PHOTOELECTRON TRANSFER BETWEEN A CHARGED DERIVATIVE OF CHLOROPHYLL AND FERRICYANIDE AT THE LIPID BILAYER-WATER INTERFACE

Abstract— Flash illumination of a lipid bilayer containing a positively charge pigment: chlorophyll b cholyl hydrazone and separating two salt solutions, one of which contained ferricyanide, resulted in a photovoltage of ∼20mV, acceptor side negative. The positive charge on the pigment resulted in several novel effects. (1) The photo-emf is twice that of chlorophyll a and five times that of chlorophyll b at a given concentration. A higher surface concentration of the charged derivative is the likely cause of this effect. (2) The pheophytin of chlorophyll b cholyl hydrazone produces about one-half the photo emf of the magnesium derivative whereas pheophytin a or b produced only one-tenth the signal. This may be a reflection of the changed redox potential of the cation chlorophyll b cholyl hydrazone. (3) A voltage drop of 100 mV across the membrane, the acceptor side negatively biased, causes a 3–4-fold increase in the charge recombination rate. Biasing the acceptor side 100 mV positive has no effect. Chlorophyll a or b do not show this field effect. This asymmetric effect is explained as a movement of the more polar chlorophyll dication towards the water interface, leading to more rapid reaction with donor. Thus the kinetics of the charge reversal are a sensitive and specific probe of the polar interfacial region of the lipid bilayer-water interface.     

Phenoxyaluminium compounds IV. syntheses and structures of monomeric (2,6-DI-t-Butyl-4-methylphenoxy)aluminium compounds

The preparations of monomeric dialkyl(2,6-di-t-butyl-4-methylphenoxy)aluminium (alkyl = methyl, i-butyl) and i-butylbis(2,6-di-t-butyl-4-methyl-phenoxy)aluminium are described and their reactions, PMR and ESR spectra are reported.     

A comparative study of dimerization of chlorophylls and pheophytins by fluorescence and odmir

Optical and ODMR data for dimers of pheophytin a and b and chlorophyll a and b are presented. It is proposed that pheophytin a forms a parallel dimer arising from π-π interaction, binding being essentially different from that in the corresponding chlorophyll dimer. The dimer of phcophytin a is less stable (K ≈ 10⁴ ol/mol) than that of chlorophyll a(K ≈ 10⁶ ol/mol).     

On the photodecomposition of chlorophyll in vitro. I. Reaction rates

Abstract— Chlorophyll solutions are irreversibly bleached by light in the presence of oxygen. The action spectra parallel the absorption spectra for both chlorophyll a and b. The reaction is of second order with a Q₁₀ of 1.26. The reaction rates for chlorophylls a and b are of the same order of magnitude. Depending upon the light source, the initial rate for chlorophyll a is slightly higher, by a factor of 1.15 to 1.30. The rate for pheophytin is lowe 3 by several orders of magnitude. No pheophytin has been detected in the reaction products of the irradiated chlorophyll solutions in the absence of water.     

Chromatographic determination of changes in pigments in spinach (Spinacia oleracea L.) during processing

The content of individual chlorophyll and carotenoid pigments is determined in three spinach varieties (Lorelei, Springfield, and Ballet) after processing. Raw spinach and spinach that is steam-blanched for 3, 9, or 15 min is stored frozen at -24 degrees C for 6 months. In addition, spinach is air-dried at 75 degrees C, packed in atmospheric air or nitrogen, and stored at ambient temperature for 6 months. Processing has a significant effect on the content of individual chlorophyll and carotenoid pigments; however, there are no differences between varieties in their content of total and individual pigments in raw, frozen spinach. Increasing blanching time resulted in decreased contents of chlorophyll a and b and increased contents of chlorophyll a' and b' and pheophytin a and b because of pheophytinization. Changes in the color because of pheophytinization are only detected after 15 min blanching. The carotenoid pigments are more stable than the chlorophyll pigments during blanching. (all-E)-Violaxanthin is significantly reduced, caused by degradation to other xanthophylls, such as neochrome, during blanching. There are no significant differences in the content of chlorophyll a and b of dried spinach and blanched, frozen spinach. Formation of chlorophyll a' and b', pheophytin a and b, and chlorophyll a-1 and b-1 is observed after drying. The content of pheophytin a and b is significantly lower in dried versus blanched frozen samples. In dried spinach that is stored in atmospheric air, the content of beta-carotene [599 mg/kg dry matter (DM)] is significantly lower compared with nitrogen (766 mg/kg DM), and the content of (all-E)-lutein is lower than in blanched frozen spinach. Neochrome is not detected in raw spinach but in steam-blanched and dried spinach. No differences are observed in the content of (all-E)-neoxanthin, (9'Z)-neoxanthin, (all-E)-violaxanthin, (all-E)-lutein epoxide, or neolutein A and B between spinach that is stored frozen after 3 min blanching and dried spinach.     

