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1.
Clin Radiol ; 77(6): 399-408, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35177229

RESUMO

Castleman Disease (CD) is a rare entity that typically presents as an enhancing nodal mass in the mediastinum or head and neck region on computed tomography (CT). It may manifest as unicentric or multicentric regions of lymph node enlargement. A key clinical issue in the context of CD is delayed diagnosis, which contributes adversely to patient outcome, given that accurate diagnosis facilitates earlier treatment of this curable disease. This article will address relevant imaging aspects, with reference to typical and atypical imaging features of CD, illustrated using examples from our specialist centre; the imaging journey for patients with CD; and will provide practical pointers to radiologists in differentiating CD from other benign and malignant causes of enhancing lymphadenopathy, including lymphoma and neoplastic adenopathy. We will also review current classification tools and staging challenges with reference to World Health Organization guidelines, International Working Group guidelines as well as the Lugano classification. Finally, we will discuss the potential role of additional imaging techniques in CD, highlighting novel imaging methods and expanded utilities from our specialist centre.


Assuntos
Hiperplasia do Linfonodo Gigante , Linfadenopatia , Radiologia , Hiperplasia do Linfonodo Gigante/diagnóstico por imagem , Hiperplasia do Linfonodo Gigante/patologia , Diagnóstico Diferencial , Humanos , Linfadenopatia/diagnóstico por imagem , Radiografia , Tomografia Computadorizada por Raios X
2.
Clin Radiol ; 77(2): 79-87, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34579859

RESUMO

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare but emerging T-cell non-Hodgkin lymphoma. It has two distinct subtypes, "effusion-only" or "mass-forming" disease, arising around implants in patients with in situ or previous history of textured-surface breast implants. The clinical, histopathological and imaging features are unique and nuanced as compared to primary breast malignancy and other lymphoma categories. Prompt recognition and diagnosis triggers referral to appropriate BIA-ALCL centres and initiation of treatment, with potential for excellent prognosis. Definitive management of both subtypes involves implant and capsule removal; systemic therapy is reserved for mass-forming disease and advanced-stage disease. There have been recent crucial advances in the diagnostic pathway, with publication of national and international guidelines: from the UK Medicines Healthcare products Regulatory Agency (MHRA) Plastic, Reconstructive and Aesthetic Surgery Expert Advisory Group (PRASEAG), and the United States National Comprehensive Cancer Network (NCCN). This review provides a practical guide to the clinical work-up of BIA-ALCL, enabling optimisation of the diagnostic imaging pathway, with representative cases.


Assuntos
Implantes de Mama/efeitos adversos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/etiologia , Diagnóstico por Imagem/métodos , Linfoma Anaplásico de Células Grandes/diagnóstico por imagem , Linfoma Anaplásico de Células Grandes/etiologia , Mama/diagnóstico por imagem , Feminino , Humanos , Prognóstico
3.
Clin Radiol ; 76(11): 789-800, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34217434

RESUMO

Chronic lymphocytic leukaemia (CLL) is the most common leukaemia in adults. It is a malignancy of CD5 B-cells characterised by small, mature-appearing lymphocytes accumulating in the blood, bone marrow, and lymphoid tissues. Richer transformation (RT) is an important adverse complication. Detection of RT is critical to allow initiation of appropriate therapy. CLL staging and response evaluation is complicated and nuanced. From our extensive tertiary centre experience of several hundred CLL cases over the last decade, we detail key computed tomography (CT) and positron-emission tomography (PET) imaging features of the natural history of CLL. The authors present an original imaging-based patient-management paradigm for the investigation of potential RT, which will inform global practice. Potential applications of whole-body diffusion weighted imaging, novel PET radiotracers, minimal residual disease, and ct-DNA are addressed.


Assuntos
Leucemia Linfocítica Crônica de Células B/diagnóstico por imagem , Leucemia Linfocítica Crônica de Células B/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Idoso , Progressão da Doença , Humanos , Pessoa de Meia-Idade
4.
Clin Radiol ; 76(5): 391.e1-391.e18, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33579517

RESUMO

Non-Hodgkin's lymphoma (NHL) encompasses over 40 different haematological malignancies, including low and high-grade neoplasms, such as follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) respectively. A key clinical issue in the context of NHL is delayed and inaccurate diagnosis, which contributes adversely to patient morbidity and mortality. This article will address relevant imaging aspects, with particular reference to advancements in NHL imaging, including computed tomography (CT), integrated positron-emission tomography (PET)-CT, and magnetic resonance imaging (MRI). We provide multiparametric (anato-functional) imaging display items, including histological correlation. We will also introduce our original concept of "Specialist Integrated Haematological Malignancy Imaging Reporting" (SIHMIR), a paradigm shift in lymphoma radiology.


