Norisoprenoids in Quince - American Chemical Society

Chapter 30

Natural Precursors of Thermally Induced C Norisoprenoids in Quince Downloaded via YORK UNIV on December 16, 2018 at 21:09:36 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.

13

P. Winterhalter and P. Schreier Lehrstuhl für Lebensmittelchemie, Universität Würzburg, Am Hubland, 8700 Würzburg, Federal Republic of Germany

High resolution gas chromatographic (HRGC) and spectroscopic (MS; FTIR; H-NMR) studies of quince fruit constituents revealed the occurrence of several free and glycosidically-bound precursors, which generate C norisoprenoids upon thermal treatment. 4-Hydroxy-7,8-dihydro-β-ionol was identified as a natural precursor of the isomeric theaspiranes, the major volatile constituents in quince fruit juice. Four thermally-induced megastigma-6,8-dien-4-ones were identified, and 4-hydroxy-β-ionol was established as their natural precursor. Sugar conjugates that play a principal role as antecedents of C norisoprenoids include glycosidically bound 3-oxo-α-ionol, which thermally produces megastigmatrienones. In addition, heat treatment of the conjugate of 3-hydroxy-β-ionol yields bicyclo[4.3.0]nonanes and 3,4-didehydro-β-ionol. The glycoside of 7,8-dihydrovomifoliol was previously substantiated to be thermally degraded to theaspirones. 13

13

Many i n t e r e s t i n g n o r i s o p r e n o i d aroma compounds have been i d e n t i f i e d i n f r u i t s , v e g e t a b l e s and i n p a r t i c u l a r , t e a (1) and tobacco (2). The f o r m a t i o n o f these f l a v o r - s i g n i f i c a n t components has been a t t r i b u t e d t o t h e d e g r a d a t i o n o f h i g h e r m o l e c u l a r weight t e r p e n o i d s , such a s c a r o t e n o i d s , by b i o c h e m i c a l and nonenzymic r e a c t i o n s i n p l a n t t i s s u e s (3). These d e g r a d a t i o n s i n v o l v e c l e a v a g e o f 9 " ^ Q > Cg-Cg, 7 ~ Q and C^-Cy bonds o f the polyene c h a i n t o produce com pounds c o n t a i n i n g Ï 3 , 11, 10, and 9 carbon atoms, r e s p e c t i v e l y . However, o u r knowledge about t h e immediate p r e c u r s o r s o f n o r i s o p r e n o i d s and t h e r e a c t i o n s by which they a r e formed i s r a t h e r s c a r c e . Several v o l a t i l e C- n o r i s o p r e n o i d s have p r e v i o u s l y been i d e n t i f i e d i n s t e a m - d i s t i l l e d q u i n c e f r u i t o i l , i n which they a r e regarded t o c o n t r i b u t e t o the o v e r a l l f l a v o r i m p r e s s i o n . These i n c l u d e isomeric theaspiranes, various bicyclononane derivatives, 3 , 4 - d i d e h y d r o - P - i o n o l , and i s o m e r i c megastigmatrienones and t h e a spirones (4,5). T h i s r e p o r t concerns the i d e n t i f i c a t i o n o f a d d i t i o n a l n o r i s o p r e n o i d s and t h e i r n a t u r a l p r e c u r s o r s i n q u i n c e f r u i t . C

C

c

3

0097-6156/89AM09-0320$06.00/0 ο 1989 American Chemical Society Parliment et al.; Thermal Generation of Aromas ACS Symposium Series; American Chemical Society: Washington, DC, 1989.

c

30.

WINTERHALTER & SCHREIER

Thermally Induced C

n

Norisoprenoids

I s o m e r i c T h e a s p i r a n e s and t h e i r N a t u r a l P r e c u r s o r s The spiroethers 1A and IB are well-known constituents of several f r u i t aromas (6-12) and are widely used in the flavor industry (13).

