Chemical Constituents of Cape Aloe and Their Synergistic Growth-Inhibiting Effect on Ehrlich Ascites Tumor Cells

The constituents of cape aloe were investigated after a preliminary screening of the growth-inhibiting effect on Ehrlich ascites tumor cells (EATC) of several extracts of this plant. Ten compounds were isolated from the dichloromethane (CH₂Cl₂) extract that showed the strongest activity, and their structures were elucidated as aloe-emodin (1), p-hydroxybenzaldehyde (2), p-hydroxyacetophenone (3), pyrocatechol (4), 10-oxooctadecanoic acid (5), 10-hydroxyoctadecanoic acid (6), methyl 10-hydroxyoctadecanoate (7), 7-hydroxy-2,5-dimethylchromone (8), furoaloesone (9), and 2-acetonyl-8-(2-furoylmethyl)-7-hydroxy-5-methylchromone (10) based on MS and various NMR spectroscopic techniques. Compounds 2–7 were isolated for the first time from cape aloe. Compounds 4–7 and 10 showed a significant growth-inhibiting effect, and compound 1 exhibited a remarkable synergistic effect on compounds 8–10, which was not observed with the treatment by each compound alone on EATC. These results suggest that the strong growth-inhibiting effect of the CH₂Cl₂ extract was dependent not on one compound alone, but on the synergistic effect from the combination of compound 1 and the other compounds.     

Rubralactone,Rubralides A,B and C,and Rubramin Produced by Penicillium rubrum

Rubralactone (1), rubralides A, B and C (2–4), rubramin (5), and 2-formyl-3,5-dihydroxy-4-methylbenzoic acid (6), were isolated from Penicillium rubrum, and their structures established by spectroscopic methods including 2D NMR. The effects on plant growth of 1–6 were examined using the lettuce seedling bioassay. Compound 1 promoted root growth. Compounds 2, 3 and 5 inhibited the growth of lettuce seedlings, but 4 and 6 did not have any inhibitory effect on their growth.     

一株海洋真菌Aspergillus jensenii LW128的次级代谢产物及其抗菌活性研究

【目的】研究一株西北太平洋深海沉积物来源真菌Aspergillus jensenii LW128的次级代谢产物及其抗菌活性。【方法】利用硅胶柱色谱(silica gel column chromatography)、凝胶柱色谱(Sephadex LH-20 column chromatography)和反相高效液相色谱(reversed-phase high-performance liquid chromatography, RP-HPLC)等方法对菌株的发酵粗提物进行分离纯化得到单体化合物;将核磁共振波谱(nuclear magnetic resonance, NMR)、质谱(mass spectrometry, MS)数据与相关文献报道数据进行比对后确定化合物结构;采用肉汤微量稀释法测定化合物的抗菌活性。【结果】从海洋真菌Aspergillus jensenii LW128中分离并鉴定了10个已知化合物,分别为diorcinol D(1)、diorcinol K(2)、diorcinol I(3)、(+)-(7S)-7-O-methylsydonic acid (4)、(+)-s...     

Opioid Peptides: Synthesis and Biological Activity of New Endomorphin Analogues

Summary Syntheses are described of new endomorphin 1 and 2 peptoid–peptide hybrids in which Tyr¹ and either one or both Phe³ and Phe⁴ have been replaced by N-substituted-glycine. The preparation is also described of two glycosylated Hyp²-endomorphin 2 analogues in which either 2,3,4,6-tetra-O-acetyl glucose or glucose are β-O-glycosidically linked to the hydroxyproline residue. The Hyp²-endomorphin sequences have also been elongate by adding a C-terminal β-alanine residue and several linear dimers have been prepared by coupling either the native peptides or the modified analogues. The cyclo endomorphin 2 has also been synthesized. Preliminary pharmacological experiments on isolated organ preparations showed that the agonist activities of both endomorphin 1 and 2 are not significantly affected by the Pro/Hyp substitution. Phe⁴/Nphe substitution in the endomorphin 1 reduced the potency on guinea pig ileum (GPI) by about 100 times and abolished the agonist activity on mouse vas deferens (MVD) preparation. The decrease of the agonist activity induced by modification of one phenylalanine residue only, either Phe³ or Phe⁴, is lower on endomorphin 2. Either modification of both Phe³ and Phe⁴ or glycosylation of the Hyp²-endomorphin 2 cancelled any agonist activity on both preparations. The linear peptide dimers [endomorphin 1]₂, [endomorphin 2]₂, [Hyp²-endomorphin 1]₂, [Hyp²-endomorphin 2]₂, [Hyp²-endomorphin 1-Hyp²-endomorphin 2]₂ or [Hyp²-endomorphin 2-Hyp²-endomorphin 1]₂, are 7–19 times less potent than endomorphin 1 on GPI and significantly less active than endomorphins 1 and 2 on MVD. The other afforded modifications significantly affected or abolished the agonist activity of the resulting endomorphin analogues on both GPI and MVD preparations.The α-amino acid residues are of the L-configuration. Standard abbreviations for amino acid derivatives and peptides are according to the suggestions of the IUPAC-IUB Commission on Biochemical Nomenclature (1984) Eur. J. Biochem., 138, 9–37. Abbreviations listed in the guide published in (2003) J. Peptide Sci., 9, 1–8 are used without explanation.     

