摘要:

Bioactivity-guided fractionation ofMonarda fistulosaL. (F005), using the brine shrimp lethality test (BST) and crown gall tumor potato disc assay (PD), led to the isolation of the bioactive monoterpenes, thymoquinone (1), and thymol (2).1, surprisingly, exhibited selective cytotoxicities against certain cell lines. Of over 60 human tumor cell lines evaluated,1was very selective for SF-539 (CNS) with an LC50< 2.51 × 10−2μg/ml. Other cell lines targeted by1were PC-3 (prostate), M-14 (melanoma), OVCAR-5 (ovarian), and MCF-7 (breast). The reduction of1to thymohydroquinone (3) resulted in a 1.7 fold decrease in the cytotoxic potency for PC-3. Thymol (2), although not significantly cytotoxic, demonstrated strong pesticidal activity, more potent than rotenone, in the yellow fever mosquito larvae assay (YFM). None of the compounds,1–3, approached the IC50value of rotenone in inhibiting oxygen uptake in the rat liver mitochondrial bioassay, suggesting that they must have another mode of action.

ISSN:1057-5634    

DOI:10.1080/10575639808044955

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Starting from 3-ethoxy-2-cyclohexenone, 4-(p-methoxyphenylethyl)-2-cyclohexenone (1), a natural ketone isolated from the gametophytic tissues of the liverwortPlagiochila longispina, was preparedviaa simple two-step approach in 63% overall yield.

ISSN:1057-5634    

DOI:10.1080/10575639808044956

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The methanol extract of the stem bark ofTrichilia estipulataafforded four aryltetralin lignan glycosides which were identified on the basis of spectroscopic analysis of their acetates as (−)-isolariciresinol-3α-O-β-D-xylopyranoside and the new lignans (+)-4′-0-methyl-9′-deoxiisolariciresinol-3α-O-β-D-glucopyranoside, (−)-lyoniresinol-3α-L-rhamnopyranoside.

ISSN:1057-5634    

DOI:10.1080/10575639808044957

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Four new compounds were isolated from the aerial parts ofAristolochia constricta(Aristolochiaceae). Their structures were elucidated on the basis of spectral and chemical data to be 10-amino-1-carboxy-3,4-dimethoxy-6-hydroxyphenanthrene lactam N-β-D-glucopyranoside (1); 10-amino-1-carboxy-3,4-dimethoxy-6-hydroxyphenanthrene lactam N-β-D-(6′-trans-p-coumaroyl)-glucopyranoside (2); 10-amino-1-carboxy-3,4,6-trimethoxyphenanthrene lactam N-β-D-glucopyranoside (3); 10-amino-1-carboxy-3,4,6-trihydroxyphenanthrene lactam N-β-D-glucopyranoside (4).

ISSN:1057-5634    

DOI:10.1080/10575639808044958

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The fermentation broth of bacterial strain A108, isolated from tissues aseptically excised fromPalythoasp., was found to exhibit plant growth promotion activity in an agrochemical screen employed in our laboratory. Bioassay-guided fractionation and purification yielded three compounds, cyclo[L-(4-hydroxyprolinyl)-L-leucine], cyclo[L-(4-hydroxyprolinyl)-D-leucine], and cyclo[L-(4-hydroxyprolinyl)-L-phenylalanine]. All three compounds stimulated plant growth. Two of the three diketopiperazines are previously known compounds associated with drought resistance and growth promotion in rice seedlings; a similar function forPalythoaspp. is hypothesized. Cyclo[L-(4-hydroxyprolinyl)-L-phenylalanine] is the only one of the three previously isolated from a marine source.

ISSN:1057-5634    

DOI:10.1080/10575639808044959

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Two new aromatic compounds, guaymasol (1) and epiguaymasol (2), have been isolated from cultures of aBacillusspecies (isolate CNA-995) taken from a deep-sea sediment core. The structures, including relative stereochemistry, were assigned on the basis of spectral analyses of the natural products and their acetonide derivatives.

ISSN:1057-5634    

DOI:10.1080/10575639808044960

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

5-Methoxy-1-oxo-tetrahydro-β-carboline has been isolated from IndianNothapodytes foetidaalong with camptothecin, 9-methoxycamptothecin and 20-O-acetylcamptothecin. The occurrence of the former in the plant provided an evidence of the biogenetic formation of camptothecins from indole precursors via strictosidine derivatives.

ISSN:1057-5634    

DOI:10.1080/10575639808044961

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Boveinine(1), a minor pyrrolizidine alkaloid, was isolated from the aerial parts ofHeliotropium boveiand its structure was determined to be 1-[(2′-hydroxy-2′ -(1-hydroxy-1-methylethyl)-3′-methoxybutanoyl-oxymethyl]-5, 6-dihydropyrrolizidine-7-one.

ISSN:1057-5634    

DOI:10.1080/10575639808044962

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Three new pregnane-type steroidal alkaloids salignenamide-A 1 [(20S, 2′Z) - 20 - (N,N- dimethylamino) - 3β - (3′, 4′ - dimethyl-2-pentenamido)-pregnane], salignenamide-B 2 [(20S,2′Z)-20- (N,N-dimethylamino)-3β-(3′-methyl-2′-butenamido)-pregna-4, 14-diene] and 2,4-diacetoxyepipachysamine-D 3 [(20S)-20-(N,N-dimethylamino)-3β-benzamido-2β, 4β-diacetoxypregnane] have been isolated from the ethanolic extracts of the whole plant ofSarcococca saligna.The structures of these steroidal alkaloids were established on the basis of detailed spectroscopic studies.

ISSN:1057-5634    

DOI:10.1080/10575639808044963

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Using a combination of P388 cytotoxicity testing, protein phosphatase enzyme inhibition assays and an ELISA immunoassay, okadaic acid(1), the causative agent of diarrhetic shellfish poisoning (DSP), has been found inRaspalia agminata, and detected in two other species of New Zealand sponges.

ISSN:1057-5634    

DOI:10.1080/10575639808044964

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor