Clinical and molecular characterization of a novel PLIN1 frameshift mutation identified in patients with familial partial lipodystrophy

Perilipin 1 is a lipid droplet coat protein predominantly expressed in adipocytes, where it inhibits basal and facilitates stimulated lipolysis. Loss-of-function mutations in the PLIN1 gene were recently reported in patients with a novel subtype of familial partial lipodystrophy, designated as FPLD4. We now report the identification and characterization of a novel heterozygous frameshift mutation affecting the carboxy-terminus (439fs) of perilipin 1 in two unrelated families. The mutation cosegregated with a similar phenotype including partial lipodystrophy, severe insulin resistance and type 2 diabetes, extreme hypertriglyceridemia, and nonalcoholic fatty liver disease in both families. Poor metabolic control despite maximal medical therapy prompted two patients to undergo bariatric surgery, with remarkably beneficial consequences. Functional studies indicated that expression levels of the mutant protein were lower than wild-type protein, and in stably transfected preadipocytes the mutant protein was associated with smaller lipid droplets. Interestingly, unlike the previously reported 398 and 404 frameshift mutants, this variant binds and stabilizes ABHD5 expression but still fails to inhibit basal lipolysis as effectively as wild-type perilipin 1. Collectively, these findings highlight the physiological need for exquisite regulation of neutral lipid storage within adipocyte lipid droplets, as well as the possible metabolic benefits of bariatric surgery in this serious disease.

Nucleotide sequence of the gene for the M(r) 32,000 thylakoid membrane protein from Spinacia oleracea and Nicotiana debneyi predicts a totally conserved primary translation product of M(r) 38,950

The gene for the so-called M(r) 32,000 rapidly labeled photosystem II thylakoid membrane protein (here designated psbA) of spinach (Spinacia oleracea) chloroplasts is located on the chloroplast DNA in the large single-copy region immediately adjacent to one of the inverted repeat sequences. In this paper we show that the size of the mRNA for this protein is approximately 1.25 kilobases and that the direction of transcription is towards the inverted repeat unit. The nucleotide sequence of the gene and its flanking regions is presented. The only large open reading frame in the sequence codes for a protein of M(r) 38,950. The nucleotide sequence of psbA from Nicotiana debneyi also has been determined, and comparison of the sequences from the two species shows them to be highly conserved (>95% homology) throughout the entire reading frame. Conservation of the amino acid sequence is absolute, there being no changes in a total of 353 residues. This leads us to conclude that the primary translation product of psbA must be a protein of M(r) 38,950. The protein is characterized by the complete absence of lysine residues and is relatively rich in hydrophobic amino acids, which tend to be clustered. Transcription of spinach psbA starts about 86 base pairs before the first ATG codon. Immediately upstream from this point there is a sequence typical of that found in E. coli promoters. An almost identical sequence occurs in the equivalent region of N. debneyi DNA.

Structures of the genes for the beta and epsilon subunits of spinach chloroplast ATPase indicate a dicistronic mRNA and an overlapping translation stop/start signal

A 2,4-kilobase-pair region of spinach chloroplast DNA adjacent to the gene for the large subunit of ribulosebisphosphate carboxylase has been analyzed by RNA hybridization, in vitro transcription/translation, and DNA sequence determination. The analysis indicates that this region carries the genes for the beta and epsilon subunits of chloroplast ATPase and that the two genes are cotranscribed into a dicistronic mRNA with 4-base-pair overlap between the stop codon of the beta-subunit gene and the start codon of the epsilon-subunit gene. The ATPase and carboxylase genes are transcribed divergently with respect to each other. The deduced amino acid sequences of the beta and epsilon subunits from spinach show 67% and 26% homology, respectively, with the published sequences of the beta and epsilon subunits of Escherichia coli ATPase.

A pathogenic role for endothelin in Raynaud's phenomenon?

Plasma endothelin response to a standardized cold challenge in 7 patients with primary Raynaud's phenomenon and 7 controls using a sensitive radioimmunoassay was measured. There was no difference between resting levels of plasma endothelin in patients with primary Raynaud's phenomenon (2.6 fmol/ml) and controls (2.4 fmol/ml). A decrease in plasma endothelin levels in both groups of patients during the initial phase of the cold challenge was detected; this was more pronounced in the patients with Raynaud's phenomenon. These results suggest that there is no persistent stimulus to overproduction of endothelin. The fall in levels in patients with Raynaud's phenomenon during the initial phase of the cold challenge might suggest that a different vasoconstrictive factor is initiating the start of the vasospastic process, with the decreased endothelin levels being a reactive response to increased vasoconstriction produced by this alternative factor.

