A combination of commercial and traditional food-source-derived enzymatic treatment acts as a potential tool to produce functional yuzu (Citrus junos) powder

Enzymatic modifications have been applied in citrus to enhance their physicochemical and biological properties and reduce their bitterness. Notwithstanding, research on the combination of enzyme treatment of yuzu is lacking. In this study, yuzu was treated with a combination of isolated cellulase NY203, pectinase UF, and cellulase KN, and this enzymatic treatment was found to increase monosaccharide, naringenin, and hesperetin levels. In contrast, dietary fiber, cellulose, hemicellulose, lignin, and pectin levels were decreased. Moreover, the enzymes disintegrated the inner and outer surface structures and chemical bonding of yuzu, thus improving its solubility rate, water-holding capacity, oil-adsorption capacity, cholesterol-binding capacity, and water-swelling capacity. Furthermore, NY203 + UF + KN combination treatment reduced the bitterness of treated yuzu by 50 % compared with the control. Additionally, NY203 + UF + KN treatment yielded a 28 % decrease in lipid accumulation and two-fold higher lipolytic activity in 3T3L-1 adipocytes. These findings are potentially beneficial to the food/nutraceutical industries regarding functional yuzu powder production.

Transcatheter Aortic Valve Replacement in Bicuspid Aortic Valve: A Case Report

Among other valvular heart disease Aortic stenosis (AS) is the most common in the developed world. Transcatheter Aortic Valve Replacement (TAVR) is most acceptable treatment option for patient with severely calcified aortic stenosis with high and intermediate risk group. Among several challenges, one of the main challenges is to deal with bicuspid aortic valve (BAV). Non-circular annulus, bulky leaflets leading to perivalvular leaks and risk for rupture and often very severe calcification may contribute to periprocedural strokes leading to poor clinical outcome. This case, a 68-year-old woman with a history of type 2 diabetes mellitus (DM), hypothyroidism, bicuspid aortic valve and severe aortic stenosis, bronchial asthma, who had repeatedly refused any suggestion for open heart surgery, was our volunteer candidate for TAVR. After successful TAVR the peak pressure gradient decreased from 100mmHg to 17mmHg. So, TAVR could be a viable option for highly selected patients with severe aortic stenosis and bicuspid aortic valve who have favourable anatomy.

Rootstock effects on bitter pit incidence in 'Honeycrisp' apples are associated with changes in fruit's cell wall chemical properties

Bitter pit (BP) is a physiological disorder of apples that often appears during or after cold storage. Despite being defined as a calcium deficiency disorder, BP is a complex process that is not only affected by the total Ca²⁺ content in the fruit but also by the proper cellular Ca²⁺ homeostasis and partitioning. Early investigations have also suggested that rootstocks could affect BP development and severity. In the present study, rootstock effects on BP development were assessed on 'Honeycrisp' trees that were grafted on 14 different rootstocks (B.10, G.11, G.202, G.214, G.30, G.41, G.935, G.969, M.26 EMLA, M.9, V.1, V.5, V.6, and V.7). We evaluated BP incidence at harvest, and three months after cold storage for four, and three growing seasons, respectively. BP incidence was significantly reduced in 'Honeycrisp' trees on B.10 compared to other rootstocks, whereas trees on V.6 showed the highest percentage of BP at harvest and after cold storage. 'Honeycrisp' apples were collected from three different rootstocks (B.10, G.41, and V.6) two months after cold storage and evaluated for mineral nutrient composition, Ca²⁺ homeostasis, and cell wall properties, e.g., pectin content, pectin de-esterification rate and pectin methylesterase (PME) activity. Water-soluble and insoluble pectin content was markedly higher in fruits from B.10 than in G.41 and V.6. We also observed increased PME enzyme activity and a greater degree of water-insoluble pectin de-esterification in 'Honeycrisp' apples from V.6 compared to those from B.10. A significantly higher Ca²⁺ was found in the fruits from B.10 than G.41 and V.6. Higher Ca²⁺ and lower Mg²⁺ levels were also observed in the cell wall and water-insoluble pectin fractions of the fruits from B.10 compared to G.41 and V.6. However, the ratio of cell wall-bound Ca²⁺ to total Ca²⁺ was lower in B.10 compared to G.41 and V.6. Together, our results indicate that the tolerance of B.10 to BP could be attributed to a reduced PME activity and lower pectin de-esterification level, which in turn reduced the amount of Ca²⁺ cross-linked with pectin, and probably increased the apoplastic free calcium concentrations that is essential for maintaining cell membrane integrity and reducing BP development.

