CC-1065 and the duocarmycins: unraveling the keys to a new class of naturally derived DNA alkylating agents.

Key studies defining the DNA alkylation properties and selectivity of a new class of exceptionally potent, naturally occurring antitumor antibiotics including CC-1065, duocarmycin A, and duocarmycin SA are reviewed. Recent studies conducted with synthetic agents containing deep-seated structural changes and the unnatural enantiomers of the natural products and related analogs have defined the structural basis for the sequence-selective alkylation of duplex DNA and fundamental relationships between chemical structure, functional reactivity, and biological properties. The agents undergo a reversible, stereoelectronically controlled adenine-N3 addition to the least substituted carbon of the activated cyclopropane within selected AT-rich sites. The preferential AT-rich non-covalent binding selectivity of the agents within the narrower, deeper AT-rich minor groove and the steric accessibility to the alkylation site that accompanies deep AT-rich minor groove penetration control the sequence-selective DNA alkylation reaction and stabilize the resulting adduct. For the agents that possess sufficient reactivity to alkylate DNA, a direct relationship between chemical or functional stability and biological potency has been defined.

Pictorial keys to arthropods, reptiles, birds and mammals of public health significance.

Mode of access: Internet.

The keys to prosperity.

Bibliographical footnotes.

Keys to spring plants,

"For the identification of the Pteridophyta, Gymnospermae and the commoner species of early-flowering Angiospermae found in the vicinity of Ithaca, New York."

Pictorial keys to anthropods, reptiles, birds and mammals of public health importance.

Bibliography: p. 187-192.

Keys to identification of families and genera of insects ...

Vol. IV has title: Literature to the orders, families, genera, and species of insects and medical entomology.

Keys to the North American genera and higher groups of aquatic insects in their larval and adult stages,

Leaves variously numbered.

Synopsis and catalog of the thysanoptera of North America, with a translation of Karny's Keys to the genera of thysanoptera and a bibliography of recent publications,

Bibliography: p. 83-88.

Keys to the genera and species of the heteroptera of the North eastern states (exclusive of Capsidae).

Typewritten.

Keys to subfamilies, tribes, genera and subgenera of the Gerridae of the world

University of Kansas, Department of Entomology contribution no. 1047.

Keys to teaching junior high school music,

Mode of access: Internet.

Keys to teaching elementary school music /

Includes index.

Pictorial keys to arthropods, reptiles, birds, and mammals of public health significance.

"Previously issued under the same title by the Centers of Disease Control and PRevention of the U. S. Public Health Service, Atlanta, Georgia"--t.p. verso.