Seasonal variation in the content of a febrifugine and isofebrifugine alkaloid mixture in aerial parts of <Emphasis Type="Italic">Hydrangea macrophylla</Emphasis> var. <Emphasis Type="Italic">Otaksa</Emphasis>, with special reference to its antimalarial activity

Febrifugine and isofebrifugine alkaloid mixtures extracted from the leaves and buds of Hydrangea macrophylla var. Otaksa, collected during different months, in Japan, were quantified using high-performance liquid chromatography. Leaves collected during the flowering season, namely from June to August, contained 0.16–0.31 mg/g of the alkaloid mixture, whereas those collected from September to December had less than 0.03 mg/g of the mixture. However, extracts of buds harvested from October to February contained a consistently larger amount (more than 0.49 mg/g) of the alkaloids. Hot-water extracts from the leaves and buds collected during different seasons were evaluated for antimalarial activity against Plasmodium yoelii 17XL in mice. The extract of leaves collected in August demonstrated high antimalarial activity, and all mice that received the extract survived the infection. In contrast, the extract of leaves collected in December showed little activity. The extract of buds collected in December cleared parasites, but with subsequent mortality to mouse. The present results show that the amount of antimalarial agent—febrifugine and isofebrifugine mixture—in H. macrophylla var. Otaksa is both part- and season-dependent, suggesting that the choice of plant parts and their harvesting season are important factors worth considering in the pharmacological use of medicinal plants.     

A new phenylethanoid glycoside from the fruits of <Emphasis Type="Italic">Callicarpa japonica</Emphasis> Thunb. var. <Emphasis Type="Italic">luxurians</Emphasis> Rehd.

A new phenylethanoid glycoside, named acetyl forsythoside B (1), was isolated from the fruits of Callicarpa japonica Thunb. var. luxurians Rehd. (Verbenaceae) along with forsythoside B (2), brandioside (3), poliumoside (4), actioside (5), and apigenin 7-galacturonide (6). The structures of 1–6 were determined on the basis of spectroscopic data. In addition, the antioxidative activity of 1–4 and 6 was evaluated by the ferric thiocyanate method. All of the tested compounds except 6 exhibited almost the same activity as 3-tert-butyl-4-hydroxyanisole. The radical-scavenging effect of 1–6 on the stable free radical 1,1-diphenyl-2-picrylhydrazyl was also examined. Compounds 1–5 showed almost twice the activity compared to α-tocopherol.     

(<Emphasis Type="Italic">Z</Emphasis>)-3-Hexenyl diglycosides from <Emphasis Type="Italic">Spermacoce laevis</Emphasis> Roxb.

A new (Z)-3-hexenyl O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside was isolated from the aerial part of Spermacoce laevis, along with 17 known compounds: (6S,9R)-roseoside, (Z)-3-hexenyl O-β-d-glucopyranoside, (Z)-3-hexenyl O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside, (Z)-3-hexenyl O-α-l-arabinopyranosyl-(1→6)-β-d-glucopyranoside, phenyethyl O-β-d-glucopyranoside, phenyethyl O-α-l-arabinopyranosyl-(1→6)-β-d-glucopyranoside, phenyethyl O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside, benzyl O-α-l-arabinopyranosyl-(1→6)-β-d-glucopyranoside, benzyl O-β-d-xylopyranosyl-(1→6)-β-d-glucopyranoside, asperuloside, 6α-hydroxyadoxoside, asperulosidic acid, kaempferol 3-O-β-d-glucopyranoside, kaempferol 3-O-rutinoside, quercetin 3-O-β-d-galactopyranoside, quercetin 3-O-α-l-rhamnopyranosyl-(1→6)-β-d-galactopyranoside, and rutin. The structure determinations were based on physical data and spectroscopic evidence.     