Diversity in blueberry genotypes and developmental stages enables discrepancy in the bioactive compounds, metabolites, and cytotoxicity

Eight blueberry cultivars at three developmental stages were investigated for metabolite profiling, antioxidant, and anticancer activities. Cultivars- and developmental stages-variations were determined in total phenolic, flavonoid, DPPH, and FRAP antioxidant assays. The anticancer capacity was equal against A549, HepG2, and Caco-2 cancer cells, whereas the inhibition rate was dose-, incubation period-, cultivar-, and developmental stages-dependent. The untargeted metabolite profiling by UPLC-TOF-MS analysis of two contrast cultivars, 'Vernon' and 'Star', throughout the developmental stages revealed 328 metabolites; the majority of them were amino acids, organic acids, and flavonoids. The multivariate statistical analysis identified five metabolites, including quinic acid, methyl succinic acid, chlorogenic acid, oxoadipic acid, and malic acid, with positively higher correlations with all anticancer activities. This comprehensive database of blueberry metabolites along with anticancer activities could be targeted as natural anticancer potentials. This study would be of great value for food, nutraceutical, and pharmaceutical industries as well as plant biotechnologists.

Removal of astringency in persimmon fruits (Diospyros kaki) subjected to different freezing temperature treatments

The effects of two different freezing temperatures (- 20 °C and - 80 °C) on the astringency trait of persimmon fruits during 15 to 60 days of storage were investigated. The levels of soluble and insoluble tannins, proanthocyanidins and other physicochemical characteristics were evaluated. Storage at - 20 °C and - 80 °C temperatures up to 60 days has been found to be an effective method to remove astringency of persimmon fruits. Proanthocyanidin concentration was negligible at both temperatures during storage. Total soluble solid contents were decreased as 3.34 from 4.59 (mg/g DW) whereas, insoluble tannin contents were increased as 20.30 from 16.45 (mg/g DW) by freezing temperatures treatment during storage. Comparatively, higher soluble tannin content 11.68 (mg/g DW) and lower insoluble tannin content 10.02 (mg/g DW) was observed in control (day 0). Therefore, the astringency of persimmon fruits incubated at - 20 °C and - 80 °C was markedly reduced and after 15 up to 60 days of storage, the astringent taste virtually disappeared. The proanthocyanidin contents were decreased as 0.02 from 0.52 (mg/g DW) at - 20 °C storage and 0.17 from 0.47 (mg/g DW) at - 80 °C storage, in comparison with the control 2.65 (mg/g DW). The moreover, along with the removal of astringency, other physicochemical parameters including color, pH, moisture content, total soluble solid, and sensory attributes were also conserved on freezing at both the temperatures. These findings suggest that freezing temperature treatments aid the removal of astringency from persimmon fruits which could be used in different food preparations or as supplements.

Untargeted Metabolomics and Antioxidant Capacities of Muscadine Grape Genotypes during Berry Development

