Enzymic activities involved in the oothecal sclerotization of the praying mantid,Tenodera aridifolia sinensis saussure

The enzyme(s) responsible for the sclerotization of mantid ootheca is secreted by the left colleterial gland. From an extract of the glands of Tenodera aridifolia sinensis, two soluble enzyme fractions of different activities were obtained. One fraction acted on N-acetyldopamine (NADA), a precursor of a representative sclerotizing agent, and produced NADA-quinone. The other did not act on NADA itself but converted the quinone to a highly reactive intermediate, such as quinone methide, which was able to react nonenzymically with nucleophilic compounds. Other insoluble enzyme preparations obtained from the silk and pupal cuticle of the Japanese giant silk moth, Dictyoploca japonica, also had these two activities.     

Prey capture in mantids: Prothoracic tibial flexion reflex

We describe a prothoracic leg tibial flexion reflex (PTFR) of the praying mantis Tenodera aridifolia sinensis which is initiated by tactile stimulation of the movable spines of the ventro-medial border of the femur. This flexion reflex may be responsible for the continuous grasping of a captured prey by the mantid.     

On the metabolism of N-acetyldopamine in Periplaneta americana

N-acetyldopamine is rapidly and extensively converted to N-acetyldopamine 3-O-phosphate and N-acetyldopamine 3-O-sulphate in the newly ecdysed cockroach, Periplaneta americana. Dopamine 3-O-sulphate also serves as a naturally occurring precursor of N-acetyldopamine 3-O-sulphate in vivo.Radioisotope experiments revealed that the N-acetyldopamine moiety of these esters is incorporated into the cuticle during sclerotization and that the phosphate and sulphate moieties are not (not, at least, as the intact esters). It is suggested that N-acetyldopamine 3-O-phosphate and N-acetyldopamine 3-O-sulphate may be the forms in which the eventual cuticular sclerotizing agent (N-acetyldopamine?) is transported from the blood into the epidermis by a ‘carrier’ protein.     

N-Substituted acetamide glycosides from the stems of Ephedra sinica

Five new N-mono-/bis-substituted acetamide glycosides, N-{4-O-[3-O-(4-O-α-l-rhamnopyranosyl-β-d-glucopyranosyl)-α-l-rhamnopyranosyl]-phenethyl}-acetamide (1), N-methyl-N-{4-O-[3-O-(4-O-α-l-rhamnopyranosyl-β-d-glucopyranosyl)-α-l-rhamnopyranosyl]-phenethyl}-acetamide (2), N-methyl-N-{4-O-[3-O-(6-O-benzoyl-4-O-α-l-rhamnopyranosyl-β-d-glucopyranosyl)-α-l-rhamnopyranosyl]-phenethyl}-acetamide (3), N-methyl-N-{4-O-[3-O-(6-O-benzoyl-β-d-glucopyranosyl)-α-l-rhamnopyranosyl]-phenethyl}-acetamide (4), and N-methyl-N-{4-O-[3-O-(6-O-trans-cinnamoyl-4-O-α-l-rhamnopyranosyl-β-d-glucopyranosyl)-α-l-rhamnopyranosyl]-phenethyl}-acetamide (5), along with one known acetamide derivative, N-methyl-N-(4-hydroxyphenethyl)-acetamide, the shared aglycone of 2–5, were isolated from the ethanol extract of the stems of Ephedra sinica. The structures of these new compounds were elucidated on the basis of extensive spectroscopic examination, mainly including multiple 1D and 2D NMR and HRESIMS examinations, and qualitative chemical tests. All N,N-bissubstituted acetamide glycosides were found to show the obvious rotamerism, as in the case of the isolated known N-methyl-N-(4-hydroxyphenethyl)-acetamide, under the experimental NMR conditions, with the ratios of integrated intensities between anti- and syn-rotamers always being found to be about 4 to 3.     

Identification of novel fatty acid glucosides from the tropical fruit Morinda citrifolia L.

