New Flavonoids from Lysimachia christinae Hance

A chemical investigation of Lysimachia christinae, a traditional Chinese medicine used as an effective conservative treatment for gall stones, hepatolithiasis, and urinary calculi, resulted in the isolation of two new flavonoids, myricetin 3,3′‐di‐α‐L ‐rhamnopyranoside ( 1 ) and quercetin 3,3′‐di‐α‐L ‐rhamnopyranoside ( 2 ), along with the five known flavonoids quercetin 3‐[O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐galactopyranoside], amentoflavone, hyperin, quercetin 3‐β‐D ‐glucopyranoside, and kaempferol 3‐α‐L ‐rhamnopyranoside. Amentoflavone was reported for the first time from the genus Lysimachia, and quercetin 3‐[O‐α‐L ‐rhamopyranosyl‐(1→2)‐β‐D ‐galactopyranoside] was isolated from this plant for the first time. The structures of the new compounds were elucidated on the basis of their chemical reactions and extensive spectroscopic analyses, including UV, mass, and NMR spectra.     

Two New Cyclic Tetrapeptides of Streptomyces rutgersensis T009 Isolated from Elaphodus davidianus Excrement

Two new cyclic tetrapeptides, cyclo(l ‐Val‐l ‐Leu‐l ‐Val‐l ‐Ile) ( 1 ) and cyclo(l ‐Leu‐l ‐Leu‐l ‐Ala‐l ‐Ala) ( 2 ), and 15 known compounds, cyclo(Gly‐l ‐Leu‐Gly‐l ‐Leu) ( 3 ), cyclo(l ‐Ser‐l ‐Phe) ( 4 ), cyclo(l ‐Leu‐l ‐Ile) ( 5 ), cyclo(l ‐Tyr‐l ‐Phe) ( 6 ), cyclo(Gly‐l ‐Trp) ( 7 ), cyclo(l ‐Leu‐l ‐Tyr) ( 8 ), cyclo(Gly‐l ‐Phe) ( 9 ), cyclo(l ‐Phe‐trans‐4‐hydroxy‐l ‐Pro) ( 10 ), cyclo(l ‐Leu‐l ‐Leu) ( 11 ), cyclo(l ‐Val‐l ‐Phe) ( 12 ), cyclo(l ‐Val‐l ‐Leu) ( 13 ), cyclo(l ‐Ile‐l ‐Ile) ( 14 ), cyclo(l ‐Tyr‐l ‐Tyr) ( 15 ), turnagainolide A ( 16 ), and bacimethrin ( 17 ) were isolated from the fermentation broth of Streptomyces rutgersensis T009 obtained from Elaphodus davidianus excrement. Their structures were identified on the basis of spectroscopic analysis. Meanwhile, the absolute configurations of the amino acid residues of compounds 1 and 2 were determined by advanced Marfey method. Compound 3 was obtained from a natural source for the first time. The X‐ray single crystal diffraction data of bacimethrin ( 17 ) were also reported for the first time. Compounds 1  –  17 exhibited no antimicrobial activities with the MICs > 100 μg/ml.     

A New Hydrolyzable Tannin from Balanophora harlandii with Radical‐Scavenging Activity

One new hydrolyzable tannin, 1‐O‐[(E)‐p‐coumaroyl]‐3‐O‐galloyl‐β‐D ‐glucopyranose ( 1 ), was isolated from the rhizome of Balanophora harlandii, together with 18 known phenolic compounds. Their structures were determined by detailed spectroscopic analysis. Of the known compounds, 3‐O‐caffeoyl‐D ‐glucopyranose ( 6 ) was obtained as a natural product for the first time, and compounds 2 – 6 and 8 – 19 were identified for the first time from this plant. The radical‐scavenging activity of the isolated compounds was tested by a DPPH assay.     