Homo Dinucleoside-α-hydroxyphosphonate Diesters as Prodrugs of the Antiviral Nucleoside Analogues 2′,3′-Dideoxythymidine and 3′-Azido-2′,3′-dideoxythymidine

Abstract

The synthesis of a new prodrug system for antiviral nucleosides AZT (1) and ddT (2) based on α-hydroxybenzylphosphonates 3 is described. 3 hydrolyze via different mechanisms yielding the H-phosphonate monoesters 4 or nucleoside monophosphates 5, respectively. 3 were more lipophilic than 1, 2 and showed marked activity against HIV-1/2.     

Di-ddU-α-Hydroxyphosphonate and α-Hydroxy- α- METHYLPHOSPHONATES as Potential Prodrugs of Antiviral Nucleoside Analogues

Abstract

The synthesis of a potential new prodrug system for the antiviral nucleoside ddU 1 based on α-hydroxybenzylphosphonates 2 and 3 is described. In principle, 2, 3 are able to hydrolyze via different mechanisms yielding ddU H-phosphonate 4 or ddU monophosphate 5, respectively.     

Synthesis of N-substituted indole-2-carboxamides and investigation of their biochemical responses against free radicals

The antioxidant role of novel N-substituted indole-2-carboxamides (I2CDs) was investigated for their inhibitory effects on superoxide anion (O₂^? ) and lipid peroxidation (LP). Among the synthesized I2CDs, 3, 4, 6, 8 and 9 significantly inhibited O₂^{· ?} with an inhibition range at 70–98%. Examination of substituent effects on activity showed that both the ortho- and para-positions of the benzamide residue needs to be dichlorinated in order to get a maximum inhibitory effect on superoxide anion. In general, halogenated derivatives were found more active then the non-halogenated ones. However, none of the I2CDs had a significant inhibitory effects on the level of lipid peroxidation; only compounds 7 and 10 moderately decreased LP levels by over 50% at 10^{? 3} M concentrations.     

Evaluation of new chalcone derivatives as polyphenol oxidase inhibitors

A newly series of 4-(phenylurenyl)chalcone (4a–j) and 4′-(phenylurenyl/thiourenyl)chalcone (9a–l) derivatives were synthesized and their inhibitory effects on the diphenolase activity of banana tyrosinase were evaluated. Tyrosinase has been purified from banana on an affinity gel comprised of Sepharose 4B-l-tyrosine-p-aminobenzoic acid. The result showed that 4a–j inhibited the PPO enzyme activity. Conversely, 9a–h and 9i–l showed activator effect on tyrosinase enzyme activity.     

<Emphasis Type="Italic">Alansmia</Emphasis>, a new genus of grammitid ferns (Polypodiaceae) segregated from <Emphasis Type="Italic">Terpsichore</Emphasis>

Alansmia, a new genus of grammitid ferns is described and combinations are made for the 26 species known to belong to it. Alansmia is supported by five morphological synapomorphies: setae present on the rhizomes, cells of the rhizome scales turgid, both surfaces of the rhizome scales ciliate, laminae membranaceous, and sporangial capsules setose. Other diagnostic characters include pendent fronds with indeterminate growth, concolorous, orange to castaneous rhizome scales with ciliate or sometimes glandular margins, hydathodes often cretaceous, and setae simple, paired or stellate. The group also exhibits the uncommon characteristic of producing both trilete and apparently monolete spores, sometimes on the same plant. New combinations are made for Alansmia alfaroi, A. bradeana, A. canescens, A. concinna, A. contacta, A. cultrata, A. dependens, A. diaphana, A. elastica, A. glandulifera, A. heteromorpha, A. immixta, A. kirkii, A. lanigera, A. laxa, A. longa, A. monosora, A. reclinata, A. semilunaris, A. senilis, A. smithii, A. spathulata, A. stella var. stella, A. stella var. flava, A. turrialbae, A. variabilis, A. xanthotrichia. Lectotypifications are made for Alansmia concina, A. variabilis, Polypodium ciliare, P. flexile, and P. ovalescens. The genus is named in honor of pteridologist Alan R. Smith.     

