Studies on the constituents of Luffa acutangula Roxb. I. Structures of acutosides A--G, oleanane-type triterpene saponins isolated from the herb.

From the herb of Luffa acutangula ROXB. (Cucurbitaceae), seven oleanane-type triterpene saponins, acutosides A--G, were isolated and their structures were determined. Acutoside A is oleanolic acid 3-O-beta-D-glucopyranosyl-(1----2)-beta-D-glucopyranoside. Acutosides B, D, E, F and G have a common prosapogenin structure, acutoside A, and only differ in the structures of the ester-linked sugar moieties. Acutoside B is a 28-O-[O-beta-D-xylopyranosyl-(1----4)-O-alpha-L-rhamnopyranosyl-(1----2) -alpha-L-arabinopyranosyl] ester, D is a 28-O-[O-beta-D-xylopyranosyl-(1----3)-O-beta-D-xylopyranosyl-(1----4)-O- alpha-L-rhamnopyranosyl-(1----2)-alpha-L-arabinopyranosyl] ester, E is a 28-O-[O-alpha-L-arabinopyranosyl-(1----3)-O-beta-D-xylopyranosyl-( 1----4)-O-alpha-L-rhamnopyranosyl-(1----2)-alpha-L-arabinopyranosyl] ester, F is a 28-O-[O-beta-D-xylopyranosyl-(1----3)-[O-beta-D-xylopyranosyl-(1----4)-O -alpha-L-rhamnopyranosyl-(1----2)-alpha-L-arabinopyranosyl] ester, and G is a 28-O-beta-D-xylopyranosyl-(1----3)-[O-alpha-L-arabinopyranosyl-(1- ---3)-O-beta-D-xylopyranosyl-(1----4)]-O-alpha-L- rhamnopyranosyl-(1----2)-alpha-L-arabinopyranosyl] ester. Acutoside C is a machaelinic acid (=21 beta-hydroxyoleanolic acid) saponin having the same sugar moiety as that of acutoside B.     

Saponins from Chinese folk medicine, "zhu jie xiang fu," Anemone raddeana REGEL

From the Chinese folk medicine "Zhu jie xian fu" (roots of Anemone raddeana REGEL, Ranunculaceae), two new oleanane-type glycosides, named raddeanosides R8 (1) and R9 (2), were isolated. The structures of 1 and 2 were determined as 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-beta-D-glucopyranosyl- (1----2)-alpha-L-arabinopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1----4)-O-beta-D-glucopyranosyl-(1----6)-b eta-D- glucopyranoside and 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-beta-D-glucopyranosyl-(1----2)-al pha-L- arabinopyranosyl 27-hydroxyoleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1----4)-O-beta-D-glucopyranosyl-(1----6)-b eta-D- glucopyranoside, respectively.     

Steroidal saponins and alkaloids from the bulbs of Lilium brownii var. colchesteri

The fresh bulbs of Lilium brownii var. colchesteri were found to contain five steroidal saponins: 26-O-beta-D-glucopyranosylnuatigenin 3-O-alpha-L-rhamnopyranosyl-(1----2)-beta-D-glucopyranoside (6), 26-O-beta-D-glucopyranosylnuatigenin 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----4)]- beta-D-glucopyranoside (7), brownioside (8), deacylbrownioside (9) and 27-O-(3-hydroxy-3-methylglutaroyl)isonarthogenin 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----4)- beta-D-glucopyranoside (10); and two steroidal alkaloids: beta 1-solamargine (11) and solasodine 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----4)- beta-D-glucopyranoside (12); along with several phenolic constituents. Compounds 7, 10 and 12 are new naturally-occurring compounds.     

Saponins from leaves of Acanthopanax hypoleucus Makino.

From the leaves of Acanthopanax hypoleucus Makino (Araliaceae), five triterpenoidal saponins, having oleanolic acid and hederagenin as sapogenins, were isolated. On the basis of chemical and spectral data, the structures of two new saponins, named hypoleucosides A (1), and B (5) were elucidated as follows: 1; 3-O-beta-D-glucopyranosyl 11 alpha-methoxy-oleanolic acid 28-O-beta-D-glucopyranosyl ester, 5; 3-O-beta-D-glucopyranosyl-(1----2)-alpha-L-arabinopyranosyl-(1---- 4)-beta-D-glucopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1----6)-beta-D-glucopyranosyl ester.     

