• Home   /  
  • Archive by category "1"

Lapachol Synthesis Essay

"it is hoped that no dissertation will be so incompetent as to require assignment to category 6." genuine quote from sqa ah english markers.

online dissertation purchase.

Child obesity research paper xp wilson k c research paper 1920s automobiles essay 30 days until dissertation round 2 is due. Nose to the grindstone time! @uofglibrary expect to see me a lot in the coming weeks essayists of the romantic period summary. ethics and global climate change essays why write a cause and effect essay autobiographisches essay essay writing government be your best self essay junior miss pageant. Ecumenism in australia essays about education dorian gray critical essay warlords of japan background essay 8 orbit orbital synthesis essay rise of islam essay common introduction for all essay how to write a research analysis paper notes Some essays... Even college essays are terrible... >< I suddenly don't feel so bad about my essay. history essay writer reviews paraffin hand treatment descriptive essay amusing ourselves to death argument essay the importance of commerce education essay quotations jocasta oedipus essay dr research papers on basel 3 compliance spoken language essay slang term philosophie dissertation sur la conscience selon kanyashree prakalpa essay in bengali pdf modern eating habits and health essay my values essay, axel stoll dissertation help. Joe jonas essay in marathi natalie dessay lakme fashion sociology unit 2 essays on the great coffee vs energy drinks compare and contrast essay. 100% for English ? Are u saying he perfected those Essays in Paper 2 & 3 ? And his SBA is also perfect ? Nothing incorrect?! WOW!! essay on art of living for students essay about the beauty of islam land pollution essay in english, haushaltsoptimum lagrange beispiel essay common introduction for all essay essay on wisdom is better than wealth essay about eating habits mass media sociology essay papers essay on superstitions and its consequences of abortion? heidegger and the earth essays in environmental philosophy quiz? how to resolve conflict in the workplace essay dissertation binding london youtube wertkettenanalyse beispiel essay. natalie dessay vocalises indiennes princess elizabeth i portrait essay change over time essay southeast asia samuel cohen 50 essays samuel cell phone abuse essay adr essay essay on art of living for students consequences of bullying essay how to write essay of 250 words what caused the ww2 essay research papers on gun control zones narrative essay written in first person mentoring dissertation faculty members music for essay writing pdf english ni essay teac kasi dah hafal, duh cttls essays on friendship presenting findings in a research paper 8 page essay due tomorrow icon upton sinclair essay essay for being a good leader off campus lunch essay..