Polar Constituents from Sageretia Thea Leaf Characterized by HPLC‐SPE‐NMR Assisted Approaches

Nine glycosides ( 1–9 ) were characterized from the n‐butanol‐soluble fraction of the ethanolic extract of the leaves of Sageretia thea by the general approach. Among these, Compounds 6 and 7 were identified as a mixture. Application of HPLC‐SPE‐NMR in two selected fractions led to the separation of this mixture and the characterization of three additional minors ( 10–12 ). Among these, 7‐O‐methylmyricetin 3‐O‐α‐l ‐arabinofuranoside ( 8 ) is a new natural product and eight compounds, i.e. glucofragulin A ( 1 ), quercetin‐3‐O‐α‐l ‐arabinopyranoside ( 5 ), 3‐O‐β‐d ‐galactopyranoside ( 6 ), 3‐O‐β‐d ‐glucopyranoside ( 7 ), and 3‐O‐α‐l ‐arabinofuranoside ( 11 ), myricetin‐3‐O‐α‐l ‐arabinofuranoside ( 9 ) and 3‐O‐β‐d‐glucopyranoside ( 10 ), and quercetrin ( 12 ), are found for the first time from the title plant.     

Tributyltin(IV) Schiff base complexes with amino acid derivatives: synthesis,characterization and biological activity

The synthesis in one‐pot reactions and structural characterization of six new tri‐n‐butyltin(IV) derivatives of Schiff bases are reported. The compounds are derived from a condensation reaction between l ‐alanine, l ‐valine, l ‐isoleucine, l ‐methionine, l ‐phenylalanine or l ‐tryptophan and 3,5‐di‐tert‐butyl‐2‐hydroxybenzaldehyde. Characterization was completed using elemental analysis, infrared spectroscopy, mass spectrometry, one‐ and two‐dimensional solution NMR (¹H, ¹³C and ¹¹⁹Sn) as well as solid‐state ¹¹⁹Sn NMR. In addition, the crystal structures of three of the compounds were confirmed using single‐crystal X‐ray diffraction. Although five‐coordinated and polymeric in the solid state, the tin compounds are four‐coordinated and monomeric in solution. The coordination environment around the triorganotin units comprises three carbon atoms and two oxygen atoms from two ligands in a trigonal bipyramidal geometry. The anti‐proliferative effect of these compounds on the cervical carcinoma cell lines HeLa, CaSki and ViBo was screened in vitro, the compounds showing cytotoxic activity against all three strains and null or low cytotoxic activity (necrotic) as well. Copyright © 2016 John Wiley & Sons, Ltd.     

Speciation of phenyltin(IV) compounds using high‐performance liquid chromatography: Part 1. The direct analysis of mixed standard solutions of tetraphenyltin,triphenyltin chloride,triphenyltin hydroxide and triphenyltin acetate

A rapid speciation high‐performance liquid chromatography (HPLC) method has been developed for the simultaneous determination of phenyltin compounds. The commercially important products of triphenyltin‐chloride, ‐acetate, ‐hydroxide and tetraphenyltin were separated by reversed‐phase HPLC on a Waters Spherisorb S5W ODS‐2 (octadecylsilica) column using an isocratic mixture of 90:10 (v/v) acetonitrile:water as the mobile phase at a flow rate of 1 ml min^?1. The phenyltin compounds were detected by UV detection at 254 nm and the total elution time is 8 min. The elution order is triphenyltin‐chloride, ‐acetate, ‐hydroxide and tetraphenyltin. Detection limits were 0.01 ppm for each of the triphenyltin compounds and 0.02 ppm for tetraphenyltin. Spiked water samples containing the three biocidal triphenyltin compounds could also be analysed simultaneously by the above method without the need for any prior derivatization, following extraction with toluene. The versatility of the method in sensing substituent group variations on the phenyl ring was also demonstrated by the successful resolution of the hydroxides, tris(p‐chlorophenyl)tin hydroxide, diphenyl(p‐chlorophenyl)tin hydroxide and triphenyltin hydroxide. Copyright © 2002 John Wiley & Sons, Ltd.     