Zur Aktivierung partiell silylierter Kohlenhydrate mittels Triphenylphosphan/Azodicarbonsäureester

On the Activation of Partially Silylated Carbohydrates Using Triphenylphosphane/Diethylazodicarboxylate Reaction of methyl α-D-glucopyranoside ( 1 ) with two equivalents of t-butyldimethylchlorosilane yields methyl 2,6-bis[O-(t-butyldimethylsilyl)]-α-D-glucopyranoside ( 1a ) and methyl 3,6-bis[O(t-butyldimethylsilyl)]-α-D-glucopyranoside ( 1b ) in a ratio of 4:1. The anomeric β-pyranoside 2 affords methyl 2,6-bis[O(t-butyldimethylsilyl)]-β-D-glucopyranoside ( 2a ) and methyl 3,6-bis[O(t-butyldimethylsilyl)]-β-D-glucopyranoside ( 2b ) in nearly equal amounts. 2b is isomerized to methyl 4,6-bis[O(t-butyldimethylsilyl)]-β;-D-glucopyranoside ( 2c ) (83%) and 2a (10%) with triphenylphosphane/diethylazodicarboxylate. Structures were assigned by NMR.-analysis and CD.-analysis of the corresponding benzoates 1c , 1d and 2d and of the acetates 2e and 2f . 1a is transformed into methyl 4-azido-2, 6-bis[O(t-butyldimethylsilyl)]-4-deoxy-α-D-galactopyranoside ( 3 ) with triphenylphosphane/diethylazodicarboxylate/HN₃. 2a and 2c yield the 3-azido-allosides 5 and 7 respectively under similar conditions. The activation by triphenylphosphane/diethylazodicarboxylate is high enough to introduce also p-nitrobenzoate groups with inversion of configuration at the reaction center. By this way 1a and 2a give methyl 2, 6-bis[O(t-butyldimethylsilyl)]-4-O-p-nitrobenzoyl-α-D-galactopyranoside ( 4 ) and methyl 2, 6-bis[O-(t-butyldimethylsilyl)]-3-O?ptrobenzoyl-β-D-allopyranoside ( 6 ) respectively. For elucidation of structures the acetate derivatives 3a-7a were prepared.     

Über enolisierte Derivate der Chlorophyllreihe. 132-Desmethoxycarbonyl-173-desoxy-132,173-cyclochlorophyllid a-enol und eine Methode zur Einführung von Magnesium in porphinoide Ligandsysteme unter milden Bedingungen. (Vorläufige Mitteilung)

Enol derivatives in the chlorophyll series. 13²-Desmethoxycarbonyl-17³-desoxy-13²,17³-cyclochlorophyllide a-enol and a method for the introduction of magnesium into porphinoid ligands under mild conditions Magnesium transfer from the iodo-magnesium salt of 3,5-di-t-butyl-4-hydroxy-toluene (BHT) into methyl pheophorbide a is a fast process in methylenechloride/ether solution at ambient temperature. This procedure for the introduction of magnesium into labile chlorin ligands has made possible the preparation of a crystalline 13², 17³-cyclochlorophyllide a-enol. Concomitant use of the lithium salt of BHT facilitates the more critical insertion of magnesium into methyl bacteriopheophorbide a. The preparative success of these magnesium transfers depends crucially upon the solvent system used. Under conditions where the complexation of methyl pheophorbide a with iodo-magnesium-BHT is essentially complete within 2 minutes at 12° in methylenechloride/ether solution, strong inhibition of the magnesium transfer is observed by cosolvents such as pyridine, dimethylacetamide, dioxan or tetrahydrofuran.     