Three muscadine grape genotypes (Muscadinia rotundifolia (Michx.) Small) were evaluated for their metabolite profiling and antioxidant activities at different berry developmental stages. A total of 329 metabolites were identified using UPLC-TOF-MS analysis (Ultimate 3000LC combined with Q Exactive MS and screened with ESI-MS) in muscadine genotypes throughout different developmental stages. Untargeted metabolomics study revealed the dominant chemical groups as amino acids, organic acids, sugars, and phenolics. Principal component analysis indicated that developmental stages rather than genotypes could explain the variations among the metabolic profiles of muscadine berries. For instance, catechin, epicatechin-3-gallate, and gallic acid were more accumulated in ripening seeds (RIP-S). However, tartaric acid and malonic acid were more abundant during the fruit-set (FS) stage, and malic acid was more abundant in the veraison (V) stage. The variable importance in the projection (VIP > 0.5) in partial least-squares–discriminant analysis described 27 biomarker compounds, representing the muscadine berry metabolome profiles. A heatmap of Pearson’s correlation analysis between the 27 biomarker compounds and antioxidant activities was able to identify nine antioxidant determinants; among them, gallic acid, 4-acetamidobutanoic acid, trehalose, catechine, and epicatechin-3-gallate displayed the highest correlations with different types of antioxidant activities. For instance, DPPH and FRAP conferred a similar antioxidant activity pattern and were highly correlated with gallic acid and 4-acetamidobutanoic acid. This comprehensive study of the metabolomics and antioxidant activities of muscadine berries at different developmental stages is of great reference value for the plant, food, pharmaceutical, and nutraceutical sectors.

Effects of superfine grinding using ball-milling on the physical properties, chemical composition, and antioxidant properties of Quercus salicina (Blume) leaf powders

BACKGROUND

Quercus salicina (Blume) leaves are traditionally used as folk medicine in some Asian countries. The aim of this study was to evaluate the effects of ball milling for different periods (0, 6, 12, 18, and 24 h) on the physicochemical properties of superfine Quercus salicina (Blume) leaf (QSL) powders.

RESULTS

The particle sizes, water-holding capacity, angle of repose, and redness of the superfine QSL powder decreased with increasing ball-milling times, whereas the water solubility index, bulk density, tapped density, brightness, and yellowness were found to increase. Significantly higher (P > 0.05) total phenolic and flavonoid contents, and antioxidant activities, were observed for the superfine QSL powders obtained after 24 h ball-milling time. A total of 12 phenolic compounds in free and cell-wall-bound forms were quantified in the superfine QSL powder. Free phenolics such as protocatechuic acid, caffeic acid, rutin, and p-coumaric acid were increased and all cell-wall-bound phenolics were decreased with increasing ball-milling times. The antioxidant activity of the free phenolics increased with increasing ball-milling times, and the cell-wall-bound forms decreased.

CONCLUSION

Superfine grinding by ball milling for 24 h can thus be used to produce superfine QSL powder with higher free phenolic metabolite content and antioxidant activity, and improved water solubility index, color, bulk, and tapped densities. This study will be useful for the food / nutraceutical / pharmaceutical industries in the manufacturing of active food ingredients or value-added products using QSL powders. © 2020 Society of Chemical Industry.

Aqueous green tea infusion extracted by ultra-sonication method, but not by conventional method, facilitates GLUT4 membrane translocation in adipocytes which potently ameliorates high-fat diet-induced obesity

Green tea contains bioactive compounds, such as polyphenols, responsible for its health-promoting effects, including antiobesity and antidiabetic effects. We previously reported that ultra-sonication extraction (UE) could efficiently increase the extraction yield of green tea compounds. In the present study, we found that the extract obtained using UE contained higher phenolic and flavonoid contents than that obtained using the conventional method. We therefore considered the extract as a bioactive metabolite-rich functional green tea extract (BMF-GTE), and tested its glucose-lowering effect by generating an adipocyte cell line stably expressing 7myc-GLUT4-GFP. We found that BMF-GTE treatment increased GLUT4 translocation to the plasma membrane. Moreover, BMF-GTE administration attenuated weight gain in mice fed a high-fat diet (HFD). Importantly, HFD-induced glucose tolerance was ameliorated in the mice receiving BMF-GTE. Therefore, we conclude that BMF-GTE worked against obesity and diabetes, at least partially, by enhancing GLUT4 translocation in adipocytes. PRACTICAL APPLICATIONS: As green tea is one of the most consumed beverages worldwide, its health effects have been widely tested. In our previous studies, we found that ultra-sonication extraction (UE) has the potential to increase the aqueous extraction yield of green tea compounds compared to conventional extraction techniques. In this study, we examined the biological effect of bioactive metabolite-rich functional green tea extract (BMF-GTE) obtained using UE; we observed that administering BMF-GTE lowered the body weight and increased insulin sensitivity in mice fed a high-fat diet, potentially by facilitating the membrane translocation of GLUT4 in adipocytes. Therefore, this study suggests that the extract obtained with UE had antiobesity and antidiabetic properties, indicative of a potential application of UE in maximizing the beneficial effects of green tea on human health.