A Simple and Efficient Procedure for Synthesis of Optically Active 1,2,4‐Triazolo‐[3,4‐b]‐1,3,4‐Thiadiazole Derivatives Containing l‐Amino Acid Moieties

Some new and optically active 1,2,4‐triazolo thiadiazoles bearing N‐phthaloyl‐l ‐amino acids were synthesized by reaction of 4‐amino‐5‐(3‐ or 4‐)pyridyl‐3‐mercapto‐(4H)‐1,2,4‐triazoles with N‐phthaloyl‐l ‐amino acids in the presence of phosphorus oxychloride. All the newly synthesized compounds were confirmed by IR, ¹H NMR, ¹³C NMR and elemental analysis.     

Flavonol Glycosides with α‐Glucosidase Inhibitory Activities and New Flavone C‐Diosides from the Leaves of Machilus konishii

Seventeen flavonoids, five of which are flavone C‐diosides, 1 – 5 , were isolated from the BuOH‐ and AcOEt‐soluble fractions of the leaf extract of Machilus konishii. Among 1 – 5 , apigenin 6‐C‐β‐D ‐xylopyranosyl‐2″‐O‐β‐D ‐glucopyranoside ( 2 ), apigenin 8‐C‐α‐L ‐arabinopyranosyl‐2″‐O‐β‐D ‐glucopyranoside ( 4 ), and apigenin 8‐C‐β‐D ‐xylopyranosyl‐2″‐O‐β‐D ‐glucopyranoside ( 5 ) are new. Both 4 and 5 are present as rotamer pairs. The structures of the new compounds were elucidated on the basis of NMR‐spectroscopic analyses and MS data. In addition, the ¹H‐ and ¹³C‐NMR data of apigenin 6‐C‐α‐L ‐arabinopyranosyl‐2″‐O‐β‐D ‐glucopyranoside ( 3 ) were assigned for the first time. The isolated compounds were assayed against α‐glucosidase (type IV from Bacillus stearothermophilus). Kaempferol 3‐O‐(2‐β‐D ‐apiofuranosyl)‐α‐L ‐rhamnopyranoside ( 12 ) was found to possess the best inhibitory activity with an IC₅₀ value of 29.3 μM .     

Development of a high‐performance liquid chromatography procedure to identify known and detect novel C‐13 oligosaccharide moieties in diterpene glycosides from Stevia rebaudiana (Bertoni) Bertoni (Asteraceae): Structure elucidation of rebaudiosides V and W

As an aid for structure elucidation of new steviol glycosides, reversed‐phase C18 high‐performance liquid chromatography method was developed with several previously characterized diterpene glycosides, to identify known and detect novel aglycone‐C13 oligosaccharide moieties and indirectly identify C‐19 interlinkages. Elution order of several diterpene glycosides and their aglycone‐C13 oligosaccharide substituted with different sugar arrangements were also summarized. Comparison of the retention time of a product obtained after alkaline hydrolysis with the aglycone‐C‐13 portions of known compounds reported herein allowed us to deduce the exact positions of the sugars in the C‐13 oligosaccharide portion. The elution position of several steviol glycosides with an ent‐kaurene skeleton was helpful to describe an identification key. Two previously uncharacterized diterpene glycosides together with two known compounds were isolated from a commercial Stevia rebaudiana leaf extract. One was found to be 13‐[(2‐O‐β‐d ‐xylopyranosyl‐ 3‐O‐β‐d ‐glucopyranosyl‐β‐d ‐glucopyranosyl)oxy]ent‐kaur‐16‐en‐19‐oic acid‐(2‐O‐β‐d ‐glucopyranosyl‐β‐d ‐glucopyranosyl) ester (rebaudioside V), whereas the other was determined to be 13‐[(2‐O‐β‐d ‐xylopyranosyl‐ 3‐O‐β‐d ‐glucopyranosyl‐β‐d‐ glucopyranosyl)oxy]ent‐kaur‐16‐en‐19‐oic acid‐(2‐O‐α‐l ‐rhamnopyranosyl‐3‐O‐β‐d ‐glucopyranosyl‐β‐d ‐glucopyranosyl) ester (rebaudioside W). Previously reported compounds were isolated in gram quantities and identified as rebaudioside J and rebaudioside H. In addition, a C‐19 sugar‐free derivative was also prepared from rebaudioside H to afford rebaudioside H₁. Chemical structures were partially determined by the high‐performance liquid chromatography method and unambiguously characterized by using one‐dimensional and two‐dimensional nuclear magnetic resonance experiments.     

