Aklaloids and others

8/12/2019 Aklaloids and others

1/24

CH PTER~EvIEwO LITERATURE

2.1 Introduction

The microorganisms have unlimited potential to perform selectivebiochemical t r an s f ~ r m a t i o ns .~ ~he application of microbes t achieve desiredfunctional changes represents one of the most fascinating aspects of man's scientificand technological deve lopment. While tracing the history of the use ofmicroorganisms, it is evident that, ancient civilizations have made use of yeasts asearly as 3000 BC, to convert the sugar moiety of certain plant materials into ethylalcoh01.~ The scientific basis of t is was unlcnown until 1857, when Pasteurpublished his paper on fermentati~n.~ollowing this severdl attempts were made toobtain desirable changes in substrate molecules. Thus Boutroux 1880) succeeded inthe conversion of glucose into gluconic acid.8 Propionic acid from n-propanol andfructose from mannitol were obtained by ~ r o w n . ~

Later, Bertrand succeeded in converting sorbitol to sorbose and glycerol todihydroxy acetone. l These conversions re st ll used for the preparation of theabove mate on an industrial scale. However, mod of the early microbialtransformations have been mainly confined to reactions involving carbohydrates,12simple aliphatic and aromatic c ~ m ~ o u n d s ~ ~ - ~ ~nd steroid^. -^^ Until 1959, therewere few known examples of transformations of compounds of other structuralclasses.16 However, a rapid development too place in this area, following the


2/24

classification of microbd transformations by Stodola which encouraged morefundamental studies involving different classes and typ s of substrate^.^ Mosl ofthe microbial conversions of organic compounds have been confined to thepharmaceutically and commercially imprtant n tur l products such as steroids andterpenoids. Microbial transformations of alkaloids and steroidal alkaloids are arecent field of investigation.

2.2 Microbial Transformation of teroids

The oxidation and reduction of steroidal alcohol and ketones by ye sts andbacteria were irstobserved by Mamoli and ~ e r c e l l o n e . ~ ~ ~ ~urray nd Petersonsucceeded to introduce oxygen functions into steroids using microbes.24 They usedhizopus nrrhizus to convert progesterone into 11-a-hydroxy progesterone from

which the naturally occuring ad r e d hormone, cortisome could be synthesized.24However, 6-P 11-0-dihydroxy progesterone and 11-a-hydroxy-5-a-pregnane-3 20-dione were also formed in this conversion. Generally the oxygenation at C-11 ofsteroid system makes them pharmacologically active a s antiinflammatory agents.This microbial process is extremely important hecause the introduction of ahydroxyl group at 11 psi tion is chermcally very difficult to achieve. Furtherstudies showed that a closely re l a d fungus hiropu nigriuuu cw effect thisconversion in almost quantitative yield.25

The microbial enzymes display widespread and remarkable ability tohydroxylate steroids. It has been possible to introduce a hydroxyl group at everyunsubstituted position of the steroid mo~ecule.~ ydroxylations giving the 11-a and6 P hydroxy derivatives are most common and 11 a hydroxylations of manysteroidal systems have been scaled up. The conversion of 16-a 17-a-oxido-4-pregnene-3.20-dione to 11-u-l~vcirc~xy- a. 17auxido-4pregnrrre : 2 0diow by a


3/24

strain of Rhiropus species was established and it was found that the fermentationwent faster when done on a laboratory scale.26 Pregnenolone was converted loprogesterone, 1I-a-hydroxy progesterone and 68 1lu.-dihydroxy progesterone by astrain of Aspergilk orchroceus NRRL 05) .~ Colingsworth er al. showed thatunninghumella blokeslee~w ould produce cortisone and m i s o l from Reichsteins

compounds ( I ) . ~ ~ oth of h e x biooxidations viz., I 1-a-hydroxy aacm ul'progesterone and 11-~hyUroxylation f Reichstein s compounds ( 1 have been madecommercially viable for producing adrenal hormones.

Reichsteins compounds w s hydroxylated to cortisol by immobilization of ahydroxylator Curvuloria lwuua in a medium containing 2.5 dimethylsu~phoxide .~~tudies hy Dulaney er d showed that the genus Aspergilluspossessed the ability to carry out 11-a-hydroxylation hesides hydroxylaaons at the6 3 and 17a positions, whereas most of the strains of Penicilliwn favoured 15ahydroxy ati ion.^


4/24

Bloom and Shull fmt observed the epoxidation of an isolated double bondusing microorgani~ms.~~hus auvlinghameUa blakesleeana or bnubia h a f aor other 1 ffhydroxylating organisms converted 9-dehydro Reichsteins compoundsto 9@ 1IF-oxido derivative and 98, 1 ~xide20&hydro xyderivative.31 Theirwork led to the theory that 'a microorganism capable of introducing an axialhydroxyl function t C, of a s tur ted steroid can also be used for introducing anepoxide grouping xi l t C, in the corresponding umalwated~ubstrate .~'

Aromatization of steroids was observed with several microorganisms.19-Nortestosterone was converted by Septomyxa h is to e-ne and e s b a d i ~ l . ~ ~A strain of Coryneboaerim simpkx converted 19-hydroxymethylepidehydmmdrosterone to estrone in 74% yield.33 Estradiol was t r a n s f d to the2-hydroxy nd 4-hydroxy derivatives by str in of spcrgiilluc aIliacewM

The antiinflammalory activity of well known steroids requires ll$-hydroxyor 1I-keto functions in pregnene structures and s increased by a f~rther~ oublebond.4 Therefore, this type of bioconversion is very important after the11-hydroxylation or oxidation process. Nobile et al reponed the conversion ofcortisol to prednisolone, a compound with greater antihfbmatory effects and lesssalt retention properties th n cortisol, by strains of Corynebacterim simpler andmany other Recent reports show th t use of immobilised viablecells of Anhrobacter .~imp~'e.?~.~'nd nhrobaaer globifonnis 8enhanced the yieldand efficiency of this conversion. he conversion of 16a-methyl-3B,17ar-dihy oxy-5a-pre oane-2hne-3R~te o I -methyl-17cr-hydroxy-pregna-14-diene-3.2Wone was about 63% with mixed culture of My wh c te r iwns m e gm s and Anhrobacter s i m p k ~ . ~ ~ncubation of I&-methyl 17-or-hydroxy-pregna-1.4-diene-3,20-dionewith bsidia glauca gave 55% yield of 1 a-hydroxy


5/24

d e r i ~ a t i v e . ~ ~0 yield of androsta-1.4-diene-3.17-dione was obtained whendehydroisoandrosterone was incubated with uor iwn oxysponcm 40

Testosterone was converted by ycobactenm phki to androstane-l,4diene-3.17-dio11e.~'Bucillrrs sphntvicus strains (ATCC 7054 and 7055) on the other handtransformed testosterone to androst-4-ene-3,17-di0ne.~ lso a strain ofSrreptomyces hydrogenans effecfected the same c o n v e r ~ i o n . ~ ~strain of Aspergillusfwnrg ncr was reported to convert teszosterone to the 15p-hydroxy

Degradation of the side chain of cholesterol y microorganisms had beenknown since 19 13. Androsta- 1.4-diene-3.17-dione was isolated as a product, whencholesterol was incubated with Mycohcreriwn phlei in the presence of chelatingagents like 8-hydroxy quinoline.41 Recent reports show that a mutant ofCorynebacreriwn (Cho1.73) was able to CoIIVeIt cholesterol to 20-&)xy-pregna-1.4-diene-3-one in quantitative yields. 5 Many phytosterols were also converted toandrosta-1.4-diene-3,17-dione, by a strain of Anhrobacrer simpler (ATCC 6946).*

2.3 Microbial transformation of steroidal alkaloids

Steroidal alkaloids are hydroxylated in the same way as steroids. Conessine2 ) underwent microbiological allylic oxidations to give the 7cr-hydroxy 3) and

7P-hydroxy 4) derivatives, besides the la-hydroxy derivative (5) in the presenceof Gloeosporiwn fiuctigenum f. a m e r i c ~ n u ~ ~ompounds (3) and (4) were alsoproduced tiom 2) by C u n n i n ~ m m ~ ~ l l uchindau NRRL A 1 1 4 ~ 8 ) . ~ ~ut a strainof rachybanys purvispora transformed Conessine to con-4-enin-2-one nd luhydroxy con-4-enin-30ne.~'