Two new fatty acid glucosides, 1,6-di-O-octanoyl-β-D-glucopyranose (1) and 6-O-(β-D-glucopyranosyl)-1-O-decanoyl-β-D-glucopyranose (2), were isolated from a methanol extract of the fruit of Morinda citrifolia L. along with five known saccharide fatty acid esters. The structures of these compounds were determined by combination of spectral and chemical analyses. These fatty acid glucosides exhibited inhibitory effect against copper-induced low-density lipoprotein oxidation. Compound 2 had the strongest effect, which was almost comparable to that of butylated hydroxytoluene.     

Tetra-acylated cyanidin 3-sophoroside-5-glucosides from the flowers of Iberis umbellata L. (Cruciferae)

The structures of 11 acylated cyanidin 3-sophoroside-5-glucosides (pigments 1-11), isolated from the flowers of Iberis umbellata cultivars (Cruciferae), were elucidated by chemical and spectroscopic methods. Pigments 1-11 were acylated with malonic acid, p-coumaric acid, ferulic acid, sinapic acid and/or glucosylhydroxycinnamic acids.Pigments 1-11 were classified into four groups by the substitution patterns of the linear acylated residues at the 3-position of the cyanidin. In the first group, pigments 1-3 were determined to be cyanidin 3-O-[2-O-(2-O-(acyl)-β-glucopyranosyl)-6-O-(trans-p-coumaroyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside], in which the acyl moiety varied with none for pigment 1, ferulic acid for pigment 2 and sinapic acid for pigment 3. In the second one, pigments 4-6 were cyanidin 3-O-[2-O-(2-O-(acyl)-β-glucopyranosyl)-6-O-(4-O-(β-glucopyranosyl)-trans-p-coumaroyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside], in which the acyl moiety varied with none for pigment 4, ferulic acid for pigment 5 and sinapic acid for pigment 6. In the third one, pigments 7-9 were cyanidin 3-O-[2-O-(2-O-(acyl)-β-glucopyranosyl)-6-O-(4-O-(6-O-(trans-feruloyl)-β-glucopyranosyl)-trans-p-coumaroyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside], in which the acyl moiety varied with none for pigment 7, ferulic acid for pigment 8, and sinapic acid for pigment 9. In the last one, pigments 10 and 11 were cyanidin 3-O-[2-O-(2-O-(acyl)-β-glucopyranosyl)-6-O-(4-O-(6-O-(4-O-(β-glucopyranosyl)-trans-feruloyl)-β-glucopyranosyl)-trans-p-coumaroyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside], in which acyl moieties were none for pigment 10 and ferulic acid for pigment 11.The distribution of these pigments was examined in the flowers of four cultivars of I. umbellata by HPLC analysis. Pigment 1 acylated with one molecule of p-coumaric acid was dominantly observed in purple-violet cultivars. On the other hand, pigments (9 and 11) acylated with three molecules of hydroxycinnamic acids were observed in lilac (purple-violet) cultivars as major anthocyanins. The bluing effect and stability on these anthocyanin colors were discussed in relation to the molecular number of hydroxycinnamic acids in these anthocyanin molecules.     

Synthesis of prumycin and related compounds

Prumycin (1) and related compounds have been synthesized from benzyl 2-(benzyloxycarbonyl)amino-2-deoxy-5,6-O-isopropylidene-β-d-glucofuranoside (4). Benzoylation of 4, followed by deisopropylidenation, gave benzyl 3-O-benzoyl-2-(benzyloxycarbonyl)amino-2-deoxy-β-d-glucofuranoside (6), which was converted, via oxidative cleavage at C-5–C-6 and subsequent reduction, into the related benzyl β-d-xylofuranoside derivative (7). Benzylation of 3-O-benzoyl-2-(benzyloxycarbonyl)-amino-2-deoxy-d-xylopyranose (8), derived from 7 by hydrolysis, afforded the corresponding derivatives (9, 11) of β- and α-d-xylopyranoside, and compound 7 as a minor product. Treatment of benzyl 3-O-benzoyl-2-(benzyloxycarbonyl)amino-2-deoxy-4-O-mesyl-β-d-xylopyranoside 10, formed by mesylation of 9, with sodium azide in N,N-dimethylformamide gave benzyl 4-azido-3-O-benzoyl-2-(benzyloxy-carbonyl)amino-2,4-dideoxy-α-l-arabinopyranoside (13), which was debenzoylated to compound 14. Selective reduction of the azide group in 14, and condensation of the 4-amine with N-[N-(benzyloxycarbonyl)-d-alaninoyloxy]succinimide, gave the corresponding derivative (15) of 1. Reductive removal of the protecting groups of 15 afforded 1. Prumycin analogs were also synthesized from compound 14. Evidence in support of the structures assigned to the new derivatives is presented.     