Two New C19‐Diterpenoid Alkaloids with Anti‐inflammatory Activity from Aconitum iochanicum

Two new C₁₉ ‐diterpenoid alkaloids, 7,8‐epoxy‐franchetine ( 1 ) and N(19)‐en‐austroconitine A ( 2 ), were isolated from Aconitum iochanicum . Compound 1 was a new C₁₉ ‐diterpenoid alkaloid with a 7,8‐epoxy unit. Their structures were elucidated by comprehensive spectroscopic analyses including UV , IR , MS , 1D and 2D NMR . Biological activity tests indicated that two new compounds exhibited inhibitory activity against nitric oxide (NO ) production in LPS ‐activated RAW264 .7 macrophages. Compared with positive control, the two new compounds showed weak anti‐inflammatory effects with the inhibition rate of 27.3% and 29.2%, respectively.     

Terpenoids from Two Dicranopteris Species

Two new compounds, (6S,13S)‐6‐{[β‐D ‐glucopyranosyl‐(1→4)‐α‐L ‐rhamnopyranosyl]oxy}cleroda‐3,14‐dien‐13‐ol ( 1 ) and kadsuric acid 3‐methyl ester ( 2 ), together with nine known compounds, (6S,13E)‐6‐{[β‐D ‐glucopyranosyl‐(1→4)‐α‐L ‐rhamnopyranosyl]oxy}cleroda‐3,13‐dien‐15‐ol ( 3 ), (6S,13S)‐6‐[6‐O‐acetyl‐β‐D ‐glucopyranosyl‐(1→4)‐α‐L ‐rhamnopyranosyl]oxy}‐13‐{[α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐fucopyranosyl]oxy}cleroda‐3,14‐diene ( 4 ), (6S,13S)‐6‐{[6‐O‐β‐D ‐glucopyranosyl‐(1→4)‐α‐L ‐rhamnopyranosyl]oxy}‐13‐{[α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐fucopyranosyl]oxy}cleroda‐3,14‐diene ( 5 ), 15‐hydroxydehydroabietic acid ( 6 ), 15‐hydroxylabd‐8(17)‐en‐19‐oic acid ( 7 ), junicedric acid ( 8 ), (4β)‐kaur‐16‐en‐18‐oic acid ( 9 ), (4β)‐16‐hydroxykauran‐18‐oic acid ( 10 ), and (4β,16β)‐16‐hydroxykauran‐18‐oic acid ( 11 ) were isolated from the fronds of Dicranopteris linearis or D. ampla. Their structures were established by extensive 1D‐ and 2D‐NMR spectroscopy. Compounds 1 and 3 – 8 showed no anti‐HIV activities.     