Four new oleanane saponins from Anemone anhuiensis

Four new oleanane triterpene saponins, anhuienosides C-F, together with three known saponins, were isolated from the rhizomes of Anemone anhuiensis (Ranunculaceae). The structures of anhuienosides C-F were elucidated as 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3-O-beta-D-xylopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, respectively.     

Structures of two new steroidal glycosides, soladulcosides A and B from Solanum dulcamara

The structures of two new steroidal glycosides named soladulcosides A and B, isolated from the aerial parts of Solanum dulcamara including new sapogenols, were elucidated as (22R, 25R)-3 beta, 15 alpha, 23 alpha-trihydroxy-5 alpha-spirostan-26-one 3-O-alpha-L-rhamnopyranosyl-(1----2)-beta-D-glucopyranoside and (22R, 25R)-3 beta,23 alpha-dihydroxy-5 alpha-spirostan-26-one 3-O-alpha-L-rhamnopyranosyl-(1----2)-[alpha-L-rhamnopyranosyl-(1----4)]- beta-D-glucopyranoside, respectively.     

Five new bidesmoside triterpenoid saponins from Stauntonia chinensis

Eleven triterpenoid saponins (1-11) were isolated from Stauntonia chinensis DC. (Lardizabalaceae), including five new compounds, yemuoside YM(21-25) (1-3, 6, 7) structures of which were elucidated by chemical methods and a combination of MS, 1D- and 2D- NMR experiments including DEPT, (1)H--(1)H COSY, HSQC, HMBC, TOCSY, and NOESY as 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-rhamnopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonicacid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (1), 3-O-beta-D-xylopyranosyl-(1 --> 3)-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl-akebonic acid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (2), 3-O-beta-D-glucopyranosyl-(1 --> 3)-alpha-L-arabinopyranosyl-akebonic acid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (3), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-rhamnopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (6), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-arabinopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (7).     

Structures of two new fibrinolytic saponins from the seed of Luffa cylindrica Roem

Two new fibrinolytic saponins, lucyosides N and P, were isolated from the seeds of Luffa cylindrica Roem. (Cucurbitaceae). On the basis of chemical and spectral evidence, lucyoside N was characterized as 3-O-beta-D-galactopyranosyl-(1----2)-beta-D-glucuronopyranosyl-28- O-beta-D-xylopyranosyl-(1----4)-[beta-D-glucopyranosyl-(1----3)]-alpha-L -rhamnopyranosyl-(1----2)-alpha-arabinopyranosyl quillaic acid. Lucyoside P was characterized as a gypsogenin glycoside with the same sugar moiety as lucyoside N.     

1H and 13C NMR spectral data of new saponins from Cordia piauhiensis

Two new bidesmoside triterpenoid saponins were isolated from stems of Cordia piauhiensis. Their structures, characterized as 3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl pomolic acid 28-O-beta-D-glucopyranosyl ester (1) and 3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (2), were unequivocally established after extensive NMR (1H, 13C, DEPT 135 degrees, COSY, HSQC, HMBC, TOCSY, and NOESY) studies.     

Lupane-triterpene glycosides from the leaves of Acanthopanax gracilistylus

A novel lupane-triterpene glycoside, called wujiapioside B (1), was isolated from the leaves of Acanthopanax gracilistylus (Araliaceae) together with three known lupane-triterpene glycosides, acankoreoside C (2), acantrifoside A (3) and 3-epibetulinic acid 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (4). Based on spectroscopic data, the chemical structure of 1 was determined as 3alpha,23-dihydroxy-lup-20(29)-en-28-oic acid 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester. Compounds 2-3 were obtained for the first time from this plant and compound 4 has not been isolated from Acanthopanax genus yet.     

