Lingling L. Rogers

Muricoreacin and murihexocin C, mono-tetrahydrofuran acetogenins, from the leaves of annona muricata in honour of professor G. H. Neil Towers 75th birthday

Bioactivity-directed fractionation of the leaves of Annona muricata L. (Annonaceae) resulted in the isolation of two new Annonaceous acetogenins, muricoreacin (1) and murihexocin C (2). Compounds 1 and 2 showed significant cytotoxicities among six human tumor cell lines with selectivities to the prostate adenocarcinoma (PC-3) and pancreatic carcinoma (PACA-2) cell lines.

UNUSUAL BIOACTIVE ANNONACEOUS ACETOGENINS FROM GONIOTHALAMUS GIGANTEUS

Abstract Pyranicin (1) and pyragonicin (2) are the first mono-tetrahydropyran annonaceous acetogenins, and goniotrionin (3) possesses an unusual hydroxylated-allylic moiety. 1–3 were isolated from the bark of Goniothalamus giganteus using activity-directed fractionation with the brine shrimp lethality test. Both 1 and 2 are selectively cytotoxic against the pancreatic cell line (PACA-2) in a panel of six human solid tumor cell lines with 1 showing ten times the potency of adriamycin, while 3 showed more potent selectivity against the breast cell line (MCF-7).

Bioactive Monoterpenes from Monarda fistulosa (Lamiaceae)

Abstract Bioactivity-guided fractionation of Monarda fistulosa L. (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, 1 was very selective for SF-539 (CNS) with an LC50 < 2.51 × 10−2 μg/ml. Other cell lines targeted by 1 were PC-3 (prostate), M-14 (melanoma), OVCAR-5 (ovarian), and MCF-7 (breast). The reduction of 1 to 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 IC50 value of rotenone in inhibiting oxygen uptake in the rat liver mitochondrial bioassay, suggesting that they must have another mode of action.

Glabracins A and B, two new acetogenins from Annona glabra

Two new bioactive bis-THF Annonaceous acetogenins, glabracins A (1) and B (2), and two previously known acetogenins, javoricin (3) and bullatanocin (4), have been isolated from the leaves of Annona glabra by activity-directed fractionation using the brine shrimp lethality test (BST). The structures of 1 and 2 were elucidated based on spectroscopic and chemical methods, and the absolute stereochemistries were partially determined by the advanced Mosher ester method. 1 and 2 showed selective cytotoxicities to certain human tumor cell lines, and 1 was significantly more potent although 1 and 2 differ only in the stereochemistry of their vicinal diols at C-23/24.

Annojahnin from Annona jahnii: a possible precursor of mono-tetrahydrofuran acetogenins

A new cytotoxic Annonaceous acetogenin, annojahnin (1), was isolated from the twigs of Annona jahnii (Annonaceae) by bioactivity-directed fractionation using lethality to brine shrimp. Compound 1 represents an unusual type of C-37 Annonaceous acetogenin, lacking either tetrahydrofuran (THF) or epoxide rings, bearing a keto group at C-10, and possessing a double bond located two methylenes away from a vicinal diol. The structure and absolute configuration of 1 were elucidated by 1H and 13C NMR, COSY, and single-relayed COSY and from chemical derivatives. 4-Deoxy-18/21-trans-annomontacin 10-one (4) and 4-deoxy-18/21-cis-annomontacin-10-one (5), two semisynthetic mono-THF acetogenins, were prepared from 1 by reactions that mimic the biogenetic pathways. These acetogenins showed selective cytotoxicities, comparable or superior to adriamycin, among six human solid tumor cell lines. Reduction of the 10-keto of 1, to the racemic 10-OH derivative (3), retained the bioactivities as did the conversion of 1 to 4 and 5.

Volkensinin: A new limonoid from Melia volkensii

Abstract Bioactivity-directed fractionation of the root bark of M. volkensii Gurke (Meliaceae) resulted in the isolation of a new compound: volkensinin ( 1 ). The structure of 1 , which contains a unique 5-membered C ring, has been elucidated by the analysis of spectral data. Compound 1 showed weak cytotoxicities against six human tumor cell lines.

Mono-tetrahydrofuran acetogenins from Goniothalamus giganteus.

Goniotetracin and a mixture of (2,4-cis and trans)-gonioneninone, new, bioactive, mono-tetrahydrofuran (THF) gamma-lactone and ketolactone acetogenins, were isolated from the bark of Goniothalamus giganteus (Annonaceae) by activity-directed fractionation using the brine shrimp lethality test (BST). The structures were elucidated based on spectroscopic and chemical methods. Their absolute stereochemistries were determined by the advanced Mosher ester method. Both showed selective and significant cytotoxicities, comparable to the potency of adriamycin, to the human pancreatic tumour cell line (PACA-2), while goniotetracin and goniothalamicin were comparable to the activity of rotenone against yellow fever mosquito larvae.

Annodienin and Jahnonacin: New Bioactive Nontetrahydrofuran Annonaceous Acetogenins from the Twigs of Annona Jahnii

Abstract Annodienin (1) and jahnonacin (2), two new bioactive non-tetrahydrofuran Annonaceous acetogenins, have been isolated from the EtOH extract of the twigs of Annona jahnii Saff., using fractionation directed by brine shrimp lethality. These new compounds are unsaturated acetogenins and have a diol system. Compound 1 bears two double bonds in the aliphatic chain. The structures were elucidated by spectral analyses of the parent compounds and/or simple chemical derivatives, especially by employing 1H-NMR and 2D-NMR experiments. These acetogenins showed selective cytotoxicities, with potencies similar to adriamycin, among six human solid tumor cell lines.

Cholesterol from Japanese Beetles, Popillia japonica

Abstract An extract of adult Japanese beetles, Popillia japonica Newman (Coleoptera: Scarabaeidae), collected in commercial Japanese beetle traps, afforded a large amount (nearly 0.2 mg/g of fresh weight) of cholesterol. As phytophagous insects, Japanese beetles feed on a variety of plants. Since little or no cholesterol can be obtained from their diet, they must be able to utilize phytosterols to generate and store cholesterol.