Use of autografts for the treatment of leg ulcers in elderly patients

Human keratinocytes obtained from seven elderly patients who had long-standing leg ulcers of venous or rheumatoid origin were grown into sheets for autografting on to their ulcers on at least one and, in some cases, two occasions. Following the application of the autografts on to the ulcers the appearance of the ulcer base improved with an increase in the vascularity of the granulation tissue and decrease in the amount of exudate. An 'edge effect' was also noted in five cases, with the previously indolent-looking edge of the ulcer appearing healthier and more active. However, over a 4-month follow-up period there was no complete re-epithelialization in any of the ulcers despite these initial improvements.

The use of calcipotriol in HIV-related psoriasis

We report the case of a 28-year-old homosexual man with advanced HIV disease (CDC classification group IV A) who developed erythrodermic psoriasis which responded to calcipotriol, a topical vitamin D analogue. We believe this to be the first reported case of HIV-related psoriasis responsive to this form of treatment. Systemic therapy for HIV-related psoriasis is limited because of immunosuppressive effects. We suggest that calcipotriol may prove to be a useful therapeutic option in these patients.

The chloroplast beta-subunit allows assembly of the Escherichia coli F0 portion of the energy transducing adenosine triphosphatase

The effect of the expression of the chloroplast F1-ATPase beta-subunit in two Escherichia coli beta-subunit mutant strains was investigated. The amount of chloroplast beta-subunit formed in E. coli was increased by introducing a 'Shine-Dalgarno' sequence upstream from the translation start site. The chloroplast beta-subunit was membrane bound but was unable to functionally replace the mutant beta-subunit in a strain carrying the uncD409 allele [corrected]. However, in an E. coli mutant strain unable to form the beta- and epsilon-subunits the presence of the chloroplast beta-subunit enabled the assembly of a functional proton pore [corrected]

The chloroplast CF0I subunit can replace the b-subunit of the F0F1-ATPase in a mutant strain of Escherichia coli K12

The amino acid sequence of the CF0I subunit from the chloroplast F0F1-ATPase has only a low similarity to the amino acid sequence of the b-subunit of the E. coli F0F1-ATPase. However, secondary and tertiary structure predictions plus the distribution of hydrophobic and hydrophilic amino acids have indicated that these two subunits serve a similar function. This proposition was investigated directly. A cDNA clone for the chloroplast atpF gene, encoding the CF0I subunit, was altered by site-directed mutagensis such that the translation start site corresponded to the N-terminus of the mature protein. An E. coli mutant strain carrying a chain-terminating mutation in the uncF gene, encoding the b-subunit, was transformed with the plasmid carrying the altered atpF gene. The resultant transformant was able to grow on succinate and gave a growth yield similar to that of a wild-type control. Assays on membrane preparations from the transformant also clearly indicated that the mature CF0I subunit from spinach chloroplasts was able to replace the E. coli b-subunit in the E. coli F0F1-ATPase.

Spinach chloroplast rpoBC genes encode three subunits of the chloroplast RNA polymerase

Sequence analysis of a 12,400 base-pair region of the spinach chloroplast genome indicates the presence of three genes encoding subunits of the chloroplast RNA polymerase. These genes are analogous to the rpoBC operon of Escherichia coli, with some significant differences. The first gene, termed rpoB, encodes a 121,000 Mr homologue of the bacterial beta subunit. The second and third genes, termed rpoC1 and rpoC2, encode 78,000 and 154,000 Mr proteins homologous to the N and C-terminal portions, respectively, of the bacterial beta' subunit. RNA mapping analysis indicates that the three genes are cotranscribed, and that a single intron occurs in the rpoC1 gene. No splicing occurs within the rpoC2 gene or between rpoC1 and rpoC2. Furthermore, the data indicate the possibility of an alternative splice acceptor site for the rpoC1 intron that would give rise to a 71,000 Mr gene product. Thus, with the inclusion of the alpha subunit encoded by rpoA at a separate locus, the chloroplast genome is predicted to encode four subunits (respectively called alpha, beta, beta', beta") equivalent to the three subunits of the core enzyme of the E. coli RNA polymerase.

A gene cluster in the spinach and pea chloroplast genomes encoding one CF1 and three CF0 subunits of the H+-ATP synthase complex and the ribosomal protein S2

The regions of the spinach and pea chloroplast genomes containing the ATP synthase genes atpA, atpF and atpH have been sequenced. The encoded proteins, CF1 alpha, CF0I and CF0III, are well conserved between spinach and pea, and analogous to the alpha, b and c subunits of the Escherichia coli ATP synthase complex. The atpF gene is split by a single intron, and the exon/intron boundaries have been defined by isolating and sequencing a partial cDNA clone. Two other genes, designated atpI and rps2, located upstream from atpH, have also been sequenced. They encode a 27,000 Mr hydrophobic protein analogous to the F0a subunit of E. coli ATP synthase and a basic protein analogous to the S2 protein of the E. coli 30 S ribosomal subunit. Transcriptional analysis by electron microscopy of RNA-DNA hybrids, Northern blotting and primer extension experiments shows that these genes are transcribed and processed into a complex set of transcripts, with 5' ends mapping upstream from the rps2, atpI and atpH genes.

Characterization of the spinach chloroplast genes for the S4 ribosomal protein, tRNA(Thr) (UGU) and tRNA (Ser) (GGA)

The map location and nucleotide sequence of the genes for the S4 ribosomal protein (rps4) and for tRNA(Thr) (UGU) (trnT) and tRNA(Ser) (GGA) (trnS) on spinach chloroplast DNA have been determined. rps4 lies approximately 5 kb 3' to atpBE in the large single copy region and is transcribed in the same direction as atpBE. It has a 178 bp leader sequence, a 603 bp coding region and 620 bp 3' tail. The sequence of the coding region is 83% homologous with that of maize rps4 (29) and the deduced amino acid sequences from the two species are 7% homologous. The spinach and Escherichia coli S4 proteins are only 36% homologous. As in the case of maize, trnT lies upstream from and on the same strand as rps4 whereas trnS lies downstream and on the opposite strand. Transcription of rps4 apparently proceeds past trnS.

Structure of the spinach chloroplast genes for the D2 and 44 kd reaction-centre proteins of photosystem II and for tRNASer (UGA)

We have determined the sequence of the spinach (Spinacia oleracea) chloroplast genes for the photosystem II proteins, D2 and the 44 kd reaction-centre, chlorophyll a-binding protein, and for tRNASer (UGA). The 3' end of the D2 gene overlaps the first 50 bp of the 5' end of the gene for the 44 kd protein. Northern RNA hybridization analysis indicates the two genes are cotranscribed into a single 3.5 kb RNA. The predicted molecular weight of the 353-residue D2 protein is 39536 and that of the 473-residue 44 kd protein is 51816. Both proteins are hydrophobic containing at least five possible membrane-spanning domains. D2 shows significant homology to the 32 kd herbicide-binding protein (Zurawski et al., (1982) Proc. Natl. Acad. Sci. USA 79, 7699-7703), and parts of the 44 kd protein show obvious similarities to parts of the 51 kd reaction-centre, chlorophyll a-binding protein of photosystem II (Morris and Herrmann (1984) Nucleic Acids Res. 12, 2837-2850). The gene for tRNASer (UGA) which is on the opposite strand to and transcribed towards the photosystem II genes is 72% homologous with the corresponding Escherichia coli tRNASer.

Organization and nucleotide sequence of the genes for spinach chloroplast tRNA(Glu) and tRNA (Tyr.)

The map location and nucleotide sequence of the genes and flanking regions for tRNAUUC (Glu) (trnE) and tRNAGUA (Tyr) (trnY) from spinach (Spinacia oleracea) chloroplast DNA have been determined. The genes lie approximately midway between the genes for tRNAGGU (Thr) (trnT) and tRNAGUC (Asp) (trnD) on BamH1 fragment 8b, the arrangement being trnT, 458 bp, trnE, 64 bp, trnY, 409 bp, trnD. trnE and trnY are encoded by the same DNA strand as trnD and the direction of their transcription is divergent with respect to the transcription of trnT. trnE and trnY are 89% and 74% homologous, respectively, with the corresponding Euglena gracilis chloroplast genes. The corresponding homologies between the spinach chloroplast and E. coli genes are 72% and 61%. trnE is unusual in that it has the sequence 5'ATTCNA rather than 5'GTTCNA in the TΨ arm. Northern hybridizations to chloroplast RNA with restriction fragments carrying trnE and trnY sequences indicated that both genes are transcribed in vivo.

