Author: claimsbot

1. A method of characterizing an RNA-protein complex, the method comprising:
a) expressing in a cell an epitope-tagged RNA-binding protein thereby forming an RNA-protein complex,
b) lysing the cell to produce a cell lysate;
c) contacting the lysate with a ligand that specifically binds to the epitope tag;
d) isolating the RNA-protein complex from the lysate; and
e) identifying at least one RNA andor at least one protein, other than the epitope-tagged protein, from the isolated RNA-protein complex;
wherein the nucleic acid encoding the epitope-tagged RNA-binding protein is under the control of a tissue-specific promoter.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A group B streptogramin derivative of formula (I) or a salt thereof:
wherein:
(A) Y is chosen from (i) a nitrogen atom and (ii) \u2550CR3\u2014 groups, and
(1) when Y is chosen from \u2550CR3\u2014 groups, R1 is chosen from
(a1) a hydrogen atom, C1\u2013C8 alkyl groups, and C2\u2013C8 alkenyl groups,
(b1) C3\u2013C8 cycloalkyl groups, and saturated and unsaturated C3\u2013C8 heterocyclyl groups,
(c1) an unsubstituted phenyl group,
(d1) a phenyl group substituted with at least one substituent chosen from halogen atoms, a hydroxyl group, alkyl groups, alkyloxy groups, alkylthio groups, alkylsulphinyl groups, alkylsulphonyl groups, an amino group, alkylamino groups, and dialkylamino groups, and
(e1) groups \u2014NR\u2032R\u2033, wherein
R\u2032 and R\u2033, which are identical or different, are each chosen from a hydrogen atom and C1\u2013C3 alkyl groups, or
R\u2032 and R\u2033, which are identical or different, form, together with the nitrogen atom to which they are attached, a 3- to 8-membered heterocyclyl group, wherein one of said members, in addition to said nitrogen atom, may be an atom chosen from an oxygen atom, a sulphur atom, and a nitrogen atom, and wherein said heterocyclyl group is optionally substituted with a group chosen from alkyl groups, C2\u2013C8 alkenyl groups, C3\u2013C6 cycloalkyl groups, saturated and unsaturated 4- to 6-membered heterocyclyl groups, a benzyl group, an unsubstituted phenyl group, and a substituted phenyl group, as defined above in (d1),

(f1) halomethyl groups, a hydroxymethyl group, and alkyloxymethyl groups,
(g1) alkylthiomethyl groups, wherein said alkyl portion is optionally substituted with an \u2014NR\u2032R\u2033 group, and wherein said R\u2032 and said R\u2033 are as defined above in (e1),
(h1) alkylsulphinylmethyl groups, alkylsulphonylmethyl groups, an acyloxymethyl group, a benzoyloxymethyl group, a cyclopropylaminomethyl group, and \u2014(CH2)nNR\u2032R\u2033 groups, wherein n is chosen from integers ranging from 1 to 4, and wherein said R\u2032 and said R\u2033 are as defined above in (e1), and
(i1) when R3 is a hydrogen atom, R1 is additionally chosen from a formyl group, a carboxyl group, alkyloxycarbonyl groups, and \u2014CONR\u2032R\u2033 groups, wherein said R\u2032 and said R\u2033 are defined as above in (e1), and

(2) when Y is a nitrogen atom, R1 is chosen from
(a2) options (a1), (b1), (c1), (d1), and (e1) as defined above, and
(b2) \u2014XRo groups, wherein X is chosen from an oxygen atom, a sulphur atom, a sulphinyl group, a sulphonyl group, and an \u2014NH\u2014 group, and wherein Ro is chosen from (i) (C1 to C8) alkyl groups, (ii) (C3 to C6) cycloalkyl groups, (iii) saturated and unsaturated 3- to 8-membered heterocyclyl groups, (iv) 3- to 8-membered heterocyclylmethyl groups in which the heterocyclyl portion is attached to the methyl group by a carbon atom, (v) an unsubstituted phenyl group, (vi) phenyl groups substituted with at least one group chosen from halogen atoms, a hydroxyl group, alkyl groups, alkyloxy groups, alkylthio groups, alkylsulfinyl groups, alkylsulfonyl groups, an amino group, alkylamino groups, and dialkylamino groups, (vii) \u2014(CH2)nNR\u2032R\u2033 groups, wherein R\u2032 and R\u2033 are as defined above in (e1), and wherein n is chosen from integers ranging from 2 to 4, and (viii) if X is an NH group, Ro may also be a hydrogen atom;
(B) R2 is chosen from a hydrogen atom and C1\u2013C3 alkyl groups,
(C) R3 is chosen from a hydrogen atom, alkyl groups, a carboxyl group, alkyloxycarbonyl groups, and carbamoyl groups of formula \u2014CO\u2014NR\u2032R\u2033, wherein said R\u2032 and said R\u2033 are defined as above in (e1),
(D) Ra is chosen from a methyl group and an ethyl group, and
(E) Rb, Rc, and Rd are defined as follows:
(1) Rb and Rc are each a hydrogen atom, and
Rd is chosen from a hydrogen atom, a methylamino group, and a dimethylamino group, or