CHLOROPHYLLS IN POLYMERS. II. PHEOPHYTIN a IN POLYMERS and THE INFLUENCE OF STRETCHING ON THE STATE OF CHLOROPHYLLS IN ANHYDROUS POLYMER FILMS

Abstract— In the first part of this study the spectral properties of pheophytin a in rigid, unstretched anhydrous polyvinyl alcohol and nitrocellulose films have been studied in order to establish the influence of the central magnesium atom on the state of chlorophylls in polymer systems. The absorption, fluorescence, excitation spectra and fluorescence intensity decays in the polymer films and in the solutions from which they are cast are reported. It is shown that pheophytin a aggregate formation is influenced by the nature of the polymer system. An aggregate of pheophytin a is found in polyvinyl alcohol films over a wide concentration range. On the other hand, pheophytin a exists in the monomeric form in unstretched nitrocellulose films at concentrations below 6 × 10^-6 mol/g.
In the second part of this work, the influence of stretching of the films on the state and distribution of embedded chlorophyll pigments, is described. Here we show that the chlorophyll a molecules are found to undertake a heterogenous distribution in polyvinylalcohol matrices, since stretching partially disrupts the pocket-like structures present in unstretched films. In contrast, chlorophyll a and pheophytin a molecules can be embedded in a monomeric state in nitrocellulose matrices and moreover they remain homogeneously distributed upon stretching. The chlorophyll/nitrocellulose system is concluded to be a useful model system for studies of donor-donor energy transfer processes.     

New Acetylcholinesterase‐Inhibitory Pregnane Glycosides of Cynanchum atratum Roots

Three new pregnane glycosides, cynatroside A ( 1 ), cynatroside B ( 2 ), and cynatroside C ( 3 ), isolated from the roots of Cynanchum atratum (Asclepiadaceae), were characterized as 7β‐{[O‐α‐L ‐cymaropyranosyl‐(1→4)‐O‐β‐D ‐digitoxopyranosyl‐(1→4)‐β‐D ‐oleandropyranosyl]oxy}‐3,4,4a,4b,5,6,7,8,10,10a‐decahydro‐6α‐hydroxy‐4b‐ methyl‐2‐(2‐methyl‐3‐furyl)phenanthren‐1(2H)‐one ( 1 ), 7β‐{[O‐β‐D ‐cymaropyranosyl‐(1→4)‐O‐α‐L ‐diginopyranosyl‐(1→4)‐β‐D ‐cymaropyranosyl]oxy}‐3,4,4a,4b,5,6,7,8,10,10a‐decahydro‐2,6α‐dihydroxy‐4b‐methyl‐2‐(2‐methyl‐3‐furyl)phenanthren‐1(2H)‐one ( 2 ), and 7β‐{[O‐α‐L ‐cymaropyranosyl‐(1→4)‐O‐β‐D ‐digitoxopyranosyl‐(1→4)‐β‐L ‐cymaropyranosyl]oxy}‐3,4,4a,4b,5,6,7,8,10,10a‐decahydro‐2,6α‐dihydroxy‐4b‐methyl‐2‐(2‐methyl‐3‐furyl)phenanthren‐1(2H)‐one ( 3 ), respectively. In addition, ten known constituents were identified, i.e., cynascyroside D ( 4 ), glaucoside C ( 5 ), glaucoside D ( 6 ), atratoside A ( 7 ), 2,4‐dihydroxyacetophenone ( 8 ), 4‐hydroxyacetophenone ( 9 ), syringic acid ( 10 ), azelaic acid ( 11 ), suberic acid ( 12 ), and succinic acid ( 13 ). Among these compounds, 1 – 4 significantly inhibit acetylcholinesterase activity.     

Isotopic effect on tautomeric behavior of 5‐(2,6‐disubstituted‐aryloxy)‐tetrazoles

Isotopic effect on tautomeric behaviors of the synthesized 5‐phenoxy‐ (1a), 5‐(2,6‐dimethylphenoxy)‐ (1b), 5‐(2,6‐diisopropylphenoxy)‐ (1c), 5‐(2,6‐dimethoxyphenoxy)‐ (1d) and 5‐(4‐methylphenoxy)‐tetrazole (1e) were investigated in DMSO‐d₆ by adding one drop of D₂O. Among 1a–e, 1a, 1d and 1e show small rotational barrier around C5? O1 and O1? C6 while in 1b and 1c there are distinguishable rotational barrier about that bonds. The ¹H NMR spectra of 1b and 1c show slightly different chemical shifts for two methyl and isopropyl groups on those phenyl ring, respectively, while the chemical shifts difference (Δδ) between two methyl and two isopropyl groups were enhanced by adding D₂O. The ¹³C NMR spectra of 1b show two overlapped singlets for methyl groups after adding D₂O. Representatively, the calculations of compound 1c were performed with GAUSSIAN‐03and the rotational barrier about C5? O1 and between isopropyl group and phenyl ring in 1c was calculated with B3LYP/6‐31G(d) basis set. Copyright © 2011 John Wiley & Sons, Ltd.     