Application of Exogenous dsRNAs-induced RNAi in Agriculture: Challenges and Triumphs

In recent years, RNA interference (RNAi) machinery has widely been explored by plant biologists for its potential applications in disease management, plant development, and germplasm improvement. RNAi-based technologies have mainly been applied in the form of transgenic plant generation and host-induced-gene-silencing (HIGS). However, the approval of RNAi-based transgenic plants has always been challenging due to the proclaimed concerns surrounding their impacts on human health and the environment. Lately, exogenous applications of double-stranded RNAs (dsRNAs), short interfering RNAs (siRNAs), and hairpin RNAs (hpRNAs) has emerged as another technology that could be regarded as more eco-friendly, sustainable, and publicly acceptable than genetic transformation. Inside the plant cell, dsRNAs can undergo several steps of processing, which not only triggers RNAi machinery but may also involve transitive and systemic silencing, as well as epigenetic modifications. Therefore, along with the considerations of proper exogenous applications of dsRNAs, defining their final destination into plant cells is highly relevant. In this review, we highlighted the significance of several factors that affect dsRNA-induced gene silencing, the fate of exogenous dsRNAs in the plant cell, and the challenges surrounding production technologies, cost-effectiveness, and dsRNAs stability under open-field conditions. This review also provided insights into the potential applications of exogenous dsRNAs in plant protection and crop improvement.

A review of encapsulation of carotenoids using spray drying and freeze drying

Carotenoids are potent antioxidants, but they are highly unstable and susceptible during processing and storage. Encapsulation technologies protect against degradation and are capable of releasing individual or combination of bioactive substances during processing as well as development of various functional food products. Moreover, encapsulating agents can be used to increase the stability of carotenoids and form a barrier between the core and wall materials. Suitable encapsulating agents, temperature, and drying methods are the most important factors for the encapsulation process. In this report, we reviewed the current status of encapsulation of carotenoids from different fruits, vegetables, spices, seaweeds, microorganisms, and synthetic sources using various types of encapsulating agents through spray drying and freeze drying. We also focused on the degradation kinetics and various factors that affect the stability and bioavailability of encapsulated carotenoids during their processing and storage.

Characterization of p-Coumaric acid-induced soluble and cell wall-bound phenolic metabolites in relation to disease resistance to Xanthomonas campestris pv. campestris in Chinese cabbage

To characterize the p-coumaric acid (pCA)-induced phenolic metabolites in relation to the disease resistance against Xanthomonas campestris pv. campestris (Xcc.), the responses of soluble- and cell wall-bound flavonoid and hydroxycinnamic acids compounds to the pretreatment of pCA or the inhibitor of the 4-coumarate-CoA ligase, 3,4-(methylenedioxy) cinnamic acid (MDCA), following Xcc inoculation were assessed, and the resulting data were interpreted with regard to susceptibility to Xcc in Chinese cabbage (Brassica rapa var. pekinensis). At 12 days post-inoculation (DPI) with Xcc, disease symptom development could be distinguished by necrotic lesions, and characterized by an enhanced lipid peroxidation. Overall, pCA acts as a positive stimulus for an accumulation of hydroxycinnamic acids and flavonoids, while MDCA acts as a negative regulator. Pretreatment with pCA resulted in an accumulation of specific hydroxycinnamic acids, pCA, ferulic acid (FA), and sinapic acid (SiA) in both soluble and cell wall-bound forms in Xcc-inoculated leaves, while MDCA pretreatment decreased accumulation in a dose-dependent manner. Two flavonoid compounds, epigallocatechin (EGC) and epigallocatechin gallate (EGCG), showed a similar response to pCA and MDCA pretreatments. These results indicate that a lower disease symptom development in pCA-pretreated leaves was associated with a higher accumulation of hydroxycinnamic acids and flavonoids, and vice-versa in MDCA- and non-pretreated (control) leaves.