Chromone and flavonol glycosides from <Emphasis Type="Italic">Delphinium hybridum</Emphasis> cv. “Belladonna Casablanca”

One new chromone and six known flavonol glycosides were isolated from the stems and leaves of Delphinium hybridum cv. “Belladonna Casablanca” (Ranunculaceae). The new chromone glycoside was elucidated as 2-methyl-chromone-5,7-diol 7-O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside (1). The six known flavonol glycosides were designated as compounds 2–5, being kaempferol-type glycosides, and compounds 6 and 7, being quercetin-type glycosides. The structures of these glycosides were determined by two-dimensional nuclear magnetic resonance (2D NMR) spectroscopic analysis and chemical evidence.     

Bridelioside,a new lignan glycoside from <Emphasis Type="Italic">Bridelia glauca</Emphasis> Bl. f. <Emphasis Type="Italic">balansae</Emphasis> (Tucht.) Hatusima

A new lignan glycoside, bridelioside, has been isolated from Bridelia glauca f. balansae. The structure of bridelioside was elucidated be (+)-isolariciresinol 2a-O-α-l-arabinopyranoside on the basis of spectral data.     

Lignan glycosides and flavonoids from <Emphasis Type="Italic">Saraca asoca</Emphasis> with antioxidant activity

Five lignan glycosides, lyoniside, nudiposide, 5-methoxy-9-β-xylopyranosyl-(−)-isolariciresinol, icariside E₃, and schizandriside, and three flavonoids, (−)-epicatechin, epiafzelechin-(4β→8)-epicatechin and procyanidin B₂, together with β-sitosterol glucoside, were isolated from a methyl alcohol (MeOH) extract of Saraca asoca dried bark. Their structures were determined by 1D and 2D nuclear magnetic resonance (NMR) and mass spectroscopic analysis. Antioxidant activities were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging assay.     

Monoterpene glycoside and flavonoids from <Emphasis Type="Italic">Blumea lacera</Emphasis>

The dichloromethane extract of air-dried leaves of Blumea lacera (Asteraceae) afforded α-pinene-7β-O-β-d-2,6-diacetylglucopyranoside (1), 5,4′-dihydroxy-6,7,3′-trimethoxyflavone (2), and 3,5,4′-trihydroxy-6,7,3′-trimethoxyflavone (3). Compounds 1–3 showed moderate activity against Candida albicans, low activity against Trichophyton mentagrophytes, and were inactive against Aspergillus niger. Compounds 1 and 3 indicated low activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus and were inactive against Bacillus subtilis, while 2 was inactive against all four bacteria tested.     

Antileishmanial amides and lignans from <Emphasis Type="Italic">Piper cubeba</Emphasis> and <Emphasis Type="Italic">Piper retrofractum</Emphasis>

The n-hexane, ethyl acetate, methanol, and acetone extracts of Piper cubeba Linn. and P. retrofractum Vahl. (Piperaceae) were evaluated in vitro against promastigotes of Leishmania donovani, and all exhibited significant in vitro activity at 100 μg/ml. Two lignans, cubebin and hinokinin, were isolated from the hexane extract of P. cubeba; and one bis-epoxy lignan, (−)-sesamin, and two amides, pellitorine and piplartine, were isolated from the hexane and methanol extracts of P. retrofractum. Cubebin and piplartine showed significant antileishmanial activity in vitro at 100 μM and were further tested in vivo in a hamster model of visceral leishmaniasis. Piplartine showed activity at 30 mg/kg dose. This is the first report of antileishmanial activity of these two plants and their isolated constituents. NIPER Communication No. 395.     

Lignan glycosides from the leaves of <Emphasis Type="Italic">Osmanthus heterophyllus</Emphasis>

Seven known lignan glycosides were isolated from the leaves of Osmanthus heterophyllus: (+)-syringaresinol 4-O-β-d-glucopyranoside, (+)-syringaresinol 4, 4′-O-di-β-d-glucopyranoside, (+)-medioresinol 4, 4′-O-di-β-d-glucopyranoside, (+)-medioresinol 4-O-β-d-glucopyranoside, (+)-pinoresinol 4, 4′-O-β-d-glucopyranoside, (+)-epipinoresinol 4-O-β-d-glucopyranoside and phillyrin. Their structures were determined on the basis of spectral data.     