6/24

Solasodine 6) sinriklrly underwent allylic oxidations to give the 7a-hydroxy( 7 ) and 7p-hydroxy (8) derivatives along with the 9a-hydroxy 9) and a-hydroxy10)derivatives in the presence of IIelicosrylwn pin~ome 49

'I'omatidine 1 1. was ccnv erted to the 7a-hydroxy (12). 9cu-.hydroxy (1 3) and7 n , 1 la-dihydroxy (14) deriva flves by the same mould H. P i r i J i ~ f m e ~


7/24

I - - > Rl = = R3 = H12--> R3 = H , Rl = O H13--> Rl = R3 = H,R2 = OH

HOR

Tomatine 15) was reported to form a conjincubation with a strain of N m r d i a r e s m c l ~ . ~ ~steroidal alkaloids or their glycosides are rarely ob s e~ ed . ~

strain of spergillus nigtprwhen grown in a malt agar medium at pH = 4.5, in thepresence of crude glycoalka11:ids from Solanum k b i a n u n ~ ydrolysed the same tothe aglycone solasodine ~ 6 ) . ~


8/24

2.4 Microbial Transforalption of Aikaloids

Compared to alicyclic compounds, alkaloids with heterocyclic structures aregenerally more & Ticult to transform. heterocyclic atom is frequently a targetof attack for undesired degradations. This is shown by low yields and usually byunfavourable material balances On the other hand, ring linkage vla suchheteroatoms may yield &rically unfavourable substrate structures, which areresistant to attack or only attacked non specifically 5 The work on the microbialtransformation of alkaloids have been reviewed by Tamm and ini in and recentlyby Iizuka and ~ a i t o ' ~nd 11a vis. ~~

2.4.1 Tropa alkaloids

Niemen er al isculaled a bacterium, nhrobacrer oxydans from soil whichwas overgrown with "deadly night shade" bushes (Atropa belladonna) capable ofutilising atropine (dl-hyoscyamine) 16)j as the sole source of carbon andnitrogen.55.56 The sulphate of atropine was hydrolysed by this organism to tropine(17) and tropic acid (18). Tropine was oxidistxl via., tropinone (19) to tropinic acid20) and probably, broken by oxidation to yield 2,s-dioxoheptanedioic acid (21) and

methyl arnine. Tropic acid was subsequently demtwxylated and oxidizd via..phenyl acetaldehyde (22) to phenyl acetic acid (23) which inhibited further k t n i a lgrowth.55.s7 Hyoscyamine and scopolamine (24) were broken down in the sameway by this organism but nortropine (25) was not t r a n ~ f o r m e d . ~ ~ - ~ ~amm reportedthat tropinone (19) was reduced by Fusarium lini to 7-tropine (26) and tropine( 1 7 ) . ~


9/24


10/24

The nansfonnation of tropine to 7-'-.@opine was effected by the synergesticachon of 2 bacterial strains, an aerohic spore producing UuciNus lvei and anenterococcal wa in ~ i ~ l o c a r u r . ~ 'he reaction did not occur via the intermed~ teketo compound (19) . But it proceeded via the dehydration product 2 tropene (27) towhich addition of water took place as shown by the incorporation of tritia ted waterin the fin l product (26).62 CH