(2) Rb is a hydrogen atom,
Rc is chosen from a hydrogen atom, a chlorine atom, a bromine atom, and C3\u2013C5 alkenyl groups, and
Rd is chosen from \u2014N(CH3)R\u2032\u2033 groups, wherein
R\u2032\u2033 is chosen from
(a) alkyl groups, C2\u2013C4 hydroxyalkyl groups, and C2\u2013C8 alkenyl groups, wherein said C2\u2013C8 alkenyl groups are optionally substituted with a group chosen from
(i) an unsubstituted phenyl group, a (C3\u2013C6)cycloalkylmethyl group, a benzyl group, and
(ii) a benzyl group substituted with at least one substituent as defined with respect to said substituted phenyl groups in (d1) above,
(iii) heterocyclylmethyl groups and heterocyclylethyl groups, wherein said heterocyclyl portions of said heterocyclylmethyl groups and said heterocyclylethyl groups are chosen from saturated and unsaturated 5- to 6-membered heterocyclyl groups comprising from 1 to 2 heteroatoms chosen from a sulphur atom, an oxygen atom, and a nitrogen atom, and wherein said heterocyclyl groups are optionally substituted with a group chosen from alkyl groups, C2\u2013C8 alkenyl groups, C3\u2013C6 cycloalkyl groups, saturated and unsaturated 4- to 6-membered heterocyclyl groups, an unsubstituted phenyl group, a benzyl group, and a substituted phenyl group as defined above in (d1),
(b) a cyanomethyl group, and
(c) \u2014CH2CORe groups, wherein Re is chosen from
(i) \u2014OR\u2032e groups, wherein R\u2032e is chosen from a hydrogen atom, C1\u2013C6 alkyl groups, C2\u2013C6 alkenyl groups, a benzyl group, and heterocyclylmethyl groups, wherein said heterocyclyl portion is chosen from 5- to 6-membered heterocyclyl groups comprising from 1 to 2 heteroatoms chosen from a sulphur atom, an oxygen atom, and a nitrogen atom,
(ii) alkylamino groups, alkylmethylamino groups, heterocyclylamino groups and heterocyclylmethylamino groups, wherein said heterocyclyl portion of said heterocyclylamino groups and said heterocyclylmethylamino groups is chosen from 5- to 6-membered saturated heterocyclyl groups comprising from 1 to 2 heteroatoms chosen from a sulphur atom, an oxygen atom, and a nitrogen atom, and wherein said heterocyclyl groups are optionally substituted with a group chosen from alkyl groups, a benzyl group, and alkyloxycarbonyl groups, or
(3) Rb is a hydrogen atom, and
Rd is chosen from an \u2014NHCH3 group and an \u2014N(CH3)2 group, and Rc is chosen from a chlorine atom, and a bromine atom, and when Rd is an \u2014N(CH3)2 group, Rc is chosen from C3\u2013C5 alkenyl groups, or

(4) Rb and Rd are each a hydrogen atom, and
Rc is chosen from halogen atoms, alkylamino groups, dialkylamino groups, alkyloxy groups, a trifluoromethoxy group, thioalkyl groups, C1\u2013C6 alkyl groups, and trihalomethyl groups, or

(5) Rb and Rc are each a hydrogen atom, and
Rd is chosen from halogen atoms, an ethylamino group, a diethylamino group, a methylethylamino group, alkyloxy groups, a trifluoromethoxy group, alkylthio groups, alkylsulphinyl groups, alkylsulphonyl groups, C1\u2013C6 alkyl groups, a phenyl group, and trihalomethyl groups, or

(6) Rb is a hydrogen atom, and
Rc is chosen from halogen atoms, alkylamino groups, dialkylamino groups, alkyloxy groups, a trifluoromethoxy group, thioalkyl groups, and C1\u2013C3 alkyl groups, and
Rd is chosen from halogen atoms, an amino group, alkylamino groups, dialkylamino groups, alkyloxy groups, a trifluoromethoxy group, thioalkyl groups, C1\u2013C6 alkyl groups, and trihalomethyl groups, or