Assuntos
Linfoma não Hodgkin/diagnóstico por imagem , Linfoma não Hodgkin/patologia , Imageamento por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Sistemas de Informação em Radiologia , Tomografia Computadorizada por Raios X/métodos , Humanos , Estadiamento de Neoplasias
5.
Br J Cancer ; 109(3): 615-22, 2013 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-23868012

RESUMO

BACKGROUND: Endovaginal MRI (evMRI) at 3.0-T with T2-weighted (T2-W) and ZOnal Oblique Multislice (ZOOM)-diffusion-weighted imaging (DWI) potentially improves the detection of stage Ia/Ib1 cervical cancer. We aimed to determine its sensitivity/specificity, document tumour-to-stromal contrast and establish the effect of imaging on surgical management. METHODS: Following ethical approval and written informed consent, 57 consecutive patients with suspected stage Ia/Ib1 cervical cancer underwent evMRI at 3.0-T using T2-W and ZOOM-DWI. Sensitivity/specificity were calculated against histopathology for two independent observers. Tumour-to-stromal contrast was determined on T2-W, and diffusion-weighted (b=800 s mm(-2)) images and apparent diffusion coefficients (ADCs) were recorded. In patients due for radical vaginal trachelectomy (RVT), change of surgical management based on imaging findings was documented. RESULTS: Sensitivity/specificity for detecting tumour was the following: reporting read 88.0/81.8%, anonymised read 92.0/81.8% (observer 1); 84.0/72.7% (observer2; median tumour volume=1.7 cm(3)). Intraobserver agreement was excellent (kappa=0.89) and the interobserver agreement was good (kappa=0.65). Tumour-to-stromal contrast was greater on ZOOM-DWI compared with T2-W images (3.35±2.36 vs 1.39±0.95; P<0.0004). Tumour and stromal ADCs were significantly different (P<0.00001). In 31 patients due for RVT, evMRI altered surgical management in 12 (38.7%) cases (10 cone-biopsy, 2 chemoradiotherapy). CONCLUSION: T2-W+ZOOM-DWI evMRI has high sensitivity/specificity for detecting stage Ia/Ib1 cervical tumours; in patients due for RVT, the surgical management was altered in ∼39%.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Procedimentos Cirúrgicos em Ginecologia/métodos , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/cirurgia , Adulto , Idoso , Feminino , Preservação da Fertilidade/métodos , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Sensibilidade e Especificidade
6.
Science ; 281(5375): 428-31, 1998 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-9665888

RESUMO

The pupal defensive secretion of the coccinellid beetle Epilachna borealis is composed principally of a combinatorial library of macrocyclic polyamines. These compounds constitute a previously unrecognized family of natural products, characterized by extremely large-ring lactonic structures derived from a small set of (2-hydroxyethylamino)alkanoic acids. The combinatorial assembly of these simple building blocks generates a high degree of structural diversity, which is further increased by slow, spontaneous intramolecular rearrangement of the macrocycles.


Assuntos
Aminoácidos/química , Besouros/química , Poliaminas/química , Aminoácidos/análise , Aminoácidos/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Besouros/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Isomerismo , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Poliaminas/análise , Poliaminas/isolamento & purificação , Poliaminas/metabolismo , Poliésteres/análise , Poliésteres/química , Poliésteres/metabolismo , Pupa/química , Pupa/metabolismo
7.
J Ovarian Res ; 12(1): 50, 2019 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-31128592