Three new dinormonoterpenoid glucosides from pericarps of Myriopteron extensum

Three new dinormonoterpenoid glucosides, rel-(3R,4R)-3-(1-hydroxypropan-2-yl)-3,4-epoxypentane-1,5-diol-1-O-β-d-glucopyranoside (1), rel-(3R,4S)-3-(1-hydroxypropan-2-yl)-3,4-epoxypentane-1,5-diol-1-O-β-d-glucopyranoside (2), and rel-(3R,4S)-3-(1-hydroxy-2-propen-2-yl)-3,4-epoxypentane-1,5-diol-1-O-β-d-glucopyranoside (3), were isolated from the edible pericarps of Myriopteron extensum (Wight & Arn.) K. Schum. (Asclepiadaceae). Their structures were elucidated by chemical and spectroscopic methods including HRESIMS, 1D and 2D NMR. Dinormonoterpenoid glucosides were reported from Asclepiadaceae for the first time. Compounds 1–3 were evaluated for their cytotoxicity against five human cancer cell lines HL-60, SMMC-7221, A-549, MCF-7, and SW-480, but they did not exhibit cytotoxicity on the tested cell lines.     

Chromone acyl glucosides and an ayanin glucoside from Dasiphora parvifolia

Two new chromone acyl glucosides, 5-hydroxy-7-O-(6-O-p-cis-coumaroyl-β-D-glucopyranosyl)-chromone (1) and 5-hydroxy-7-O-(6-O-p-trans-coumaroyl-β-D-glucopyranosyl)-chromone (2), and a new flavonoid glucoside, ayanin 3′-O-β-D-glucopyranoside (3) were isolated from aerial parts of Dasiphora parvifolia, together with flavonoid glycosides (4–10), catechins (11, 12), and hydrolysable tannins (13, 14). The chemical structures of these compounds were elucidated on the basis of spectroscopic data. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and the hyaluronidase inhibitory activity of these compounds were evaluated.     

Diazomethane-catalysed rearrangement of α-d-glucopyranosyl esters of N-acylamino acids into 2-O-acylaminoacyl-α-d-glucopyranoses

Both anomers of 1-O-[N-(tert-butoxycarbonyl)-L-α-glutamyl]-d-glucopyranose (2) were converted into the unprotected 1-esters, characterised as the trifluoroacetate salts 3α and 3β. On esterification with diazomethane and acetylation, the N-acetylated derivative of 3β and 2β gave the peracetylated 1-O-[5-methyl N-acetyl- and -tert-butoxycarbonyl-L-glutam-1-oyl]-β-d-glucopyranoses (4β and 6β), respectively. Similar treatment of 2α and 3β led to acyl migration, to yield 1,3,4,6-tetra-O-acetyl-2-O-[5-methyl N-(tert-butoxycarbonyl)-L-glutam-1-oyl]-α-d-glucopyranose (7α,64%) with traces of 7β, and a mixture (≈2:1:0.2) of the N-acetyl analogue of 7α (8α), 4α, and 8β, respectively. Treatment of 1-O-[5-methyl N-(tert-butoxycarbonyl)-L-glutam-1-oyl]-α-d-glucopyranose (10) and the corresponding glutam-5-oyl isomer 12 in N,N-dimethylformamide with diazomethane for 1 h resulted in 1 → 2 O-acyl transfer to give, upon acetylation, 7α and the fully acetylated 2-O-[1-methyl N-(tert-butoxy- carbonyl)-L-glutam-5-oyl]-α-d>-glucopyranose in yields of 70 and 90 %, respectively; in the absence of diazomethane, 10 and 12 remained unchanged. Similar experiments with α-d-glucopyranosyl esters of N-acetylglycine, N-acetylalanine, and N-(tert-butoxycarbonyl)phenylalanine yielded the 2-O-acyl derivatives in high yields and with high retention of anomeric configuration. The structures of the rearrangement products were proved both spectroscopically and chemically. The results imply that diazomethane functions as a base in the migration process.     

The flavonoids of tetragonotheca (compositae)

Fifteen flavonols, five aglycones and ten glucosides were isolated from the four species of Tetragonotheca, T. repanda, T. helianthoides, T. texana and T. ludoviciana. Included among the isolated flavonols are four previously unreported 7-O-glucosides, 6-hydroxykaempferol 7-O-glucoside, 6-hydroxykaempferol 6-methyl ether 7-O-glucoside, quercetagetin 6,3′-dimethyl ether 7-O-glucoside and quercetagetin 3,6-dimethyl ether 7-O-glucoside.     

The synthesis of oligosaccharide-asparagine compounds. V. O- -D-mannopyranosyl-(1 leads to 6)-O-(2-acetamido-2-deoxy- -D-glucopyranosyl)-(1 leads to 4)-2-acetamido-N-(L-aspart-4-oyl)-2-deoxy- -D-glucopyranosylamine

O-α-d-Mannopyranosyl-(1→6)-O-(2-acetamido-2-deoxy-β-d-glucopyranosyl)-(1→4)-2-acetamido-N-(l-aspart-4-oyl)-2-deoxy-β-d-glucopyranosylamine (12), used in the synthesis of glycopeptides and as a reference compound in the structure elucidation of glycoproteins, was synthesized via condensation of 2,3,4,6-tetra-O-acetyl-α-d-mannopyranosyl bromide with 2-acetamido-4-O-(2-acetamido-3-O-acetyl-2-deoxy-β-d-glucopyranosyl)-3,6-di-O-acetyl-2-deoxy-β-d-glucopyranosyl azide (5) to give the intermediate, trisaccharide azide 7. [Compound 5 was obtained from the known 2-acetamido-4-O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-d-glucopyranosyl)-3,6-di-O-acetyl-2-deoxy-β-d-glucopyranosyl azide by de-O-acetylation, condensation with benzaldehyde, acetylation, and removal of the benzylidene group.] The trisaccharide azide 6 was then acetylated, and the acetate reduced in the presence of Adams' catalyst. The resulting amine was condensed with 1-benzyl N-(benzyloxycarbonyl)-l-aspartate, and the O-acetyl, N-(benzyloxycarbonyl), and benzyl protective groups were removed, to give the title compound.     

Thiophenes,polyacetylenes and terpenes from the aerial parts of Eclipata prostrata

One new bithiophenes, 5-(but-3-yne-1,2-diol)-5′-hydroxy-methyl-2,2′-bithiophene (2), two new polyacetylenic glucosides, 3-O-β-d-glucopyranosyloxy-1-hydroxy-4E,6E-tetradecene-8,10,12-triyne (8), (5E)-trideca-1,5-dien-7,9,11-triyne-3,4-diol-4-O-β-d-glucopyranoside (9), six new terpenoid glycosides, rel-(1S,2S,3S,4R,6R)-1,6-epoxy-menthane-2,3-diol-3-O-β-d-glucopyranoside (10), rel-(1S,2S,3S,4R,6R)-3-O-(6-O-caffeoyl-β-d-glucopyranosyl)-1,6-epoxy menthane-2,3-diol (11), (2E,6E)-2,6,10-trimethyl-2,6,11-dodecatriene-1,10-diol-1-O-β-d-glucopyranoside (12), 3β,16β,29-trihydroxy oleanane-12-ene-3-O-β-d-glucopyranoside (13), 3,28-di-O-β-d-glucopyranosyl-3β,16β-dihydroxy oleanane-12-ene-28-oleanlic acid (14), 3-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl oleanlic-18-ene acid-28-O-β-d-glucopyranoside (15), along with fifteen known compounds (1, 3–7, and 16–24), were isolated from the aerial parts of Eclipta prostrata. Their structures were established by analysis of the spectroscopic data. The isolated compounds 1–9 were tested for activities against dipeptidyl peptidase IV (DPP-IV), compound 7 showed significant antihyperglycemic activities by inhibitory effects on DPP-IV in human plasma in vitro, with IC₅₀ value of 0.51 μM. Compounds 10–24 were tested in vitro against NF-κB-luc 293 cell line induced by LPS. Compounds 12, 15, 16, 19, 21, and 23 exhibited moderate anti-inflammatory activities.     

Synthesis and biological activity of O-(N-acetyl-β-muramoyl-l-alanyl-d-isoglutamine)-(1→6)-2-acylamino-2-deoxy-d-glucoses

Benzoylation of benzyl 2-acetamido-2-deoxy-4,6-O-isopropylidene-α-d-glucopyranoside, benzyl 2-deoxy-2-(dl-3-hydroxytetradecanoylamino)-4,6-O-isopropylidene-α-d-glucopyranoside, and benzyl 2-deoxy-4,6-O-isopropylidene-2-octadecanoylamino-β-d-glucopyranoside, with subsequent hydrolysis of the 4,6-O-isopropylidene group, gave the corresponding 3-O-benzoyl derivatives (4, 5, and 7). Hydrogenation of benzyl 2-acetamido-4,6-di-O-acetyl-2-deoxy-3-O-[d-1-(methoxycarbonyl)ethyl]-α-d-glucopyranoside, followed by chlorination, gave a product that was treated with mercuric actate to yield 2-acetamido-1,4,6-tri-O-acetyl-2-deoxy-3-O-[d-1-(methoxycarbonyl)ethyl]-β-d-glucopyranose (11). Treatment of 11 with ferric chloride afforded the oxazoline derivative, which was condensed with 4, 5, and 7 to give the (1→6)-β-linked disaccharide derivatives 13, 15, and 17. Hydrolysis of the methyl ester group in the compounds derived from 13, 15, and 17 by 4-O-acetylation gave the corresponding free acids, which were coupled with l-alanyl-d-isoglutamine benzyl ester, to yield the dipeptide derivatives 19–21 in excellent yields. Hydrolysis of 19–21, followed by hydrogenation, gave the respective O-(N-acetyl-β-muramoyl-l-alanyl-d-isoglutamine)-(1→6)-2-acylamino-2-deoxy-d-glucoses in good yields. The immunoadjuvant activity of these compounds was examined in guinea-pigs.     

Biotransformation of naringin and naringenin by cultured Eucalyptus perriniana cells

The biotransformation of naringin and naringenin was investigated using cultured cells of Eucalyptus perriniana. Naringin (1) was converted into naringenin 7-O-β-d-glucopyranoside (2, 15%), naringenin (3, 1%), naringenin 5,7-O-β-d-diglucopyranoside (4, 15%), naringenin 4′,7-O-β-d-diglucopyranoside (5, 26%), naringenin 7-O-[6-O-(β-d-glucopyranosyl)]-β-d-glucopyranoside (6, β-gentiobioside, 5%), naringenin 7-O-[6-O-(α-l-rhamnopyranosyl)]-β-d-glucopyranoside (7, β-rutinoside, 3%), and 7-O-β-d-gentiobiosyl-4′-O-β-d-glucopyranosylnaringenin (8, 1%) by cultured cells of E. perriniana. On the other hand, 2 (14%), 4 (7%), 5 (13%), 6 (2%), 7 (1%), naringenin 4′-O-β-d-glucopyranoside (9, 4%), naringenin 5-O-β-d-glucopyranoside (10, 2%), and naringenin 4′,5-O-β-d-diglucopyranoside (11, 5%) were isolated from cultured E. perriniana cells, that had been treated with naringenin (3). Products, 7-O-β-d-gentiobiosyl-4′-O-β-d-glucopyranosylnaringenin (8) and naringenin 4′,5-O-β-d-diglucopyranoside (11), were hitherto unknown.     

Stilbene glucosides from the bulbs of Iris tingitana

Two new dimeric stilbene glucosides, tingitanol A (1) and tingitanol B (2) together with trans-resveratrol 3-O-glucopyranoside (3) in addition to three known isoflavones, 5-O-methylgenistein (4), 5-O-methylgenistein 7-O-β-d-glucopyranoside (5) and betavulgarin (6) have been isolated for the first time from the fresh bulbs of Iris tingitana Boiss. & Reut. Their structures were established on the basis of the spectral data and direct comparison with values from previously identified analogues. Additionally, the isolated compounds (1–6) were evaluated for the free radical scavenging activity.     