Tropane alkaloids from <Emphasis Type="Italic">Erythroxylum emarginatum</Emphasis>

A tropane alkaloid, anhydroecgonine methyl ester N-oxide (2), was isolated for the first time as a naturally occurring compound, with anhydroecgonine methyl ester (1) from the bark of Erythroxylum emarginatum. Compound 1 was also isolated from the twigs. Their structures were elucidated mainly by spectroscopic methods.     

Chemical studies on monoterpenoid indole alkaloids from medicinal plant resources <Emphasis Type="Italic">Gelsemium</Emphasis> and <Emphasis Type="Italic">Ophiorrhiza</Emphasis>

We have proved that the plant of origin of “Yakatsu”, one of the ancient medicines stored in Shosoin Repository, is Gelsemium elegans (Loganiaceae). Exhaustive investigation of the alkaloids in this plant as well as its closely related plant, G. sempervirens, resulted in the isolation of more than 50 compounds, including new gelsedine-, sarpagine-, and yohimbane-type alkaloids. Pharmacological study of representative and new Gelsemium alkaloids revealed that the gelsedine-type alkaloids exhibit potent cytotoxic activity against the A431 human epidermoid carcinoma cell line. It was found that Ophiorrhiza pumila (Rubiaceae) produces a remarkable anti-tumor alkaloid, camptothecin, and its related alkaloids, including new compounds that might be the biogenetic precursors of camptothecin. Chemical investigation of callus cultures, regenerated plants, and hairy roots of O. pumila revealed that the regenerated plants and the hairy roots produce almost the same alkaloids, including camptothecin, as do the wild-type plants.     

Studies of the chemical constituents of the flower buds of <Emphasis Type="Italic">Magnolia kobus</Emphasis> and <Emphasis Type="Italic">M. salicifolia</Emphasis>

The constituents of the flower buds of Magnolia kobus DC. and M. salicifolia MAXIM. have been investigated. We isolated and identified six bis-tetrahydrofuran-type and three tetrahydrofuran-type lignan derivatives from M. kobus, and one bis-tetrahydrofuran-type lignan and eight phenylpropanoid-type derivatives from M. salicifolia. The structures of these compounds were elucidated on the basis of chemical and spectroscopic evidence.     

Two novel A-<Emphasis Type="Italic">seco</Emphasis>-rearranged lanostane triterpenoids from <Emphasis Type="Italic">Abies sachalinensis</Emphasis>

Further chemical study led to two new A-seco-rearranged lanostane triterpenoid derivatives (1–2) and one known compound Abiesanolide C (3) from the ethyl acetate (EtOAc) soluble fraction of the MeOH extract of Abies sachalinensis needles. The new compounds were identified as 3,4-seco-8-(14→13R)abeo-17,13-friedo-9β-lanosta-4(28), 7, 14, 24-tetraen-26,23-olide-23-hydroxy-3-oic acid and methyl-3,4-seco-8-(14→13R) abeo-17,13-friedo-9β-lanosta-4(28), 7, 14, 24-tetraen-26,23-olide-23-hydroxy-3-oate, respectively. Structural determination of these compounds were carried out by the spectral studies especially by the two digital (2D)-NMR and high-resolution (HR)-MS experiences.     

New triterpenoid saponins from <Emphasis Type="Italic">Argania spinosa</Emphasis>

Five new triterpene saponins, arganine L (1), O (2), P (3), Q (4) and R (5), were isolated from the barks of Argania spinosa (L.) Skeels. Arganines L-P and R are bidesmosidic saponins. The structures of 1–5 were elucidated as 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[β-d-apiofuranosyl-(1–3)-β-d-xylopyranosyl-(1–4)-α-l-rhamnopyranosyl-(1–2)-α-l-arabinopyranosyl] bayogenin, 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[β-d-xylopyranosyl-(1–4)-α-l-arabinopyranosyl] bayogenin, 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[α-l-arabinopyranosyl] bayogenin, 3-O-[β-d-xylopyranosyl-(1–4)-β-d-glucuronopyranosyl] bayogenin, and 3-O-[β-d-apiofuranosyl-(1–4)-β-d-glucuronopyranosyl]-28-O-[β-d-xylopyranosyl-(1–4)-α-l-rhamnopyranosyl-(1–2)-α-l-arabinopyranosyl] bayogenin, respectively, mainly on the basis of their spectroscopic data.     