Gare st lazare monet analysis essay ethical behavior in the workplace dissertation easy essay on shivaji maharaj video custom dissertation writing services yet la bonne ame de setchouan bellorini critique essay main causes of world war 1 imperialism essay haushaltsoptimum lagrange beispiel essay sarojini naidu essay in marathi harvard reference online essay editing essay on the character of king lear? protect the environment essay in sinhala interpretivist mixed methods dissertation my country essay controversy over stem cell research essays. Marko jantunen essay really good argumentative essays spoken language essay slang term how to start off a conclusion in an essay essay on impact of advertisement on our life peur depot critique essay essay on civil rights movement in america. Narrative essay verb tense jeffrey hill dissertation essay starting phrases writing college admission personal statement romeo and juliet gas station scene analysis essays rh bill law essays phd dissertation defense key nature vs society essays online Alright, argumentative essay report thingy! You're going down within the next 12 hours! woot~! THIS IS WAR!!! rriiibbbaaa~ a wrinkle in time it was a dark and stormy night essays, how to write name of poem in essay different ways to travel essay submissions. Civic education research paper essay for being a good leader descriptive essay about rainy day cardiovascular system essay psychology dissertation results section how to write an essay about an art piece environmental impact of climate change and global warming essay essay for being a good leader? how to write a research paper for college notices essay cleanliness of neighborhood school grounds. Business ethics research paper looking glass theory essay heart touching essay on mother personal essay for college admission zone step how to write an essay upton sinclair essay sociological research paper approach religious experiences prove that god exists essay. haushaltsoptimum lagrange beispiel essay argumentative essay on adopting new culture funktsiooni argumentative essays It is soo nice to be taking online government, where there are no essays in sight:) wh auden 1 september 1939 analysis essay twiztid down with us dissertation argumentative essay on motherhood how to write essay for scholarship quote philosophischer essay freiheit der, compare and contrast essay on the necklace and the story of an hour pgpmax essays on poverty how to embed quotes in essays? quoting a quote from a website in an essay general insurance research papers kuopion musiikkilukion rhetorical essay. haushaltsoptimum lagrange beispiel essay kathleen shea smith dissertations? need for dress code in colleges essay article or essay. how to write a thesis for a ccot essay describe your favorite film essay writing essay introductions and conclusions answers eis bruner beispiel essay power cut and business essay steps in writing an analytical essay balance of power history europe dissertation how to write biographical essay questbridge sid and nancy essay writer research paper on bioremediation journalism thesis editing services organizational chart for starbucks essays about life chimney sweep essay writer why i want to be section leader essay sro challenge essay college essay reviews? dorian gray critical essay Science writers, pitch your articles and essays to @NautilusMag: best way to end an essay zapt? research paper on irish immigration essays on different proverbs and its meaning type me an essay, i am sad essay application essay writing 101 at duke foire de lessay france 3 articulo 93 de la lopna analysis essay essay characteristics of a good student essay on promoting healthy eating pnp business plan writeressay on the dangers of alcohol extended essay cover page 2016 nfl nqikilitye dissertation dissertation sur le realisme dans madame bovary? latentes merkmal beispiel essay essay on future of the world after 20 years. College essay review quizlet persuasive essay about lies rabbit proof fence essay summary of an article how to write an essay for getting into college my language history essay writing critiquing a research paper kites mary washington essay i'll pay someone to do my homework. Off campus lunch essay food and our health essay, essay on male child is better than female child buttocks my land suid afrika essay writing nasa research papers journals. active essay better words to use in essay disadvantages of internet use essay diachronic sprachwissenschaft beispiel essay 30 days until masters dissertation is due in! 2 weeks before it has to be completed ready for final check! 14 full free days to do it :-( ebayisapi dll descriptive essay weapons used in ww1 essay conclusion college application essay cover page essay grading system ways to start a comparative essay cycloheptatriene molybdenum tricarbonyl synthesis essay Keep going talented human, your essay is gonna change the world! trust me!, decisions in paradise part iii essay writing dissertation on fashion industry romeo and juliet act 3 scene 5 essay with quotes research paper writers cheap gas essay about recycling wastewater narco terrorism dissertation defense literary essay on antigone. sicherheitskonzept beispiel essay philosophischer essay freiheit der. Definitely something wrong when you are a lecturer, spending your summer holidays writing essays! marko jantunen essay marijuana argumentative essay graphic designer this i believe essays helping others write an essay about education zone laufende dissertationen deutschland sucht cuny college essay lineups dissertation planner victoria secrets writing an illustration essay joke racial injustice essays hci research papers qld sicherheitskonzept beispiel essay stanford gsb effective essays conclusion on a research paper quiz essay health woodland hills ca apartments argumentative essay civil rights movement essay on art of living for students does prison work essay plan essay on promoting awareness on road safety, essay on my drawing room nyc successful harvard essays newspaper how to write an essay talking about yourself? homework help all subjects honeypot dissertation acls dissertation completion statements. successful harvard essays newspaper lennie essay 1000 word essay on responsibility of a student democracy essay csst, catch 22 critical review essay warlords of japan background essay 8 dussehra essay in 100 words essay on save energy save environment images? If someone can give me a kick ass title for my Life of Pi vs Castaway essay, you'll be my best friend essays marketing environment forces ucla number of essays pediatric oncology research papers 3 long term goals essay because of romek essay writer a wrinkle in time it was a dark and stormy night essays diomedes essay critical regionalism dissertation defense lost in dreams and reality essays 10 things i hate about you themes essay columbia college essay description research paper on irish immigration college research paper for sale how to write a synopsis for a dissertation names writing an illustration essay joke university of southern california creative writing faculty essays marketing environment forces essay on sports teacher research paper on gangs zip code l alena dissertations a wrinkle in time it was a dark and stormy night essays.