Application of centrifugal partition chromatography coupled with evaporative light scattering detection for the isolation of saikosaponins‐a and ‐c from Bupleurum falcatum roots

Centrifugal partition chromatography (CPC) coupled with evaporative light scattering detection (ELSD) was applied to separate saikosaponins‐a and ‐c preparatively from Bupleurum falcatum roots. The two‐phase solvent system composed of ethyl acetate/n‐butanol/methanol/water (15:1:3:15 by volume) was used to yield saikosaponins‐a (36.1 mg) and ‐c (28.7 mg) from 370 mg of saponin‐rich extract. The purities of isolated compounds were 96.6 and 97.3% for saikosaponins‐a and ‐c, respectively. Structure identification of these compounds was accomplished by comparison of spectroscopic data of ESI‐MS, ¹H NMR, and ¹³C NMR with those of previously reported values.     

A Hydroxylated Lupeol‐Based Triterpenoid Ester Isolated from the Scurrula parasitica Parasitic on Nerium indicum

(3β,7β)‐7‐Hydroxylup‐20(29)‐en‐3‐yl hexadecanoate ( 1 ), a new lupeol‐based triterpenoid ester, along with sixteen known compounds, 7β,15α‐dihydroxylup‐20(29)‐ene‐3β‐O‐palmitate ( 2 ), lupeol palmitate ( 3 ), lupeol ( 4 ), 3‐oxolup‐20(29)‐ene ( 5 ), ursolic acid ( 6 ), cycloeucalenol ( 7 ), stigmasterol ( 8 ), β‐sitosterol ( 9 ), β‐daucosterol ( 10 ), quercetin ( 11 ), quercetin 3‐O‐α‐L ‐arabinoside ( 12 ), quercetin 3‐O‐α‐L ‐rhamnoside ( 13 ), catechin ( 14 ), gitoxigenin 3‐O‐α‐L ‐rhamnoside ( 15 ), gitoxigenin 3‐O‐α‐D ‐glucoside ( 16 ), and digitoxigenin 3‐O‐α‐L ‐rhamnoside ( 17 ), was isolated from the leaves of the Southern China mistletoe, Scurrula parasitica Linn parasitic on Nerium indicum Mill . Their structures were elucidated by spectroscopic analyses, including 2D‐NMR techniques. Cytotoxic activities of compounds 1 – 7 and 11 – 17 were evaluated against three cancer cell lines, PANC‐1, HL‐60, and SGC‐7901, revealing that compounds 4, 6, 11 , and 15 – 17 exhibited effective cytotoxicities, while others were inactive. A structure? activity relationship study of compounds 1 – 5 indicated that the 3‐OH group in lupeol‐based triterpenoids is essential for antitumor activity.     

Two New Phenolic Compounds from Artemisia iwayomogi

Two new phenolic compounds, (Z)‐5′‐hydroxyjasmone 5′‐O‐{6″‐O‐[(E)‐caffeoyl]‐β‐D ‐glucopyranoside} ( 1 ) and quercetin‐7‐O‐β‐D ‐glucuronide methyl ester ( 2 ), along with ten known phenolic compounds, 3 – 12 , were isolated from the aerial parts of Artemisia iwayomogi. Their structures were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR, and HR‐ESI‐TOF‐MS techniques. The inhibitory effects of compounds 1 – 12 on the LPS‐stimulated production of IL‐12 p40, IL‐6, and TNF‐α in bone marrow‐derived dendritic cells were evaluated.     

Three New Pregnane Alkaloids from Veratrum taliense

Three new alkaloids, 3‐O‐acetylveralkamine ( 1 ), veralkamine 3‐(β‐D ‐glucopyranoside) ( 2 ), and 6,7‐epoxyverdine ( 3 ), together with five known alkaloids, veramitaline, veralkamine ( 4 ), angeloylzygadenine, veratroylzygadenine, and veramiline 3‐(β‐D ‐glucopyranoside), were isolated from the whole plants of Veratrum taliense. Their structures were elucidated on the basis of spectroscopic analysis, and the NMR data of veralkamine ( 4 ) are given for the first time. In addition, the cytotoxic activities of all isolated compounds, except for veramitaline, were tested.     