Two new neolignan glycosides from leaves of <Emphasis Type="Italic">Osmanthus heterophyllus</Emphasis>

Two new neolignan glycosides, (7R, 8R)-threo-guaiacylglycerol-8-O-4′-sinapyl ether 7-O-β-d-glucopyranoside (1) and (7S, 8R)-5-methoxydehydrodiconiferyl alcohol 4-O-β-d-glucopyranoside (2), and four known ones (3–6), were isolated from the leaves of Osmanthus heterophyllus. The structures of compounds 1–6 were established on the basis of spectral and chemical data.     

Two new maltol glycosides and cyanogenic glycosides from <Emphasis Type="Italic">Elsholtzia rugulosa</Emphasis> Hemsl.

Two new maltol glycosides, maltol 6′-O-β-d-apiofuranosyl-β-d-glucopyranoside and maltol 6′-O-(5-O-p-coumaroyl)-β-d-apiofuranosyl-β-d-glucopyranoside, were isolated from Elsholtzia rugulosa Hemsl. along with 11 known compounds including prunasin and amygdalin. The structures were determined on the basis of spectroscopic and chemical evidence. This is the second example of isolation of cyanogenic glycosides from Lamiaceous plants.     

A new kaempferol trioside from <Emphasis Type="Italic">Solidago altissima</Emphasis> L.

A new kaempferol trioside [kaempferol 3-O-rutinoside 7-O-β-d-apiofuranoside, (1)] was isolated together with nine phenolic compounds, trans-tiliroside (2), caffeic acid (3), chlorogenic acid (4), 3-O-caffeoylquinic acid (5), 4-O-caffeoylquinic acid (6), 3-O-coumaroylquinic acid (7), 4-O-coumaroylquinic acid (8), 3,5-di-O-caffeoylquinic acid (9) and 4,5-dicaffeoylquinic acid (10) from the leaves of Solidago altissima L. The structure elucidations of the compounds were based on the analyses of spectroscopic data.     

Total synthesis and full NMR assignment of ourouparine,a yohimbane-type indole alkaloid isolated from <Emphasis Type="Italic">Gelsemium</Emphasis><Emphasis Type="Italic">sempervirens</Emphasis>

A yohimbane-type indole alkaloid, ourouparine, was found in Gelsemium sempervirens, and its structure was elucidated by spectroscopic analysis and total synthesis.     

Chemical constituents of <Emphasis Type="Italic">Polyalthia parviflora</Emphasis> stem

From the stem of Polyalthia parviflora, four compounds were isolated, including p-hydroxyphenylethyl p-coumarate (1), p-hydroxyphenylethyl ferulate (2), dehydrodiscretamine (3) and (−)-discretamine (4). Complete ¹H and ¹³C NMR assignments were obtained for 1, 3 and 4 for the first time.     

Prenylated xanthones from <Emphasis Type="Italic">Hypericum ascyron</Emphasis>

Three new prenylated xanthones, 1,3,5-trihydroxy-6,7-[2′-(1-methylethenyl)-dihydrofurano]-xanthone (1), 1,3,5-trihydroxy-6,7-[2′-(1-hydroxy-1-methylethyl)-dihydrofurano]-xanthone (2), and 1,3,5-trihydroxy-6-O-prenyl-xanthone (3), together with eight known compounds were isolated from the leaves of Hypericum ascyron. Compound 3 has an O-prenyl moiety, and therefore represents the first reported xanthone to have an O-prenyl moiety from genus Hypericum. The structures of the isolated compounds were established based on spectroscopic data and on a comparison with values for previously identified analogues.