60 research outputs found
Steroidal tetraoxanes: synthesis and biologycal activity
U toku izrade ove doktorske disertacije sintetisani su
tetraoksani derivata holne kiseline i ispitana je njihova
antimalarijska, citotoksiÄna i antiproliferativna aktivnost. U
toku rada dobijeni su sledeÄi rezultati:
1. Razvijena su dva postupka za sintezu bis-steroidnih
tetraoksana: 1) direktna peroksiacetalizacija
odgovarajuÄih 3-keto derivata holne kiseline, 2)
derivatizacija prethodno dobijenih bis-steroidnih
tetraoksana. Primenom oba postupka sintetisano je 14
bis-steroidnih tetraoksana derivata holne kiseline, 123-
136. Prema prvom postupku sintetisani su bis-steroidni
tetraoksani 123 - 128. Proizvodi 123 i 124 dobijeni su
reakcijom ketona 119 sa 30% H2O2 / 50% H2SO4, u
prinosu od 25% i 28%, a proizvodi 125 - 128 u
reakcijama ketona 121 i 122 sa (Me3Si)2O2 / TMSOTf,
na 0 oC u prinosu 28 ā 50% (Shema 24). UtvrÄeno je da
u reakcijama ketona 119 sa (Me3Si)2O2 / TMSOTf i 121 i
122 sa 30% H2O2 i 50% H2SO4 dominantno nastaju
proizvodi Baeyer ā Villiger-ove reakcije. Prema drugom
postupku sintetisani su tetraoksani 127ā 136124 na dva naÄina: a) hidrolizom 1,25 M rastvorom
NaOH u smeŔi CH2Cl2 / MeOH na sobnoj temperaturi u
toku 3 dana (72 ā 79%); b) hidrolizom pomoÄu NaOH u
smeÅ”i i-PrOH / H2O (3:1, v/v) na temperaturi kljuÄanja u
toku 15 min. (90 ā 95%, Shema 24). Kiseline 129 i 130
prevedene su preko meÅ”ovitog anhidrida u amide 131 ā
136 (54 ā 81%) kao i prethodno sintetisane amide 127 i
128 (Shema 25). Izolovana su oba predviÄena
diastereomera a na osnovu spektralnih podataka i
analize monokristala derivata 123 X-zracima, pripisana
je struktura sintetisanim derivatima: cis-C(2)C(2a) seriji
pripadaju derivati 123, 125, 127, 129, 131, 133 i 135, a
trans-C(2)C(2a) seriji pripadaju derivati 124, 126, 128,
130, 132, 134 i 136.
2. Razvijen je postupak za sintezu gem-dihidroperoksida
derivata holne kiseline (137, 145 i 146, Shema 29) koji
uspeŔno može da se primeni i za dobijanje gemdihidroperoksida
jednostavnih cikliÄnih ketona (149, 150
i 76, Shema 30). Gem-dihidroperoksidi su sintetisani
reakcijom odgovarajuÄeg ketona i 30% H2O2 u smeÅ”i
CH2Cl2 / CH3CN (1:3, v/v) u prisustvu katalitiÄkih koliÄina
konc. HCl u visokom prinosu (> 90%). Postupak razvijen
u toku ovog rada je jednostavniji, ekonomiÄniji i bitno
poboljŔan u odnosu na postupke do sada opisane u
literaturi (ref. 45, 47, Shema 13).
3. Sintetisana su 53 meŔovita tetraoksana derivata holne
kiseline, 138 ā 144b. Metil-estri 138 dobijeni su
kuplovanjem gem-dihidroperoksida 137 sa
jednostavnim, supstituisanim i nesusptituisanim,
cikliÄnim ketonima (~ 30%, Shema 27). Reakcija se vrÅ”i
u dihlormetanu, u prisustvu katalitiÄkih koliÄina H2SO4.
Reakcijom ciklopentanona, cikloheksanona i
ciklooktanona dobijen je i izolovan po jedan proizvod, a
svaki od prohiralnih 4-metil-, 4-etil-, 4-t-butil- i 4-fenilcikloheksanona
daju oba oÄekivana diastereoizomera.
Reakcijama 2,6-dimetil-, 2-metil-cikloheksanona i. mentona proizvodi su izolovani u obliku odgovarajuÄih
smeŔa. Reakcija gem-dihidroperoksida 137 sa
aromatiÄnim karbonilnim jedinjenjima - 2-furil-metilketon,
4-nitroacetofenon, 6-metoksitetralon-1-on i pmetoksibenzaldehid
- nije dala oÄekivane proizvode.