(7) Rc is a hydrogen atom, and
Rb and Rd are each a methyl group, and
unless otherwise stated, said alkyl groups, said alkenyl groups, and said acyl groups are chosen from, respectively, straight and branched alkyl groups, straight and branched alkenyl groups, and straight and branched acyl groups, and
unless otherwise stated, said alkyl groups and said acyl groups comprise from 1 to 4 carbon atoms.
2. A group B streptogramin derivative according to claim 1, wherein
(A) Y is chosen from a nitrogen atom and \u2550CR3\u2014 groups, and
(1) when Y is chosen from \u2550CR3\u2014 groups, R1 is chosen from
(a1) a hydrogen atom,
(b1) C1\u2013C8 alkyl groups, C3\u2013C8 cycloalkyl groups, and saturated and unsaturated C3\u2013C8 heterocyclyl groups,
(c1) an unsubstituted phenyl group,
(d1) a substituted phenyl group, wherein at least one substituent is chosen from an amino group, alkylamino groups, and dialkylamino groups, and
(e1) groups \u2014NR\u2032R\u2033, wherein
R\u2032 and R\u2033, which are identical or different, are each chosen from a hydrogen atom, and C1\u2013C3 alkyl groups, or R\u2032 and R\u2033, which are identical or different, form, together with the nitrogen atom to which they are attached, a 3- to 8-membered heterocyclyl group, wherein one of said members, in addition to said nitrogen atom, may be an atom chosen from an oxygen atom, a sulphur atom, and a nitrogen atom, and wherein said heterocyclyl group is optionally substituted with an alkyl group,

(f1) halomethyl groups, and a hydroxymethyl group,
(g1) alkylthiomethyl groups, wherein said alkyl portion is optionally substituted with an \u2014NR\u2032R\u2033 group, and wherein said R\u2032 and said R\u2033 are as defined above in (e1),
(h1) alkylsulphinylmethyl groups, alkylsulphonylmethyl groups, an acyloxymethyl group, a cyclopropylaminomethyl group, and \u2014(CH2)nNR\u2032R\u2033 groups, wherein n is chosen from integers ranging from 1 to 4, and wherein said R\u2032 and said R\u2033 are as defined above in (e1), and
(i1) when R3 is a hydrogen atom, R1 is additionally chosen from a formyl group, and \u2014CONR\u2032R\u2033 groups, wherein said R\u2032 and said R\u2033 are defined as above in (e1), and

(2) when Y is a nitrogen atom, R1 is chosen from
(a2) options (a1), (b1), (c1), (d1), and (e1) as defined above, and
(b2) \u2014XRo groups, wherein X is chosen from an oxygen atom, a sulphur atom, a sulphinyl group, a sulphonyl group, and an \u2014NH\u2014 group, and wherein Ro is chosen from
(i) C1\u2013C8 alkyl groups,
(ii) 3- to 8-membered heterocyclylmethyl groups, wherein said heterocyclyl portion is attached to said methyl group by way of a carbon atom, and
(iii) \u2014(CH2)nNR\u2032R\u2033 groups, wherein said R\u2032 and said R\u2033 are defined as above in (e1) and n is chosen from integers ranging from 2 to 4,
(B) R2 is chosen from a hydrogen atom and C1\u2013C3 alkyl groups,
(C) R3 is chosen from a hydrogen atom, a carboxyl group, and alkyloxycarbonyl groups,
(D) Ra is chosen from a methyl group and an ethyl group, and
(E) Rb, Rc, and Rd are defined as follows:
(1) Rb and Rc are each a hydrogen atom, and
Rd is chosen from a hydrogen atom, a methylamino group, and a dimethylamino group, or

(3) Rb is a hydrogen atom, and
Rd is chosen from an \u2014NHCH3 group and an \u2014N(CH3)2 group, and
Rc is chosen from a chlorine atom and a bromine atom.
3. A group B streptogramin derivative according to claim 1, wherein
(A) Y is chosen from a nitrogen atom and \u2550CR3\u2014 groups, and
(1) when Y is chosen from \u2550CR3\u2014 groups, R1 is chosen from
(a1) a hydrogen atom,
(b1) C1\u2013C3 alkyl groups, C3\u2013C8 cycloalkyl groups, and saturated and unsaturated C3\u2013C8 heterocyclyl groups,
(c1) an unsubstituted phenyl group,
(d1) a phenyl group substituted with an amino group, and
(e1) an acyloxymethyl group,