FAR-INFRARED SPECTRA OF LANGMUIR-BLODGETT FILMS OF CHLOROPHYLL a,CHLOROPHYLL b,PHEOPHYTIN a and THEIR ADDUCTS WITH WATER and DIOXANE*

Fourier transform infrared spectra in the low frequency region (500–150cm^?1) of Langmuir-Blodgett films of chlorophyll a (Chi a), chlorophyll b (Chi b) and pheophytin a have been studied. Correlations between spectral changes in monolayer and multilayers of Chi a and Chi b and their adducts with water and dioxane have been established. Spectroscopic evidence has indicated that, although there are no individual absorption bands that can be assigned to pure Mg-nitrogen and/or Mg-oxygen stretching or bending modes, there are several bands in the400–200 cm^?1 region of the spectra containing considerable contributions from metal-nitrogen and metal-oxygen vibrational modes. These specific vibrations exhibit marked intensity changes and shifts upon water and dioxane interaction. The different states of chlorophyll aggregation in Langmuir-Blodgett mono- and multilayers films resulted in noticeable changes in their far-IR spectra.     

Synthesis of Novel Series of 6‐Chloro‐1,1‐dioxo‐1,4,2‐benzodithiazine Derivatives with Potential Biological Activity

A series of 6′‐chloro‐1′,1′‐dioxo‐2′H‐spiro[benzo[d][1,3,7]oxadiazocine‐4,3′‐(1,4,2‐benzodithiazine)]‐2,6(1H,5H)‐dione derivatives 2a , 2b and 3a , 3b have been synthesized starting from 3‐aminobenzodithiazines 1a , 1b and isatoic anhydride. Subsequent reactions of 2a with 3‐chlorophenyl isocyanate gave condensation products 4 and 5 . Compound 2a was also converted into 3‐(2‐aminobenzamido)‐6‐chloro‐7‐methyl‐1,1‐dioxo‐1,4,2‐benzodithiazine derivatives 6 , 7 , 8 , 9 , 10 . The mechanisms of the reactions are discussed.     

CHLOROPHYLL-PHOTOSENSITIZED OXIDATION OF HYDROQUINONE AND p-PHENYLENEDIAMINE DERIVATIVES

Abstract— ESR and photovoltaic studies on light-induced one-electron transfer between chlorophyll a and electron donors in the absence of oxygen show (1) the possible conversion of photo-reduced chlorophyll a and p-benzosemiquinone ion radicals to their non-ionic radicals in methanol solutions of low pH, (2) the production of ESR absorption of tetrachloro-p-benzosemi-quinone even in benzene, enhanced by the addition of triethylamine or methanol, and (3) the transfer of one electron from tetramethyl-p-phenylenediamine to either excited chlorophyll a or pheophytin a in methanol at pH above 3.6 but not to pheophytin a at pH below 1 0 where its radical cation appears to accept an electron from excited pheophytin a . Bacteteriochloro-phyll is also shown to be capable of photooxidizing hydroquinones and tetramethyl-p-phenyl-enediamine.
The presence of oxygen enhances chlorophyll a -photosensitized oxidation of hydroquinone and tetrachloro-hydroquinone by one-electron transfer to oxygen and of trimethylhydro-quinone probably by two-electron trnasfer to oxygen. A free radical from excited chlorophyll a-oxygen interaction is formed in these reactions, but rapidly quenched in the case of trimethyl-hydroquinone. This, kind of free radical is not formed in pheophytin a . Tetramethyl- p -phenyl-enediamine readily undergoes chlorophyll a-photosensitized oxidation by oxygen in any pH region.     