RESUMO

INTRODUCTION: The management of Serous Tubal Intraepithelial Carcinoma (STIC) found at the time of Risk-Reducing Salpingo-Oophorectomy (RRSO) remains unclear. We set out to analyse the incidence of peritoneal carcinomas developed after prophylactic surgery and to formulate further guidance for these patients. METHODS: This is a retrospective study of 300 consecutive RRSO performed at the Royal Marsden Hospital between January 2008 and January 2017. RESULTS: The median age at RRSO was 47.8 years (range 34 to 60 years) and median BMI was 26.2 kg/m2 (range 16 to 51 kg/m2). A total of 273 patients (91%) were tested for BRCA mutations. Of these, 124 (45.4%) had a BRCA 1 mutation, 118 (43.2%) had a BRCA 2 mutation, 2 (0.7%) had both a BRCA 1 and a BRCA 2 mutation and 29 (10.6%) had no BRCA mutation detected. Isolated STIC lesions were identified in 7 cases (2.3%) and p53 signatures in 75 cases (25%). There were five (1.6%) incidental tubal carcinomas and one (0.3%) ovarian carcinoma at the time of surgery. Two (28.6%) of the 7 patients with STIC identified following RRSO had high grade serous peritoneal carcinoma diagnosed at 53 and 75 months. One (0.3%) patient from the other 287 patients from our series with no STIC diagnosis or incidental carcinomas at RRSO developed high grade serous carcinoma of peritoneal origin after 92 months. CONCLUSION: This study demonstrates that when a STIC lesion is identified following RRSO there is a significantly higher risk of a subsequent peritoneal cancer. Although there is no published consensus in literature, we recommend that consideration should be given for long term follow-up if a STIC lesion is identified at RRSO.


Assuntos
Cistadenocarcinoma Seroso/epidemiologia , Cistadenocarcinoma Seroso/secundário , Neoplasias das Tubas Uterinas/patologia , Neoplasias das Tubas Uterinas/cirurgia , Neoplasias Peritoneais/epidemiologia , Neoplasias Peritoneais/secundário , Adulto , Proteína BRCA1/genética , Proteína BRCA2/genética , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/prevenção & controle , Neoplasias das Tubas Uterinas/genética , Feminino , Humanos , Incidência , Pessoa de Meia-Idade , Mutação , Ovariectomia , Neoplasias Peritoneais/genética , Neoplasias Peritoneais/prevenção & controle , Procedimentos Cirúrgicos Profiláticos , Estudos Retrospectivos , Salpingectomia
8.
J Mass Spectrom ; 52(6): 347-352, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28321994

RESUMO

In the past, chrome yellow (lead chromate, PbCrO4 ), a bright orange-red substance, has been widely used as an inorganic pigment in the production of paints, coatings, and plastics. Herein, we demonstrate that laser desorption/ionization mass spectrometry (LDI-MS) is a powerful tool for the detection of lead chromate in solid residues. In fact, lead chromate in trace amounts is easily detectable by LDI-MS even from residues left as latent prints. For example, a latent print obtained by stamping the exposed laterally cut surface of a pencil over 50 years old on an acetonitrile-moistened paper, was successfully imaged for both lead and chromate using a Synapt G2 HDMS mass spectrometer. After rastering the print with a 355 nm laser beam and recording positive- and negative-ion mass spectra over the range m/z 50-1200, we generated false-color 'heat maps' (single-ion images) for 208 Pb+• (m/z 207.98) and Cr2 O6-• (m/z 199.85). The heat maps matched closely with the faint visual image of the pencil imprint. Moreover, our results confirmed that lead chromate was used in the pigment coatings of old pencils. Evidently, LDI-MS imaging is an efficient procedure to survey for the presence of lead and chromate in minerals and other materials. Copyright © 2017 John Wiley & Sons, Ltd.

9.
J Chem Ecol ; 12(3): 669-85, 1986 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24306907

RESUMO

The Dufour glands of worker ants of Tetramorium caespitum, and the morphologically similar T. impurum are filled with similar, but species-specific mixtures of linear hydrocarbons and three homologous sesquiterpene corhpounds. Glands of workers ofT. caespitum contain, on average, 70 ng of oil containing C13 to C17 linear hydrocarbons with n-pentadecane (64%) and a mixture of pentadecenes (14%) as major components.T. impurum glands are smaller and contain an average of 40 ng of the same mixture but with n-pentadecane (49%) and a sesquiterpenoid compound (19%) the major components. Two isomeric pentadecenes, (Z)-6-pentadecene and (Z)-7-pentadecene are present in both species.T. semilaeve workers contain on average only 30 ng of a simple mixture of hydrocarbons with pentadecane contributing more than 90% of the total.