H

1B

1A

They were i d e n t i f i e d among the main v o l a t i l e constitutents of quince f r u i t j u i c e after careful i s o l a t i o n at i t s natural pH (3.7), employ ing high-vacuum d i s t i l l a t i o n / s o l v e n t extraction (HVD/SE) at 40°C. However, using f r u i t j u i c e neutralized to pH 7.0 for flavor i s o l a t i o n , HRGC and HRGC-MS revealed only traces of these components (14). These results demonstrate that spiroethers 1A/1B were o r i g i n a l l y not present in the intact f r u i t , but were formed at the natural pH of quince f r u i t juice after mild heat treatment from an unstable, less v o l a t i l e precursor. This precursor was i d e n t i f i e d as 4-hydroxy-7,8-dihydro-|3-ionol (4). Its synthesis from Α - ο χ ο - β - i o n o l 2 as outlined in Figure 1, showed coincidence of HRGC and spectral data (MS, FTIR) with those of the constituent isolated from natural quince f r u i t (Winterhalter, P . ; Schreier, P. J . Agric. Food Chem., in press). Prior to t h i s , d i o l 4 had not been described in the l i t e r a t u r e . The mechanism of theaspirane formation from the natural precursor 4 can be considered to occur by prototropic dehydration of the corresponding a l l y 1 - 1 , 6 - d i o l , as previously described for monoterpene d i o l s by Ohloff et a l . (15)> giving r i s e to tetrahydrofuran derivatives (Figure 2). Bicyclo[4.3.0]nonanes, Precursors

3,4-Didehydro-f3-ionol

and

their

Natural

Upon employing the more rigorous simultaneous distillationextraction (SDE) technique (100°C; pH 3.7) to i s o l a t e the quince f r u i t v o l a t i l e s , the resulting aroma composition d i s t i n c t l y differed from that obtained by HVD/SE. After SDE the hydrocarbon 5, the b i c y c l i c alcohol 6 and 3,4-didehydro-p-ionol (7) were i d e n t i f i e d as

OH

5

6

7

Parliment et al.; Thermal Generation of Aromas ACS Symposium Series; American Chemical Society: Washington, DC, 1989.

321

322

THERMAL GENERATION OF AROMAS

2

Figure 1. Synthesis of (4) from 4-oxo-(3-ionol ionol (3).

3

4

4-hydroxy-7,8-dihydro-(3-ionol (2) v i a 4-oxo-7,8-dihydro-£-

Figure 2. Proposed mechanism for theaspirane 1A/1B formation by prototropic dehydration of 4-hydroxy7,8-dihydro-f^-ionol (4) according to Ohloff et a l . (Réf. 15).


30. WINTERHALTER& SCHREIER

Thermally Induced C Norisoprenoids ]3

MAJOR VOLATILES. I N S M A L L E R AMOUNTS, S E V E R A L ISOMERS OF 5 W I T H MV 1 7 4 A N D A N I S O M E R OF A L C O H O L 6 W I T H MW 1 9 2 WERE D E T E C T E D . RECENTLY, J A P A N E S E RESEARCHERS HAVE DEMONSTRATED THAT T H E N O R I S O P R E N O I D ALCOHOL 7 HAS A K E Y ROLE AS A FLAVOR I N T E R M E D I A T E , BUT INFORMATION ABOUT ITS N A T U R A L P R E C U R S O R WAS NOT PROVIDED ( 4 , 5 ) . POTENTIAL S T R U C T U R E S FOR T H E P R E C U R S O R OF 7 C O M P R I S E D I O L S 8 A N D 9; IN E I T H E R C A S E , S I M P L E DEHYDRATION CAN AFFORD A D O U B L E BOND I N T H E 3,4-POSITION. F U R T H E R M O R E , T H E H Y D R O X Y L G R O U P OF 7 COULD C O N C E I V ABLY BE GLYCOSIDICALLY-BOUND.

