2(S),4(R)-4-(β-d-Galactopyranosyloxy)-4-isobutyl-glutamic acid: A new amino acid in Reseda odorata

2(S),4(R)-4-(β-d-Galactopyranosyloxy)-4-isobutylglutamic acid (I) has been isolated from the flowers of Reseda odorata, wherein it occurs in substantial quantity. Hydrolysis of I gives d-galactose, 2(S),4(R)-4-hydroxy-4-isobutylglutamic acid (II) and 3(R),5(S)-3-hydroxy-3-isobutyl-2-pyrrolidone-5-carboxylic acid (III) and its treatment with nitrous acid yields a galactoside of a non-nitrogenous hydroxy acid lactone (IV). The structures of I and its degradation products are supported by PMR, ¹³C-NMR and other spectroscopic methods. ¹³C-NMR spectroscopy of the model compound 2-(β-d-galactopyranosyloxy)isobutyric acid confirmed the structure of the natural product. The S- (or l-) configuration at C(2) in the amino acid moiety of I has been established by the use of the Clough—Lutz—Jirgenson rule and the R-configuration at C(4) of the same unit has been assigned tentatively. I represents the first example of a glycoside of a higher plant amino acid in which the carbohydrate residue is linked to an aliphatic hydroxy group.     

Two sesquiterpene lactones from Trichogonia gardneri

The structures and stereochemistries of two sesquiterpene lactones from Trichogonia gardneri were established as (6R,7S,8S,9S,IOR)-4E-9,10-dihydroxy-8-tigloxygermacr-4-en-6,12-olide) and (5R*,6R*,7S*,8S*,9R*)-14-acetoxy-3-chloro-9-hydroxy-2-oxo-8-tigloxyguia-1(10),3-dien-6,12-of olide by a combination of NMR spectrometry and X-ray diffraction. The results show that the structures of several sesquiterpene lactones which were isolated previously from related species require revision.     

Two new sesquiterpenes from Ligularia dictyoneura

The detailed investigation of the whole plant of Ligularia dictyoneura was performed during a search for unique chemical skeletons. One novel noreremophilane-type sesquiterpene, (4S, 5R, 8R, 10S)-1-nor-10-hydroxy-8-methoxyeremophil-7(11)-en-12,8-olide (1) and one new highly oxygenated eremophilane, 1β-angeloyloxy-6α, 10β-dihydroxyeremophil-7(11), 8-dien-12, 8-olide (2), were obtained. Their structures, including the absolute configuration, were elucidated by spectroscopic data and CD analysis.     

Sesquiterpenoids from the aerial parts of Chloranthus elatior

Thirteen sesquiterpenoids were isolated from the EtOH extract of the aerial parts of Chloranthus elatior. On the basis of spectroscopic methods, the structures of the new naturally occurring compounds were elucidated to be (1R,4R,5R,8S,10R)-1-hydroxy-4-methoxy-eudesm-7(11)-en-12,8-olide (1), 1αH,5βH,6αH,7αH-4β,10β,15-trihydroxyaromadendrane (2), and (1S,4S,5S,6R,7R,10S)-1,4-dihydroxymaaliane (3), respectively.     

New eudesmane sesquiterpenes from Alpinia oxyphylla and determination of their inhibitory effects on microglia

The fruits of Alpinia oxyphylla are used as healthcare products for the protection on neurons and prevention of dementia. Two new noreudesmane sesquiterpenoids, (5R,7S,10S)-5-hydroxy-13-noreudesma-3-en-2,11-dione (1) and (10R)-13-noreudesma-4,6-dien-3,11-dione (2), and a new eudesmane sesquiterpenoid, (5S,8R,10R)-2-oxoeudesma-3,7(11)-dien-12,8-olide (3), as well as 12 known sesquiterpenoids, were isolated from the fruits of A. oxyphylla. The structures of the new compounds (1–3) were elucidated on the basis of spectroscopic data and circular dichroism experiments. All isolates were evaluated their neuroprotective potential by inhibitory assay on nitric oxide (NO) and tumor necrosis factor-α (TNF-α) production in lipopolysaccharide (LPS)-induced mouse microglia BV-2 cells.     