(2) when Y is a nitrogen atom, R1 is chosen from
(a2) options (a1), (b1), (c1), (d1), and (e1), as defined above, and
(b2) \u2014XRo groups, wherein X is chosen from an oxygen atom, a sulphur atom, and an \u2014NH\u2014 group, and wherein Ro is chosen from
(i) C1\u2013C4 alkyl groups,
(ii) \u2014(CH2)nNR\u2032R\u2033 groups, wherein R\u2032 and R\u2033, which are identical or different, are each chosen from a hydrogen atom, and C1\u2013C3 alkyl groups, or R\u2032 and R\u2033, which are identical or different, form, together with the nitrogen atom to which they are attached, a 3- to 8-membered heterocyclyl group, wherein one of said members, in addition to said nitrogen atom, may be an atom chosen from an oxygen atom, a sulphur atom, and a nitrogen atom, and wherein said heterocyclyl group is optionally substituted with an alkyl group, and n is chosen from integers ranging from 2 to 4, and
(B) R2 is chosen from a hydrogen atom and C1\u2013C3 alkyl groups,
(C) R3 is chosen from a hydrogen atom and alkyloxycarbonyl groups,
(D) Ra is chosen from a methyl group and an ethyl group, and
(E) Rb, Rc, and Rd are defined as follows:
(1) Rb and Rc are each a hydrogen atom, and
Rd is chosen from a hydrogen atom, a methylamino group, and a dimethylamino group, or

(2) Rb is a hydrogen atom,
Rd is chosen from an \u2014NHCH3 group and an \u2014N(CH3)2 group, and
Rc is a chlorine atom.
4. A group B streptogramin derivative according to claim 1, wherein said group B streptogramin derivative is 2\u2033-methylpyrido2,3\u20135\u03b3,5\u03b4pristinamycin IE.
5. A group B streptogramin derivative according to claim 1, wherein said group B streptogramin derivative is 2\u2033-cyclopropylpyrido2,3\u20135\u03b3,5\u03b4pristinamycin IE.
6. A group B streptogramin derivative according to claim 1, wherein said group B streptogramin derivative is pyrido2,3\u20135\u03b3,5\u03b4pristinamycin IE.
7. A group B streptogramin derivative according to claim 1, wherein said group B streptogramin derivative is 2\u2033-ethylpyrido2,3\u20135\u03b3,5\u03b4(4\u03b6-methylamino)(4\u03b6-dedimethylamino)pristinamycin IE.
8. A group B streptogramin derivative according to claim 1, wherein said group B streptogramin derivative is 4\u03b5-chloro-2\u2033-(ethyl)-pyrido2,3\u20135\u03b3,5\u03b4(4\u03b6-methylamino)(4\u03b6-dedimethylamino)pristinamycin IE.
9. A process for preparing a group B streptogramin derivative according to claim 1, wherein said Y is chosen from said \u2550CR3\u2014 groups, and said R3 is not an alkyl group, said process comprising:
(a) reacting, for a time and under conditions sufficient to form the group B streptogramin derivative, an enamino ester of formula (II):
\u2003wherein R1 is chosen from R1 of formula (I) and R is chosen from alkyl groups and residues of easily hydrolysable esters, wherein said residues are other than said alkyl groups,
\u2003with a 5\u03b4-methylenepristinamycin derivative of formula (III):
\u2003wherein
Ra, Rb, Rc, and Rd are chosen from, respectively, Ra, Rb, Rc, and Rd of formula (I),
(i) R2 is chosen from R2 of formula (I), and
R4 is a hydrogen atom, or

(ii) R2 is a hydrogen atom, and
R4 is chosen from a hydrogen atom and dialkylamino groups,
(b) optionally, where appropriate, converting said group B streptogramin derivative, prepared by (a) above, to a group B streptogramin derivative wherein said R3 is a carboxyl group,
(c) optionally decarboxylating said group B streptogramin derivative, prepared by (b) above, wherein said R3 is a carboxyl group, to a group B streptogramin derivative wherein said R3 is a hydrogen atom, or
(d) optionally converting said group B streptogramin derivative, prepared by (b) above, wherein said R3 is a carboxyl group, to a group B streptogramin derivative wherein said R3 is a carbamoyl group,
(e) optionally converting said group B streptogramin derivative, prepared by (a) or (c) above, wherein said R1 is a hydroxymethyl group, to a group B streptogramin derivative wherein said R1 is a formyl group, and
(i) optionally converting said group B streptogramin derivative, wherein said R1 is a formyl group, to a group B streptogramin derivative wherein said R1 is a carboxyl group, and
(ii) optionally converting said group B streptogramin derivative, wherein said R1 is a carboxyl group, to a group B streptogramin derivative wherein said R1 is chosen from alkyloxycarbonyl groups and \u2014CONR\u2032R\u2033 groups, and