10.
Leukemia ; 22(6): 1139-43, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18401419

RESUMO

Peripheral T-cell lymphomas (PTCLs) are fatal in the majority of patients and novel treatments, such as protein tyrosine kinase (PTK) inhibition, are needed. The recent finding of SYK/ITK translocations in rare PTCLs led us to examine the expression of Syk PTK in 141 PTCLs. Syk was positive by immunohistochemistry (IHC) in 133 PTCLs (94%), whereas normal T cells were negative. Western blot on frozen tissue (n=6) and flow cytometry on cell suspensions (n=4) correlated with IHC results in paraffin. Additionally, western blot demonstrated that Syk-positive PTCLs show tyrosine (525/526) phosphorylation, known to be required for Syk activation. Fluorescence in situ hybridization showed no SYK/ITK translocation in 86 cases. Overexpression of Syk, phosphorylation of its Y525/526 residues and the availability of orally available Syk inhibitors suggest that Syk merits further evaluation as a candidate target for pharmacologic PTK inhibition in patients with PTCL.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Linfoma de Células T Periférico/enzimologia , Proteínas Tirosina Quinases/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Criança , Pré-Escolar , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 9/genética , Feminino , Citometria de Fluxo , Humanos , Técnicas Imunoenzimáticas , Imunofenotipagem , Hibridização in Situ Fluorescente , Peptídeos e Proteínas de Sinalização Intracelular/genética , Linfoma Extranodal de Células T-NK/enzimologia , Linfoma Extranodal de Células T-NK/genética , Linfoma Extranodal de Células T-NK/patologia , Linfoma Anaplásico de Células Grandes/enzimologia , Linfoma Anaplásico de Células Grandes/genética , Linfoma Anaplásico de Células Grandes/patologia , Linfoma Cutâneo de Células T/enzimologia , Linfoma Cutâneo de Células T/genética , Linfoma Cutâneo de Células T/patologia , Linfoma de Células T Periférico/genética , Linfoma de Células T Periférico/patologia , Masculino , Pessoa de Meia-Idade , Fosforilação , Proteínas Tirosina Quinases/genética , Quinase Syk , Translocação Genética , Tirosina/metabolismo
11.
Histopathology ; 50(4): 498-508, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17448026

RESUMO

AIMS: To identify distinguishing histological, immunophenotypic and molecular genetic features between angioimmunoblastic T-cell lymphoma (AITL) and peripheral T-cell lymphoma (PTL). METHODS: Nodal T-cell lymphomas examined (n =137), included AITL (n = 89), PTL (n = 22), anaplastic large cell lymphoma (n = 16) and 'AITL/PTL indeterminate' (n = 10) with overlapping features between AITL and PTL, showing morphology typical of AITL but lacking follicular dendritic cell expansion. Immunohistochemistry for CD3, CD20, CD21 and CD10, in situ hybridization for Epstein-Barr virus encoded RNA (EBER) and polymerase chain reaction for T-cell and B-cell clonality analysis were performed. RESULTS: Of the AITLs, 74/89 showed typical morphology, whereas 15/89 showed hyperplastic follicles. AITL and 'AITL/PTL indeterminate' showed a polymorphous infiltrate and prominent vascularity in all cases. In both groups, CD10 was present in the majority and clear cells and EBER positivity were specific (but not universal) features lacking in PTL. Detection of T-cell clonality was significantly higher in AITL (90%) compared with PTLu (59%). CONCLUSION: Clear cells and EBV infection (when present) are useful distinguishing features and CD10 a sensitive and specific marker of AITL. Hyperplastic follicles are present in a significant minority of AITL. AITL/PTL indeterminate probably falls within the spectrum of AITL rather than PTL.


Assuntos
Linfadenopatia Imunoblástica/diagnóstico , Linfoma de Células T Periférico/diagnóstico , Antígenos CD20/metabolismo , Linfócitos B/patologia , Complexo CD3/metabolismo , Células Clonais , Diagnóstico Diferencial , Rearranjo Gênico , Herpesvirus Humano 4/genética , Humanos , Linfadenopatia Imunoblástica/genética , Linfadenopatia Imunoblástica/patologia , Cadeias Pesadas de Imunoglobulinas/genética , Imuno-Histoquímica , Imunofenotipagem , Linfoma de Células T Periférico/genética , Linfoma de Células T Periférico/patologia , Neprilisina/metabolismo , Reação em Cadeia da Polimerase , RNA Viral/análise , Receptores de Antígenos de Linfócitos T gama-delta/genética , Receptores de Complemento 3d/metabolismo , Sensibilidade e Especificidade , Linfócitos T/patologia
12.
J Chem Ecol ; 32(12): 2687-94, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17077999

RESUMO

The acceptance of Solanum surattenses as a host plant for the larvae of Manduca sexta was explained by the presence of feeding stimulants in foliage. Bioassay-guided fractionation of plant extracts resulted in the isolation of a highly active compound (1), which was identified as a furostan derivative {26-O-beta-D-glucopyranosyl-(25R)-furosta-5-ene-3-beta-yl-O-alpha-L-rhamnopyranosyl-(1''-2')-O-alpha-L-rhamnopyranosyl-(1'''-3'')-O-beta-D-glucopyranoside}. This compound has the same steroidal core substructure as that in a stimulant (indioside D) previously identified from potato foliage. However, the sugar substituents attached to the core are different.