Two new cytotoxic eudesmane sesquiterpenoids from Artemisia anomala

Two new eudesmane sesquiterpenoids artanoate (1) and eudesmanomolide (2) were isolated from the aerial parts of Artemisia anomala S. Moore. Their structures were elucidated as methyl (4R, 5S, 6S, 7S, 10R)-1-oxo-4, 6-dihydroxy-eudesma-2, 11 (13)-dien-12-oate (1) and (1R, 5R, 6R, 10R)-3, 13-diacetoxy-1-hydroxy-3, 7(11)-diene-12, 6-olide (2) on the basis of extensive spectroscopic analyses. Compound 1 showed cytotoxicity against HCT-8 cell lines with IC₅₀ value of 9.13 μM, and compound 2 exhibited inhibitory activities against HCT-8 and A549 cell lines with IC₅₀ values of 3.76 and 5.49 μM, respectively.     

Cembranolides from the stem bark of the southern African medicinal plant,Croton gratissimus (Euphorbiaceae)

The stem bark of Croton gratissimus (Euphorbiaceae) yielded four cembranolides, including the first reported example of a 2,12-cyclocembranolide, (+)-[1R*,2S*,7S*,8S*,12R*]-7,8-epoxy-2,12-cyclocembra-3E,10Z-dien-20,10-olide, whose structure was confirmed by means of single crystal X-ray analysis. This compound showed moderate activity against the PEO1 and PEO1TaxR ovarian cancer cell lines.     

Steroidal saponins of Asparagus curillus

Three spirostanol and two furostanol glycosides were isolated from a methanol extract of the roots of Asparagus curillus and characterized as 3-O-[α-l-arabinopyranosyl (1→4)- β-d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-[{α-l-rhamnopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-(25S)-5β-spirostan- 3β-ol, 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β- d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]- 22α-methoxy-(25S)-5β-furostan-3β, 26-diol and 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]- (25S)-5β-furostan-3β, 22α, 26-triol respectively.     

Neolignans from an Aniba species

A benzene extract of the trunk of an Aniba species (Lauraceae) contained benzyl benzoate, benzyl salicylate, sitosterol and the neolignans (2S,3S,3aR)-3a-allyl-5-methoxy-3-methyl-2-piperonyl-2,3,3a,6-tetrahydro-6-oxobenzofuran (burchellin); (2S,3S,3aR)-3a-allyl-5-methoxy-3-methyl-2-veratryl-2,3,3a,6-tetrahydro-6-oxobenzofuran; (2S,3S,3aR)-3a-allyl-5,7-dimethoxy-3-methyl-2-veratryl-2,3,3a,6-tetrahydro-6-oxobenzofuran; (2S,3S,5S)-5-allyl-5-methoxy-3-methyl-2-veratryl-2,3,5,6-tetrahydro-6-oxo-benzofuran; (2R,3R)-7-methoxy-3-methyl-5-propenyl-2-veratryl-2,3-dihydrobenzofuran; rel-(1R,5R,6R,7R,8S)-1-allyl-8-hydroxy-3-methoxy-7-methyl-4-oxo-6-piperonylbicyclo[3,2,1]oct-2-ene (guianin); rel-(1S,5S,6S,7R,8R)-1-allyl-8-hydroxy-3,5-dimethoxy-7-methyl-4-oxo-6-piperonylbicyclo[3,2,1]oct-2-ene; rel-(1S,5S,6S,7R,8R)-8-acetoxy-1-allyl-3-hydroxy-5-methoxy-7-methyl-4-oxo-6-piperonyl-bicyclo[3,2,1]oct-2-ene; rel-1S,5S,6S,7R,8R)-8-acetoxy-3,5-dimethoxy-7-methyl-4-oxo-6-piperonylbicyclo[3,2,1]oct-2-ene; rel-(1R,5S,6R,7R)-1-allyl-3-methoxy-7-methyl-4,8-dioxo-6-piperonylbicyclo[3,2,1]oct-2-ene.     

Steroidal saponins of Asparagus adscendens

From the methanol extract of the fruits of Asparagus adscendens sitosterol-β-d-glucoside, two spirostanol glycosides (asparanin A and B) and two furostanol glycosides (asparoside A and B) were isolated and characterized as 3-O-[β-d-glucopyranosyl (1→2)-β-d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl}-(25S)-5β-spirostan-3β-ol,3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl|} -26-O-(β- d-glucopyranosyl)-22α-methoxy-(25S)-5β-furostan-3β,26-diol and 3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl}-26-O-(β-d-glucopyranosyl)- 25S)-5β-furostan-3β,22α, 26-triol, respectively.     