Ethnomedicinal plants used by the Nag clan of the Rai Ghatual tribe of Moulvibazar district, Bangladesh

Context:

Medicinal practices of the tribes of Bangladesh remain largely un-documented.

Aims:

The aim of the present study was to conduct an ethnomedicinal survey and documentation among the Nag clan of the Rai Ghatual tribe of Bangladesh.

Settings and Design:

The survey was carried out among the Nag clan of the Rai Ghatual tribal community of Moulvibazar district. The clan, according to them, is the only Nag clan of the Rai Ghatual tribe in Bangladesh. The clan has three tribal healers, still continuing their traditional medicinal practices.

Materials and Methods:

Interviews of the healers were carried out with the help of a semi-structured questionnaire and the guided field-walk method.

Results:

The Nag clan healers were observed to use 28 different plant species distributed into 22 families for treatment of ailments such as fever, loss of appetite, male infertility, dysentery, lower abdominal pain during menstruation, jaundice, stomachache, burning sensations during urination, bodily pain and weak health.

Conclusions:

This is the first reported study of the traditional medicinal practices of Nag clan healers. Several of the plants can be validated in their uses on the basis of existing scientific literature. The medicinal plants used by the Nag healers warrant further scientific studies, for the plants are readily available and can form alternative medicinal sources instead of costlier biomedical drugs.

Ethnomedicinal plants of the Bauri tribal community of Moulvibazar District, Bangladesh

Context:

Bangladesh reportedly has more than 100 tribal communities; however, documentation of their medicinal practices is markedly absent.

Aim:

The aim of the present study was to conduct an ethnomedicinal survey among the little known Bauri tribe of Bangladesh, whose tribal medicinal practices are yet to be documented.

Settings and Design:

The survey was carried out among the Bauri tribal community of Purbo Tila village in Moulvibazar District. The community is believed to be the only Bauri community in the country and had four tribal healers who continue their traditional medicinal practices.

Materials and Methods:

Interviews of the healers were carried out with the help of a semi-structured questionnaire and the guided field-walk method where the healers took the interviewers on guided field-walks through areas from where they collected their medicinal plants. Here they identified the plants and described their uses.

Results:

The Bauri healers were observed to use 40 different plant species and one bird species for treatment of ailments such as fever, respiratory tract disorders, pain, gastrointestinal disorders, eye problems like cataract and conjunctivitis, jaundice, abscess, cardiovascular disorders, urinary problems, paralysis, dog bite, snake bite, helminthiasis, lesions on the tongue or lips and piles. Leaves were the major plant part used and constituted 38.3% of total uses followed by fruits at 14.9%.

Conclusions:

A review of the relevant scientific literature showed that a number of medicinal plants used by the Bauri healers possess pharmacological activities, which were in line with the traditional uses, thus validating their use by the Bauri tribe.

Medicinal plants used by the Mandais--a little known tribe of Bangladesh

The Mandais are a little known tribe of Bangladesh inhabiting the north central regions, particularly Tangail district of Bangladesh. Their population has been estimated to be less than 10,000 people. Although the tribe has for the most part assimilated with the mainstream Bengali-speaking population, they to some extent still retain their original tribal customs, including their traditional medicinal practices. Since this practice is also on the verge of disappearance, the objective of the present study was to conduct an ethnomedicinal survey among Mandai tribal practitioners to document their use of medicinal plants for treatment of various ailments. Four traditional practitioners were found in the exclusive Mandai-inhabited village of Chokchokia in Tangail district. Information was collected from the practitioners with the help of a semi-structured questionnaire and guided field-walk method. It was observed that the four traditional practitioners used a total of 31 plants distributed into 23 families for treatment. The various ailments treated included diabetes, low semen density, jaundice, gastrointestinal tract disorders (stomach ache, indigestion, dysentery, and diarrhea), leucorrhea, pain (rheumatic pain, joint pain), skin disorders, respiratory tract disorders (coughs, mucus, and allergy), debility, fever, and helminthiasis. From the number of plants used (seven), it appeared that gastrointestinal tract disorders formed the most common ailment among the Mandai community, possibly brought about by the low income status of the people coupled with unhygienic conditions of living.