Triterpene glycosides ofHedera helix I. The structures of glycosides L-1, L-2a,L-2b,L-3, L-4a,L-4b,L-6a,L-6b,L-6c,L-7a,and L7-b from the leaves of common ivy

The leaves of common ivy have yielded 11 triterpene glycosides: the 3-O-α-L-pyranosides of oleanolic acid (1), of echinocystic acid (2), and of hederagenin; the 3-O-[O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside]s of oleanolic acid (4), of echinocystic acid (5), and of hederagenin (6); the O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester of hederagenin 3-O-α-L-pyranoside (7); the O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester of hederagenin 3-O-[O-α-L-pyranosyl-(1→2)-α-L-arabinopyranoside] (9); and the O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl esters of oleanolic acid, echinocystic acid, and hederagenin 3-O-[O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside]s (8), (10), and (11), respectively. This is the first time that compounds (1), (2), (5), (7), (9), and (10) have been found in this plant. Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 742–746, November–December, 1994.     

Steroidal glycosides and aromatic compounds from Smilax riparia

Two new steroidal glycosides named riparosides A (1) and B (2), and two aromatic compounds (3, 4), together with four known flavonoid derivatives have been isolated from the EtOH extract of the rhizomes and roots of Smilax riparia A. DC. The structure of riparoside A (1) was determined to be 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranosyl 3beta,20alpha-dihydroxy-5alpha-furost-22(23)-ene 26-O-beta-D-glucopyranoside. Riparoside B (2) was characterized as 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranosyl 3beta,16beta-dihydroxy-5alpha-pregnan-20-one 16-O-[5-O-beta-D-glucopyranosyl 5-hydroxy-4-methyl-pentanoic acid]-ester 26-O-beta-D-glucopyranoside. Compounds 3 and 4 were elucidated as a sucrosyl ferulic acid ester and 7-O-methyl-10-oxythymol gentiobioside, respectively.     

Saponins from Amaranthus hypochondriacus.

Four triterpenoid saponins were isolated from Amaranthus hypochondriacus which are grain crops in the Nepal, Mexico and South America. Their structures were elucidated based on spectral evidence to be: (1) 3-O-alpha-L-rhamnopyranosyl(1----3)-beta-D-glucuronopyranosyl-2 beta,3 beta-dihydroxyolean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester. (2) 3-O-alpha-L-rhamnopyranosyl(1----3)-beta-D-glucuronopyranosyl-2 beta,3 beta- dihydroxyolean-12-en-23-al-28-oic acid 28-O-beta-D-glucopyranosyl ester; (3) 3-O-alpha-L-rhamnopyranosyl(1----3)-beta-D-glucuronopyranosyl-2 beta, 3 beta-dihydroxy-30-norolean-12,20(29)-dien-28-oic acid 28-O-beta-D-glucopyranosyl ester. (4) 3-O-alpha-L-rhamnopyranosyl (1----3)-beta-D-glucuronopyranosyl-2 beta, 3 beta-dihydroxy-30-norolean-12, 20(29)-dien-23-al-28-oic acid 28-O-beta-D-glucopyranosyl ester.     

Microbial hydroxylation and glycosidation of oleanolic acid by Circinella muscae and their anti-inflammatory activities

Biotransformation of oleanolic acid (OA) by Circinella muscae AS 3.2695 was investigated. Nine hydroxylated and glycosylated metabolites (1–9) were obtained. Their structures were elucidated as 3β,7β-dihydroxyolean-12-en-28-oic acid (1), 3β,7β,21β-trihydroxyolean-12-en-28-oic acid (2), 3β,7α,21β-trihydroxyolean-12-en- 28-oic acid (3), 3β,7β,15α-trihydroxyolean-12-en-28-oic acid (4), 7β,15α-dihydroxy- 3-oxo-olean-12-en-28-oic acid (5), 7β-hydroxy-3-oxo-olean-12-en-28-oic acid (6), oleanolic acid-28-O-β-D-glucopyranosyl ester (7), 3β,21β-dihydroxyolean-12-en-28- oic acid-28-O-β-D-glucopyranosyl ester (8), and 3β,7β,15α-trihydroxyolean-12-en- 28-oic acid-28-O-β-D-glucopyranosyl ester (9) by spectroscopic analysis. Among them, compounds 4 and 9 were new compounds. In addition, anti-inflammatory activities were assayed and evaluated for the isolated metabolites. Most of the metabolites exhibited significant inhibitory activities on lipopolysaccharides-induced NO production in RAW 264.7 cells.     