Selektivnom hidrolizom C(24) metil-estarske grupe
tetraoksana 138 sa NaOH u smeŔi i-PrOH / H2O (3:1,
v/v) na temperaturi kljuÄanja dobijene su odgovarajuÄe
karboksilne kiseline 139 (72 ā 93%), koje su preko
meÅ”ovitog anhidrida prevedene u odgovarajuÄe amide
140 ā 144b (~ 80%, Shema 28). Na osnovu spektralnih
podataka i analize monokristala kiseline 139g X-zracima
odreÄena je konfiguracija C(4ā) atoma 4ā-metil derivata.
UtvrÄeno je da derivati 138f, 139f i 140f ā 143f
pripadaju (4āR) seriji, a da derivati 138g, 139g i 140g ā
143g pripadaju (4āS) seriji...Within this thesis a cholic acid-derived 1,2,4,5-
tetraoxacyclohexanes (tetraoxanes) were synthesised and
characterised, their in vitro antimalarial activity was
evaluated and cytotoxicity determined. In addition, the
tetraoxanes reported in this thesis were evaluated as
potential antiproliferatives against various cancers cell lines.
The results can be summarised as follows:
1.Two procedures for preparation of bis steroidal
tetraoxanes were developed: 1) direct
peroxyacetalisation of the corresponding 3-keto cholic
acid derivatives, 2) transformation of the previously
prepared tetraoxanes into its derivatives. 14 bis-
Steroidal tetraoxanes, 123-136, were prepared utilising
both procedures. Tetraoxanes 123-128 were obtained
according to the first procedure. Compounds 123 and
124 were prepared by reacting of ketone 119 with 30%
H2O2 / 50% H2SO4 in 25% and 28% yield, respectively,
while the compounds 125-128 were obtained from the
ketones 121 and 122 using TMS2O2 / TMSOTf at 0 oC,
in 28-50% yield (Scheme 24). Ketone 119 with TMS2O2 /
TMSOTf, as well as ketones 121 and 122 with 30%
H2O2 / 50% H2SO4, afforded as main products the
Baeyer-Villiger products. Procedure 2) was utilised for
preparation of tetraoxanes 127-136. The carboxylic
acids 129 and 130 were obtained by selective hydrolysis
of C(24) methyl ester moiety of tetraoxanes 123 and
124, respectively, utilising a) hydrolysis with 1.25 M
NaOH/CH2Cl2-CH3OH at r.t. for 3 days (72-79%), and b)
hydrolysis with NaOH / i-PrOH-H2O (3:1, v/v) at reflux for
15 min (90-95%, Scheme 24). The acids 129 and 130
were further transformed via their mixed anhydrides into
corresponding amides 131-136 (54-81%), as well as into
previously synthesised amides 127 and 128 (Scheme
25). Both predicted diastereomers were isolated and
their structures was assigned from corresponding
spectral data and confirmed by X-ray analysis of
tetraoxane 123 monocrystal: compounds 123, 125, 127,
129, 131, 133, and 135 belong to cis-C(2)C(2a) series,
and to corresponding trans-C(2)C(2a) series belong the
compounds 124, 126, 128, 130, 132, 134, and 136.
2. The procedure developed for the synthesis of cholic
acid-derived gem-dihydroperoxides (137, 145, 146,
Scheme 29) was also applied for synthesis gemdihydroperoxides
of simple cyclic systems (149, 150 and
76, Scheme 30). It embodies the treatment of a ketone
with 30% H2O2 in CH2Cl2-CH3CN mixture (1:3, v/v) in the
presence of cat. HCl (> 90%). The procedure developed
within this thesis represents a significant improvement in
terms of simplicity and economy as compared with the
known ones (ref. 45, 47, Scheme 13).