A family of depsi-peptide fungal metabolites, as selective and competitive human tachykinin receptor (NK2) antagonists: fermentation, isolation, physico-chemical properties, and biological activity

Four tachykinin (NK2) receptor inhibitors, SCH 378161 (1), SCH 217048 (2), SCH 378199 (3), and SCH 378167 (4) were isolated from the fermentation broth of a taxonomically unidentified fungus. These compounds were separated from the fermentation broth by ethyl acetate extraction. Purification and separation of the individual compounds were achieved by NK2 assay-guided fractionation using gel filtration, reverse phase chromatography and HPLC. They were identified to be a family of depsipeptides by spectroscopic and degradation studies. Compounds 1 and 3 contain proline and differ as an amide and acid whereas 2 and 4 contain pipecolic acid and differ in being an amide and acid. All of these compounds contain an identical hydroxy acid. They are selective NK2 inhibitors with Ki values ranging from 27-982 nM and demonstrate no activity at 10 microM in the NK1 and NK3 assays. In addition, compounds 1 and 2 inhibited NKA-induced increases in the concentration of intracellular Ca2+, [Ca2+]i, in a CHO cell expressing the human NK2 receptor; this inhibition was competitive in nature with pA2 values of 7.2 and 7.5, respectively. These data demonstrate that these natural products are selective and competitive receptor antagonists of the human NK2 receptor.

Novel fungal metabolites as cell wall active antifungals: fermentation, isolation, physico-chemical properties, structure and biological activity

Two novel antifungal compounds, 1 (SCH 466457), and 2 (SCH 466456), active in a "cell wall" assay, were isolated from the fermentation broth of an unidentified fungus. The active compounds were separated from the broth filtrate by adsorption on a macroreticular resin and were purified on reverse phase HPLC. Detailed mass spectrometric and NMR experiments and degradative studies helped in elucidating the structures of these compounds. The compounds were identified to be peptides containing amino acids such as alanine, aminoisobutyric acid, proline, leucine, valine, glycine and a previously identified beta-keto acid, 2-methyl 3-oxotetradecanoic acid. (5) Both compounds were active against Candida, dermatophytes and Aspergillus (Geometric Mean MIC's, 8.9, 20 and 16 microg/ml, and 64, 128 and 23 microg/ml, respectively for 1 and 2).

Chemical modifications and structure activity studies of ziracin and related everninomicin antibiotics

Chemical modifications of eveminomicin antibiotics, particularly ziracin (1), were carried out to study the SARs as well as the chemical properties of this class of compounds. Use of allyl ether group for protection and selective deprotection of phenolic groups provided access to a variety of novel analogs of the title compounds, some of which exhibited the same high in vitro potency as the parent compounds.

A depsipeptide fungal metabolite inhibitor of cholesteryl ester transfer protein

The organic extract of the fermentation broth of a fungus was found to contain a depsipeptide SCH 58149 (1), containing three amino acids and a beta-hydroxy acid, by spectroscopic studies. The amino acids were phenyl alanine, alanine and leucine and the beta-hydroxy acid is 3-hydroxy-4-methyl octanoic acid. SCH 58149 exhibited weak activity against cholesterol ester transfer protein (CETP) with an IC50 of 50 microM.

Fast atom bombardment mass spectrometric characterization of peptides

Structural characterization of peptides in the range of 500-5000 Da, using fast atom bombardment (FAB) and Cs+ ion liquid secondary ion mass spectrometry (SIMS), is reviewed. These include synthetic peptides Kemptamide (mol wt 1516); GIF-C15 (mol wt 1875), an isolated natural product as an acylated pentapeptide; and polypeptides generated from enzymatic digests of proteins. MS data is shown to reveal molecular weight and sequence information as well as determine disulfide bonds between cysteine residues and glycosylation sites in the case of a glycopeptide. The complementarity of MS technique to classical biochemical methods for peptide characterization is highlighted. The reader is briefly acquainted with two newer ionization techniques namely, electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI). Synthetic chemists and biochemists can refer to the in-depth review articles that are cited throughout this article.