(f) optionally mono-N-demethylating said group B streptogramin derivative, prepared by (a), (b), (c), (d), or (e) above, wherein Rd is a dimethylamino group, to a group B streptogramin derivative wherein Rd is a methylamino group, and
(g) optionally converting said group B streptogramin derivative, prepared by (a), (b), (c), (d), (e), or (f) above, to a salt.
10. A process for preparing a group B streptogramin derivative according to claim 1, wherein said Y is chosen from \u2550CR3\u2014 groups and said R3 is chosen from a hydrogen atom and alkyl groups, said process comprising:
(a) reacting a pyridinium salt of formula (IV):
\u2003wherein
X\u2212is an anion
R3 is chosen from a hydrogen atom and alkyl groups,
R5 is chosen from
(i) residues of ketones of formula R1\u2014CO\u2014, wherein
R1 is chosen from said R1 of formula (I) except that said R1 is not chosen from \u2014NR\u2032R\u2033 groups,

(ii) a protected hydroxyl group,
(iii) a nitrophenyl group, and
(iv) when preparing a group B streptogramin derivative for which said R1 is an amino group, R5 is a cyano group,
with a 5\u03b4-methylenepristinamycin derivative of formula (III):
\u2003wherein
Ra, Rb, Rc, and Rd are chosen from, respectively, Ra, Rb, Rc, and Rd of formula (I),
R4 is a hydrogen atom, and
R2 is chosen from R2 of formula (I), and

(b) optionally
(i) liberating said protected hydroxyl group of said group B streptogramin derivative, prepared by (a) above, or
(ii) when preparing a group B streptogramin derivative for which said R1 is an aminophenyl group, reducing said nitrophenyl group of said group B streptogramin derivative, prepared by (a) above, to an aminophenyl group, or

(c) optionally, to prepare a group B streptogramin derivative for which R1 is a \u2014CH2NR\u2032R\u2033 group, reacting an amine of formula HNR\u2032R\u2033, wherein R\u2032 and R\u2033 are defined as in formula (I), with a group B streptogramin derivative, prepared by (a) above, wherein R1 is a halomethyl group,
(d) optionally converting said group B streptogramin derivative, prepared by (a) above, wherein said R1 is a hydroxymethyl group, to a group B streptogramin derivative wherein said R1 is a formyl group, and
(i) optionally converting said group B streptogramin derivative, wherein said R1 is a formyl group, to a group B streptogramin derivative wherein said R1 is a carboxyl group, and
(ii) optionally converting said group B streptogramin derivative, wherein said R1 is a carboxyl group, to a group B streptogramin derivative wherein said R1 is chosen from alkyloxycarbonyl groups and \u2014CONR\u2032R\u2033 groups, and

(e) optionally mono-N-demethylating said group B streptogramin derivative, prepared by (a), (b), (c), or (d) above, wherein Rd is a dimethylamino group, to a group B streptogramin derivative wherein Rd is a methylamino group, and
(f) optionally converting said group B streptogramin derivative, prepared by (a), (b), (c), (d) or (e) above, to a salt.
11. A process for preparing a group B streptogramin derivative according to claim 1, wherein said Y is a nitrogen atom, said process comprising:
(a) reacting a compound chosen from amidine salts and compounds of formula (V), wherein said compounds of formula (V) are chosen from derivatives of isourea and derivatives of isothiourea:
\u2003wherein said R1 is chosen from said R1 of formula (I),
provided that said R1 is not chosen from \u2014XRo groups, wherein X is chosen from a sulphonyl group and a sulphinyl group, and
provided that when said R1 is chosen from \u2014NR\u2032R\u2033 groups, said R1 is an amino group,

with a 5\u03b4-methylenepristinamycin derivative of formula (III):
\u2003wherein
Ra, Rb, Rc, and Rd are chosen from, respectively, Ra, Rb, Rc, and Rd of formula (I),
R4 is a dialkylamino group, and
R2 is chosen from R2 of formula (I),