Chemotaxonomic significance of lindenane sesquiterpenoid dimers and eudesmane sesquiterpenoids from Chloranthus henryi Hemsl. var. hupehensis (Pamp.) K. F. Wu

Seventeen known compounds were isolated from the 95% alcohol extract of the aerial parts of Chloranthus henryi Hemsl. var. hupehensis (Pamp.) K. F. Wu, including five lindenane sesquiterpenoid dimers (1–5) and twelve eudesmane sesquiterpenoids (6–17). In the present research, compounds 3 sarcaglabrin C, 6 neolitacumone C, 7 ent-Atractylenolide III and 8 dehydrocarissone were reported from the Chloranthus genus for the first time, and compounds 1 spicachlorantin B, 2 chloramultilide C, 4 shizukaol B, 5 japonicone C, 9 6α-hydroxyeudesma-4(15),7(11),8(9)-triene-12,8-olide, 10 ent-(3R)-3-hydroxyatractylenolide III, 11 8βH-hydroxyeudesma-4(14),7(11)-dien-12,8-olide, 12 lasianthuslactone A, 13 (5S,6R,8S,10R)-6-hydroxyeudesma-4(15),7(11)-diene-12,8-olide, 14 4β-hydroxy5α,8β(H)-eudesm-7(11)-en-8,12-olide, 15 4β,8β-dihydroxy-5α(H)-eudesm-7(11)-en-8,12-olide, 16 curcolonol and 17 1β, 8β-dihydroxyeudesm - 3,7(11)-dien-8α,12-olide were firstly isolated from the plant. Their structures were elucidated on the basis of extensive spectroscopic and chemical analyses. Moreover, the chemotaxonomic significance of the isolated compounds is discussed.     

Synthesis of (2S,4R,5S)-2,4,6-Trimethyl-5-heptanolide,a Sex Pheromone Component for Macrocentvus grandii

(2S,4R,5S)-2,4,6-Trimethyl-5-heptanolide (1), a sex pheromone component for Macrocentvus grandii, was synthesized by starting from methyl (R)-citronellate (2) and employing bromolactonization (10→11) as the key reaction.     

Saponins from Astragalus hareftae (NAB.) SIRJ.

Four cycloartane- (hareftosides A–D) and oleanane-type triterpenoids (hareftoside E) were isolated from Astragalus hareftae along with fifteen known compounds. Structures of the compounds were established as 3,6-di-O-β-d-xylopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane (1), 3,6,24-tri-O-β-d-xylopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane (2), 3-O-β-d-xylopyranosyl-3β,6α,16β,25-tetrahydroxy-20(R),25(S)-epoxycycloartane (3), 16-O-β-d-glucopyranosyl-3β,6α,16β,25-tetrahydroxy-20(R),24(S)-epoxycycloartane (4), 3-O-[β-d-xylopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→2)-O-β-d-glucuronopyranosyl]-soyasapogenol B (5) by the extensive use of 1D- and 2D-NMR experiments along with ESI-MS and HR-MS analyses.     

Neolignans from Ocotea catharinensis

The trunk bark of Ocotea catharinensis yielded, besides the known bicyclo(3.2.1)octanoid neolignans canellin-C and 5′-methoxycanellin-C, two epimers rel-(1R,4S and 4R,5S,6R,7S,8R)-1-allyl-4,8-dihydroxy-3,5-dimethoxy-7-methyl-6-piperonyl-bicyclo(3.2.1)oct-2-enes and rel-(1R,5S,6R,7S,8R)-1-allyl-3,8-dihydroxy-5-methoxy-7-methyl-6-piperonyl-4-oxobicyclo(3.2.1)oct-2-ene. The hydrobenzofuranoid neolignans are represented by the equally novel (2S,3S,5R)-5-allyl-5,7-dimethoxy-3-methyl-2-piperonyl-2,3,5,6-tetrahydro-6-oxobenzofuran and (2R,3S,3aS)-3a-allyl-5,7-dimethoxy-3-methyl-2-piperonyl-2,3,3a,6-tetrahydro-6-oxobenzofuran.     

Cycloartanes from Lindheimera texana

The following new cycloartanes were isolated from the aerial parts of Lindheimera texana: (16S,23S)- and (16S,23R)-16,23-epoxycycloart-24-en-3-one, (3S,16S,23S)- and (3S,16S,23R)-16,23-epoxycycloart-24-en-3ol, (16S,23R)-16,23-epoxy-23,25-epidioxycycloartan-3-one, (16S)-23,24,25,26,27-pentanorcycloartan-3-one-16,22-olide, (16S,23S,24R)- or (16S,23R,24S)-23,24-epoxycycloartan-3-one-16,25-diol and (16S,23ζ,24ζ)-cycloartan-3-one-16,23,24,25-tetrol. Structures were established by chemical transformations and spectroscopic methods and, in the case of (16S,23R)-16,23-epoxy-23,25-epidioxycycloartan-3-one, by X-ray crystallography. Norambreinolide, several known labdanes and oleanolic acid were also isolated.     

