• Journal of Marine Bioscience and Biotechnology
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• v.1 no.3
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• pp.144-155
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• 2006

This report reviews the literatures on chemical constituents of marine sponges of the genus Spongosorites and also highlights our own research. Specific biological activities of the metabolites from these sponges include: cytotoxic, antitumor, antibacterial, antifungal, antiviral, anti-inflammatory, and other pharmacological activities.

• Natural Product Sciences
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• v.21 no.4
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• pp.278-281
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• 2015

Chemical investigation on a colonial marine tunicate, Didemnum sp. led to the isolation of a series of indole alkaloids including a new (1) and two known metabolites (2-3). Based on the spectroscopic analysis including 1D and 2D NMR along with MS spectra, the structure of 1 (16-epi-18-acetyl herdmanine D) was elucidated as a new amino acid derivative. The absolute configuration of 1 was determined by comparison of specific rotation with the known compound. The structures of compounds 2 and 3 were also identified as bromoindole containing compounds N-(6-bromo-1H-indole-3-carbonyl)-L-arginine and (6-bromo-^1H-indol-3-yl) oxoacetamide, respectively, based on $^1H$ and $^{13}C$ NMR data, MS data and specific rotation value. Their pharmacological potentials as antibacterial agents and FXR antagonists were investigated, but no significant activity was found. However, the structural similarity of compound 1 to compound 4 suggested the anti-inflammatory potential of compound 1.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.186-195
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• 2015

Anthranilate synthase (AS) is a key enzyme in the biosynthesis of tryptophan (Trp), which is the precursor of bioactive metabolites like indole-3-acetic acid and other indole alkaloids. Alpha anthranilate synthase 2 (OsASA2) plays a critical role in the feedback inhibition of tryptophan biosynthesis. In this study, two vectors with single (F124V) and double (S126F/L530D) point mutations of the OsASA2 gene for feedback-insensitive ${\alpha}$ subunit of rice anthranilate synthase were constructed and transformed into wildtype Dongjinbyeo by Agrobacterium-mediated transformation. Transgenic single and double mutant lines were selected as a single copy using TaqMan PCR utilized nos gene probe. To select intergenic lines, the flanking sequence of RB or LB was digested with a BfaI enzyme. Four intergenic lines were selected using a flanking sequence tagged (FST) analysis. Expression in rice (Oryza sativa L.) of the transgenes resulted in the accumulation of tryptophan (Trp), indole-3-acetonitrile (IAN), and indole-3-acetic acid (IAA) in leaves and tryptophan content as a free amino acid in seeds also increased up to 30 times relative to the wildtype. Two homozygous event lines, S-TG1 and D-TG1, were selected for characterization of agronomic traits and metabolite profiling of seeds. Differentially expressed genes (DEGs), related to ion transfer and nutrient supply, were upregulated and DEGs related to co-enzymes that work as functional genes were down regulated. These results suggest that two homozygous event lines may prove effective for the breeding of crops with an increased level of free tryptophan content.

• Natural Product Sciences
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• v.26 no.3
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• pp.214-220
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• 2020

Brassica oleracea var. gongylodes (red kohlrabi) is a biennial herbaceous vegetable whose edible bulbotuber-like stem and leaves are consumed globally. Sliced red kohlrabi tubers were extracted using methanol and the concentrated extract was partitioned successively with dichloromethane (CH₂Cl₂), ethyl acetate (EtOAc), n-butanol (n-BuOH) and water (H₂O). Repeated column chromatography of EtOAc fraction through silica, sephadex LH-20 and RP-18 gel led to isolation of eleven compounds of which compound 1 was a new glycosylated indole alkaloid derivative, 1-methoxyindole 3-carboxylic acid 6-O-β-D-glucopyranoside. Others were known compounds namely, β-sitosterol glucoside (4), 5-hydroxymethyl-2-furaldehyde (5), methyl-1-thio-β-D-glucopyranosyl disulfide (6), 5-hydroxy-2-pyridinemethanol (7), (3S,4R)-2-deoxyribonolactone (8), n-butyl-β-D-fructopyranoside (9), uridine (10) and three fructose derivatives, D-tagatose (11), β-D-fructofuranose (12) and β-D-fructopyranose (13). Similarly, isolation from CH₂Cl₂ fraction gave two known indole alkaloids, indole 3-acetonitrile (2) and N-methoxyindole 3-acetonitrile (3). The structure elucidation and identification of these compounds were conducted with the help of ¹³C and ¹H NMR, HMBC, HMQC, EIMS, HR-ESIMS and IR spectroscopic data, and TLC plate spots visualization. Compounds 2, 3, 4, 5, 6, 7, 8 and 9 are noted to occur in kohlrabi for the first time. Different bioactivities of these isolated compounds have been reported in literature.

• Natural Product Sciences
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• v.11 no.3
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• pp.145-149
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• 2005

A methanol soluble extract from the dried hooks and stems of Uncaria rhynchophylla showed a strong inhibitory activity against monoamine oxidase in mouse brain. Using a bioassay-guided purification of this extract, a known ${\beta}-carboline$ type alkaloid, harman (1), was obtained as an active constituent. In addition, five known indole alkaloids, isocorynoxeine (2), isorhynchophylline (3), corynoxeine (4), cadambine (5), and $3{\alpha}-dihydrocadambine$ (6), were isolated and found to be weakly active or inactive.

