Elucidation of the Structure and Biological Activity of a New Sesquiterpene from Cistus creticus L.

Transcript

1 Elucidation of the Structure and Biological Activity of a New Sesquiterpene from Cistus creticus L. Konstantinos atzellis, Georgia Pagona, Apostolos Spyros, Costas Demetzos, aralambos E. Katerinopoulos Department of Chemistry, University of Crete, eraklion 71409, Crete, Greece, and School of Pharmacy, Department of Pharmaceutical Technology, Panepistimiopolis Zografou 15771, University of Athens, Athens, Greece a 6 A B 2 8a

2

3

4

5

6

7 Composition of the Essential il from the Resin of C. creticus L. Components Rt % στο δείγµα ladano3.d methyl butanoic acid Tricyclene α-pinene Camphene Thuja-2,4(10)-diene Benzaldehyde β-pinene Phenol exanoic acid α-phellandrene α-terpinene p-cymene Limonene γ-terpinene Acetophenone Terpinolene Linalool ,5-heptadien-2-one, 6-methyl (E)- 19 [R]-(+)-Norinone trans-pinocarveol Camphor Methylcamphenilol Isoborneol Borneol Terpineol p-cymen-8-ol α-terpineol Myrtenol Verbenone trans-carveol Cyclohexene-1- carboxaldehyde, 4-(1- methylethyl) Bornyl acetate Thymol Carvacrol Megastigmatrienenone α-cubebene Longicyclene Copaene β-boutbonene Components Rt % στο δείγµα ladano3.d butanone,4-(2,2-dimethyl-6- methylenecyclo hecyl-) Eugenol methyl ether Isocaryohryllene β-caryophyllene α-guaiene β-cubebene α-caryophyllene Arromadendrene Drimane Sesquiterpene Eremophilene Ledene α-muurolene ,1,4α-trimethyl-5,6- dimethylenedecahydronaphthale ne γ-cadinene δ-cadinene Cubenene Cyclohexane,1-methyl-2,4- bis(1-methylethenyl)- (1.alpha,2.beta,4,beta) Palustrol Iasocaryorhyllene , Caryophyllene xide Epiglobulol Ledol Cubenol β-selinenol [11]-Selinen-4α-ol Viridiflorol Sclareol xide (cisa/b) β-selinene Manoyl xide Epimanoyl xide Kaur-16-ene Manool unulane-16-dien-3-ol (7α-Isopropenyl-4,5- dimethyloctahydroindene-4-yl) methanol 74. 4α-7,7,10αtetramethyldodecahydrobenzolf) chromen-3-ol xomanoyle xide Total in the mixture 80.56%

8 Analysis of the components of Labdanum by Gas Chromatography Mass Spectrum of Major Component 204

9 3 4 4a a cis-drima-7,9(11)-diene 9 10 trans-drima-7,9(11)-diene

10 A + 23B trans πορεια cis πορεια cis πορεια ίχνη ίχνη 12 SiMe 3 SiMe 3 ιαχωρισµός Separation of διαστερεοϊσοµερών diastereomers A + 18B 15A + 15B Br 19A + 19B Br 16A + 16B

11 10 eq EG, Ph t-buk, t-bu 1 eq PTSA 60 C, 4h, 93% MeI, C 6 6, 0 C,74% N 2 N 2, DEG K, 200 C, 98% NaB 4, Et, PPTS -30 C, 2h, 88% Et: 2 9:1 reflux, 1.5h, 99% 10%Pd/C Et, 95% 9B 7 10%Pd/C Et, 3.5h 90%, (+8% of 12) 6 Jones 10 91%, (+1.5%of 8) 12 8

12 1 8a 4a 5 beta-equatorial alcohol 9B trans-attack to alpha face alpha-axial alcohol 9A cis-attack to beta face

13

14 SiMe 3 8 LDA, Me 3 SiCl 0 C, 79% 13 TBAF, MeI TF, 90% 15A - 15B PBP, Ac 2.5h, rt, 94% 33 C 3 Li TF/MPA 7:1-78 o C έως RT 24 h 47% Burgess reagent (Me 2 CNS 2 NEt 3 ) Et 3 N, TF reflux, 48h 17 C 2 DBU, toluene 3.5h, reflux, 93% 16A - 16B Br 2 (85%)