A revision of Casimirella,including Humirianthera (Icacinaceae)

Casimirella Hassler (1913) is accepted and Humirianthera Huber (1914) considered a synonym. Casimirella diversifolia and C. lanata from Brazil are described as new species. Casimirella ampla (Miers) based on Leretia ampla Miers, C. crispula (Howard) based on Humirianthera crispula Howard, and C. rupestris (Ducke) based on Humirianthera rupestris Ducke are new combinations.     

Synthesis and Reactions of Some Glycosylamine Derivatives of 6-Azauracil Nucleosides

Abstract

Reaction of the silylated 6-azauracil (2) with 2-acetamido-1,3,4,6-tetra-O-acetyl-2-deoxy-D-glucose (3) gave 1-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-ß-D-glucopyranosyl)-6-azauracil (4), which gave the free nucleoside 5 on deblocking. Acetalation of 5 gave the monoacetal 6 which was oxidized into the ketone 7. Reduction of 7 gave the allo-nucleoside 9 which on hydrolysis afforded the free nucleoside 10. Alternatively, compound 10 was obtained from mesylation of 6 to give 8 followed by subsequent acetolysis and hydrolysis.     

Morphology and postembryonic development of males and females of Bosmina longispina Leydig (Crustacea, Anomopoda) from a North Iceland population

We investigated the morphology of adult and juvenile stages of females and males of Bosmina longispina Leydig from a North Icelandic population. There are additional setae near the basis of the second antenna and between its branches in adult males, not described in Bosmina, but known from other Anomopoda. New features of female morphology are also found. The development of the first limb and postabdomen of the male is described in detail. In juvenile males of B. longispina (belonging to subgenus Eubosmina), characteristics of morphology, similar to those in adult males of other subgenera are found.Abbreviations af antennal flap - as additional setae of male - bs basis of seta of clasper - bc basis of postabdominal claws - ch clasper hook - cl clasper - cs seta of clasper - cw claws of postabdomen - de distal endite of the first limb - dr dorsal row of denticles on male postabdomen - df dorsal fold of carapace - eh ejector hooks of limb I - ep epipodite - ex exopodite - fp frontal head pore - fs frontal seta - hs hair sensilla - in incision of juvenile male postabdomen - ir interrupted rows of setules on postabdomen - Ip lateral head pore - mp median head pore - mpr maxillar process of limb I - mr main row of denticles on postabdominal claws - pe predistal endite of limb I - pf preantennal fold of valve - pl plate above postabdominal setae - ps postabdominal setae - rs rudimentary setae - sr second row of denticles near basis of claws - vf ventral fold of valve - vr ventral row of denticles on male postabdomen     

New Neplanocin Analogues. V. A Potent Adenosylhomocysteine Hydrolase Inhibitor Lacking Antiviral Activity. Synthesis And Antiviral Activity Of 6″-Carboxylic Acid Derivatives Of Neplanocin A 1

Abstract

The 6′-carboxylic acid derivative of neplanocin A 3 was synthesized from NPA, and was converted to the corresponding methyl ester 4 and amides 5 and 6. These were evaluated for their anti-RNA-virus activities. Of the derivatives synthesized, only 5 was active against RNA viruses within the concentration range of 0.14-4.88 μg/mL. Compounds 3 and 5 showed a potent inhibitory effect on S-adenosylhomocysteine (AdoHcy) hydrolase from rabbit erythrocytes. Although a close correlation between the inhibitory effect of adenosine analogues on AdoHcy hydrolase and their antiviral potency has been demonstrated, 3 did not show any anti-RNA-virus activities.

     

Stenogrammitis, a new genus of grammitid ferns segregated from Lellingeria (Polypodiaceae)

Stenogrammitis , a new genus of grammitid ferns, is segregated from Lellingeria based on morphological and molecular evidence. It differs from Lellingeria by linear leaves usually less than 5 mm wide, clathrate iridescent rhizome scales that are glabrous except for a single apical cilium, veins unbranched and only one per segment, fertile veins usually with the dark sclerenchyma visible beneath the sporangia, and x = 33. In contrast, Lellingeria has broader laminae, veins pinnate within the segments, and fertile veins not visible beneath the sporangia. Melpomene, which is sister to Stenogrammitis and Lellingeria, differs from those two genera by reddish setae on the leaves and rhizome scales papillate at the apex. Some species of Stenogrammitis are also distinctive by hemidimorphic laminae that have the fertile portion less dissected than the sterile. Stenogrammitis is pantropical and currently comprises 24 species, 12 of which occur in the Neotropics, six in Africa, four in Madagascar, and two on Pacific Islands. New combinations are made for Stenogrammitis aethiopica, S. anamorphosa, S. ascensionensis, S. boivinii, S. delitescens, S. jamesonii, S. hartii, S. hellwigii, S. hildebrandtii, S. limula, S. luetzelburgii, S. myosuroides, S. nutata, S. oosora, S. paucipinnata, S. prionodes, S. pumila, S. ruglessii, S. rupestris, S. saffordii, S. strangeana, S. tomensis, S. subcoriacea, and S. wittigiana. Lectotypifications are made for Grammitis muscosa, Polypodium itatiayense, P. oosorum var. micropecten, P. serrulatum forma major, P. serrulatum forma minor, S. luetzelburgii, S. myosuroides, and S. wittigiana. Illustrations are presented for the diagnostic characters of the genus, as well as a map with the geographical distribution.     