Synthesis of enantiopure 7-[3-azidopyl]indolizidin-2-one amino acid. A constrained mimic of the peptide backbone geometry and heteroatomic side-chain functionality of the ala-lys dipeptide

Enantiopure N-(BOC)amino-7-[3-azidopropyl]indolizidin-2-one acid 1 has been synthesized by displacement of the methanesulfonate of its 7-hydroxypropyl counterpart 11 with sodium azide and subsequent ester hydrolysis. N-(BOC)Amino-7-[3-hydroxypropyl]indolizidin-2-one ester 11 was obtained from a sequence commencing with the alkylation of (2S,8S)-di-tert-butyl 5-oxo-2,8-di-[N-(PhF)amino]azelate 5 (PhF = 9-(9-phenylfluorenyl)). Stereoselective allylation of 5, regioselective olefin hydroboration, selective primary alcohol protection as a silyl ether, and oxidation of the secondary alcohol gave (2S,4R,8S)-di-tert-butyl 4-[3-tert-butyldimethylsiloxypropyl]-5-oxo-2,8-di-[N-(PhF)amino]azelate 9 as a pure diastereomer in 33% overall yield. Linear ketone 9 was then converted into the indolizidinone heterocycle by a route featuring reductive amination, lactam cyclization, and isolation by way of a silyl ether which provided the (6S,7R)-isomer of 11.     

Periandradulcins A, B and C: phosphodiesterase inhibitors from Periandra dulcis Mart

During the course of our screening of bioactive natural products, three new saponins named periandradulcins A (1), B (2) and C (3) were isolated as phosphodiesterase (PDE, EC 3.1.4.17) inhibitors from 80% MeOH extract of the roots of Periandra dulcis Mart. (Leguminosae) by a combination of column chromatography and reversed- and normal-phase high-performance liquid chromatography (HPLC). On the basis of 1H-, 13C- and two-dimensional nuclear magnetic resonance (NMR) spectral data and chemical evidence, their chemical structures were characterized as 3-O-beta-[alpha-L-rhamnopyranosyl(1----2)-beta-D-xylopyranosyl(1----2)-b eta-D- glucuronopyranosyl]-30-hydroxyl-25-formylolean-18-ene-22 beta-O-syringate, 3-O-beta-[alpha-L-rhamnopyranosyl(1----2)-beta-D- xylopyranosyl(1----2)-beta-D-glucuronopyranosyl]-22 beta-hydroxyl-25- formylolean-12-ene and 3-O-beta-[alpha-L-rhamnopyranosyl(1----2)-beta-D- glucopyranosyl(1----2)-beta-D-glucuronopyranosyl]-22 beta-hydroxyl-25-formylolean-18-ene, respectively. The concentrations of periandradulcins A, B and C required to give 50% inhibition (IC50 values) of PDE from bovine heart, were 0.033, 7.6 and 7.7 microM, respectively. Compound 1 was the most potent among the known PDE inhibitors; it inhibited PDE-I (IC50:0.0022 microM) twenty and forty times more effectively than PDE-II and -III, respectively.     

Synthesis of tricyclic analogues of methyllycaconitine using ring closing metathesis to append a B ring to an AE azabicyclic fragment