(b) optionally oxidizing said group B streptogramin derivative, prepared by (a) above, wherein X is a sulphur atom, to prepare a group B streptogramin derivative, wherein said R1 is an \u2014XRo group for which X is chosen from a sulphonyl group and a sulphinyl group,
(c) optionally reacting said group B streptogramin derivative prepared by (b) above, wherein said R1 is an \u2014XRo group for which X is a sulphonyl group, with HNR\u2032R\u2033, to prepare a group B streptogramin derivative, wherein said R1 is chosen from \u2014NR\u2032R\u2033groups,
(d) optionally mono-N-demethylating said group B streptogramin derivative, prepared by (a), (b) or (c) above, wherein Rd is a dimethylamino group, to a group B streptogramin derivative, wherein Rd is a methylamino group, and
(e) optionally converting said group B streptogramin derivative, prepared by (a), (b), (c), or (d) above, to a salt.
12. A process for preparing a group B streptogramin derivative according to claim 1, wherein said Y chosen from \u2550CR3\u2014 groups, and
(1) R3 is as defined in formula (I),
R1 is chosen from a hydrogen atom, alkyl groups, alkenyl groups, cycloalkyl groups, aromatic heterocyclyl groups, a phenyl group, substituted phenyl groups, halomethyl groups, a hydroxymethyl group, alkyloxymethyl groups, alkylthiomethyl groups, alkylsulphinylmethyl groups, alkylsulphonylmethyl groups and \u2014(CH2)nNR\u2032R\u2033 groups, and
R2 is a hydrogen atom, or alternatively,

(2) when R3 is a hydrogen atom,
R1 is chosen from a formyl group, a carboxyl group, alkyloxycarbonyl groups, and \u2014CONR\u2032R\u2033 groups, as defined in formula (I), and
R2 is a hydrogen atom,
said process comprising:
(a) reacting a formyl enamine of formula (VI):
\u2003wherein:
R1 is chosen from a hydrogen atom, alkyl groups, alkenyl groups, cycloalkyl groups, aromatic heterocyclyl groups, a phenyl group, substituted phenyl groups, a hydroxymethyl group, alkyloxymethyl groups, alkylthiomethyl groups, and \u2014(CH2)nNR\u2032R\u2033 groups, and
R3 is defined as in formula (I), provided that said R3 is not a carboxyl group,

with a group B streptogramin derivative of formula (VII):
\u2003wherein Ra, Rb, Rc, and Rd are defined as, respectively, Ra, Rb, Rc, and Rd in formula (I),
(b) optionally converting said group B streptogramin derivative, prepared by (a) above, wherein R3 is chosen from \u2014CONR\u2032R\u2033 groups and alkyloxycarbonyl groups, to a group B streptogramin derivative of formula (I), wherein said R3 is a carboxyl group,
(c) optionally oxidizing said group B streptogramin derivative, prepared by (a) or (b) above, wherein said R1 is chosen from alkylthiomethyl groups, to a group B streptogramin derivative, wherein said R, is chosen from alkylsulphinylmethyl groups and alkylsulphonylmethyl groups,
(d) optionally converting said group B streptogramin derivative, prepared by (a) or (b) above, wherein said R1 is a hydroxymethyl group,
(i) to a group B streptogramin derivative, wherein said R1 is chosen from halomethyl groups, and
(ii) optionally converting said group B streptogramin derivative, wherein said R1 is chosen from halomethyl groups, to a group B streptogramin derivative, wherein said R1 is chosen from \u2014CH2NR\u2032R\u2033 groups, and

(e) optionally converting said group B streptogramin derivative, prepared by (a) above, wherein said R1 is a hydroxymethyl group, to a group B streptogramin derivative, wherein said R1 is a formyl group,
(i) optionally converting said group B streptogramin derivative, wherein said R1 is a formyl group, to a group B streptogramin derivative, wherein said R1 is a carboxyl group, and
(ii) optionally converting said group B streptogramin derivative, wherein said R1 is a carboxyl group, to a group B streptogramin derivative, wherein said R1 is chosen from alkyloxycarbonyl groups and \u2014CONR\u2032R\u2033 groups, and