Junctions of the large single copy region and the inverted repeats in Spinacia oleracea and Nicotiana debneyi chloroplast DNA: sequence of the genes for tRNAHis and the ribosomal proteins S19 and L2

This work describes the organization, at the nucleotide sequence level, of genes flanking the junctions of the large single copy regions and the inverted repeats of Spinacia oleracea (spinach) and Nicotiana debneyi chloroplast DNAs. In both genomes, trnH1, the gene for tRNA-His(GUG) is located at the extremity of the large single copy region 3' to psbA, the gene for the 35 kd Photosystem 2 protein. Both psbA and trnH1 are transcribed towards the inverted repeat. In spinach, the first 48 codons of rps19, the gene for the chloroplast ribosomal protein S19, lie in the inverted repeat and the last 44 codons lie in the large single copy region at the end opposite to that carrying trnH1. The gene for a protein homologous to the E. coli ribosomal protein L2, rp12, is in the inverted repeat immediately 5' to rps19 and, like rps19, is transcribed towards the large single copy region. In N. debneyi, but not in spinach, rp12 is interrupted by a 666 bp insertion. The gene for tRNA-lle(CAT), trnl1, is located in the inverted repeats of spinach and N. debneyi, 5' to rp12 and is transcribed in the same direction as rp12.

Sequence of the genes for tRNACys and tRNAAsp from spinach chloroplasts

We have determined the map location and primary structure of two fragments of spinach chloroplast DNA which encompass the genes for tRNACysGCA and tRNAAspGUC. Identification of the genes for these two RNA species is based on the sequence of their anticodon triplets and on a comparison of the sequences with those of the equivalent tRNAs from Escherichia coli. Each gene occurs only once on the spinach chloroplast genome and neither contains an intervening sequence. Hybridization of the restriction fragments carrying these genes to chloroplast tRNA showed that both genes are transcribed in vivo.

Genes and transcripts for the P700 chlorophylla apoprotein and subunit 2 of the photosystem I reaction center complex from spinach thylakoid membranes

A photosystem I reaction center complex has been purified to homogeneity by a procedure involving partial solubilization of spinach thylakoid membranes, ion exchange chromatography and centrifugation in sucrose gradients. The complex contains 7 polypeptides: the P700 chlorophylla apoprotein with an apparent molecular weight of 67 kd, which at high resolution splits into two bands, and smaller polypeptides of 22 (subunit 2), 18.5, 18, 16, 12 and 10 kd.Stable transcripts for the P700 chlorophylla apojprotein and subunit 2 were found in plastid and cytosolic RNA, respectively. The apoprotein product obtained by translation in a mRNA-dependent cell-free rabbit reticulocyte lysate and also by DNA-programmed transcription-translation of cloned plastid DNA fragments inE. coli lysates was indistinguishable immunologically and electrophoretically from the authentic protein. However, the product immunologically related to subunit 2 was 4 kd larger than the mature compound indicating that this protein is encoded in the nucleus and synthesized as a precursor.The gene for the P700 chlorophylla apoprotein has been physically mapped on the spinach plastid chromosome by hybrid selection mapping and DNA-programmed cell-free transcription-translation using cloned restriction fragments of plastid DNA. There is one gene copy per chromosome and it is located centrally in the large single-copy region of the circular DNA molecule. This gene is uninterrupted and is transcribed in the same direction as that of the large subunit of ribulose bisphosphate carboxylase/oxygenase. Its transcript is approximately 4 kb longer than the 2 kbp structural gene.

