNR ISOF

CNR-ISOF

Massimo Capobianco

Maria Luisa Navacchia

UNIFE-Dipartimento di Scienze Chimiche e Farmaceutiche

Daniela Perrone

Elena Marchesi

Lara Mari

UNIFE-Dipartimento di Scienze Chimiche Mediche

Riccardo Gavioli

Fabio Sforza

biological evaluation

•synthesis and characterization of

modified bile acids

• click-chemistry

synthesis and characterization

of modified nucleosides

Synthesis of: 3a-azido-bile acids and 8-alkynylic-2’-deoxyadenosines

Conjugate synthesis via click-chemistry

i: CuSO4 . 5 H2O, sodium ascorbate, THF–tBuOH–H2O (1.5 : 1 :1), 25 °C, 18 h, 70%; or microwave 80 °C, 30 min, 73%.

Synthesis of 8-alkynylated-2’-deoxyadenosines

This reaction can be smoothly performed in water and leads to a simple purification of the thioalkylnylated

nucleoside that only requires the extraction of the compound with warm EtOAc from the aqueous crude mixture.

M. L. Capobianco and M. L. Navacchia PCT Int. Appl. WO 2012164484 A1 2012

This reaction can be smoothly performed and leads to a simple purification of the alkylnylated

nucleoside that requires a filtration on florisil.

n

N

NN

N

NH2

O

OH

OH

BrN

NN

N

NH2

O

OH

OH

n

DMF

Pd(PPh3)2Cl2CuI

50 °C

+

n = 3

SH

N

NN

N

NH2

O

OH

OH

BrN

NN

N

NH2

O

OH

OH

S

+H2O, TEA

100 °C, 2 h3

3

Biological evaluation

in vitro cytotoxicity toward human fibroblast cells and anti-proliferative activity against four human

cancer cell lines: Leukemic T Jurkat and K562, colon carcinoma HCT116 and ovarian cancer A2780

Cytotoxic activity of bile acid-based conjugates and

alkynyl deoxyadenosines dA-A, HdA-A, and SdA-A on human cancer cell lines and human fibroblast cellsa

Anti-proliferative activity of conjugated compounds against the K562 cell line

Percentage of apoptotic K562 cells determined after 24 h treatment with HdA-CDC, SdA-CDC and HM-CDC (50–10 mM) by annexin V staining.

Conclusion

• Best activity was shown by CDC- based derivatives and could be correlated to the lipophilicity and to the 7a-OH group orientation;

• furthermore, except dA-UDC and HM-bile acid series, all new conjugates did not show any significant cytotoxicity towards the human fibroblast cells whereas some of them strongly and selectively inhibited cell proliferation and induced apoptosis in leukemic K562 cells; • therefore, these derivatives constitute a starting lot of candidate drugs.

O

OMe

OH

X

…however many questions are still open

Do other nucleobases work?

Does the ribo form work?

How much important is the triazole ring?

N

NN

N

NH2

O

OHOH

OH

n

NH

NN

N

O

O

H (OH)OH

OHNH

2

n

NH

N

O

O

H (OH)OH

OHO

n

H-A-A H-dG-A, H-G-A

n = 3 n = 3

n = 3

H-dU-A, H-U-A

click

O

OMe

N3

OHN

3

OH

OH

O

NH

N3

OH

SO3

N3-TUDCA

2

Nor-23-N3-CDC 7aOH

Nor-23-N3-UDC7-OH

N3-CDC 7aOH

N3-UDC7-OH

A new lot of 27 bioconjugates is waiting for the biological assay

SH

OH

OH

N

NN

N

NH2

O

OH

OH

S

OH

OH

N

NN

N

NH2

O

OH

OH

Br

+

H2O, TEA

100 °C, 2h

Nor-23-SH-CDC 7aOH

Nor-23-SH-UDC7-OH

Adenosine Or Deoxyadenosine Derivatives Modified At Position 8 And A Method Of Synthesis Thereof ; Massimo L. Capobianco and Maria Luisa Navacchia PCT Int. Appl. WO 2012164484 A1 2012. Labeling Deoxyadenosine for the Preparation of Functional Conjugated Oligonucleotides; Massimo L. Capobianco,* Elena Marchesi, Daniela Perrone and Maria Luisa Navacchia Bioconj., 2013, 24, 1398-1407. Synthesis and in vitro cytotoxicity of deoxyadenosine-bile acid conjugates linked with 1,2,3-triazole; Daniela Perrone,* Olga Bortolini, Marco Fogagnolo, Elena Marchersi, Lara Mari, Chiara Massarenti, Maria Luisa Navacchia,* Fabio Sforza, Katia Varani and Massimo Luigi Capobianco New J. Chem., 2013, 37, 3557-3557.

References