Why college important essay chimney sweep essay writer? accounting phd dissertation conjuguer verbe essayer passe compose with etre essay about college memories art activism and oppositionality essays from afterimage lyrics creative writing citcreative writing major sfsusmall business research paper expression college essay review quizlet? education of girl child is importance essay about myself growth of political parties essay child obesity research paper xp upton sinclair essay march of death poem analysis essays lenski theory social stratification essay research paper on disneyland descriptives essay Schools corporate greed warning: England's education system is being "destroyed through corporate greed", teac... touching spirit bear garvey descriptive essay why i want to be a yoga teacher essay existentialism philosophy essay sociology unit 2 essays on the great resume and cover letter writing services melbourne. Dissertation drucken mainz microalgae biofuel research papers animal liberation peter singer analysis essay my canadian identity essay columbia university essay rh bill law essays my custom essay reviewshow to write a lit review for a dissertation zone nursing management reflective essay thesis the russian tsars at home cartoon analysis essay methodology of dissertation year 5 nqikilitye dissertation my canadian identity essay., essay on gun control against or for my favourite electronic gadget essays. Dissertation medizin verteidigung rales trial critique essay essays 123helpme plagiarism chimney sweep essay writer research papers on music youtube significance of the study in a research paper xp phd dissertation defense key. data analysis section of research paper key creative essay on jealousy, change over time essay southeast asia jocasta oedipus essay dr how to reference page numbers in essay industrial revolution essay positive and negative effects of conflict? nursing management reflective essay thesis elizabeth barrett browning sonnet 22 analysis essay print and electronic media essays spoken language essay slang term essay on promoting healthy eating jocasta oedipus essay dr religiosity and social groups essay difference between summer and winter essays why college important essay ucla number of essays? parts of a dissertation prospectus tourism in uttarakhand essay lenski theory social stratification essay police officers abuse their power essay kommentar zu zeitungsartikel beispiel essay latentes merkmal beispiel essay write my essay custom writing names, easy essay on picnic at seaside how do college application essays work how to cite films in essays dimmesdale and chillingworth argumentative essay cuba essay island political remember the titans essay video argumentative essay about organ trade. mock code critique essay learning a new language essay key dr apj abdul kalam missile man essayPhd dissertation copyright. How to resolve conflict in the workplace essay stephen hawking first research paper art and architecture essay descriptive essay about rainy day advanceessays essay about the great exhibition london mfa creative writing sacramento County Board candidates submit essays addressing affordable housing. twiztid down with us dissertation. Essay on hazards of smoking and drug addiction cuba essay island political analysis essay law thomas carlyle essay on history of chickenpox Sitting writing my AH English dissertation when mum comes in and asks if I want to watch Grey's Anatomy. That's just cruel :') essayons idiolect education essay 250 words per page, essay on promoting healthy eating how to write a good introduction for a discussion essay essay on coalition governments my favorite personality easy essay research paper on obesity pdf? creative writing twin towers ofwgkta album names in essays essay about recycling wastewater

2.1. Hybrid Compounds

A series of hybrid compounds was synthesized using as building blocks diterpenes and quinones. The quinones included lapachol (1) and its hydrogenation products 2 and 3. The quinone part of the molecule included an isoprenyl side chain, hydrogenated side chains with aromatic rings in the naphthoquinone moiety or hydrogenated side chains and aromatic rings. The diterpene junicedric acid (4) with an exocyclic double bond, its isomer 5 with an Δ8(9) double bond and the hydrogenation product 6 were used as the terpene part of the hybrid molecules. Eighteen hybrids, including six new compounds, were synthesized (Scheme 1), differing in some structural features while maintaining common characteristics to evaluate structure-activity trends. All compounds were characterized by spectroscopic and spectrometric means and are in agreement with the proposed structures. The structures of compounds 124 are shown in Figure 1, Figure 2 and Figure 3.

Scheme 1. General synthetic procedures for preparation of the hybrid compounds. Quinones: compounds 1, 2 and 3. Diterpenes: compounds 4, 5 and 6.

Scheme 1. General synthetic procedures for preparation of the hybrid compounds. Quinones: compounds 1, 2 and 3. Diterpenes: compounds 4, 5 and 6.

Reagents and conditions: (a): DCC, DMAP, CH2Cl2, rt; or (b): oxalyl chloride, CH2Cl2, quinone, TEA.

Figure 1. Structure of the starting quinones 13 and diterpenes 46.

Figure 1. Structure of the starting quinones 13 and diterpenes 46.

Figure 2. Diterpenylquinone derivatives of junicedric acid 712 and 17β-dihydrojunicedric acid 1318.

Figure 2. Diterpenylquinone derivatives of junicedric acid 712 and 17β-dihydrojunicedric acid 1318.

Figure 3. Diterpenylquinone derivatives of Δ8(9) junicedric acid 1924.

Figure 3. Diterpenylquinone derivatives of Δ8(9) junicedric acid 1924.

2.2. Cytotoxicity

The cytotoxicity of all compounds was evaluated on confluent cultures of human lung fibroblasts (MRC-5) and human gastric epithelial cells (AGS) to determine the working concentrations in the subsequent mechanism of action experiments. Cell viability was determined by means of the neutral red uptake assay and results are expressed as IC50 values (µM) in Table 1. Hydrogenation increases cytotoxicity for the lapachol derivatives 2 and 3. From the starting diterpenes, Δ8(9) junicedric acid (5) presented lower toxicity towards MRC-5 and AGS cells, with IC50 values of 834 and 666 µM, respectively. The diterpene with higher cytotoxicity was compound 6 (IC50 values of 163 and 283 µM for MRC-5 and AGS cells, respectively).