Neolignans from the fruits of Licaria armeniaca

Fruits of Licaria armeniaca contain, besides eight known lignoids, three novel neolignans: (1S,5R,6S,7R,8R)-8-acetoxy-1-allyl-3,5-dimethoxy-7-methyl-6-(3′-methoxy-4′,5′-methylenedioxyphenyl)-4-oxobicyclo[3.2.1]oct-2-ene; (1S,5R,6S,7R)-1-allyl-3-methoxy-7-methyl-6-(3′-methoxy-4′,5′-methylenedioxyphenyl)-4,8-dioxobicyclo[3.2.1]oct-2-ene and (1S,5R,6S,7R)-1-allyl-3-methoxy-7-methyl-6-(3′,4′,5′-trimethoxyphenyl)-4,8-dioxobicyclo[3.2.1]oct-2-ene.     

Neo-clerodane diterpenoids from Teucrium salviastrum

From the aerial parts of Teucrium salviastrum six new neo-clerodane diterpenoids, teusalvins A–F, have been isolated, together with the previously known diterpenes teucvidin teucroxide. The structures of teusalvins A [15,16-epoxy-2,6-diketo-neo- cleroda-13(16),14-dien-20,12S-olide-18R19-hemiacetal], B [15,16-epoxy-2β-hydroxy-6-keto-neo-cleroda-13(16),14-dien-20,12S-olide-18R,19-hemiacetal], C [15,16-epoxy-6β,18,19-trihydroxy-neo-cleroda- 3,13(16),14-trien-20,12R-olide], D [15,16-epoxy-2β,6β,18,19-tetrahydroxy-neo-cleroda-3,13(16),14-trien-20,12S-olide], E [15,16-epoxy-2β,6β,12S,18-tetrahydroxy-neo-cleroda-3,13(16),14-trien-20,19-olide] and F [15,16; 19,2α-diepoxy-6β,8-dihydroxy-neo-cleroda-3,13(16),14-trien-20,12S-olide] were established mainly by spectroscopic means and, in the case of teusalvin F, by X-ray diffraction.     

New steroidal saponins of Agave americana

Two new saponins, agavasaponin E and agavasaponin H have been isolated from the methanolic extract of Agave americana leaves and their structures elucidated. Agavasaponin E is 3-O-[β-d-xylopyranosyl-(1→2glc1)-α-l-rhamnopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→3glc 1)-β-d-glucopyranosyl-(1→4)-β-d-glucopyranosyl-(1→4)-α-d-galactopyranosyl]-(25R)-5α-spirostan-12-on-3β-ol, whereas agavasaponin H is 3-O-[β-d-xylopyranosyl-(1→2 glc 1)-α-l-rhamnopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→3 glc 1)-β-d-glucopyranosyl-(1→4)-β-d-glucopyranosyl-(1→4)-β-d-galactopyranosyl]-26-O-[β-d-glucopyranosyl]-(25R)-5α-furostan-12-on-3β,22α,26-triol.     

Beshornin and beshornoside,steroidal saponins of Beshorneria yuccoides

Two new saponins beshornin and beshornoside have been isolated from the methanolic extract of Beshorneria yuccoides leaves and their structures elucidated. Beshornin is 3-O-[α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranosyl- (1 → 2)-[α-l-rhamnopyranosyl-(1 -+ 4)-P-D-glucopyranosyl-(1 → 3)]-β-d-glucopyranosyl-(1 → 4)-β-d- galactopyranosyl-(25R)-5α-spirostan-3β-ol, whereas beshornoside is 3-O-[α-l-rhamnopyranosyl-(1 → 4)- β-d)-glycopyranosyl-(1 → 2)]-[α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 3)]-β-d-glucopyranosyl- (1 → 4)-β-d-galactopyranosyl 26-O-[β-d]-glucopyranosyl-(25R)-5α-furostan-3β,22α,26-triol.     

Steroidal saponins of Yucca filamentosa: Yuccoside C and protoyuccoside C

Two new saponins, yuccoside C and protoyuccoside C, have been isolated from the methanolic extract of Yucca filamentosa root and their structures elucidated. Yuccoside C is 3-O-[α-d-galactopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, whereas protoyuccoside C is 3-O-[α-d-galactopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosy]-(25S)-5β-furostan-3β,22α,26-triol.