15 Comparing NMR data of the cis- and the trans-analog with those of Demedzos et al 13 CNMR C 1 C 2 C3 C 4 C 4a C 5 C 6 C 7 C 8 C 8a C 9 C 10 C 11 C 12 C 13 A.F. Barreto et al. trans-product Akita et.al. trans-product C. Demetzos et al E. Katerinopoulos et al, cis -product Η NMR 7 (C) 9 (C 2 ) 9 (C 2 ) 10 (C 3 ) 11 (C 3 ) 12 (C 3 ) 13 (C 3 ) Polovnika et al. trans-product A.F. Barreto et al. trans-product. Akita et.al. trans-product C. Demetzos et al E. Katerinopoulos et al cis -product

16 1 -NMR SPECTRUM 3 methyl groups : 1.73ppm (s), 0.92ppm (s), 0.79ppm (d, next to tertiary carbon) 3 olefinicη : 4.70ppm (d) 5.34ppm (bd) ppm (t1)

17 13 C-NMR SPECTRUM 15 carbon atoms, 4 olefinic ppm (t1)

18 DEPT 45 o ppm (f1) 100 DEPT SPECTRA

19 DEPT SPECTRA DEPT 90 o : C ppm (f1)

20 DEPT SPECTRA DEPT 135 o : C 3 & C positive peaks, C 2 negative peaks. Peak at 108 ppm: exocyclic double bond! ppm ( t1 )

21 Initial Remarks Molecular Weight: 204 Molecular Formula: C Degree of Unsaturation: 4 Primary Carbons: 3 Secondary Carbons: 6 Tertiary Carbons: 3 Quaternary Carbons: 3 Two double bonds, two rings, isopropenyl group? 3 4 4a a

22 - gcsy SPECTRUM 3 4 4a a Me Me 8' 7

23 - gcsy SPECTRUM Position Proton δ 1 (ppm) CSY (m) 2,2, (m) 1, 2, (m) 1, 2, 3, (m) 3, (brd, 12.9) 2,2, 3, 4, a (m) 3, (m) 3,3, (brd, 6.0) 6, (m) 5, 6, (m) 5, 6, a (brd, 13.0) 6, 6, (brd, 13.0) (dd, 13.0,13.0) 7, (s) (d,4.5) (d,7.0) 1 Τα πρωτόνια που χαρακτηρίζονται π.χ. Η-8, δηλώνουν πρωτόνια ψευδοαξονικής διαµόρφωσης.

24 C- gmqc SPECTRUM Correlation of carbons and protons in each group 3 4 4a a

25 General Conclusions C- gmqc SPECTRUM Carbon δ 13 C (ppm) Proton δ 1 C (m) C C (m) 1.39 (m) 1.76 (m) 1.28 (brd) C (m) C (brd) C (m) 1.84 (m) C (brd) C (brd) 1.11 (dd) C (s) C (d) C (s) C (d)

26 - interaction through space NESΥ SPECTRUM 3 4 4a a Me Me

27 Conclusions from NE interactions Me Me 8 The resonance of axial Η-8 appears as a pseudotriplet (doublet of doublets) due to the J coupling with Η-8 και Η-7 ( 2 J 7,8 = 3 J 8,8 = 13z). These J values correspond to a trans-diaxial conformation for Η-8 and Η-7, while it suggests an equatorial conformation for the bulky isopropenyl group that is facing the same direction with Η-8. A strong ΝΟΕ observed between Η-12 και Η-13 confirms the proximity of the two methyl groups. Moreover, the proton Η-8 interacts strongly with the Η-12 a fact indicating that the Me-12 is axial. Finally, axial -7 interacts strongly with -1 that must be also axial, confirming that Me-13 is equatorial. 8' 7 All three groups adopt a syn conformation!

28

29 Comparing NMR Spectra values. 13 CNMR C 1 C 2 C3 C 4 C 4a C 5 C 6 C 7 C 8 C 8a C 9 C 10 C 11 C 12 C 13. Itokawa et al C. Demetzos et al α Isolated Eremophilene Η NMR. Itokawa et al. 5 (C) 11 (C 2 ) 11 (C 2 ) 10 (C 3 ) 12 (C 3 ) 13 (C 3 ) 5.37 (m) 4.70 (brs) 1.73 (s) 0.79 (d, 6.0) 0.92 (s) C. Demetzos et al α Isolated Eremophilene 5.33 (brd, 6.0) 4.69 (d, 4.5) 1.72 (s) 0.78 (d, 7.0) 0.91 (s). [α] D ο ± 0.55 (c=2.5, CCl3). [α] D -11.1ο (c=0.18, CCl3), Itokawa,. et al. Chem. Pharm. Bull. 1985, 33, 1148.

30

31 $ Konstantinos atzellis Georgia Pagona Apostolos Spyros Manolis Roussakis Ministry of Education, Greece Region of Crete University of Crete Kostas Demetzos Kostas Economakis