2.4.2 Pyridine alkaloids

The microbial degradation of nicotine has been reviewed by Kuffner er al. in1 9 6 3 . ~ ~ strain of Pseudomonar species degraded nicotine to give 3-(3-carboxypropanoyl) pyridine.64 It was produced via the intermediate Pseudo-oxynicotine,subsequently isolated from the same fermentation reaction.65 Nicotine on incubationwith Pseudomonas nicorinophagu gave 3-(3-carboxy propanoyl) pyridine,3- 3-carboxy-propanoy1)-6-hydroxy pyridine and methylamine.66 Microorganismsbelonging to the genera Pseudomonm. Alcaligenes, Achromobacrer, Bacterium,Bacillus nd anrhobacrer, utilised nictoine as the sole carbon and nitrogensource.67 68 fter a series of investigations, Riaenberg et al 69 73 and Decker era ~ . ' ~ - oncluded that the initial step in the degradation of rucocinr by Anhrobac teroxyd nr was 6-hydrc)xylation of the pyridine ring to give 6hydroxy nicotine.Further transformation of 6-hydroxy nicotine was investigated with cell free enzymepreparations. 6-Hydroxy nicotine was dehydrogenated to give 6-hydroxy-N-methylmyosmine which 'on hydration gave 6-hydroxy pseudo o ~ ~ n i c o t i n e ~ ~nd onfurther degradation yielded 2,Gdihydroxy pyridine and 4-methylaminobutyric


11/24

a ~ i d . ~ ~ . ~nhrobacrer globi ormis was also reported to degrade nicotine to give6-hydroxy nicotine and 6 hydroxy N methylmy~smine.~~

Nicotine N -oxide w a degraded by this organism to give N-methylmyosmine and 3-(3-carboxy r~ropanoy1)pyridine. hus it is seen that nicotine nd it s

oxide are metabolised in different pathways. P e f l i ~ a J f ~ ~ o S UJTS 2 )pathogen of tobacco, transformed nicotine to nor nicotine and W n g h a m e l hechinulnra ( I F 0 4 4 4 4 ) converted nicotine to N-methyl myosmine and norn i~o t ine .~~

Yamashita er al. repo~ted he isolation of R +) nicotine 28) from R,Snicotine by selective degradation of S(-) nicotine 29) usin cell free enzymes fromArthrobacter o ~ ~ d a n s . ~ ~ome strains of P s e u d o m o m pun'& were also able toeffect Uus resolution.81-83 it was reported that 28) was also degaded by P. pufidat a slower rate in this re soh ~tiorl .~

Hydrolysis of ricinirle (30) (which is difficult to hydrolyse chemically) wascarried out by a P s e u d o m o m str in to give the acid (3I ) . ~ ~


12/24

2 4 3 lsoquino line alkaloids

The microbial transformation of morphine alkaloids w s investigated byIizuka and coworkers.85 Thebaine (32) w s converted to 144-hydroxy codeinone(33) and 14f-hydroxy codeine (34) by the fungus hztneter sunguinea hc yield ofthe products varied depending upon the composition of the medium. his fungusconverted codeinone (35) to 14p-hydroxy codeinone 33). 14jbhydroxy odeine (34)and codeine (36).87 The same organism lso produced (33). (34) and (36) fromneopinone (37) depending ulx,n the composition of the medium.87


13/24

Several 14-substituted morphine alkaloids wit a, -tuWlturatad C carbonylgroups were found to be stereospecifically red~ ced .~ ' hus 14p-acetoxy codeinone(38) was converted into 14P-hydroxy codeine (34) by Trames sunguinea n 70yield.88 On the other hand, 14B-bromocodeinone (39) andenvent only an enzymaticreduction to give l4gbromo codeine (40). ~

The microbial transformation of 6.14-endoetheno teb a hydro thehvinederivatives, very powerful analgesics, were studied by using Cwvu nghomPlla andylaria ~ t r a i n s . ~hus 7cr acetyl 6.14endo etheno eln hydrothebaine (41) was

transformed to (42) and (43). Microbial dealkylation of these ompounds was foundto be superior to chemical methods.w


14/24

Microbial transformations of 10.1 1-dimethoxy aporphine 44) were studiedto determine the potential of rrucroorganism to produce monometboxy aporphines.Thus unninghamella e l e g m ATCC 9245) converted 44) quantitatively intoisoapocodeine (45). A Srrepranyces species SP-WISC 1158) gave a mixture ofisoapocodeine (45) nd apocodeine 46) in 20 and 24 yield5 respectively. I t wasfound that the 10-methoxyl group was more susceptible to m&)lic cleavage thanthe sterically hindered 11-melhoxyl floup.91 A preparative scale regiospecificconversion of 44) to (45) was cunducted using C eleganr (ATCC 9245) by Smithand ~ a v i s . ~ ' . ~