Application of high‐performance countercurrent chromatography for the isolation of steroidal saponins from Liriope plathyphylla

High‐performance countercurrent chromatography (HPCCC) with electrospray light‐scattering detection was applied for the first time to isolate a spirostanol and a novel furostanol saponin from Liriope platyphylla. Due to the large differences in K_D values between the two compounds, a two‐step HPCCC method was applied in this study. The primary HPCCC employed methylene chloride/methanol/isopropanol/water (9:6:1:4 v/v, 4 mL/min, normal‐phase mode) conditions to yield a spirostanol saponin ( 1 ). After the primary HPCCC run, the solute retained in the stationary phase (SP extract) in HPCCC column was recovered and subjected to the second HPCCC on the n‐hexane/n‐butanol/water system (1:9:10 v/v, 5 mL/min, reversed‐phase mode) to yield a novel furostanol saponin ( 2 ). The isolated spirostanol saponin was determined to be 25(S)‐ruscogenin 1‐O‐β‐d ‐glucopyranosyl (1→2)‐[β‐d ‐xylopyranosyl (1→3)]‐β‐d ‐fucopyranoside (spicatoside A), and the novel furostanol saponin was elucidated to be 26‐O‐β‐d ‐glucopyranosyl‐25(S)‐furost‐5(6)‐ene‐1β‐3β‐22α‐26‐tetraol‐1‐O‐β‐d ‐glucopyranosyl (1→2)‐[β‐d ‐xylopyranosyl‐(1→3)]‐β‐d ‐fucopyranoside (spicatoside D).     

Synthesis of star‐shaped poly(D,L‐lactic acid‐alt‐glycolic acid)‐b‐poly(L‐lactic acid) with the poly(D,L‐lactic acid‐alt‐glycolic acid) macroinitiator and stannous octoate catalyst

Two types of three‐arm and four‐arm, star‐shaped poly(D,L ‐lactic acid‐alt‐glycolic acid)‐b‐poly(L ‐lactic acid) (D,L ‐PLGA50‐b‐PLLA) were successfully synthesized via the sequential ring‐opening polymerization of D,L ‐3‐methylglycolide (MG) and L ‐lactide (L ‐LA) with a multifunctional initiator, such as trimethylolpropane and pentaerythritol, and stannous octoate (SnOct₂) as a catalyst. Star‐shaped, hydroxy‐terminated poly(D,L ‐lactic acid‐alt‐glycolic acid) (D,L ‐PLGA50) obtained from the polymerization of MG was used as a macroinitiator to initiate the block polymerization of L ‐LA with the SnOct₂ catalyst in bulk at 130 °C. For the polymerization of L ‐LA with the three‐arm, star‐shaped D,L ‐PLGA50 macroinitiator (number‐average molecular weight = 6800) and the SnOct₂ catalyst, the molecular weight of the resulting D,L ‐PLGA50‐b‐PLLA polymer linearly increased from 12,600 to 27,400 with the increasing molar ratio (1:1 to 3:1) of L ‐LA to MG, and the molecular weight distribution was rather narrow (weight‐average molecular weight/number‐average molecular weight = 1.09–1.15). The ¹H NMR spectrum of the D,L ‐PLGA50‐b‐PLLA block copolymer showed that the molecular weight and unit composition of the block copolymer were controlled by the molar ratio of L ‐LA to the macroinitiator. The ¹³C NMR spectrum of the block copolymer clearly showed its diblock structures, that is, D,L ‐PLGA50 as the first block and poly(L ‐lactic acid) as the second block. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 409–415, 2002     

Highly biodegradable copolymers composed of chiral depsipeptide and L‐lactide units with favorable physical properties