Assuntos
Comportamento Alimentar/efeitos dos fármacos , Manduca/efeitos dos fármacos , Oligossacarídeos/isolamento & purificação , Solanum/química , Animais , Glicosídeos , Larva , Manduca/fisiologia , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Extratos Vegetais/química , Esteroides , Estimulação Química
13.
Anal Chem ; 69(10): 1827-36, 1997 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-9164159

RESUMO

Vapor-phase infrared spectra allow the determination of the stereochemistry of carbon-carbon double bonds conjugated with a vinyl group. Cis and trans isomers of unsubstituted 1,3-alkadienes can be differentiated on the basis of the differences observed in the 900-1000 cm-1 region (spectra of cis isomers show two bands at 993 and 906 cm-1, while those of trans compounds show three absorptions at 998, 949, and 902 cm-1) and the 1590-1650 cm-1 region (the C=C stretch bands are observed at 1595 and 1642 cm-1 for cis compounds and at 1604 and 1650 cm-1 for trans compounds). Compounds bearing CH2=CHC(CH3)=CHCH2- and CH2=CHC(=CH2)-CH2- structural moieties, referred to as alpha- and beta-type compounds, are frequently encountered as natural products. For compounds bearing alpha-type groups, the cis/trans configuration of the trisubstituted double bond can be determined unambiguously. An absorption at 3095-3091 cm-1, for the =CH2 stretch vibration, is common to both of these groups; however, due to the presence of two =CH2 groups, the relative intensity of the band is much higher for beta-type compounds. For alpha-type compounds, a cis configuration at the C-3 carbon atom is characterized by a =CH2 wag absorption at 907-906 cm-1. For beta-type compounds and 3E-alpha-type compounds, this band appears at 899-897 cm-1. In addition, a wavy "fingerprint" pattern with two minima at 1632 (low intensity) and 1595-1594 cm-1 (high intensity) is characteristic for beta-type compounds. Our generalizations are based on spectra of cis and trans ocimene, myrcene, and dehydration products of many 3-methyl-1-alken-3-ols. Six isomers of farnesene can be characterized by GC/FT-IR. Furthermore, gas-phase IR allows the determination of the configuration of the trisubstituted double bond at C-3 in alpha-type farnesene congeners. For example, the homo- and bishomofarnesene isomers from Myrmica ants were shown to include a 3Z bond.


Assuntos
Compostos de Vinila/química , Cromatografia Gasosa/métodos , Isomerismo , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Compostos de Vinila/análise
14.
J Chem Ecol ; 10(10): 1453-68, 1984 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24318345

RESUMO

The trail pheromone of the antTetramorium caespitum L. is a 70∶30 mixture of 2,5-dimethylpyrazine and 3-ethyl-2, 5-dimethylpyrazine. The average total amount of the two pyrazines present in the poison vesicle was found to be 3.9 ng per ant, of which 2.7 ± 0.4 ng is 2,5-dimethylpyrazine and 1.15 ±0.25 ng is 3-ethyl-2,5-dimethylpyrazine. The pyrazines constitute only 0.03% of the volume of the poison vesicle but account for the whole of the trail-following activity. A 70∶30 mixture of the respective pyrazines evoked the highest activity in artificial trail-following tests.

15.
Anal Chem ; 66(10): 1696-703, 1994 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-8030784

RESUMO

Gas-phase Fourier-transform infrared spectra allow unambiguous determination of the configuration of the double bonds of long-chain unsaturated compounds bearing RCH=CHR' type bonds. Although the infrared absorption at 970-967 cm-1 has been used previously for the identification of trans bonds, the absorption at 3028-3011 cm-1 is conventionally considered to be incapable of distinguishing cis and trans isomers. In this paper, we present a large number of gas-phase spectra of monounsaturated long-chain acetates which demonstrate that an absorption, highly characteristic for the cis configuration, occurs at 3013-3011 cm-1, while trans compounds fail to show any bands in this region. However, if a double bond is present at the C-2 or C-3 carbon atoms, this cis=CH stretch absorption shows a hypsochromic shift to 3029-3028 and 3018-3017 cm-1, respectively. Similarly, if a cis double bond is present at the penultimate carbon atom, this band appears at 3022-3021 cm-1. All the spectra of trans alkenyl acetates showed the expected C-H wag absorption at 968-964 cm-1. In addition, the spectra of (E)-2-alkenyl acetates show a unique three-peak "finger-print" pattern which allows the identification of the position and configuration of this bond. Furthermore, by synthesizing and obtaining spectra of appropriate deuteriated compounds, we have proved that the 3013-3011 cm-1 band is representative of the C-H stretching vibration of cis compounds of RCH=CHR' type.