3. 53 Mixed tetraoxanes derived from cholic acid were
prepared (138-144b). Mixed steroidal tetraoxane methyl
esters 138 were synthesised by coupling of gemdihydroperoxide
137 to simple substituted and nonsubstituted
cycloalkanones (~30%, Scheme 27). The
coupling reaction was performed in dichloromethane in
the presence of cat. H2SO4. The reaction of
cyclopentanone, cyclohexanone and cyclooctanone
afforded only one corresponding tetraoxane each, while
the reaction of 4-methyl, 4-ethyl, 4-t-butyl, and 4-
phenylcyclohexanone afforded both expected
diastereomers each. Aromatic ketones failed to produce
a tetraoxane in a reaction with the same
dihydroperoxide. Selective hydrolysis of tetraoxanes 138
with NaOH / i-PrOH-H2O as above afforded the
corresponding acids 139 (72-93%), which were via their
mixed anhydrides transformed into corresponding
amides 140-144b (~80%, Scheme 28). The
configuration at C(4") in 4"-methyl series was
determined by X-ray analysis of tetraoxane acid 139g. It
is found that tetraoxanes 138f, 139f, and 140f-143f
belong to (4"R)-series, while their respective (4"S)
diastereoisomers are 138g, 139g, and 140g-143g..
Peroksidni antimalarici
The problem of endemic malaria continues unabated globally. Malaria affects 40 % of the global population, causing an estimated annual mortality of 1.5-2.7 million people. The World Health Organization (WHO) estimates that 90 % of these deaths occur in sub-Saharan Africa among infants under the age of five. While a vaccine against malaria continues to be elusive, chemotherapy remains the most viable alternative towards treatment of the disease. During last years, the situation has become urgent in many ways, but mainly because of the development of chloroquine-resistant (CQR) strains of Plasmodium falciparum (Pf). The discovery that artemisinin (ART, 1), an active principle of Artemisia annua L., expresses a significant antimalarial activity, especially against CQR strains, opened new approaches for combating malaria. Since the early 1980s, hundreds of semi-synthetic and synthetic peroxides have been developed and tested for their antimalarial activity, the results of which were extensively reviewed. In addition, in therapeutic practice, there is no reported case of drug resistance to these antimalarial peroxides. This review summarizes recent achievements in the area of peroxide drug development for malaria chemotherapy.Å irenje malarije je stalno prisutan problem na globalnom nivou. Od malarije godiÅ”nje oboli 40 % svetske populacije i oko 1,5-2,7 miliona ljudi umre. Prema podacima Svetske zdravstvene organizacije, 90 % smrtnih sluÄajeva je u zemljama podsaharske Afrike, meÄu kojima dominiraju deca starosti do 5 godina. Usled nemoguÄnosti razvoja vakcine, hemoterapija ostaje kao jedini pouzdan oblik leÄenja od ove bolesti. Poslednjih godina problem borbe protiv malarije postaje urgentan iz brojnih razloga, meÄu kojima je najznaÄajniji razvoj hlorokin-rezistentnih sojeva parazita. OtkriÄe da artemizinin (ART, 1) i njegovi derivati pokazuju izuzetnu efikasnost prema hlorokin-rezistentnim sojevima otvorilo je velike moguÄnosti u borbi protiv malarije. Od tada, posebno tokom 80-tih godina, sintetisan je veliki broj jedinjenja i rezultati njihove aktivnosti opisani su u mnogim nauÄnim publikacijama. Osim toga, u kliniÄkoj praksi nisu zabeleženi primeri pojave rezistencije parazita prema ovoj klasi antimalarika. U ovom revijalnom radu opisani su najnoviji rezultati u razvoju peroksidnih antimalarika
Peroksidni antimalarici
The problem of endemic malaria continues unabated globally. Malaria affects 40 % of the global population, causing an estimated annual mortality of 1.5-2.7 million people. The World Health Organization (WHO) estimates that 90 % of these deaths occur in sub-Saharan Africa among infants under the age of five. While a vaccine against malaria continues to be elusive, chemotherapy remains the most viable alternative towards treatment of the disease. During last years, the situation has become urgent in many ways, but mainly because of the development of chloroquine-resistant (CQR) strains of Plasmodium falciparum (Pf). The discovery that artemisinin (ART, 1), an active principle of Artemisia annua L., expresses a significant antimalarial activity, especially against CQR strains, opened new approaches for combating malaria. Since the early 1980s, hundreds of semi-synthetic and synthetic peroxides have been developed and tested for their antimalarial activity, the results of which were extensively reviewed. In addition, in therapeutic practice, there is no reported case of drug resistance to these antimalarial peroxides. This review summarizes recent achievements in the area of peroxide drug development for malaria chemotherapy.