• Natural Product Sciences
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• v.2 no.2
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• pp.90-95
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• 1996

When reserpine-producing cell strains of Rauwolfia serpentina were transferred from the dark to the light irradiation, the production of reserpine was extremely enhanced whereas the cell growth was suppressed. In an incubation period of 20 days, the most effective culture condition for reserpine production was the combination of 8 days of dark culture and following 12 days of light culture. The time courses of both cell growth and reserpine production were measured in vitro in order to clarify the effect of wave length range of light on the biosynthesis of reserpine. Although the growth of cultured cells which had been incubated under continuous red, yellow, and green lights, respectively, was similar to that of the cultured cells subcultured in the dark. The cells cultured under red light irradiation produced less reserpine than dark-grown cultures. Both blue and near-ultraviolet light inhibited the growth of cultured cells. The production of reserpine was strikingly enhanced by blue light, but was strongly inhibited by near-ultraviolet light.

• KSBB Journal
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• v.8 no.2
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• pp.110-114
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• 1993

Vinblastine, an anticancer agent was produced by chemical coupling of two different monomeric indole alkaloids, vinblastine and catharanthine in the presence of ferric ion. Vindoline was efficiently extracted from the leaves of vinca (Cafharanthus roseus) by using supercritical carbon dioxide, whereas catharanthine was chemically extracted from the in vitro cultured hairy roots. The extracted crude monomeric precursors were purified by a two-step preparative TLC. The coupling reaction was carried out in the 0.1M glycine buffer(pH 2.0, 5ml) containing 40mM FeC13 with purified vindoline(0.3mg) and catharanthine(0.3mg) at 4$^{\circ}C$. The production yields (weight %) of vinblastine and 3', 4'-anhy-drovinblastine in the products were 23.2 and 26.0, respectively. The produced vinblastine was confirmed by FAB-MS.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2950-2954
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• 2014

A series of bis and tris-indolylketones and meridianin alkaloids are prepared by one pot Michael reaction of indole and ketene S,S-acetals under solvent-free condition using mild Lewis acid $InCl_3$.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.1-15
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• 2005

Pathogens, insects and weeds have significantly reduced agricultural productivity. Thus, to increase the productivity, synthetic agricultural chemicals have been overused. However, these synthetic compounds that are different from natural products cannot be broken down easily in natural systems, causing the destruction of soil quality and agricultural environments and the gradually difficulty in continuous agriculture. Now agriculture is faced with the various problems of minimizing the damage in agricultural environments, securing the safety of human health, while simultaneously increasing agricultural productivity. Meanwhile, plants produce secondary metabolites to protect themselves from external invaders and to secure their region for survival. Plants infected with pathogens produce antibiotics phytoalexin; monocotyledonous plants produce flavonoids and diterpenoids phytoalexins, and dicotylodoneous plant, despite of infected pathogens, produce family-specific phytoalexin such as flavonoids in Leguminosae, indole derivatives in Cruciferae, sesquitepenoids in Solanaceae, coumarins in Umbelliferae, making the plant resistant to specific pathogen. Growth inhibitor or antifeedant substances to insects are terpenoids pyrethrin, azadirachtin, limonin, cedrelanoid, toosendanin and fraxinellone/dictamnine, and terpenoid-alkaloid mixed compounds sesquiterpene pyridine and norditerpenoids, and azepine-, amide-, loline-, stemofoline-, pyrrolizidine-alkaloids and so on. Also plants produces the substances to inhibit other plant growths to secure the regions for plant itself, which is including terpenoids essential oil and sesquiterpene lactone, and additionally, benzoxazinoids, glucosinolate, quassinoid, cyanogenic glycoside, saponin, sorgolennone, juglone and lots of other different of secondary metabolites. Hence, phytoalexin, an antibiotic compound produced by plants infected with pathogens, can be employed for pathogen control. Terpenoids and alkaloids inhibiting insect growth can be utilized for insect control. Allelochemicals, a compound released from a certain plant to hinder the growth of other plants for their survival, can be also used directly as a herbicides for weed control as well. Therefore, the use of the natural secondary metabolites for pest control might be one of the alternatives for environmentally friendly agriculture. However, the natural substances are destroyed easily causing low the pest-control efficacy, and also there is the limitation to producing the substances using plant cell. In the future, effects should be made to try to find the secondary metabolites with good pest-control effect and no harmful to human health. Also the biosynthetic pathways of secondary metabolites have to be elucidated continuously, and the metabolic engineering should be applied to improve transgenics having the resistance to specific pest.

• Korean Journal of Microbiology
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• v.52 no.4
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• pp.415-420
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• 2016

Chemical study of an Arctic bacterium, Pseudomonas aeruginosa (Pseudomonadaceae) led to the isolation of two diketopiperazines 1 and 2, two phenazine alkaloids 3 and 4, and an indole carbaldehyde 5, along with a benzoic acid derivative 6. The structures of the compounds were confirmed by 1D and 2D NMR, and MS experiments, as well as by comparison of their data with published values. Among the isolates, compounds 5 and 6 were isolated for the first time from P. aeruginosa of the seawater of Arctic Chuckchi Sea. Antimicrobial activities of compounds 1‒6 against a Staphylococcus aureus and Candida albicans were evaluated.