OH

OH

9

DIOLS 8 A N D 9, I D E N T I F I E D B Y U S I N Q U I N C E F R U I T FOR T H E F I R S T TIME, WERE S Y N T H E S I Z E D A N D S U B J E C T E D TO THERMAL P R O C E S S I N G I N MODEL REACTIONS (WINTERHALTER, P . ; HERDERICH, N.; SCHREIER, P. J . AGRIC. FOOD CHEM. IN PRESS). ACCORDINGLY, 4-HYDROXY-(3-IONOL ( 8 ) WAS SUBJECTED TO T H E R M A L DEGRADATION UNDER S D E C O N D I T I O N S (100°C; PH 3.7), AND THE RESULTS ARE OUTLINED I N FIGURE 3 . IN T H E S E MODEL REACTIONS, B E S I D E S A M I N O R Q U A N T I T Y OF P R E V I O U S L Y - K N O W N N O R I S O P R E N OIDS 5 , 1 0 A / 1 0 B AND 1 1 A / 1 1 B , T H E M A J O R I T Y OF D E G R A D A T I O N PRODUCTS (72£) C O N S I S T E D OF THE I S O M E R I C M E G A S T I G M A - 6 , 8 - D I E N - 4 - O N E S 1 2 A - 1 2 D . THESE LATTER NORISOPRENOIDS HAVE NOT B E E N R E P O R T E D AS YET I N THE LITERATURE. I S O M E R 1 2 B , I S O L A T E D I N P U R I F I E D FORM B Y M P L C , SHOWED A W E A K , L O N G - L A S T I N G TOBACCO NOTE W I T H A C O O L I N G E F F E C T . DIENONES 12A-12D WERE ALSO DETECTED AS TRACE COMPONENTS I N QUINCE FRUIT VOLATILES AFTER SDE SAMPLE P R E P A R A T I O N . HOWEVER, A S SHOWN I N F I G U R E 3 , E X C E P T FOR T H E LOW AMOUNT OF H Y D R O C A R B O N 5 , T H E DISTRIBUTION OF THERMAL DEGRADATION PRODUCTS FROM 8 DID NOT CORRESPOND TO T H E C O M P O S I T I O N O F THE MAJOR C ^ N O R I S O P R E N O I D S 5-7 OBTAINED A F T E R S D E OF Q U I N C E F R U I T J U I C E . C O N S E Q U E N T L Y , D I O L 8 HAD TO B E E X C L U D E D A S T H E I R P R E C U R S O R . IN A FURTHER SERIES OF EXPERIMENTS, MODEL REACTIONS TO THERMALLY-DEGRADE 3-HYDROXY-|3-IONOL ( 9 ) WERE CARRIED OUT. THE RESULTS OF T H E S E STUDIES ARE REPRESENTED I N FIGURE 4 . IN THESE MODEL REACTIONS, COMPOUNDS 5 , 6 AND 7 AS WELL AS U N I D E N T I F I E D ISOMERS O F 5 A N D 6 WERE A L L FOUND I N AMOUNTS V E R Y S I M I L A R TO THE NATURAL QUINCE FLAVOR COMPOSITION OBTAINED BY SDE CONDITIONS. HOWEVER, AS SHOWN IN FIGURE 4 , ADDITIONAL P R O D U C T S WERE FOUND COMPRISING THE MEGASTIGMATRIENOLS 13, 1 4 AND THE TENTATIVELYASSIGNED BICYCLIC ALCOHOL 15. THESE L A T T E R COMPOUNDS WERE NOT DETECTABLE IN QUINCE FRUIT J U I C E . T H U S , THE DIOL 9 C A M E UNDER Q U E S T I O N AS A P O S S I B L E P R E C U R S O R . ONE E X P L A N A T I O N FOR T H I S S U R P R I S I N G R E S U L T I S THAT T H E D I O L 9 IS PRESENT I N QUINCE FRUIT I N BOTH T H E F R E E AND BOUND F O R M S . TO VERIFY T H I S , THE G L Y C O S I D E S I N QUINCE FRUIT WERE I S O L A T E D B Y XAD


323

324


L

12 A

12 Β

12 C

12 0

72%

F i g u r e 3. S t r u c t u r e s o f thermal d e g r a d a t i o n products o f 4-hydroxy-(3-ionol ( 8 ) under SDE c o n d i t i o n s (100°C; pH 3.7). 5 = 2,2,6,7-tetra-methylbicyclo[4.3.0Jnona4 , 7 , 9 ( l ) - t r i e n e ; 10A/10B = E- and Z-megastigma-5,8dien-4-ones; 11A/11B » i s o m e r i c r e t r o - o t - i o n o n e s ; 12A12D « i s o m e r i c megastigma-6,8-dien-4-ones; N . I . « not identified.


J

30.


Thermally Induced C

n

Norisoprenoids

OH

13

14

15

Figure 4. Structures of thermal degradation products of 3-hydroxy-(3-ionol ( 9 ) under SDE conditions ( 1 0 0 ° C ; pH 3.7). 5 * cf. F i g . 3; 6 « 2,2,6,7-tetramethyl-bicyclo- [4.3.0]nona-4,9(l)-dien-8-ol; 7 = 3,4-didehydro(3-ionol; 13 = megastigma-5,7,9-trien-3-ol; 14 - megastigma-4,6,8-trien-3-ol; 15 « 2,2,6,7-tetramethylbicyclo[4.3.0]nona-7,9(1)-dien-4-ol.