Å irenje malarije je stalno prisutan problem na globalnom nivou. Od malarije godiÅ”nje oboli 40 % svetske populacije i oko 1,5-2,7 miliona ljudi umre. Prema podacima Svetske zdravstvene organizacije, 90 % smrtnih sluÄajeva je u zemljama podsaharske Afrike, meÄu kojima dominiraju deca starosti do 5 godina. Usled nemoguÄnosti razvoja vakcine, hemoterapija ostaje kao jedini pouzdan oblik leÄenja od ove bolesti. Poslednjih godina problem borbe protiv malarije postaje urgentan iz brojnih razloga, meÄu kojima je najznaÄajniji razvoj hlorokin-rezistentnih sojeva parazita. OtkriÄe da artemizinin (ART, 1) i njegovi derivati pokazuju izuzetnu efikasnost prema hlorokin-rezistentnim sojevima otvorilo je velike moguÄnosti u borbi protiv malarije. Od tada, posebno tokom 80-tih godina, sintetisan je veliki broj jedinjenja i rezultati njihove aktivnosti opisani su u mnogim nauÄnim publikacijama. Osim toga, u kliniÄkoj praksi nisu zabeleženi primeri pojave rezistencije parazita prema ovoj klasi antimalarika. U ovom revijalnom radu opisani su najnoviji rezultati u razvoju peroksidnih antimalarika
Antimalarijska, antimikobakterijska i antiproliferativna aktivnost fenil-supstituisanih tetraoksana
Mixed tetraoxanes of the 4"-phenyl-substituted cyclohexyl-spirotetraoxacyclohexyl-spirocholate series have been prepared and evaluated as possible antimalarials, anti-proliferatives and antimycobacterials. The activity of the (4"R or S)-phenyl series against P falciarum D6 and W2 strains was found to be at the level of artemisinin. with two compounds. the acid 4 and the amide 6, exhibiting encouraging anti-TB activity as well. Very promising in vitro results of the said tetraoxanes were obtained against solid tumours and, in some instances. the activity against a selected number of cell lines was higher than that of the antitumor drug paclitaxel.U ovom radu prikazana je sinteza serije meÅ”ovitih tetraoksana 4"-fenil-supstituisanih cikloheksil-spirotetraoksacikloheksil-spiroholata, a ispitana je i njihova in vitro aktivnost kao moguÄih antimalarika, anti-TBC agenasa i antiproliferativnih jedinjenja. Aktivnost (4"R ili S)-fenil serije na D6 i W2 sojeve P. falciparum vrlo je sliÄna aktivnosti poznatog antimalarika artemizinina. Izraženu anti-TBC aktivnost iskazala su jedinjenja 4 i 6, Äija antiproliferativna in vitro aktivnost prema nekim kompaktnim tumorima prevazilazi aktivnost leka paklitaksela
QSAR izuÄavanje steroidnih 1,2,4,5-tetraoksanskih antimalarika raÄunarskim modelovanjem
A three-dimensional QSAR pharmacophore model for antimalarial activity of steroidal 1,2,4,5-tetraoxanes was developed from a set of 17 substituted antimalarial derivatives out of 27 analogues that exhibited remarkable in vitro activity (below 100 ng/mL) against sensitive and multidrug-resistant Plasmodium falciparum malaria. The pharmacophore, which contains two hydrogen bond acceptors (lipid) and one hydrophobic (aliphatic) feature, was found to map well onto the potent analogues and many other well-known antimalarial trioxane drugs including artemisinin, arteether, artesunic acid, and tetraoxanes. The presence of at least one hydrogen bond acceptor in the trioxane or the tetraoxane moiety appears to be necessary for potent activity of this class of compounds. Docking calculations of some of these compounds with heme are consistent with the above observation as the proximity of the heme iron to the oxygen atom of the trioxane or the tetraoxane moiety favors potent activity of the compounds. Electron transfer from the oxygen of trioxane or the tetraoxane appears to be crucial for mechanism of action of the compounds. This information together with the pharmacophore should enable search for new peroxide containing antimalarial candidates from databases and custom designed synthesis of more efficacious and safer analogues.IzvrÅ”eno je trodimenzionalno modelovanje farmakofore za antimalarijsku aktivnost steroidnih 1,2,4,5-tetraoksana