Natural sources, i.e. fungal strains and species producing ergot alkaloids (EA), are surveyed together with the chemical structures of EA and a list of new natural EA discovered in the last three decades. Other topics include new efficient chromatographic methods (HPLC) for the separation and isolation of new natural EA and also immunological methods of EA detection.

Ergot alkaloids--sources, structures and analytical methods.

This article reveals the various biological activities of the heterocyclic compound, indazole, including anti-inflammatory, antimicrobial, antiHIV, anticancer, hypoglycemic, antiprotozoal, antihypertensive, and other activities. From the observed biological activities of the indazole moiety, it is concluded that the medicinal properties of indazole have to be explored in the near future for the treatment of various pathological conditions.

Indazole: a medicinally important heterocyclic moiety

One-Pot Multicomponent Cascade Reaction of N,S-Ketene Acetal: Solvent-Free Synthesis of Imidazo[1,2-a]thiochromeno[3,2-e]pyridines

Alkynones and chalcones are of paramount importance in heterocyclic chemistry as three-carbon building blocks. In a very efficient manner, they can be easily generated by palladium-copper catalyzed reactions: ynones are formed from acid chlorides and terminal alkynes, and chalcones are synthesized in the sense of a coupling-isomerization (CI) sequence from (hetero)aryl halides and propargyl alcohols. Mild reaction conditions now open entries to sequential and consecutive transformations to heterocycles, such as furans, 3-halo furans, pyrroles, pyrazoles, substituted and annelated pyridines, annelated thiopyranones, pyridimines, meridianins, benzoheteroazepines and tetrahydro-β-carbolines, by consecutive coupling-cyclocondensation or CI-cyclocondensation sequences, as new diversity oriented routes to heterocycles. Domino reactions based upon the coupling-isomerization reaction (CIR) have been probed in the synthesis of antiparasital 2-substituted quinoline derivatives and highly luminescent spiro-benzofuranones and spiro-indolones.

Palladium-Copper Catalyzed Alkyne Activation as an Entry to Multicomponent Syntheses of Heterocycles

Proteolysis and physiological regulation.

A series of novel substituted thiochromones and thiochroman-4-ones was synthesized. Compounds were designed as analogues of naphthoquinone and as potential "bioreductive alkylating agents" and were tested for antitumor activity. The lead compound, 3-(chloromethyl)thiochromone 1,1-dioxide (4), inhibited Ehrlich ascites tumor growth by 100% in CF1 male mice at 10 (mg/kg)/day ip. Similarly, 18 of the 29 related compounds demonstrated good activity in this tumor screen. Few definitive structure-activity correlations were evident regarding the nature of the 3-substituent. However, the 2,3 double bond and a sulfone or sulfoxide were required for activity. Four of the compounds synthesized showed marginal but significant activity against P-388 lymphocytic leukemia.

Synthesis and antitumor activity of a series of sulfone analogs of 1,4-naphthoquinone

Radioimmunoassay for Lysergide (LSD) in Illicit Drugs and Biological Fluids

A series of novel aziridinyl-substituted 1(2)H-indazole-4,7-diones and related 1(2)H-indazole-4,7-diones was synthesized and tested against Ehrlich ascites carcinoma growth in male CF1 mice. Ten of the test compounds, including two aziridinyl-substituted 1(2)H-indazole-4,7-diones, were found to be significantly active (inhibition of tumor growth greater than 80%) in the Ehrlich ascites carcinoma screen. Several structure-activity relationships were indicated for antitumor activity in this screen. An aziridinyl-substituted derivative, 5-aziridinyl-6-chloro-1H-indazole-4,7-dione (8a), also exhibited significant activity against the growth of P-388 lymphocytic leukemia cells in male BDF1 mice (% T/C = 145; % T/C greater than 125 is considered significant).

Synthesis and antitumor evaluation of selected 5,6-disubstituted 1(2)H-indazole-4,7-diones.

Previously reported work on N-protected activated esters of phenylalanine has been extended to include N-protected vinyl, dibromoethyl, and cyanomethyl esters of several other amino acids. These compounds have been synthesized and evaluated in Ehrlich ascites carcinoma, Walker 256 carcinosarcoma, and and P388 lymphocytic leukemia tests. Among compounds tested were derivatives of tyrosine, tryptophan, glycine, leucine, proline, aspartic acid, glutamic acid, 4-aminobutyric acid, and 6-aminocaproic acid. Compounds of greatest potential interest from this study are N-carbobenzoxyglycine 1,2-dibromoethyl ester and N-carbobenzoxy-L-leucine 1,2-dibromoethyl ester. Both compounds were highly active in Ehrlich ascites test systems (33 mg/kg/day). The glycine derivative was also active in the Walker 256 test (2.5 mg/kg/day. Values for LD50's in mice were 148 mg/kg (0.37 mmol/kg) and 225 mg/kg (0.50 mmol/kg) for glycine and leucine derivatives, respectively; therefore, these compounds do not appear to be toxic at effective dose levels.

Antineoplastic agents. 2. Structure-activity studies on N-protected vinyl, 1,2-dibromoethyl, and cyanomethyl esters of several amino acids.

A series of N-protected vinyl, 1,2-dihaloethyl, and cyanomethyl esters of phenylalanine was synthesized and these compounds were evaluated for antitumor activity against the growth of Ehrlich ascites carcinoma in CF1 male mice (33 mg/kg/day), Walker 256 carcinosarcoma in Sprague-Dawley male rats (2.5 mg/kg/day), and P388 lymphocytic leukemia in DBA/2 mice (20 mg/kg/day). Structure-activity relationships were evaluated and acute toxicity studies (LD50 determinations) in male CF1 mice were also carried out on selected compounds. Carbobenzoxy-L0phenylalanine vinyl ester (5), N-carbobenzoxy-L-phenylalanine 1,2-dibromoethyl ester (12), and N-carbobenzoxy-L-phenylalanine cyanomethyl ester (8) were found to be very potent inhibitors of Ehrlich ascites tumor growth at nontoxic doses cited above. Compounds 5 and 12 also tripled survival time in the Walker 256 system. LD50 values for compounds 5, 12, and 8 were greater than 2000 mg/kg (greater than 6.15 mmol/kg), 74 mg/kg (0.15 mmol/kg), and 150 mg/kg (0.44 mmol/kg), respectively.

Larry J. Loeffler

Papers

Synthesis and antitumor activity of a series of sulfone analogs of 1,4-naphthoquinone

Radioimmunoassay for Lysergide (LSD) in Illicit Drugs and Biological Fluids

Synthesis and antitumor evaluation of selected 5,6-disubstituted 1(2)H-indazole-4,7-diones.

Antineoplastic agents. 2. Structure-activity studies on N-protected vinyl, 1,2-dibromoethyl, and cyanomethyl esters of several amino acids.

Antineoplastic agents. 1. N-Protected vinyl, 1,2-dihaloethyl, and cyanomethyl esters of phenylalanine.