The structure of the gene for the large subunit of ribulose 1,5-bisphosphate carboxylase from spinach chloroplast DNA

A cloned fragment of spinach chloroplast DNA carrying the gene for the large subunit of ribulose bisphosphate (RuBP) carboxylase has been analysed by electron microscopy of R-loops, by hybridization to Northern blots of chloroplast RNA, by S1 nuclease mapping and by DNA sequencing. The transcribed region of the gene is 1690 +/- 3 nucleotides long and co-linear with its mRNA. It comprises a 178-179 bp 5' untranslated sequence, a 1425 bp coding region and an 85-88 bp 3' untranslated region. The deduced sequence of the 475 amino acids of the spinach large subunit protein shows 10% divergence from that of the maize large subunit protein (1). The nucleotide sequence divergence between spinach and maize over the same coding region is 16% but in the transcribed flanking regions it is 35%. Features of the spinach chloroplast gene which resemble those of bacterial genes include a 5-base Shine-Dalgarno sequence complementary to a sequence near the 3' end of chloroplast and bacterial 16S rRNA, a promoter region partially homologous to a consensus sequence of bacterial promoters, and a transcription termination region capable of forming a typical stem and loop structure.

Construction of a SalI/PstI restriction map of spinach chloroplast DNA using low-gelling-temperature-agarose electrophoresis

The restriction endonucleases SalI and PstI cleave circular chloroplast DNA of spinach (Spinacia oleracea) into 12 and 10 fragments, respectively. The sum of the fragment sizes in each of the series is equivalent to the contour length of the molecule (about 95 Md). A physical map was constructed by sequential digestions using low-gelling-temperature agarose to avoid the necessity of extracting the fragments from the gel. The circular DNA molecule of spinach chloroplasts consists of two identical sequences (each about 15 Md) arranged as an inverted repeat separated by two single-copy regions of different sizes (about 52 and 13 Md).

Low-molecular-weight (4.5S) ribonucleic acid in higher-plant chloroplast ribosomes

A species of RNA that migrates on 10% (w/v) polyacrylamide gels between 5S and 4S RNA was detected in spinach chloroplasts. This RNA (referred to as 4.5 S RNA) was present in amounts equimolar to the 5S RNA and its molecular weight was estimated to be approx. 33 000. Fractionation of the chloroplast components showed that the 4.5S RNA was associated with the 50 S ribosomal subunit and that it could be removed by washing the ribosomes with a buffer containing 0.01 M-EDTA and 0.5 M-KCl. It did not appear to be a cleavage product of the labile 23 S RNA of spinach chloroplast ribosomes. When 125I-labelled 4.5 S RNA was hybridized to fragments of spinach chloroplast DNA produced by SmaI restriction endonuclease, a single fragment (mol.wt. 1.15 times 10(6)) became labelled. The same DNA fragment also hybridized to chloroplast 5 S RNA and part of the 23 S RNA. It was concluded that the coding sequence for 4.5 S RNA was part of, or immediately adjacent to, the rRNA-gene region in chloroplast DNA . A comparable RNA species was observed in chloroplasts of tobacco and pea leaves.

Mapping of the ribosomal RNA genes on spinach chloroplast DNA

Spinach chloroplast ribosomal RNAs have been hybridized to restriction endonuclease fragments of spinach chloroplast DNA. All three RNA species (23S, 16S and 5S) hybridized to a single large fragment when the DNA was digested with either Sall or Pstl. Hybridization of 23S RNA to fragments produced by Smal yielded two radioactive bands which corresponded to the bi-molar 2.5 X 10(6) and 1.15 X 10(6) Mr fragments. 16S RNA also hybridized to two, bi-molar Smal fragments (3.4 X 10(6) and 2.5 X 10(6) Mr) and 5S RNA hybridized to the 1.15 X 10(6) Mr bi-molar Smal fragment. The 23S RNA and 16S RNA cistrons were each also shown to contain a single EcoRI site. From the data it was possible to conclude that the ribosomal RNA genes are located on the inverted repeat region of the spinach chloroplast DNA restriction map [1,2], that the sequence of the cistrons is 16S - 23S - 5S and that the size of the spacer between the 16S and 23S RNA cistrons is approximately 0.90 X 10(6) Mr.