Off-line separation and determination of rare earth elements associated with chloroplast pigments of hyperaccumulator Dicranopteris dichotoma by normal-phase liquid chromatography and ICP–MS

An off-line normal-phase liquid chromatography–ICP–MS method has been used for separation and determination of the rare earth elements (REE) associated with chloroplast pigments of Dicranopteris dichotoma. The stability of REE-bound pigments was tested, and almost no destruction of REE-bound pigments occurred during the so-called normal-phase liquid chromatography. The accumulated free REE ions on the microcrystalline cellulose column were cleaned by elution with 5 mmol L^–1 2-ethylhexyl hydrogen 2-ethylhexylphosphonate (P507), to avoid exchange of these free ions with metals from the pigments. When these precautions were taken, the method was applied to the study of REE-bound pigments in D. dichotoma. ICP–MS results showed REE were present in chlorophylls and lutein, although REE concentrations in carotene and pheophytin were both below procedural blank levels. By careful analysis of the eluate fractions containing chlorophyll a it was found that REE-bound chlorophyll a in D. dichotoma was slightly enriched in the fractions with relatively short retention time. Results indicated that the retention time of REE-bound chlorophyll a might be slightly less than that of magnesium chlorophyll a, and REE-bound chlorophylls might be of relatively low polarity in comparison with magnesium bound chlorophylls. This phenomenon could be explained by the special double-decker sandwich-structure of REE-bound chlorophylls, as was reported by us and other authors. On the basis of these results we preferred to consider that REE can replace magnesium in chlorophyll a of D. dichotoma, and that the role of REE-bound chlorophylls in photosynthesis cannot be neglected. These data might be useful for understanding of both the properties of REE-bound pigments and the effect of REE on plant photosynthesis.     

A study on chemical behaviors of some 4‐pyrones synthesized by one‐step reactions towards various amines

Cycloaddition of acetylbenzoyl ketene generated in situ as an intermediate during one‐step reaction between excess benzoylacetone and oxalylchloride to C=C double bond of cyclic enol form of benzoylacetone gave 3‐acetyl‐5‐benzoyl‐6‐methyl‐2‐phenyl‐4(4H)‐pyrone 1a . Condensation reactions of 1a together with 3,5‐dibenzoyl‐2,6‐diphenyl‐4(4H)‐pyrone 1b and 3‐benzoyl‐5‐ethoxycarbonyl‐2,6‐diphenyl‐4(4H)‐pyrone 1c with two‐fold excess primary amines provided a series of 3‐benzoyl‐1‐alkyl‐5‐(1‐alkylimino‐ethyl)‐6‐phenyl‐2‐methyl‐4(1H)‐pyridinone 2 , 3,5‐dibenzoyl‐1‐alkyl‐2,6‐diphenyl‐4(1H)‐pyridinone 3a‐c and 3‐benzoyl‐1‐alkyl‐5‐ethoxycarbonyl‐2,6‐diphenyl‐4(1H)‐pyridinone 3d,e derivatives, respectively. In addition, while prolonged reaction of n‐pentylamine with unsymmetrical pyrone derivative 1a gives a symmetrical pyridinone derivative namely 3,5‐dibenzoyl‐2,6‐dimethyl‐1‐pentyl‐4(1H)‐pyridinone 5 , much prolonged action n‐pentylamine and then aqueous n‐pentylamine on 1b resulted in degradation of the 4‐pyrone ring to give dibenzoylmethane.     

Synthese optisch aktiver Nickel-Komplexe mit porphinoidem Ligandsystem

Synthesis of Optically Active Porphine-type Nickel Complexes Both enantiomers of [1-methyl-8 H-HDP]nickel-perchlorate

1 For nomenclature see footnote 5 in this paper.

( 2a and 2b , respectively) have been synthesized by the following reaction sequence: (a) base induced addition of (?)-( R )-2-octanol to 1 , (b) separation of the two diastereomeric monoadducts 4a and 4b , (c) reaction with methyl magnesium iodide containing an excess of methyl iodide, (d) acid induced elimination of 2-octanol from the diadducts 6a and 6b . By a similar procedure both enantiomers of [1-butyl-8 H-HDP] nickel-perchlorate ( 3a and 3b , respectively) have been prepared. The reaction of 3a with butyl lithium yields in a kinetically controlled addition predominantly the optically active cis -1, 11-dibutyl adduct 8 and in minor quantity the meso - cis -1, 11-dibutyl adduct 9 .     