(f) optionally mono-N-demethylating said group B streptogramin derivative, prepared by (a), (b), (c), (d), or (e) above, wherein Rd is a dimethylamino group, to a group B streptogramin derivative, wherein Rd is a methylamino group, and
(g) optionally converting said group B streptogramin derivative, prepared by (a), (b), (c), (d), (e), or (f) above, to a salt.
13. A process for preparing a group B streptogramin derivative according to claim 1, wherein Rd is a methylamino group, said process comprising:
(a) mono-N-demethylating a group B streptogramin derivative, wherein Rd is a dimethylamino group, and
(b) optionally converting said group B streptogramin derivative, prepared by (a) above, to a salt.
14. A pharmaceutical composition comprising at least one group B streptogramin derivative or salt thereof according to claim 1, wherein said composition further comprises at least one component chosen from (i) at least one compound chosen from group A streptogramin derivatives and salts thereof, and (ii) at least one component chosen from pharmaceutically acceptable diluents and pharmaceutically acceptable adjuvants.
15. A pharmaceutical composition according to claim 14, wherein said group A streptogramin derivatives are chosen from pristinamycin IIA, pristinamycin IIB, pristinamycin IIc, pristinamycin IID, pristinamycin IIE, pristinamycin IIF, pristinamycin IIG, semisynthetic group A streptogramin derivatives, and group A streptogramin derivatives of formula (\u03b1) and salts thereof:
wherein R1 is chosen from \u2014NR\u2032R\u2033 groups, wherein
R\u2032 is chosen from a hydrogen atom and a methyl radical,
R\u2033 is chosen from (i) a hydrogen atom, (ii) alkyl groups, (iii) cycloalkyl groups, (iv) an allyl group, (v) a propargyl group, (vi) a benzyl group, (vii) \u2014OR\u2032\u2033 groups, wherein
R\u2032\u2033 is chosen from a hydrogen atom, alkyl groups, cycloalkyl groups, an allyl group, a propargyl group, and a benzyl group,

\u2003(viii) \u2014NR3R4 groups, wherein
R3 and R4 are each a methyl group, or
R3 and R4, which are identical or different, form together with the nitrogen atom to which they are attached a heterocyclyl group chosen from saturated and unsaturated 4- to 5-membered heterocyclyl groups, wherein one of said members, other than said nitrogen atom, is optionally an atom chosen from nitrogen, oxygen, and sulphur,

R2 is chosen from a hydrogen atom, a methyl group, and an ethyl group, and
said bond – – – is a single bond or a double bond.
16. A composition comprising at least one group B streptogramin derivative according to claim 1 and at least one group A streptogramin derivative chosen from pristinamycin IIA, pristinamycin IIB, pristinamycin IIC, pristinamycin IID, pristinamycin IIE, pristinamycin IIF, pristinamycin IIG, semisynthetic group A streptogramin derivatives, and group A streptogramin derivatives of formula (\u03b1) and salts thereof:
wherein R1 is chosen from \u2014NR\u2032R\u2033 groups, wherein
R\u2032 is chosen from a hydrogen atom and a methyl radical,
R\u2033 is chosen from (i) a hydrogen atom, (ii) alkyl groups, (iii) cycloalkyl groups, (iv) an allyl group, (v) a propargyl group, (vi) a benzyl group, (vii) \u2014OR\u2032\u2033 groups, wherein
R\u2032\u2033 is chosen from a hydrogen atom, alkyl groups, cycloalkyl groups, an allyl group, a propargyl group, and a benzyl group,

\u2003(viii) \u2014NR3R4 groups, wherein
R3 and R4 are each a methyl group, or
R3 and R4, which are identical or different, form together with the nitrogen atom to which they are attached a heterocyclyl group chosen from saturated and unsaturated 4- to 5-membered heterocyclyl groups, wherein one of said members, other than said nitrogen atom, is optionally an atom chosen from nitrogen, oxygen, and sulphur,

R2 is chosen from a hydrogen atom, a methyl group, and an ethyl group, and
said bond – – – is a single bond or a double bond.

1. A method for frame aggregation transmission of wireless network system, comprising:
receiving an statistical packet error rate based on channel quality, transmission opportunities N, linearly independent probability that the receiver will receive k mixed packets, and an indicator value of not correctly received packets;
calculating a network coding length k based on the statistical packet error rate, the transmission opportunities N and the indicator value;
using Mixed Generation Coding (MGC) to generate k mixed native packets and N\u2212k mixed coded packets from a plurality of retransmitted packets and a plurality of new packets, wherein the MGC is given as an equation of:
MP
i

=

{
(
\u2211
j
2

=
1
k
pre
*
\u2062
\u2062
c

i
,

j
2
\u2062

p

j
2
)