RNA polymerases of maize: partial purification and properties of the chloroplast enzyme

A DNA-dependent RNA polymerase has been solubilized and partially purified from washed chloroplasts prepared from maize seedlings. The purified enzyme was completely dependent on added DNA after purification by phospho- or DEAE-cellulose chromatography. On glycerol density gradients, the enzyme ran ahead of a marker with a sedimentation constant of 18 S, indicating a molecular weight of 500,000 or more. The instability of the highly purified enzyme made intensive study difficult, but the properties of the enzyme purified by phosphocellulose chromatography are reported. Template specificity varied during purification but the activity was always higher with denatured than with native DNA and the preference for maize DNA over calf-thymus DNA increased during purification. The enzyme required magnesium for optimal activity, was inhibited by salt concentrations in excess of 0.1 M, and had a temperature optimum of 48 degrees C. The chloroplast enzyme differed from similar activities so far reported from maize or other sources, particularly in the high salt concentrations needed to elute it from phosphocellulose. The soluble, DNA-dependent enzyme was not inhibited by either alpha-amanitin or by rifamycin-SV under the assay conditions used.

Some effects of triton x-100 on pea etioplasts

When pea etioplast preparations were treated with Triton X-100, the membranes disappeared, the pigments were solubilized, and the organelles appeared to disintegrate. Low speed centrifugation (2000g) of the preparations following treatment with Triton X-100 resulted in a pellet which contained considerable quantities of plastid material. This included RNA polymerase and DNA polymerase activity, much of the DNA, about 30% of the RNA, and 50% of the protein of the washed plastid. The amount of RNA polymerase and DNA polymerase activity associated with the low speed pellet was dependent on the pH during Triton treatment. Significant quantities of the RNA polymerase activity of chloroplasts from spinach, peas, and tobacco were also recovered in the pellet after Triton treatment.

Deoxyribonucleic Acid-dependent Ribonucleic Acid Polymerase Activity of Nuclei and Plastids from Etiolated Peas and their Response to Red and Far Red Light in Vivo

DNA-dependent RNA polymerase activity has been found in both the nuclei and etioplasts of dark-grown pea seedlings (Pisum sativum). Although these enzymes had similar over-all characteristics with respect to substrate, pH, and inhibitor responses, they could be distinguished by their different sensitivities to sonication.Brief irradiation of the seedlings with red light resulted in an increase in the activity of both the nuclear and plastid enzymes, but the time course of this response showed it to be too slow to be considered an early result of phytochrome control of metabolism. Far red light following red treatment largely prevented the increase in the activity of the nuclear enzyme. The plastid enzyme responded to far red light in a manner similar to its response to red light so that no reversal was observed when far red treatment followed red.

Kinin Activity From Plant Extracts II. Partial Purification and Fractionation of Kinins in Apple Extract

The extraction and partial purification of kinins from Pyrus malu.s cv. Granny Smith fruitlets are described. Tracing progress by means of a biological assay based on cell-division induction in tobacco pith, the kinins, extracted from fruitlets with aqueous ethanol, were partially purified by the following steps: (i) a.dsorption on a cation-exchange resin and displacement with ammonium hydroxide, (ii) adsorption on carbon and elution with pyridine-ethanol-ammonium hydroxide, and (iii) passage through a polyamide resin. When chl'omatographed on paper, the kinin �activity in. the purified extract was resolved into at least foUl' zones, each having independent activity. The kinin of the most active zone was purified 900-fold.

Discophoridin, A New Coumarin from Velleia discophora F. Muell

A new coumarin, discophoridin, isolated from Velleia discophora F. Muell., has been shown almost certainly to have structure (I). This conclusion isbasedmainly on evidence from nuclear magnetic resonance spectroscopy.

Kinin Activity From Plant Extracts

A biological assay for substances inducing cell division is described. Blocks of tobacco stem pith were cultured aseptically on 1 ml of basal medium containing mineral salts, sucrose, and vitamins. The addition of auxin to the basal medium caused cell enlargement, but the addition of kinetin alone produced no reaction.Auxin and kinetin together induced cell division, l'esulting in nests of cells readily distinguishable visually from the original cells. Callus produced in this way could be subcultured indefinitely on medium containing bot,h 3-indolylacet,ic acid (IAA)and kinetin.

The Chemistry of Western Australian Plants. IV. Duboisia hopwoodii

Examination of a large number of samples of Duboisia hopwoodii has confirmed the findings of Bottomley, Nottle, and White (1946). The methods used for the estimation of nicotine and nornicotine are described and the results summarized. These could not be correlated with locality, season, or soil type, and examination of fresh leaves showed that the alkaloid content is considerably reduced on drying. �� Samples of nicotine and nornicotine have been prepared and ursolic acid and a quercetin glycoside have been isolated from D. hopwoodii leaves.