Syntheses of copolymers composed of optically active depsipeptides (3,6‐dimethyl‐2,5‐morphorinedione) and L ‐lactide—poly(L ‐3,L ‐6‐dimethyl‐2,5‐morphorinedione‐co‐L ‐lactide), poly(L ‐3,DL ‐6‐dimethyl‐2,5‐morphorinedione‐co‐L ‐lactide), and poly(L ‐3,D ‐6‐dimethyl‐2,5‐morphorinedione‐co‐L ‐lactide)—were examined in an effort to improve the biodegradability and physical properties of homopoly(L ‐lactide). In degradation tests, the copolymers composed of 3,6‐dimethyl‐2,5‐morphorinedione and lactide in the ratios 10/90 to 13/87 exhibited high biodegradability toward proteinase K, whereas a homopolymer, poly(L ‐lactide), exhibited very poor biodegradability (only 50% after 200 h). These polymers composed of 3,6‐dimethyl‐2,5‐morphorinedione/L ‐lactide in 11/89 to 13/87 ratios also degrades rapidly after being in compost for 30 days. The resulting copolymers, however, showed relatively low elongation properties. Therefore, ternary copolymerizations of L ‐3,DL ‐6‐dimethyl‐2,5‐morphorinedione, ?‐caprolactone, and L ‐lactide were explored in an effort to improve their mechanical properties, especially the elongation, and sufficient results were obtained with an approximate ratio of 3/11/86. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 302–316, 2002     

Synthesis of poly(lactide‐ran‐MOHEL) and its biodegradation with proteinase K

Homopoly(L ‐lactide) and homopoly(D,L ‐lactide) were almost inert for biodegradation with tricine buffer or normal enzymes such as bromelain, pronase, and cholesterol esterase but biodegradable with proteinase K. Significantly enhanced biodegradation was observed when an optically active (R)‐ or (S)‐3‐methyl‐4‐oxa‐6‐hexanolide (MOHEL) unit was introduced into poly(L ‐lactide) [poly(L ‐LA)] or poly(D,L ‐lactide) [poly(D,L ‐LA)] sequences. Poly[L ‐LA‐ran‐(R)‐MOHEL] in molar ratios of 86/14 to 43/57 showed good biodegradability that was independent of crystallinity. The biodegradation of polymers with proteinase K increased in the following order: poly[D,L ‐LA‐ran‐(R)‐MOHEL] > poly[L ‐LA‐ran‐(R)‐MOHEL] > poly[D,L ‐LA‐ran‐(S)‐MOHEL] > poly[L ‐LA‐ran‐(S)‐MOHEL] > poly(R)‐MOHEL > poly(D,L ‐LA). The number‐average molecular weight, molecular weight distribution, glass‐transition temperature, and melting temperature did not change before and after the biodegradation of poly[L ‐LA‐ran‐(R)‐MOHEL], indicating that the degradation occurred from the polymer surface. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1374–1381, 2001     

New α‐Tetralone Galloylglucosides from the Fresh Pericarps of Juglans sigillata

Three new α‐tetralone galloylglucosides, 1 – 3 , were isolated from the fresh pericarps of Juglans sigillata (Juglandaceae), together with six known compounds. The structures of the new compounds were determined as 1,2,3,4‐tetrahydro‐7‐hydroxy‐4‐oxonaphthalen‐1‐yl 6‐O‐[(3,4,5‐trihydroxyphenyl)carbonyl]‐β‐D ‐glucopyranoside ( 1 ), (1S)‐1,2,3,4‐tetrahydro‐8‐hydroxy‐4‐oxonaphthalen‐1‐yl 6‐O‐[(3,4,5‐trihydroxyphenyl)carbonyl]‐β‐D ‐glucopyranoside ( 2 ), and 1,2,3,4‐tetrahydro‐7,8‐dihydroxy‐4‐oxonaphthalen‐1‐yl 6‐O‐[(3,4,5‐trihydroxyphenyl)carbonyl]‐β‐D ‐glucopyranoside ( 3 ), respectively, on the basis of detailed spectroscopic analyses, and acidic and enzymatic hydrolysis. The antimicrobial activities of the isolated compounds 2, 4 , and 7 – 9 were evaluated.