44--> R = CH45 > CH3 = H6 > R CH3, H

Fusarium solani stereospesifically and quantitatively oxidised S-(+) glaucine(47) to dehydroglaucine (49) whereas R- -) glaucine (48) was not rnetab~lised.~~


15/24

A strain of ocardla species, isolated from soil by enrichment technique,was found to use papavelrine ( 5 0 ) s the sole source of carbon and nitrogenproducing a number of metabolites and a probable pathway of degradation wasproposed.9

2 4 4 Ergot alkaloids

Brack, B T U M ~ ~nd Kobe1 first described the microbial transformation ofergot alkaloids with the fungus silocybe sernyervi~a ~~ his microorganismhydroxylated elymoclavine 51) at the 8-position to give Penniclavine 52) andisopenniclavine 53). .I\groclavine 54) was co nv en rd by the same fimgus toSetoclavme ( 5 5 )and ir;osetoclav~ne 56) in 35 and 1 yields respectively.


16/24

Studies by Beliveau and Ramstad showed that many fungi and Srrepronrycereswere also capable of this enz:ymtic hydroxylation reaction. be T eda researchgroup discovered that 3repronyces roseochromolpenes S rimosus andS purpurescens demethylatecl agroclavine (54) to give nor agroclavine (57).97 Also(54) was hydroxylated by C ~ n i d u m usakii to the 2-hydroxy derivative (58).1'Tyler er al found that (54) was hydroxylated to elymoclavine (51) with Mycelialhomogenates of Cloviceps uuspali which nonnally produces large amounts ofe lym~clav ine .~~he sarrle was also c nied out using cultures of Aspergillus and~ e n i c i l l i w n ~ ~puspali Li 189) transformed elymoclavine 51) to lysergic acidamide (59).Iw The hydrolysis of' (59) and isolysergic acid amide (60) withC purpurea gave the acids (61) and 62) respecti~ely.'~' The yields of thesemicrc~bialhydrolysis (85 to 95'6) were far better than those from chemical means(30 to 50 ).1'


17/24

The conversion of ergoline alkaloid, pergolid 63) by a strain ofelm~nrhosporiwn pecies gave the sulphoxide 64) in significant amounts. Several

organisms including a m im of spergi lk llioccur formad itnother metabolitepergolide sulphone 65).


18/24

2.4.5 Rauwolfia alkaloids

'The hydroxylation ; I Clo is more common among the Yohimbiie typealkaloids. Meyers and Pan showed that Yohirnbine (66) was hydroxylated at C lo bya wide range of microorganisms including ActinotnYceres, Phycomycefes,Ascomyceres and Fungi impegecr.103 This prop* was s in specific and notfound in any of the bacteria or yeast tested. Hartman er al. found thatmWUllnghamella balnieri A.TCC 924). C. e c h i W NRKL A1 1498) nd

Srreptomyces plotemis NWL 2364) hydroxylated yohimbine 66) , a-yohimbine70), B-yohimbiie 74) and ~3rynanthine 76) in th 10 position to give (67) 7 ,74) and 77) respectively. ' C . bolnieri (CampbellsX48), C. benholleriae NRRL

A11497) and C. eleganr NRRL A11499) transformed (66) and 70) o thehydroxy derivatives 68, and 72) respectively.'04 Calonecrria dccora (CRS)converted 66) to give 1k-hydroxy derivative 69).lo4 Alkaloids (66) and 70)were metabolised by Srre~fo~mycesmosus NRRL 234) or S. aweofacieru ATCC11834) to give the 18a-hydroxy derivatives 69) and 73) respectively.105

Ajmahcine 78) wias hydroxylated in the 10-position by GoPrgronellaurceoh;fera to give 79) in 40% yield.'06


19/24

7 0 - - > R R 3 HR 1 ;~G& 7 1 - > R R H R = O Hti 7 2 - - > R R3 H R ~ O HC C ~ N C ' R 7 3 - - > R R~ H R ~ OH

O


20/24

Probably, because Reserpine 80) and its derivatives already have hydroxyfunctions at and 18 positions, they cannot undergo the s m hydroxylatiunreactions as yohimbine.5 ethyl reserpalc (81) o incuhtitm with mpromyresaureofaciem (ATCC 13132) or S. rimosus NRRL 2234) gave methyl pseudoreserpate (82). lo