Assuntos
Alcenos/química , Feromônios/química , Gases/análise , Conformação Molecular , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
16.
J Nat Prod ; 62(1): 179-80, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9917315

RESUMO

The new compound 6'''-O-sinapoylisovitexin 6'' -O-beta-D-glucopyranoside (1) was isolated from the foliage of Alliaria petiolata, and identified by spectral studies.


Assuntos
Brassicaceae/química , Glucosídeos/isolamento & purificação , Sequência de Carboidratos , Glucosídeos/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas/métodos , Dados de Sequência Molecular , Estrutura Molecular , Espectrofotometria Ultravioleta
17.
J Chem Ecol ; 18(3): 489-98, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24254952

RESUMO

The defensive spray of a single female of the rare carabid beetle,Helluomorphoides clairvillei (subfamily Carabinae, supertribe Lebiitae, tribe Helluonini). was found to contain a mixture of compounds, including carboxylic acids (formic, acetic), aliphatic esters (principally nonyl acetate), and hydrocarbons (principally decane). In a single series of discharges, the beetle ejected a total of about 1% of its body weight as formic acid (1.1 mg). Our findings demonstrate that characterization of secretory components from even minimal samples of secretion should be possible in many cases.

18.
Anal Chem ; 65(18): 2528-33, 1993 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-8238941

RESUMO

The electron-impact mass spectra of alpha, beta-bis(methylthio) derivatives of certain terpenes and other compounds with branched alkenyl groups contain diagnostic peaks that can be used for locating the position of the double bond in the parent compound. In contrast to the spectra of dimethyl disulfide (DMDS) derivatives obtained from compounds containing CH=CH type double bonds, which show two predominant fragment ions, most of the compounds examined in the current investigation showed only one predominant fragment ion, arising from that part of the molecule which possesses the more substituted carbon of the original double bond. For example, all the derivatives from compounds with an isopropylidene moiety showed a base peak at m/z89 which can be attributed to the formation of a [(CH3)2C=SCH3]+ fragment. The application of the DMDS procedure to naturally occurring terpenes is discussed.


Assuntos
Formigas/metabolismo , Terpenos/análise , Animais , Dissulfetos/química , Cromatografia Gasosa-Espectrometria de Massas
19.
J Nat Prod ; 56(10): 1700-6, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8277310

RESUMO

Six quinones were identified from the defensive secretion of the millipede Floridobolus penneri. The two major components, 2-methyl-1,4-benzoquinone [1] and 2-methoxy-3-methyl-1,4-benzoquinone [3], previously characterized, comprise 95% of the secretion. One of the minor compounds, 2,5-dimethyl-3-methoxy-1,4-benzoquinone [4], is a new natural product. Another, 2-hydroxy-3-methyl-1,4-benzoquinone [2], had been tentatively characterized from a microbial source. The other two components are 2,3-dimethoxy-1,4-benzoquinone [5] and 2,3-dimethoxy-5-methyl-1,4-benzoquinone [6]. No sex difference in the composition of the secretion was noted.


Assuntos
Aracnídeos/fisiologia , Benzoquinonas/metabolismo , Glândulas Exócrinas/metabolismo , Animais , Aracnídeos/química , Benzoquinonas/química , Cromatografia Gasosa , Glândulas Exócrinas/química , Feminino , Espectroscopia de Ressonância Magnética , Masculino , Espectrometria de Massas , Espectrofotometria Infravermelho
20.
J Chem Ecol ; 19(10): 2089-104, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24248561

RESUMO

The cervical gland secretion of larvae ofSchizura unicornis andS. badia (Lepidoptera: Notodontidae) contains formic acid, acetic acid, and a mixture of lipophilic compounds, including 2-alkanones, 2-alkanols, and formates of the alkanols. InS. unicornis, the secretion also contains severalω-monounsaturated analogs of the alcohols, ketones, and formates. The absolute configuration of two of the alcohols (2-tridecanol and 2-pentadecanol) was established asS in both species. The larvae spray their secretion when physically disturbed, aiming it accurately in the direction of the offending agent.

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