Neurokinin receptor inhibitors: fermentation, isolation, physico-chemical properties, structure and biological activity

Seven neurokinin (NK) receptor inhibitors SCH 60059 (1), SCH 60065 (2), SCH 64879 (3), SCH 60061 (4), SCH 60063 (5), SCH 60057 (7), and SCH 64878 (9) and two uncharacterized components 6 and 8, were isolated from the fermentation broth of a fungus taxonomically classified as an Acremonium sp. These compounds were isolated from the fermentation broth by ethyl acetate extraction. Purification and separation of the individual compounds were achieved by NK1 and NK2 assay-guided fractionation using gel filtration, reverse phase chromatography and HPLC. The NK active compounds were identified to be a family of polyhydroxy isoprenoid derivatives, including glycosylated members, by spectroscopic and degradation studies. Compounds 1 approximately 5 and 7 contain nine isoprene units connected in head to tail fashion and compound 9 contains fifteen isoprene units connected in a similar manner. All these compounds showed dual inhibition in NK1 and NK2 assays with IC50 values ranging from 2.5 approximately 11 microM in the NK1 assay and 6.8 approximately 16 microM in the NK2 assay.

A family of novel macrocyclic lactones, the saccharocarcins produced by Saccharothrix aerocolonigenes subsp. antibiotica. II. Physico-chemical properties and structure determination

Six novel tetronic acid analogs were isolated from the fermentation broth of the actinomycete Saccharothrix aerocolongenes subsp. antibiotica SCC1886. The structures of these saccharocarcins were determined by their spectral data, and chemical degradation. All six compounds are derived from two modified tetronic acid homologs which differ from other tetronic acids by having an ethyl or propyl side chain at C-23 and a methyl group at C-16. They are all characterized by a novel sugar-amide at C-17.

Inhibition of c-fos proto-oncogene induction by Sch 52900 and Sch 52901, novel diketopiperazine produced by Gliocladium sp

Sch 52900 (1) and Sch 52901 (2), two new inhibitors of c-fos proto-oncogene induction, have been isolated from the fermentation of broth of the fungal culture (SCF-1168), Gliocladium sp. Along with compounds 1 and 2, a known compound verticillin A (3) was also obtained from the culture. Structure elucidation of 1 and 2, accomplished by analysis of spectral data in comparison with the data of 3, revealed both 1 and 2 were found to be closely related to the verticillin family of diketopiperazines. All three compounds prevented serum-stimulated transcription of the human c-fos promoter, using a fos/lac Z reporter gene assay, with IC50 values of 1.5, 18 and 0.5 microM of 1, 2 and 3, respectively. Northern analysis revealed the exposure of cells to compound 3 causes inhibition of both phorbol ester-induced c-fos induction of serum-induced JE induction in the absence of inhibiting RNA synthesis, as measured by [3H]uridine incorporation. There results suggest that this class of compounds exerts antitumor activity by blocking a signal transduction pathway that is common to and necessary for the induction of at least a subset of immediate early genes involved in cell proliferation.

Phospholipase D inhibitors from a Myrsine species

The phospholipase D-inhibitory activity of a methanol extract from the leaves of a New Zealand plant, Myrsine australis, has been attributed to two new saponins 1 and 2. Compound 1 was assigned as 3-0-[-beta-D-xylopyranosyl-(1-->2)-0-beta-D-glucopyranosyl-(1-->4)- -[0-beta-D -glucopyranosyl-(1-->2)]-alpha-L-arabinosyl]-16alpha-hydroxy-+ ++13beta,28-epoxyoleanane and 2 as 3beta-0-[-beta-rhamnopyranosyl-(1-->2)-0-beta-D-glucopyranosyl-(1-->4)-[ 0-beta-D-glucopranosyl]-alpha-L-arabinopyranosyl]-16alpha -hydroxy-13beta, 28-epoxyleanane. Compounds 1 and 2 showed IC50 values of 3 and 2 microM, respectively, versus phorbol 12-myrisate-13-acetate-stimulated phosphlipase D in human promyelocytic leukemic (HL-60) cells. Compounds 1 and 2 also inhibited fMLP (formyl-Met-Leu-Phe) stimulated phospholipase D with IC50 values of 8 and 24 microM, respectively.