H CO

oo

2.4.6 Colchicine

Colchicine (83) was converted to the monodemethyl derivatives by variousrrepromyces species. Thus S griseus (ATCC 10137) demethylated (83) at the Clo

position to give (& ).'I3 AlkiIIoid (83) on incubation with S. speczabilis orS griseus a different strain) gave the 2-O-demethyl derivative (85) and 3-0-demethyl derivative (86). Io8


21/24

83--> R, R, R, CH,84--> R R CH,,R, H85 -->R R, CH,, R, H86-> R - R CH. y H

2 4 7 Strychnos alkaloids

Recently some work has been carried out on Stry;hnos alkaloids . Bellet andGerard reported the conv~ersion of Strychnine 87) and bmcine 88) to thecorresponding N-oxides (89) and (90) r e ~ ~ e c t i v e l ~ . ~ ~ ~ ~he N-oxidation wasfound to e a very general reaction of various microorganisms such as bacteriaBacillus rhuringiensis. B. subtillis, Propioniboaeriwn freudenrelchii) actinomycetesSrreprontyces species UC 57, Nocurdia usreroides. N coralina) and/lngi imperfectRhuopus arrhiwr, CunninghutnelbblaRcslecm . However, a c i h rhwingienrisATCC 10792) s the only organism that provided good yields (50 ) of the

N-oxide. Og Helicosrylwn inif if om transformed strychnine 87) to the N-oxide (89)and to the 16a-hydroxy derivative (91).11


22/24

Bucherer isolated d.ifferent str ins of nhrobacrer species capable ofdecomposing strychnine.l12 One of these st~ains A snychnovonun utilisedstrychnine only s a source of carbon. Since it could grow in the mineral strychninesolution only in the presence of an inorganic nitrogen source. CI6 H w n cid92) was isolated s a degradation product in this f e r r n ~ n t a t i o n . ~ ~he sam e culture

was not able to tr an sfo m ~ he closely related alkaloids, brucine 88) or Vomicine93). A. belludonnue which was capable of deconlposing atropine, alsodecomposed strychnine in tli presence of an inorganic nitrogen source orrmng

violet dye . Brucine and vomicine were not transfe rred by this organism. 12A. srrychnopbugwn utdised strychnine both s carbon and nitrogen sourceproducing low molecular weight fragments which were not completelyc h ar ac te ri d . Brucine and vomicine were lso degraded by this strain. I 2


23/24

In another study strychnine was converted to C 16 Hanssen cid 92) byAnhrohcrer species, micnml.ganism isolated from the local soil of the habitat of theplant and 2-nitro strychnine 94). one of its derivative to bamino strychnine 95)by a microorganism belonging to Pseudomona~ pecies.'14

2 4 8 Vinca lk loids

Only few repofis ;ire available on the biotransformatjon of iaca alkaloids.Mallen er a l . I S initiated th studies of biobansformations of t is group of alkaloids.A strain of Srreprowce s Cinnamonensis A 15167) was found to transformvindoline 96) to dace?, vindoline 97) and deacetyl dihydrovindoline ether.'''Alkaloid 96) on incubation with Streptomyces griseur UI 1158) gave good yieldsof dihydrovindoline ether 98) and a novel dimeric vindoline derivative (99). Thismetabolite 99) consi:rtod of 2-dihydrovmdolint: ethcr moieties joined by a C-Cbond, which was most probably formed by an enamine conden~ation.''~


24/24

8

H3 FJch~ -cOOCH3R cM Y H 3O CC h 343 -H,

But dihydro vindoline (:1(X3) when incubated with resting ce lls of Srreptomycesgriscus produced 1-0-demethyl dihydro vindoline (101) in 10 yield.''7 A mainof the fungus Sepedonium chrysopennwt (ATCC 13378 was foun to transformvindoline (101) to o-dernetl~ylvindnline (102) with 33 yield.''8 A detailed workon the biotransformation of Vinca alkaloids w s carried out by Velluz el a1. 19

Documents

Aklaloids and others