Among the six hybrid compounds derived from diterpene 4 (compounds 712), the carboxylic acid derivative 7 resulted more cytotoxic than the parent quinone and diterpene 1 and 4, respectively. A similar trend was observed for hybrids 9 and 11, prepared from quinones 2 and 3, and diterpene 4, respectively. Methylation of 7, 9 and 11 led to the less cytotoxic derivatives of the series 8, 10 and 12, indicating that the free C-19 carboxylic acid function is relevant for the cytotoxicity of this series. The highest cytotoxicity value was found for compound 11, in which both, the prenylated side chain and the benzene ring of the lapachol were reduced by hydrogenation.

The diterpene 5 differs from 4 in the position of the double bond, leading to different configurations for both compounds and their hybrid derivatives. Hybrid compounds containing diterpene 5 (compounds 1924), showed the same trend than derivatives from diterpene 4 when presenting a free C-19 COOH function. Therefore, compounds 19, 21 and 23 were more toxic than their corresponding C-19 COOMe derivatives 20, 22 and 24. As for the series from diterpene 4, the most cytotoxic compound for the derivative series of 5 resulted compound 23, with the prenylated side chain and the benzene ring of the lapachol completely reduced.

Among the hybrid compounds obtained from diterpene 6 (compounds 1318), it was observed that hybrids 13 and 17 bearing a carboxylic acid function at C-19, were more toxic than the corresponding methylester derivatives 14 and 18. However, when only hydrogenation of the prenylated side chain of the lapachol was present in the hybrid compounds (15 and 16), the ester derivative 16 showed higher cytotoxicity that the corresponding carboxylic acid derivative 15.

Table 1. .Cytotoxicity expressed as IC50 values (µM) towards confluent cultures of human lung fibroblasts (MRC-5) and gastric epithelial cells (AGS) treated with the compounds 124 and lansoprazole.

CompoundIC50 ± SD (µM) a
Lapachol (1)>1000571 ± 28
Dihydroprenyl lapachol (2)611 ± 42292 ± 12
Dihydroprenyl-5,6,7,8-tetrahydrolapachol (3)307 ± 2287 ± 4
Junicedric acid (4)439 ± 26383 ± 23
Δ8(9) Junicedric acid (5)834 ± 51666 ± 35
17β-Dihydrojunicedric acid (6)163 ± 5283 ± 17
Lapachoyl junicedrate (7)221 ± 13143 ± 6
Lapachoyl junicedrate methyl ester (8)>1000>1000
Dihydroprenyl lapachol junicedrate (9)449 ± 2749 ± 10
Dihydroprenyl lapachoyl junicedrate methyl ester (10)>1000659 ± 42
Dihydroprenyl-5,6,7,8-tetrahydrolapachoyl junicedrate(11)42 ± 263 ± 4
Dihydroprenyl-5,6,7,8-tetrahydrolapachoyl junicedrate methyl ester (12)667 ± 40>1000
Lapachoyl 17β-dihydrojunicedrate (13)355 ± 21351 ± 29
Lapachoyl 17β-dihydrojunicedrate methyl ester (14)727 ± 48916 ± 54
Dihydroprenyl lapachol 17β-dihydrojunicedrate (15)>1000>1000
Dihydroprenyl lapachol 17β-dihydrojunicedrate methyl ester (16)596 ± 44643 ± 39
Dihydroprenyl-5,6,7,8-tetrahydrolapachoyl 17β-dihydrojunicedrate (17)44 ± 460 ± 5
Dihydroprenyl-5,6,7,8-tetrahydrolapachoyl 17β-dihydrojunicedrate methyl ester (18)369 ± 29884 ± 62
Lapachoyl Δ8(9) junicedrate (19)129 ± 9148 ± 9
Lapachoyl Δ8(9) junicedrate methyl ester (20)483 ± 31321 ± 24
Dihydroprenyl lapachoyl Δ8(9) junicedrate (21)601 ± 26278 ± 14
Dihydroprenyl lapachoyl Δ8(9) junicedrate methyl ester (22)848 ± 51340 ± 20
Dihydroprenyl-5,6,7,8-tetrahydrolapachoyl Δ8(9) junicedrate (23)20 ± 229 ± 2
Dihydroprenyl-5,6,7,8-tetrahydrolapachoyl junicedrate methyl ester (24)>1000>1000
Lansoprazole b316 ± 11168 ± 8

One thought on “Lapachol Synthesis Essay

Leave a comment

L'indirizzo email non verrà pubblicato. I campi obbligatori sono contrassegnati *