325


326

ADSORPTION AND METHANOL E L U T I O N . THE G L Y C O S I D I C EXTRACT VAS THEN SUBJECTED TO S D E ( 1 0 0 ° C ; P H 3 . 7 ) AND THE V O L A T I L E S FORMED WERE ANALYZED BY HRGC AND H R G C - M S . THE RESULTS OBTAINED I N THIS E X P E R I MENT ARE REPRESENTED I N FIGURE 5. F I R S T , I T HAS TO B E E M P H A S I Z E D THAT A SIMILAR COMPOSITION OF C^~ N O R I S O P R E N O I D PRODUCTS WAS OBTAINED A S FOUND A F T E R S D E TREATMENT OF QUINCE FRUIT J U I C E . IN ADDITION, MARMELO E T H E R ( 1 6 ) A N D MARMELO L A C T O N E ( 1 7 ) WERE ALSO IDENTIFIED. T H E S E R E S U L T S S U G G E S T E D THAT T H E T H E R M A L L Y - I N D U C E D C - « NORISOPRENOIDS FOUND I N Q U I N C E F R U I T O R I G I N A T E D FROM A SUGAR C O N J U GATE OF D I O L 9 AS A PRECURSOR. TO C O N F I R M T H I S HYPOTHESIS, THE GLYCOSIDIC E X T R A C T O F Q U I N C E F R U I T WAS F U R T H E R S U B J E C T E D TO E N Z Y M A TIC HYDROLYSIS U S I N G COMMERCIAL E M U L S I N AS A G L Y C O S I D A S E . THIS LED TO L I B E R A T I O N OF 3 - H Y D R O X Y - ( 5 - I O N O L ( 9 ) AS THE MAJOR A G L Y C O N E . IN ADDITION TO 9 , OTHER GLYCOSIDICALLY-BOUND C-~ NORISOPRENOIDS WERE IDENTIFIED, INCLUDING 3-HYDROXY-Ê-IONONE ( 1 8 ; , 3-OXO-A-IONOL ( 1 9 ) , 3 - H Y D R O X Y - 7 , 8 - D I H Y D R O - £ - I O N O L ( 2 0 ) , V O M I F O L I O L ( 2 1 ) AND 7 , 8 - D I H Y D R O V O M I F O L I O L (22) ( F I G U R E 6 ) .

M e g a s t i g m a t r i e n o n e s and t h e i r N a t u r a l P r e c u r s o r s AMONG T H E A G L Y C O N E S SHOWN I N F I G U R E 6 , 3-OXO-OFR-IONOL ( 1 9 ) P L A Y E D A ROLE A S A P R E C U R S O R OF OTHER C - « NORISOPRENOIDS DETECTED I N QUINCE FRUIT AFTER SDE SAMPLE ISOLATION. AS OUTLINED I N FIGURE 7, THE KETO-ALCOHOL 1 9 I S KNOWN TO B E D E G R A D E D TO T H E I S O M E R I C M E G A S T I G M A TRIENONES 23A-23D A N D 24A/24B ( 1 6 , 1 7 ) A F T E R THERMAL T R E A T M E N T U N D E R ACIDIC CONDITIONS.

OH

7

6

5

+ Isomers MW

MW

174

16

192

17

FIGURE 5 . MAJOR VOLATILES FORMED FROM GLYCOSIDIC EXTRACT FROM Q U I N C E F R U I T A F T E R S D E TREATMENT (100°C; PH 3 . 7 ) . 5 , 6 , 7 - C F . F I G . 4 J 1 6 - MARMELO E T H E R ? 1 7 » MARMELO L A C T O N E .


30.


Thermally Induced C . , Norisoprenoids

OH

18

19

20

21 OH

22 Figure 6. Structures of aglycones released from quince f r u i t extract after glycosidase (emulsin) treatment. 9 « 3-hydroxy-|3-ionol; 1 8 = 3-hydroxy-|5ionone; 1 9 = 3-oxo-oc-ionol; 2 0 = 3-hydroxy-7,8-dihydro(J-ionol; 2 1 = vomifoliol; 2 2 = 7,8-dihydrovomifoliol.