na osnovu struktura 17 supstituisanih derivata, izdvojenih iz grupe od 27 analoga koji pokazuju izuzetnu in vitro antimalarijsku aktivnost (ispod 100 ng/mL) prema osetljivim i rezistentnim sojevima Plasmodium falciparum-a. UtvrÄeno je da se farmakofora, koju Äine dva akceptora vodoniÄne veze (lipidni) i jedno hidrofobno mesto (alifatiÄno), dobro preklapa sa strukturama aktivnih analoga kao i sa strukturama nekih poznatih trioksanskih antimalarika, ukljuÄujuÄi artemizinin, arteetar, artesunatnu kiselinu kao i sa strukturama nekih drugih tetraoksana. Za dobru aktivnost ove klase jedinjenja važno je prisustvo bar jednog akceptora vodoniÄne veze na trioksanskom ili tetraoksanskom delu strukture. IzraÄunavanja interakcija nekih od ovih jedinjenja sa hemom saglasna su sa prethodno iznetim zakljuÄkom da je blizina gvožÄa iz hema i trioksanskog ili tetraoksanskog atoma kiseonika važna za dobru aktivnost ovih jedinjenja. Izgleda da je prenos elektrona sa trioksanskog ili tetraoksanskog atoma kiseonika osnova mehanizma dejstva ovih jedinjenja. IzvrÅ”ena modelovanja farmakofore i interakcija ovih jedinjenja se hemom mogu biti od pomoÄi u sintezi novih i efikasnijih peroksidnih antimalarika
Supplementary data for article: Å egan, S. B.; AndriÄ, F.; RadoiÄiÄ, A.; Opsenica, D. M.; Å olaja, B. A.; ZlatoviÄ, M.; MilojkoviÄ-Opsenica, D. Correlation between Structure, Retention and Activity of Cholic Acid Derived Cis-Trans Isomeric Bis-Steroidal Tetraoxanes. Journal of Separation Science 2011, 34 (19), 2659ā2667. https://doi.org/10.1002/jssc.201100185
Supporting information for: [https://doi.org/10.1002/jssc.201100185]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1212
O peroksidnim antimalaricima
Several dicyclohexylidene tetraoxanes were prepared in order to gain a further insight into structure-activity relationship of this kind of antimalarials. The tetraoxanes 2-5, obtained as a cis/trans mixture, showed pronounced antimalarial activity against Plasmodium falciparum chloroquine susceptible D6, chloroquine resistant W2 and multidrug-resistant TM91C235 (Thailand) strains. They have better than or similar activity to the corresponding desmethyl dicyclohexylidene derivatives. Two chimeric endoperoxides with superior antimalarial activity to the natural product ascaridole were also synthesized.U ovom radu prikazana je sinteza nekoliko dicikiloheksilidenskih tetraoksana u cilju sagledavanja odnosa struktura-aktivnost ove vrste antimalarika. Jedinjenja 2-5 dobijena kao (cis,trans)-smese pokazala su izraženu antimalarijsku aktivnost prema D6, W2 i TM91C235 (Thailand) sojevima P. falciparum. Ona imaju bolju ili sliÄnu aktivnost od odgovarajuÄih desmetil cikloheksilidenskih derivata. Sintetisana su i dva endoperoksida himerne strukture znatno izraženije aktivnosti od prirodnog proizvoda askaridola.
New generation of steroidal 4-aminoquinolines as potent antimalarials
Sintetisani su novi steroidni 4-amino-7hlorohinolinski derivati i isptana je njihova in vitro antimalarijska aktivnost prema CQ rezistentnim i CQ osetljivim sojevima P. falciparum.Here we present synthesis of new steroidal 4-amino-7-chloroquinolines and dscuss their in vitro antimalarial activities against CQ-resistant and CQ-susceptible P. falciparum stains
Supplementary data for article: Å egan, S. B.; TrifkoviÄ, J.; VerbiÄ, T.; Opsenica, D. M.; ZlatoviÄ, M.; Burnett, J.; Å olaja, B. A.; MilojkoviÄ-Opsenica, D. Correlation between Structure, Retention, Property, and Activity of Biologically Relevant 1,7-Bis(Aminoalkyl)Diazachrysene Derivatives. Journal of Pharmaceutical and Biomedical Analysis 2013, 72, 231ā239. https://doi.org/10.1016/j.jpba.2012.08.025
Supplementary material for: [https://doi.org/10.1016/j.jpba.2012.08.025]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1555
Supplementary data for article: AleksiÄ, I.; Å egan, S.; AndriÄ, F.; ZlatoviÄ, M.; Moric, I.; Opsenica, D. M.; Senerovic, L. Long-Chain 4-Aminoquinolines as Quorum Sensing Inhibitors in Serratia Marcescens and Pseudomonas Aeruginosa. ACS Chemical Biology 2017, 12 (5), 1425ā1434. https://doi.org/10.1021/acschembio.6b01149
Supporting information for: [https://doi.org/10.1021/acschembio.6b01149]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2461]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3089
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