The synthesis of several ABE tricyclic analogues of the alkaloid methyllycaconitine 1 is reported. The analogues contain two key pharmacophores: a homocholine motif formed from a tertiary N-ethyl amine in a 3-azabicyclo[3.3.1]nonane ring system and a 2-(3-methyl-2,5-dioxopyrrolidin-1-ly)benzoate ester 4. The synthesis of the ABE tricyclic analogues of MLA 1 began with selective allylation at C-3 of 3 to produce allyl beta-keto ester 4. Double Mannich reaction of 4 with ethylamine and formaldehyde produced bicyclic amine 5 The C-9 ketone of bicyclic amine 5 was selectively reduced to form bicyclic alcohols 6 and 7 which were subsequently allylated to form dienes 8 and 9. Ring closing metathesis of dienes 8 and 9 afforded tricyclic ethers 11 and 12, respectively, the C-8 ester of which was reduced to a hydroxymethyl group to form ABE tricyclic analogues 13 and 14. Addition of allylmagnesium bromide to the C-9 ketone of 20 afforded dienes 21 and 22, which underwent ring closing metathesis to form tricyclic esters 23 and 24, respectively. Reduction of the C-8 ethyl ester of 23 and 24 to a hydroxymethyl group afforded diols 25 and 26 respectively. The 2-(3-methyl-2,5-dioxopyrrolin-1-ly)benzoate ester was introduced by conversion of alcohols 13, 14, 25 and 26, to the anthranilate esters 16, 17, 27 and 28 using N-(trifluoroacetyl)anthranilic acid 15 followed by fusion with methylsuccinic anhydride to afford the substituted anthranilates 18, 19, 29 and 30 containing the key 2-(3-methyl-2,5-dioxopyrrolidin-1-ly)benzoate ester pharmacophore.     

Characterization of two minor saponins from Cordia piauhiensis by 1H and 13C NMR spectroscopy

A careful NMR analysis with full assignment of the 1H and 13C spectral data for two minor saponins isolated from stems of Cordia piauhiensis is reported. These saponins were isolated by high-performance liquid chromatography and characterized as 3beta-O-[alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl]pomolic acid 28-O-[beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl] ester (1) and 3beta-O-[alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl]oleanolic acid 28-O-[beta-D-xylopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl] ester (2). Their structures were established using a combination of 1D and 2D (1H, 1H-COSY, TOCSY, NOESY, gs-HMQC and gs-HMBC) NMR techniques, electrospray ionization mass spectrometry and chemical evidence.     

Triterpene saponins fromThalictrum minus. V. Structure of thalicoside B

The epigeal part ofThalictrum minus L. has yielded a new bidesmoside — thalicoside B — which has the structure of oleanolic acid 28-O-β-D-glucopyranoside 3-O-[O-α-L-rhamnopyranosyl-(1 → 2)-O-β-D-glucopyranosyl-(1 → 3)-α-L-arabinopyranoside].     

Studies on the metabolism of 4-methylpiperazine-1-carbodithioc acid 3-cyano-3,3- diphenylpropyl ester hydrochloride in rat bile by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry

4-Methylpiperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester hydrochloride (TM208) is a newly synthesized compound which has shown excellent in vivo and in vitro anticancer activity and low toxicity. In the present study, the major metabolites of TM208 in rat bile were studied by high-performance liquid chromatography/tandem mass spectrometry with an electrospray ionization (ESI) interface. It was demonstrated that TM208 was extensively metabolized in rat bile and nine metabolites (M1-M9) were definitely or tentatively identified: (2-aminoethyl)dithiocarbamic acid 3-cyano-3,3-diphenylpropyl ester (M1), (2-methylaminoethyl)dithiocarbamic acid 3-cyano-3,3-diphenylpropyl ester (M2), 4-[(4-methylpiperazin-1-yl)thioxomethanesulfinyl]-2,2-diphenylbutyronitrile (M3), 4-methylpiperazine-1-carbodithioic acid 3-cyano-3-(4-hydroxyphenyl)-3-phenylpropyl ester(M4), the sulfine of (4-methylpiperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester) (M5), 4-methylpiperazine-1-carbothioic acid S-(3-cyano-3,3-diphenylpropyl) ester (M6), piperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester (M7), 4-hydroxymethylpiperazine-1-carbothioic acid S-(3-cyano-3,3-diphenylpropyl) ester (M8) and the sulfine of [4-methylpiperazine-1-carbodithioic acid 3-cyano-3-(4-hydroxyphenyl)-3-phenylpropyl ester] (M9).