Regex alphanumeric dynamic block grouping

I need your help because I have tried in several ways to create a regular expression which I can get by groups but I have been having trouble with a variation which I don't know how to take into account:

Words:

589011 T CANNELLE FLAVOR 8
538160 TP0597C ORANGE FLAVOR
557137 APL0397C STRAWBERRY FLAVOR
556137 APL0397C STRAWBERRY FLAVOR
545129 1APL0397C MANGO FLAVOR
984320 TRANS DECENAL
533160 TP0597C ORANGE FLAVOR
530373 A PINEAPPLE FLAVOR
059311 A STRAWBERRY FLAVOR
508142 T LEMON FLAVOR
547261 A BLACKBERRY FLAVOR
536564 2T BLUEBERRY STRAWBERRY
055406 A MILK FLAVOR
054945 A BLACKBERRY FLAVOR
983347 SUSTANE
902040 ACETIC ACID

Groups 1:

589011 T
538160 TP0597C
557137 APL0397C
556137 APL0397C
545129 1APL0397C
984320
533160 TP0597C
530373 A
059311 A
508142 T
547261 A
536564 2T
055406 A
054945 A
983347
902040

Groups 2:

CANNELLE FLAVOR
ORANGE FLAVOR
STRAWBERRY FLAVOR
STRAWBERRY FLAVOR
MANGO FLAVOR
TRANS DECENAL
ORANGE FLAVOR
PINEAPPLE FLAVOR
STRAWBERRY FLAVOR
LEMON FLAVOR
BLACKBERRY FLAVOR
BLUEBERRY STRAWBERRY
MILK FLAVOR
BLACKBERRY FLAVOR
SUSTANE
ACETIC ACID

Regex Test:

1. (\d+\s?[A-Z0-9]*)\s+([A-Z\s]+)\s
2. ^([0-9\s]+(?:[A-Z0-9]+)?)\s(?:[A-Z\s]+)

The difficulty I have with these two words is that the groups should be like this:

988320 TRANS DECENAL 1 KGM 12164500 JC4 20.0000 KILO 263.98/KG 5,279.60
903040 ACETIC ACID 1 KGM 12164500 DJ4 100.0000 KILO 3.17/KG 317.00

Group 1:

988320
903040

Group 2:

TRANS DECENAL
ACETIC ACID

and not like that:

Group 1:

988320 TRANS
903040 ACETIC

Group 2:

DECENAL
ACID

^(\d+\s?\b(?:[A-Z]|[A-Z]*\d[A-Z\d]*)?\b)\s*([A-Z ]*\b)

Group 1 matches digits followed optionally by either a word with a single letter, or a word that contains a mixture of letters and digits with at least one digit. Group 2 gets all the words with just letters after that, except for the whitespace between them.

DEMO

You can try (regex101):

(\d{6}\s(?:[A-Z]\b|(?=\S*\d)[A-Z\d]+)?)\s*(.*)

This will match

• GROUP 1: 6 digits + (optionally)one character OR multiple character with digit
• GROUP 2: the rest of the line

I have assumed Group 1 and Group 2 are formed using the following decision rule.

• The string must contain six digits at the beginning of the string (string "1") followed by a space followed by a string comprised of one or more letters and digits (string "2");
• Group 1 is comprised of string 1 followed by a space, followed by string 2 if string 2 is followed by two instances of a space followed by a word comprised of capital letters, those instances being followed by a space or being at the end of the string, otherwise Group 1 is comprised of string 1 only; and
• Group 2 is comprised of the string of capital letters or digits that follow the space that follows Group 1, plus zero of more instances of a space and a word comprised of capital letters, as many such instances as possible.

One can do that using the following regular expression, where capture groups 1 and 2 will contain Groups 1 and 2, respectively (provided there is a match, of course).

^(\d{6}(?: [A-Z\d]+(?=(?: [A-Z][A-Z\d]*){2}))?) ([A-Z]+(?: [A-Z]+)*)

Demo

This regular expression can be broken down as follows.

^
(                 # begin capture group 1
  \d{6}           # match 6 digits
  (?:             # begin a non-capture group
    [ ]           # match a space
    [A-Z\d]+      # match one or more (+) upcase ltrs or digits
    (?=           # begin a positive lookahead
      (?:         # begin a non-capture group
        [ ][A-Z]  # match a space followed by a upcase ltr
        [A-Z\d]*  # match zero or more (*) upcase ltrs or digits
      ){2}        # end non-capture group and execute twice 
    )             # end positive lookahead
  )?              # end non-capture group and make it optional
)                 # end capture group 1
[ ]               # match a space
(                 # begin capture group 2
  [A-Z]+          # match one or more (+) upcase ltrs
  (?:             # begin a non-capture group
    [ ]           # match a space
    [A-Z]+        # match one or more (+) upcase ltrs
  )*              # end non-capture group and make it optional
)                 # end capture group 2

In the above I have represented each space character as a character class containing a space merely to make the space visible.