+

p
i
,

1
\u2264
i
\u2264

k
MGC
*
\u2211
j
3

=
1
k
pre
*
\u2062
\u2062
c

i
,

j
3
\u2062

p

j
3
+
\u2211
j
4

=
1
k
MGC
*
\u2062
\u2062
c

i
,
k
pre
*

+

j
4
\u2062

p
j
4

,
\u2062

k
MGC
*
<
i
\u2264
N
,
where p1, p2, . . . , pk*pre and p1, p2 . . . , pk*MGC are corresponding native packets of the previous and current generations, the parameters ci,j2, ci,j3, and ci,j4 are a random coefficients, wherein the k*MGC is given as equation:
k*MGC=\u2514N(1\u2212PrPER)\u2212r\u2518,
where the r is additional packets, the PrPER is given as equation:
PrPER=1\u2212(1\u2212PrBER)Lm,
where the Lm=h+l+32 bits, h is a number of bits allocated for a control overhead and l is a number of payload bits for the linear combination of all k native packets, wherein bit error at the receiver is assumed to follow a Bernoulli trial with probability PrBER;
creating a frame aggregation of mixed coded packets for transmission through a MAC layer; and
receiving the frame aggregation and decoding the mixed coded packets.
2. The method for frame aggregation transmission of wireless network system as claimed in claim 1, further including using Mixed Generation Coding to produce a plurality of random coefficients corresponding to the mixed coded packets.
3. The method for frame aggregation transmission of wireless network system as claimed in claim 2, wherein the frame aggregation is a MAC layer frame.
4. The method for frame aggregation transmission of wireless network system as claimed in claim 2, further including using Mixed Generation Coding to decode the mixed coded packets with the random coefficients even if some mixed coded packets are lost.
5. The method for frame aggregation transmission of wireless network system as claimed in claim 4, further including sending a block acknowledgement based on the not correctly received mixed coded packets.
6. The method for frame aggregation transmission of wireless network system as claimed in claim 2 or 4, further including using Mixed Generation Coding to decode the mixed native packets and coded packets if received packets are sufficient to decode.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

What is claimed is:

1. A buoyant body, comprising:
an exterior envelope defining a hollow watertight chamber;
said envelope including a plurality of walls having ribbed outer surfaces,
said surfaces including protrusions, ridges, grooves and channels sized and shaped to receive water and direct the water in a direction different from that which is received,
and means enabling attachment to other buoyant bodies.
2. The body according to claim 1, further comprising:
buoyancy means for adjusting buoyancy of the body.
3. The body according to claim 1, further comprising:
anchoring means for anchoring the body in water at a select position.
4. The body according to claim 1, wherein said envelope includes:
a first part and a second part, the first and second parts being symmetrical and arranged for engagement to each other to provide a complete body.
5. The body of claim 1 including a front wall, a back wall, a top wall, a bottom wall, first and second side walls in a spaced relation, a plurality of intersecting surfaces between said walls, a plurality of spaced extending yokes connected to a plurality of said walls, said yokes including passage means for enabling attachment to other buoyant bodies, the outer surfaces of said walls and yokes having ribbed areas shaped to receive water and direct water in a direction different from that which is received.
6. The body of claim 4 wherein said first and second parts include complementary opposing internal wall surfaces having engageable mating extensions and grooves for securing said parts together to form a single body.
7. The body of claim 4 wherein said side walls extend outwardly beyond the widths of the other of said walls providing a thicker central dimension.
8. The body according to claim 2 wherein said means for adjusting buoyancy includes apertures in said envelope for receiving and removing fillers into and out of the interior of said envelope, and closure means for securing said apertures.
9. An energy dissipating assembly for flowing water comprising:
a plurality of buoyant bodies connected together, each body having a plurality of external walls including ribbed outer surfaces, said surfaces including protrusions, ridges, grooves and channels sized and shaped to receive water and direct water in a direction different from that which is received to dissipate the energy of said water.
10. The assembly of claim 9 wherein each body includes passages for receiving means for attachment to other buoyant bodies.
11. The assembly of claim 10 wherein said means for attachment includes cables extending through said passages.
12. The body of claim 7 wherein said internal surfaces are of a flexible material having opposing convolutions including engageable mating protrusions and slots securing said parts together.
13. An energy dissipating assembly for flowing water comprising:
a plurality of buoyant bodies connected together;
each body having an external envelope defining a hollow watertight chamber;
each body having a plurality of external walls including ribbed outer surfaces, said surfaces including protrusions, ridges, grooves and channels sized and shaped to receive water and direct water in a direction different from that which is received to dissipate the energy of said water;
each body including a front wall, a back wall, a top wall, a bottom wall, first and second side walls in a spaced relation extending outwardly beyond the widths of the other said walls providing a thicker central dimension;
a plurality of intersecting surfaces between said walls;
a plurality of spaced extending yokes connected to a plurality of said walls;
said yokes having ribbed outer surfaces and including passages for receiving means for attachment to other buoyant bodies;
said means for attachment including cables extending through said passages;
each body including apertures in said envelope for receiving and removing fillers into and out of the interior of said envelope for adjusting the buoyancy of said body;
closure means for securing said apertures; and
anchor means for anchoring said body in water at a select position.