Miscellaneous mistletoe notes, 48–60: Descriptions of twelve new species of Loranthaceae and Viscaceae

Twelve new South American species of Loranthaceae (Aetanthus, Cladocolea, Oryctanthus, and Struthanthus) and Viscaceae (Dendrophthora and Phoradendron) are described and illustrated: Aetanthus trifolius, Cladocolea rostrifolia, Dendrophthora lanceolata, Dendrophthora rotundata, Dendrophthora tenuis, Dendrophthora werffii, Oryctanthus minor, Phoradendron pascoi, Phoradendron vasquezianum, Struthanthus apiculatus, Struthanthus schultesii, and Struthanthus sessiliflorus. Additionally, Cladocolea alternifolia, previously thought to be probably extinct, is reported to occur on Ilha Grande, just west of Rio de Janeiro, Brazil.     

Studies on the Later Stage of the Biosynthesis of Pleuromutilin

Mutilin (4) and deoxy analogues 2 and 3 are biosynthetic precursors of pleuromutilin (1) in the later stage of biosynthesis. Precursors 2 and 3 are required for studies on the oxygenation steps in biosynthesis, and were synthesized from readily available 1 via 4 by deoxygenation of the hydroxy groups. Feeding experiments with the ²H-labeled precursors confirmed their microbial conversion into 1.     

New antibacterial pentacyclic triterpenes from Myricaria elegans Royle. (tamariscineae)

Two new pentacyclic triterpenes eleganene-A (1) and eleganene-B (2), along with four known pentacyclic triterpenes betulin (3), ursolic acid (4), erythrodiol (5) and corosolic acid (6) were isolated from the aerial parts of Myricaria elegans. These compounds exhibited significant antibacterial activity. The structure of compounds 1 and 2 were deduced on the basis of their spectral analysis.     

SYNTHESIS OF 4-ACYL-1H-1,2,3-TRIAZOLIC NUCLEOSIDES

Two simple regiospecific methodologies based on triazolic ring construction in the course of synthesis were applied for the synthesis of 1,2,3-triazolic nucleoside analogues. The cycloaddition reactions between diazomalonaldehyde and appropriate glycosylamine derivatives were rather effective, producing the desired nucleosides 11, 17 and 24. Diazotization of enamines 21a and 21b led to the corresponding triazolic ribonucleoside derivatives 22a and 22b, in good yields. Deprotection reaction of 22a, 22b and 24 was easily achieved by Lewis acid catalysis, producing the corresponding ribonucleosides 23a, 23b and 25.     

Synthesis of Optically Pure (R)-4a-Methyl-4,4a,5,6,7,8-hexahydro-2(3H)-naphthalenone and Its Transformation into (+)-7-Hydroxycostal

A novel synthesis of the enone 12 starting from (+)-dihydrocarvone (3) and its transformation into (+)-7-hydroxycostal (1) are described. The ketone 10, obtained from 4 through a four-step sequence was converted to 12 by acid-catalyzed elimination and subsequent regioselective hydrogenation. Alternatively, the methoxyhydroperoxide 13 generated by the ozonolysis of 4 was subjected to the Criegee rearrangement, providing a mixture of 10 and 14, which on acid treatment, gave 11. Transformation of 12 into 19 was accomplished via a five-step reaction sequence. The reaction of 19 with the lithium alkoxide of 2-lithio-2-propenol afforded (+)-7-hydroxycostol (2), whose oxidation with manganese dioxide gave rise to (+)-7-hydroxycostal (1).     

Production of NO and N2O by the Heterotrophic Nitrifier Alcaligenes faecalis parafaecalis under Varying Conditions of Oxygen Saturation

Production of NO and N ₂ O by the heterotrophic nitrifier Alcaligenes faecalis subsp. parafaecalis was studied during growth in batch and continuous culture on peptone-meat extract medium. Depending on oxygen saturation level, medium redox status and amount of substrate supplied, the microorganisms produced 0.002–0.25 mg NO-N h^{- 1} (g protein)^{- 1} and 0.16–2.4 mg N ₂ O-N h^{- 1} (g protein)^{- 1} . Maximum rates of nitrogen oxides production were observed during peak events initiated by sudden changes of oxygen supply in the medium and were due to combined nitrification/denitrification taking place simultaneously within the cells. Based on model simulations of enzymatic kinetics of denitrification, possible mechanisms of increased nitrogen oxides production during periods of changes in oxygen supply are suggested.