327

328


23 C

23D

Figure 7. Structures of thermal degradation products of 3-oxo-a-ionol (19) under SDE conditions (100 ° C; pH 3.7). 23A-23D = isomeric megastigma-4,6,8-trien-3-ones; 24A/24B = isomeric megastigma-4,7,9-trien-3-ones. (Redrawn from réf. 16 and 17.)


30.


Thermally Induced C

J3

Norisoprenoids

Isomeric Theaspirones and their Natural Precursors Another C-« norisoprenoid aglycone in quince f r u i t , 7,8-dihydrovomif o l i o l (22) (cf. Figure 6), can be considered to be the precursor of theaspirones, which were previously found in steam-distilled quince f r u i t o i l (4). As outlined in Figure 8, a synthetic sequence from α - i o n o n e v i a dehydrovomifoliol (25) and vomifoliol (21) leads to 7,8-dihydrovomifoliol (22), from which the isomeric theaspirones 26A/26B are formed after thermal treatment (18).

alpha-Ionone

26 A/B Figure 8. Synthesis of theaspirones 26A/26B from α-ionone via dehydrovomifoliol (25), vomifoliol (21) and 7,8-dihydrovomifoliol (22). (Redrawn from ref. 18.)


329

330


Acknovledgmen t s C. Kahre's and Th. K e l l e r ' s skillful HRGC-FTIR a n a l y s e s a r e gratefully acknowledged. The a u t h o r s a l s o thank M. H e r d e r i c h , V. Lander and Th. Schmidt f o r p r a c t i c a l a s s i s t a n c e ; Dr. E. J . Brunke (Dragoco, Holzminden) and Dr. D. Lamparsky (Givaudan, Dubendorf) f o r p r o v i d i n g s e v e r a l r e f e r e n c e s u b s t a n c e s ; and the Deutsche F o r s c h u n g s g e m e i n s c h a f t , Bonn f o r f i n a n c i a l s u p p o r t .

Literature Cited 1.

2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.

Schreier, P. In Analysis of Nonalcoholic Beverages; Linskens, H.F.; Jackson, J.F., Eds.; Modern Methods of Plant Analysis, New Series, Vol. 8; Springer: Berlin, New York, 1988; pp. 296-320. Enzell, C.R.; Wahlberg, I.; Aasen, A.J. Progr. Org. Natl. Prod. 1977, 34, 1-79. Enzell, C.R. Pure Appl. Chem. 1985, 57, 693-700. Tsuneya, T.; Ishihara, M.; Shiota, H.; Shiga, M. Agric. Biol. Chem. 1983, 47, 2495-2502. Ishihara, M.; Tsuneya, T.; Shiota, H.; Shiga, M.; Nakatsu, K. J. Org. Chem. 1986, 51, 491-496. Winter, M.; Enggist, P. Helv. Chim. Acta 1971, 54, 1891-1898. Winter, M.; Kloti, R. Helv. Chim. Acta 1972, 55, 1916-1921. Renold, W.; Naf-Muller, R.; Keller, U.; Willhalm, B.; Ohloff, G. Helv. Chim. Acta 1974, 57, 1301-1308. Schreier, P.; Drawert, F.; Junker, A. J. Agric. Food Chem. 1976, 24, 331-336. Kaiser, R.; Kapeler, Α.; Lamparsky, D. Helv. Chim. Acta 1978, 61, 387-400. Idstein, H.; Schreier, P. J. Agric. Food Chem. 1985, 33, 138-143. Hirvi, T.; Honkanen, E. J. Sci. Fd. Agric. 1985, 36, 808-810. Naegeli, P. German Patent 2 610 238, 1976. Winterhalter, P.; Lander, V.; Schreier, P. J. Agric. Food Chem. 1987, 35, 335-337. Ohloff, G.; Schulte-Elte, Κ. H.; Willhalm, B. Helv. Chim. Acta 1964, 47, 602-626. Aasen, A.J.; Kimland, B.; Almquist, S. O.; Enzell, C. R. Acta Chem. Scand. 1972, 26, 2573-2576. Strauss, C. R.; Wilson, B.; Williams, P. J. Phytochemistry 1987, 26, 1995-1997. Heckman, R. Α.; Roberts. P. L. Tetrahedron Lett. 1969, 2701-2704.

RECEIVED July 6, 1989


Norisoprenoids in Quince - American Chemical Society

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