Flavonol glycosides of Phlomis spectabilis

Four flavonol glucosides, one new, have been isolated from a methanolic extract of Phlomis spectabilis. Their structures were established as the 3-glucosides and 3-(6″-(E)-p-coumaroyl)glucosides of kaempferol and of kaempferol 7,4′-dimethyl ether.     

Seven new triterpenoids from the aerial parts of Ilex cornuta and protective effects against H2O2-induced myocardial cell injury

Seven new triterpenoids (1–7), together with two known ones (8–9), were isolated from the aerial parts ofIlex cornuta. The leaves of I. cornuta are the major source of “Kudingcha”, a popular herbal tea consumed in China and other countries. The structures of compounds 1–7 were determined as 20-epi-urs-12,18-dien-28-oic acid 3β-O-α-l-arabinopyranoside (1), 20-epi-urs-12,18-dien-28-oic acid 2′-O-acetyl-3β-O-α-l-arabinopyranoside (2), 20-epi-urs-12,18-dien-28-oic acid 3β-O-β-d-glucuronopyranoside-6-O-methyl ester (3), 3β,23-dihydroxy-20-epi-urs-12,18-dien-28-oic acid (4), 23-hydroxy-20-epi-urs-12,18-dien-28-oic acid 3β-O-α-l-arabinopyranoside (5), 23-hydroxy-20-epi-urs-12,18-dien-28-oic acid 3β-O-β-d-glucuronic acid (6), 23-hydroxy-20-epi-urs-12,18-dien-28-oic acid 3β-O-β-d-glucuronopyranoside-6-O-methyl ester (7), on the basis of spectroscopic analyses (IR, ESI–MS, HR-ESI–MS, 1D and 2D NMR) and chemical reactions. Protective effects against H₂O₂-induced H9c2 cardiomyocyte injury were tested in vitro for compounds 1–9, and the data showed that compound 4 had significant cell-protective effect. Compounds 1-9 did not show significant DPPH radical scavenging activity.     

The relationship of molecular weight, and sulfate content and distribution to anticoagulant activity of heparin preparations

The crystalline intermediate 2-acetamido-6-O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-D-glucopyranosyl)-3,4-di-O-acetyl-2-deoxy-β-D-glucopyranosyl azide (5), obtained by condensation of 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-D-glucopyranosyl bromide with either 2-acetamido-3,4-di-O-acetyl-2-deoxy-β-D-glucopyranosyl azide or its 6-O-triphenylmethyl derivative, was reduced in the presence of Adams' catalyst to give a disaccharide amine. Condensation with 1-benzyl N-(benzyloxycarbonyl)-L-aspartate afforded crystalline 2-acetamido-6-O-(2-acetamido-3,4 6-tri-O-acetyl-2-deoxy-β-D-glucopyranosyl)-3,4-di-O-acetyl-1-N-[1-benzyl N-(benzyloxycarbonyl)-L-aspart-4-oyl]-2-deoxy-β-D-glucopyranosylamine (9). Catalytic hydrogenation in the presence of palladium-on-charcoal was followed by saponification to give 2-acetamido-6-O-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-1-N-(L-aspart-4-oyl)-2-deoxy-β-D-glucopyranosylamine (11) in crystalline form. From the mother liquors of the reduction of 5, a further crystalline product was isolated, to which was assigned a bisglycosylamine structure (12).     

Three new flavonol glycosides from Nervilia fordii

Three new flavonol glycosides, nervilifordizins A–C (1–3), were isolated from the whole plant of Nervilia fordii. Their structures were elucidated as rhamnazin 3-O-β-d-xylopyranosyl-(1→4)-β-d-glucopyranoside (1), rhamnazin 3-O-β-d-glucopyranosyl-(1→4)-β-d-glucopyranoside (2) and rhamnazin 3-O-β-d-xylopyranosyl-(1→4)-β-d-glucopyranoside-4′-O-β-d-glucopyranoside (3) on the basis of extensive spectroscopic analysis, including HSQC, HMBC, ¹H–¹H COSY, and chemical evidences.