Isolation and structure of two novel muscarinic receptor antagonists

The structures of two novel muscarinic receptor antagonists, 1 and 2, were determined by their spectral data and high-resolution mass measurements of their degradation products. Both are aliphatic long-chain compounds and contain amide and keto functionalities. The major microbial metabolite [1] contains three terminal guanidino groups and the minor compound [2] has two terminal guanidino groups.

Decomposition of alpha-hydroxyaryl ketones and characterization of some unusual products

Alpha-Hydroxyaryl ketones such as 2-hydroxypropiophenone and 1-(2,4-difluorophenyl)-2-hydroxy-1-propanone, the key intermediates in the preparation of antifungal agents, decompose into oxidized, rearranged, and condensed products. These products were isolated and characterized. The possible mechanisms for the formation of the products are discussed.

Rabbit and human liver contain a novel pentacyclic triterpene ester with acyl-CoA: cholesterol acyltransferase inhibitory activity

Acyl-coenzyme A (CoA):cholesterol acyltransferase (ACAT) catalyzes the intracellular fatty acid esterification of cholesterol and is thought to play a key role in lipoprotein metabolism and atherogenesis. Herein we describe the purification and characterization of a novel pentacyclic triterpene ester from rabbit liver that has ACAT inhibitory activity. The inhibitor was purified by a combination of silicic acid chromatography and preparative thin layer chromatography. The compound inhibited both rabbit and rat liver microsomal ACAT activity with an IC50 = 20 microM. The lipid did not inhibit fatty acid incorporation into triglycerides, diglycerides, monoglycerides, or phospholipids nor did it inhibit plasma lecithin:cholesterol acyltransferase activity. However, rat liver microsomal acyl-CoA:retinol acyltransferase activity was inhibited by the terpene ester. Kinetic data are consistent with a mechanism in which ACAT is inhibited by the compound in an irreversible manner. The subcellular fractionation pattern of both ACAT activity and the ACAT inhibitor were similar in rabbit liver (both were approximately equally distributed in membranes that pelleted at 10,000 X g and 100,000 X g). A lipid with similar properties to the rabbit liver inhibitor was found in many other rabbit tissues, including adrenal and spleen, as well as in human liver. Rat liver did not contain this lipid. Structural analysis by NMR, mass spectrometry, and x-ray crystallography indicated that the rabbit liver inhibitor was a fatty acid ester (mostly stearate) of a pentacyclic triterpene acid. The carbon skeleton of the triterpene moiety is a new member of the olean-12-ene triterpene family. Both the negatively charged carboxylic acid group of the triterpene moiety and the esterified fatty acid group were necessary for the ACAT-inhibitory activity of the triterpene ester. Lastly, we present preliminary data which, together with the structural homology of the rabbit triterpene with known plant compounds, suggest the hypothesis that the triterpene moiety of the rabbit ACAT inhibitor arises from dietary absorption of a plant triterpene.

Bacterial phospholipid analysis by fast atom bombardment mass spectrometry

The structural analysis of naturally occurring bacterial phospholipids in mixtures by fast atom bombardment (FAB) mass spectrometry are reported. The bacterial strains examined included several genera of actinomycetes, two strains of Escherichia coli, and one strain each of Proteus mirabilis and Pseudomonas aeruginosa. FAB mass spectrometry proved to be a useful tool for the structural identification of phospholipids in mixtures and provided stable pseudo-molecular ions and characteristic fragment ions which permitted the identification of phosphatidylethanolamine and phosphatidyl choline. Information regarding the chain length of the fatty acids, their degree of unsaturation in the chains and the presence of hydroxyl groups was also obtained. The results obtained by FAB mass spectrometry were supported by high-resolution mass spectral data, tandem mass spectrometric studies and FAB mass spectrometry of components which had been separated and partially purified by thin-layer chromatography. Each organism displayed a highly characteristic phospholipid profile suggesting the possible use of FAB mass spectrometry as a method for rapid bacterial detection and identification.