Light-Induced Synthesis of Tricyclic Thiolane Derivatives from 2(5H)-thiophenones via consecutive radical ring closure

Two α,β-unsaturated thiolactones, 5-(2-propynyl)-2(5H)-thiophenone (5) and 3,5-di(2-propenyl)?2(5H)-thiophenone (6) , were newly synthesized. Irradiation (λ = 300 nm) of 5 in MeOH containing cyclopentene afforded a 3:1 mixture of diasteroisomeric methyl 7-thiatricyclo[6.4.0.0^2,6]dodec-10-ene-12-carboxylates (8a/8b) , while irradiation of 6 in MeOH saturated with 2-methylpropene gives a 3:2 mixture of diastereoisomeric methyl 3,3,9-trimethyl-5-thiatricyclo[6.2.1.0^2,6]undecane-1-carboxylates ( 10a / 10b ).     

Beiträge zur Chemie des Phosphors. 179. Triisopropyl-undecaphosphan(3), P11(i-Pr)3 – Darstellung,Eigenschaften und Moleküldynamik

Contributions to the Chemistry of Phosphorus. 179. Triisopropyl-undecaphosphane(3), P₁₁(i-Pr)₃ – Preparation, Properties, and Molecular Dynamics Triisopropyl-undecaphosphane(3) ( 1 ) has been obtained by reacting i-PrPCl₂, P₄, and magnesium and subsequently thermolysing the crude reaction product, and has been isolated in pure form. According to a two dimensional ³¹{¹H} n.m.r. spectrum 1 is a 4, 7, 11-triisopropylpentacyclo[6.3.0.0^2,6.0^3,10. 0^5,9]undecaphosphane. Compound 1 is formed as a mixture of two configurational isomers 1a and 1b , which differ from each other in the orientation of the isopropyl groups. When crystallizing pure 1b precipitates, which in solution is retransformed into the isomeric mixture 1a , 1b by inversion of the configuration.     

Synthesis of 1,2,3-thiadiazoles

Several methods were explored for preparing certain 4,5-disubstituted-1,2,3-thiadiazoles. The reaction of phenoxyacetyl chlorides with diazoacetylamides yielded α-diazo-β-ketoacetamides which were cyclized, with hydrogen sulfide and ammonium hydroxide, to 4-carboxamido-5-phenoxymethyl-1,2,3-thiadiazoles. However, treatment of α-diazo-α-benzoylacetamides with hydrogen sulfide and ammonium hydroxide yielded hydrazones rather than thiadiazoles. The reaction of α-[(ethoxycarbonyl)hydrazono]benzenepropanoic acid ( 25 ) with thionyl chloride yielded 5-phenyl-1,2,3-thiadiazole-4-carbocylic acid (26a) , the corresponding acid chloride 26b , and 5-(phenylmethyl)-2H-1,3,4-oxadiazine-2,6(3H)dione ( 27 ). The yields of 26a, 26b , and 27 were dependent on the reaction conditions employed. Oxadiazine 27 could also be converted to acid chloride 26b with thionyl chloride. Reduction of 1-([5-(4-chlorophenoxy)methyl-1,2,3-thiadiazol-4-yl]-carbonyl)piperidine ( 10b ) with diborane yielded a boron complex which produced 1-([5-((4-chlorophenoxy)methyl)-1,2,3-thiadiazol-4-yl]methyl)piperidine ( 31 ) upon recrystallization from ethanol.     

Two New Iridoid Glycosides from Hedyotis tenelliflora Blume

Two new iridoid glycosides, teneoside A (=(2aR,5S)‐5‐[(β‐D ‐glucopyranosyl)oxy]‐2a,4a,5,7b‐tetrahydro‐4‐{[(α‐L ‐rhamnopyranosyl)oxy]methyl}‐1H‐2,6‐dioxacyclopenta[cd]inden‐1‐one; 1 ) and teneoside B (=methyl (1S,5R)‐1‐[(β‐D ‐glucopyranosyl)oxy]‐1,4a,5,7a‐tetrahydro‐5‐hydroxy‐7‐{[(α‐L ‐rhamnopyranosyl)oxy]methyl}cyclopenta[c]pyran‐4‐carboxylate; 2 ), were isolated from the roots of Hedyotis tenelliflora Blume , along with two known compounds, deacetylasperuloside ( 3 ) and scandoside methyl ester ( 4 ). Their structures were elucidated by chemical methods (acid hydrolysis) and spectroscopic analyses.